Investigating Cognitive Flexibility Training

The investigators' previous research identified two distinct subtypes of Cognitive Flexibility (CF), termed CF1 (shifting flexibility) and CF2 (strategy flexibility). The present study aims to determine whether these forms of CF can be trained, how they differ, and the extent to which improvements transfer to broader learning and cognitive skills. In addition, social functioning outcomes and the extent to which social factors moderate the effects of cognitive flexibility training are assessed. The investigators will employ a multi-modal approach combining cognitive-behavioural and neuroimaging methods to examine how brain mechanisms and cognitive performance change following CF-targeted training intervention (Structure learning) compared with active control and a no-training paradigm (passive control).

Study Overview

• Status: Not yet recruiting
• Conditions: Healthy
• Intervention / Treatment: Behavioral: Experimental (Implicit Training): Structure Learning Training; Behavioral: Active Control (Explicit Training): 'All You Can E.T.'

Detailed Description

Cognitive flexibility (CF) is critical for humans to perform complex tasks and ensures that humans exhibit appropriate behaviour in response to changing environments. The ability to shift thinking, adapt behaviour, and apply knowledge in new contexts is a core executive function that supports problem solving, self-regulation and lifelong learning. It is especially crucial during key developmental periods where the brain is rapidly changing, and later in adulthood to help maintain cognitive health. In a fast-evolving world. CF is essential for navigating uncertainty, developing new skills and thriving in dynamic work and social environments. Yet, current education and training systems often do not adequately support the development of flexible thinking, highlighting the need for more evidence-based interventions that can strengthen CF across the lifespan.

Successful implementation of cognitive flexibility involves several sub-domains within executive functions. Prior research on cognitive flexibility has portrayed it as various aspects of human cognition ranging from a cognitive skill related to set-shifting, or a by-product of cognitive processes, to part of the cognitive system. In previous work, the investigators clarified the structure of cognitive flexibility through a large behavioural study, resulting in a dual-factor model comprising distinct but complementary dimensions that show unique associations with critical outcome variables. The first factor, CF1 (shifting type flexibility) refers to the ability to switch efficiently between rules and tasks. The second factor, CF2 (strategy type flexibility) reflects the capacity to adapt problem-solving strategies based on contextual cues. Notably, previous work shows that these two forms of CF relate to different learning outcomes. Shifting flexibility predicts reading ability, while strategy flexibility is associated with mathematical proficiency, problem-solving, academic skills and creativity. These findings suggest that different forms of CF may support distinct aspects of learning and raise the possibility that training-related gains in CF may generalise beyond the trained tasks to other cognitive and behavioural domains. Improvements may emerge on tasks that closely overlap with the trained processes, for example those that use similar task structures (near transfer) or extend to more dissimilar tasks (far transfer).

Current flexibility interventions and neuroimaging studies examining CF commonly utilise tasks that tap on to executive functions such as task-set switching or the Dimensional Change Card Sort (DCCS) task. These tasks primarily target CF1 shifting type flexibility. Although effective, one concern related to using these tasks is that it does not tap merely into cognitive flexibility but also activate other executive functions such as inhibition and working memory. Hence, this reduces the precision and specificity of these tasks as training tools. The present project proposed structure learning as a more fundamental and apt training approach. It involves seeking patterns in the stochastic presentations of stimuli, without the need for explicit feedback and is in itself a basic building block for cognitive flexibility, particularly CF2 strategy flexibility.

In the educational context, structure learning is analogous to patterning, a crucial cognitive ability that underpins mathematical and reading skills. Prior research has demonstrated a close relationship between pattern understanding and cognitive flexibility. Hence, structure learning training could potentially be beneficial in improving one's cognitive flexibility. Furthermore, emerging evidence has demonstrated that domain-general training of structure learning skills produced learning that transfer well beyond the learning task (far transfer). However, there is also a paucity in studies that examined whether structure learning training per se could produce generalisable improvements in cognitive flexibility.

The present study aims to address this gap by examining whether cognitive flexibility can be trained using a structure learning intervention, compared with an active control condition (shifting related training) and a passive no-training control. This study will assess whether these interventions produce changes in neural markers and behavioural performance associated with potential gains in CF. Behavioural changes will be examined in terms of their generalisation beyond the trained tasks, specifically whether they show near and far transfer across cognitive and learning-related outcomes, and whether these effects differ for shifting and strategy related training.

Outcome variables are defined a priori and organised into prespecified cognitive domains. Corrections for multiple comparisons will be applied within each domain.

• Study Type: Interventional
• Enrollment (Estimated): 225
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Kastoori Kalaivanan, PhD; Phone Number: +6569081458; Email: kastoori.k@ntu.edu.sg
• Study Contact Backup: Name: Laura R Edmondson Chua, PhD; Phone Number: +6569081458; Email: Laura.chua@ntu.edu.sg

Study Locations

• Singapore
  • Singapore, Singapore, 637335
    • Centre for Lifelong Learning and Individualised Cognition (CLIC), Nanyang Technological University
    • Contact: Kastoori Kalaivanan, PhD; Phone Number: +6569081458; Email: kastoori.k@ntu.edu.sg
    • Contact: Laura Edmondson Chua, PhD; Phone Number: +6569081458; Email: Laura.chua@ntu.edu.sg
    • Principal Investigator: Annabel SH Chen, PhD

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Healthy volunteer (male of female) between 18 and 29 years who gave written informed consent to participate

Exclusion Criteria:

• Current and/or prior history of learning disabilities
• Current and/or prior history of neurological disorder
• Current and/or prior history of psychiatric disorder
• Current and/or prior history of cardiovascular disorder
• Predominantly left-handed
• Contraindications for MRI (e.g., pacemakers, implanted pumps, metal objects in the body)
• Claustrophobic
• Pregnancy (females)
• Lactation (females)
• Pronounced visual or auditory impairments

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Implicit Training: Structure Learning Training; Structure learning training taps on participant's ability to extract patterns from prior stimuli presentations to make predictions. Participants will view different visual stimuli, such as varying alien symbols on the screen. These are presented in sequence that are determined first by frequency statistics (the probability of a given stimulus occurring). Upon mastery, these are followed by more complex context-based statistics (the probability of a given stimulus occurring, depending on the preceding stimuli). Participants will be asked to make responses to indicate the visual stimulus they predict will appear, given variable length sequences. Participants will perform the task in the absence of explicit feedback; instead, they will be required to implicitly learn the task under uncertain conditions, such as changing frequency statistics. In such contexts, individuals must actively generate, update, or discard internal rules in response to changing patterns.	Behavioral: Experimental (Implicit Training): Structure Learning Training; Participants will undergo 6-12 sessions of Structure Learning or set-shifting training in the active control training group lasting up to 30 minutes each. Each session will be conducted in a remote-guided manner with an approximate 1-day gap in between sessions. The entire training will span a maximum of 12 days. Across the task, difficulty will progressively increase through changes in probabilistic contingencies. For example, following each symbol, one subsequent symbol may occur with 75% probability and an alternative symbol with 25% probability. Participants will first learn symbol-based contingencies (e.g., 75/25), followed by contingency reversals (25/75) requiring updating of learned associations. An additional stimulus dimension (frames surrounding symbols) will then be introduced with similar probabilistic contingencies and subsequent reversals, requiring flexible adaptation to shifting rules.
Active Comparator: Active Control (Explicit Training): 'All You Can E.T.'; The active control group will use the "All You Can E.T." (AYCET) set- shifting task developed by Prof Jan Plass (NYU-CREATE Lab), which has been shown to produce near-transfer effects on cognitive flexibility. Players must apply frequently shifting rule sets to provide differently coloured and shaped aliens with the correct food or drink that they need to survive. As the game progresses, the levels increase in rule complexity (such as the alien's food choice, their colour or appearance), number of aliens and speed of response. These changing factors require participants to continually update, switch, and inhibit their current response set. Immediate feedback is embedded into AYCET to support learning. Aliens' response accordingly to receiving the correct or incorrect item, enabling players to detect discrepancies in their current response rules.	Behavioral: Active Control (Explicit Training): 'All You Can E.T.'; The protocol for the active control condition will mirror that of the experimental arm. Participants will complete an equivalent number of training sessions, and total task time will be matched between the experimental and control groups.
No Intervention: Passive Control; The passive control group will not receive any intervention but will receive the same pre-post cognitive-behavioural and neuroimaging intervention assessments. A message containing a brain fact will be sent to participants every day to keep them engaged (to have similar daily contact with the research team).

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Structure Learning Outcome 1 - Performance Index (PI) Relative	Performance index (PI) is the minimum overlap between the distribution of participant responses and the distribution of presented targets per context. The overall PI is then the average of the performance indices across contexts. The PI relative is a normalised PI measure that quantifies participant's performance relative to random guessing.	Through training completion (adaptive, up to 12 days)
Structure Learning Outcome 2 - Strategy choice	Strategy choice is the difference between the Kullback-Leibler (KL) divergence from model matching to the response-based model and the KL divergence from model maximization to the response-based model. Positive strategy choice values indicate a strategy closer to matching, whereas negative values indicate a strategy closer to maximization.	Through training completion (adaptive, up to 12 days)
Structure Learning Outcome 3 - Strategy ICD index (measured by the integral curve difference)	Derived by calculating the integral of each participant's strategy curve and subtracting it from the integral of the exact matching curve, as defined by model matching across training.	Through training completion (adaptive, up to 12 days)
Structure Learning Outcome 4 - Learning rate	Rate of learning across the training sessions or days.	Through training completion (adaptive, up to 12 days)
Structure Learning Outcome 5 - Strategy shifting rate	Rate of strategy change across the training sessions or days.	Through training completion (adaptive, up to 12 days)
'All You Can E.T.' (AYCET) Outcome 1 - Accuracy	Accuracy is defined as the proportion of correct responses across trials, based on whether the participant selects the correct food or drink item for each alien according to the currently active rule set (e.g., colour, shape, or appearance rules). Accuracy may be computed overall and across levels of rule complexity.	Through training completion (adaptive, up to 12 days)
'All You Can E.T.' (AYCET) Outcome 2 - Response Time (RT)	Response Time (RT) is defined as the latency between stimulus presentation and participant response on each trial. Mean or median RT will be computed across correct trials to index processing speed under changing rule demands. RT may also be summarized across levels of rule complexity.	Through training completion (adaptive, up to 12 days)
Cognitive Flexibility (Strategy) Outcome 1 - Wisconsin Card Sorting Test (WCST): Proportion of perseverative errors	Proportion of error trials where participants incorrectly choose a deck based on the rule from the previous set.	Post-intervention (within one week after post-MRI scan)
Cognitive Flexibility (Strategy) Outcome 2 - Wisconsin Card Sorting Test (WCST): Learning rate	This is a parameter extracted from a sequential learning model fitted to WCST data and represents how quickly participants updated their beliefs about the values associated with choices following respective negative and positive feedback.	Post-intervention (within one week after post-MRI scan)
Cognitive Flexibility (Strategy) Outcome 3 - Wisconsin Card Sorting Test (WCST): Decision consistency	This is a parameter extracted from a sequential learning model fitted to WCST data and influenced the estimated probability of choosing a specific stimulus per trial. Larger values indicated increased exploitation whereas lower values indicated increased exploration.	Post-intervention (within one week after post-MRI scan)
Cognitive Flexibility (Strategy) Outcome 4 - Intra/Extra-Dimensional Set Shifting (IED): Extra-dimensional set errors	The number of times that the subject failed to select the stimulus compatible with the current rule on the stage where the extra-dimensional shift occurs.	Post-intervention (within one week after post-MRI scan)
Cognitive Flexibility (Strategy) Outcome 5 - Intra/Extra-Dimensional Set Shifting (IED): Extra-dimensional reversal errors	This is the total number of errors made in Stage 9. Lower errors mean better performance.	Post-intervention (within one week after post-MRI scan)
Cognitive Flexibility (Strategy) Outcome 6 - Intra/Extra-Dimensional Set Shifting (IED): Learning rate	Parameter extracted from Feature Reinforcement Model.	Post-intervention (within one week after post-MRI scan)
Cognitive Flexibility (Strategy) Outcome 7 - Intra/Extra-Dimensional Set Shifting (IED): Choice determinism	Parameter extracted from Feature Reinforcement Model.	Post-intervention (within one week after post-MRI scan)
Cognitive Flexibility (Strategy) Outcome 8 - Intra/Extra-Dimensional Set Shifting (IED): Dimension primacy	Parameter extracted from Feature Reinforcement Model.	Post-intervention (within one week after post-MRI scan)
Cognitive Flexibility (Strategy) Outcome 9 - Probabilistic Reversal Learning (PRL): Perseveration	Number of trials until the participant updates their response after the rule reversal.	Pre-intervention (within one week before pre-MRI scan) and Post-intervention (within one week after post-MRI scan)
Cognitive Flexibility (Strategy) Outcome 10 - Probabilistic Reversal Learning (PRL): Switch probability	Number of switches in the participant responses following negative feedback (i.e. trap trials: when the less likely object is correct).	Pre-intervention (within one week before pre-MRI scan) and Post-intervention (within one week after post-MRI scan)
Cognitive Flexibility (Strategy) Outcome 11 - Probabilistic Reversal Learning (PRL): Trials to criterion in block 2 (Reversal)	Number of trials before participant reach defined learning criterion during the Reversal phase.	Pre-intervention (within one week before pre-MRI scan) and Post-intervention (within one week after post-MRI scan)
Cognitive Flexibility (Strategy) Outcome 12 - Probabilistic Reversal Learning (PRL): Learning rates	Parameter extracted from the Reinforcement Learning Model based on the Rescorla-Wagner rule. Two learning rates i.e., one for positive error/reward and one for negative error/punishment can be extracted from the model.	Pre-intervention (within one week before pre-MRI scan) and Post-intervention (within one week after post-MRI scan)
Cognitive Flexibility (Strategy) Outcome 13 - Probabilistic Reversal Learning (PRL): Reinforcement sensitivity	Parameter extracted from the Reinforcement Learning Model based on the Rescorla-Wagner rule.	Pre-intervention (within one week before pre-MRI scan) and Post-intervention (within one week after post-MRI scan)
Cognitive Flexibility (Strategy) Outcome 14 - Probabilistic Reversal Learning (PRL): Stickiness	Parameter extracted from the Reinforcement Learning Model based on the Rescorla-Wagner rule.	Pre-intervention (within one week before pre-MRI scan) and Post-intervention (within one week after post-MRI scan)
Cognitive Flexibility (Shifting) Outcome 1 - Task Set Switching - Where (TSS-Where): Task switch cost in RT	Switch cost in terms of reaction time (ms) is defined as the difference between the mean reaction time across switch trials with that of repeat trials.	Pre-intervention (within one week before pre-MRI scan) and Post-intervention (within one week after post-MRI scan)
Cognitive Flexibility (Shifting) Outcome 2 - Task Set Switching - Where (TSS-Where): Task switch cost in Accuracy	Switch cost in terms of accuracy is defined as the difference between the accuracy in switch trials with that of repeat trials.	Pre-intervention (within one week before pre-MRI scan) and Post-intervention (within one week after post-MRI scan)
Cognitive Flexibility (Shifting) Outcome 3 - Task Set Switching - What (TSS-What): Task switch cost in RT	Switch cost in terms of reaction time (ms) is defined as the difference between the mean reaction time across switch trials with that of repeat trials.	Pre-intervention (within one week before pre-MRI scan) and Post-intervention (within one week after post-MRI scan)
Cognitive Flexibility (Shifting) Outcome 4 - Task Set Switching - What (TSS-What): Task switch cost in Accuracy	Switch cost in terms of accuracy is defined as the difference between the accuracy in switch trials with that of repeat trials.	Pre-intervention (within one week before pre-MRI scan) and Post-intervention (within one week after post-MRI scan)
Cognitive Flexibility (Shifting) Outcome 5 - Colour Shape Task (CST): Task switch cost in RT	Switch cost in terms of reaction time (ms) is defined as the difference between the mean reaction time across switch trials with that of repeat trials. Also used for matching between Control and Training groups.	Baseline (pre-intervention and within two weeks prior to pre-MRI scan) and Post-intervention (within one week after post-MRI scan)
Cognitive Flexibility (Shifting) Outcome 6 - Colour Shape Task (CST): Task switch cost in Accuracy	Switch cost in terms of accuracy is defined as the difference between the accuracy in switch trials with that of repeat trials. Also used for matching between Control and Training groups.	Baseline (pre-intervention and within two weeks prior to pre-MRI scan) and Post-intervention (within one week after post-MRI scan)
Cognitive Flexibility (Shifting) Outcome 7 - Colour Shape Task (CST): Change in task switch cost in RT	Change in switch cost as indexed by reaction time between pre and post intervention.	Baseline (pre-intervention and within two weeks prior to pre-MRI scan) and Post-intervention (within one week after post-MRI scan)
Cognitive Flexibility (Shifting) Outcome 8 - Colour Shape Task (CST): Change in task switch cost in accuracy	Change in switch cost as indexed by accuracy between pre and post intervention.	Baseline (pre-intervention and within two weeks prior to pre-MRI scan) and Post-intervention (within one week after post-MRI scan)
Cognitive Flexibility (Shifting) Outcome 9 - Trail Making Test (TMT): Ratio between time to complete Trail B to Trail A	Participants are asked to complete Trail A (draw lines to connect numbered items in sequence) and subsequently Trail B (draw lines to connect a set of items alternating between letters and numbers) as quickly and as accurately as possible. The ratio of the completion time of Trail B to Trail A is used to examine completion time of Trail B relative to Trail A.	Post-intervention (within one week after post-MRI scan)
Working Memory Outcome 1 - Backwards Digit Span (BDS): Total items correct	Number of digit sequences that participant successfully recalled in the reverse order.	Pre-intervention (within one week before pre-MRI scan) and Post-intervention (within one week after post-MRI scan)
Working Memory Outcome 2 - Spatial Working Memory (SWM): Between search errors	The number of times the subject incorrectly revisits a box in which a token has previously been found. Calculated across all assessed four, six and eight token trials.	Post-intervention (within one week after post-MRI scan)
Working Memory Outcome 3 - Spatial Working Memory (SWM): Strategy score	The number of times a subject begins a new search pattern from the same box they started with previously. If search is always begun from the same starting point, it is inferred that the subject is employing a planned strategy for finding the tokens. Therefore, a low score indicates high strategy use (1 = always begin the search from the same box), a high score indicates that they are beginning their searches from many different boxes. Calculated across assessed trials with 6 tokens or more.	Post-intervention (within one week after post-MRI scan)
Inhibition Outcome 1 - Stroop Task: Interference measure for RT	Difference between response latency of all correct congruent trials and response latency of all correct incongruent trials.	Baseline (pre-intervention and within two weeks prior to pre-MRI scan)
Inhibition Outcome 2 - Stroop Task: Interference measure for accuracy	Difference between proportion correct of all congruent trials and proportion correct of all incongruent trials.	Baseline (pre-intervention and within two weeks prior to pre-MRI scan)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Stress Outcome 1 - Perceived Stress Scale (PSS): Perceived Stress Scale Score	The PSS measures the degree to which situations in one's life are appraised as stressful. It contains 10 items, which ask about respondents' feelings and thoughts during the last month. Possible scores for each item range from 0 (never) to 4 (very often). Individual scores on the PSS can range from 0 to 40 with higher scores indicating higher perceived stress.	Baseline (pre-intervention and within two weeks prior to pre-MRI scan) and Post-intervention (within two weeks after post-MRI scan)
Sleep Quality Outcome 1 - Pittsburgh Sleep Quality Index (PSQI): Global PSQI Score	The PSQI measures several different aspects of sleep. The component scores comprise subjective sleep quality, sleep latency, sleep duration, habitual sleep efficiency, sleep disturbances, use of sleeping medication, and daytime dysfunction. Each item is weighted on a 0-3 interval scale. The global PSQI score is then calculated by totalling the seven component scores and can range from 0 to 21, where lower scores denote a healthier sleep quality.	Post-intervention (within two weeks after post-MRI scan)
Literacy and Numeracy Outcome 1 - Wide Range Achievement Test-5	The Wide Range Achievement Test-5 (WRAT-5) is a standardized assessment of core academic skills. Scores will be obtained from the Word Reading, Spelling, Sentence Comprehension, and Math Computation subtests to index literacy and numeracy performance. Performance will be quantified using age-normed standard scores from each subtest. Pre- to post-intervention improvement will be calculated as the change in standard scores between baseline and post-test assessment, with higher scores indicating stronger literacy and numeracy skill proficiency.	Pre-intervention (within one week before pre-MRI) and Post-intervention (within one week after post-MRI scan)
Decision Making Outcome 1 - Social Value Orientation: Social Preference Score	The social value orientation task is intended to measure an individual's preferred allocation of resources between themselves and an anonymous partner (Player B). There are six rounds, each consisting of nine options. Each option is presented in the form of points allocated to the participant and Player B. Participants are instructed to choose the option they prefer the most. A participant's social preference score can be derived by calculating the inverse tangent of the ratio between the mean allocation for Player B minus 50 and the mean allocation for themselves minus 50. A higher score indicates greater baseline nonstrategic cooperativeness.	Baseline (pre-intervention and within two weeks prior to pre-MRI scan) and Post-intervention (within two weeks after post-MRI scan)
Decision Making Outcome 2 - Prisoner's Dilemma: Proportion of cooperative choices	The prisoner's dilemma game measures an individual's strategic cooperativeness, which is indicated by the proportion of cooperative choices made by the participant across 10 repeated rounds.	Baseline (pre-intervention and within two weeks prior to pre-MRI scan) and Post-intervention (within two weeks after post-MRI scan)
Decision Making Outcome 3 - Risk Preference: Risk Preference (Positive Domain)	In the risk preference task, a participant makes nine rounds of choices between a safe (less risky) option and a risky option. The probabilities for the safe option range from a 90% chance of earning 8 points and a 10% chance of earning 12 points to a 10% chance of earning 8 points and a 90% chance of earning 12 points across the nine rounds; the probabilities for the risky option range from a 90% chance of earning 2 points and a 10% chance of earning 18 points to a 10% chance of earning 2 points and a 90% chance of earning 18 points. A participant is expected to prefer the safe option over the risky option at the beginning, but their preference should shift as the payoff probabilities of both options are gradually changed. Risk preference can be measured by the switch point from choosing the safe option to choosing the risky option or estimated from computational modelling.	Baseline (pre-intervention and within two weeks prior to pre-MRI scan) and Post-intervention (within two weeks after post-MRI scan)
Decision Making Outcome 4 - Ambiguity Aversion: Ambiguity preference	In the ambiguity aversion task, a participant makes nine binary choices between a risky option and an ambiguous option. The probabilities for the risky option are always a 50% chance of earning 10 points and a 50% chance of earning nothing. For the ambiguous option, the payoff that a participant may gain ranges from 6 points to 14 points across nine rounds, but the chance is unknown. Ambiguity preference is measured by the switch point from choosing the risky option to choosing the ambiguous option or estimated from computational modelling.	Baseline (pre-intervention and within two weeks prior to pre-MRI scan) and Post-intervention (within two weeks after post-MRI scan)
Decision Making Outcome 5 - Temporal Discounting	The Monetary-Choice Questionnaire (MCQ) is a 27-item questionnaire used to assess temporal discounting. In each item, participants choose between a smaller, immediate hypothetical monetary reward and a larger, delayed monetary reward. A discounting rate (k) is calculated based on participants' choices across the items. Lower k values indicate weaker discounting and a greater preference for delayed rewards, whereas higher values indicate stronger discounting and a greater preference for immediate rewards.	Baseline (pre-intervention and within two weeks prior to pre-MRI scan) and Post-intervention (within two weeks after post-MRI scan)
Social Orientation Outcome 1 - Personal Relative Deprivation Scale: Total personal relative deprivation score	The Personal Relative Deprivation Scale reflects the beliefs and feelings of an individual when comparing themselves with other people like them. Responses were rated on a 6-point Likert scale, with 1 as 'strongly disagree' and 6 as 'strongly agree'. The total possible score ranges from 5 to 30, with higher scores indicating higher dissatisfaction levels when deprived.	Post-intervention (within two weeks after post-MRI scan)
Social Orientation Outcome 2 - Cooperativeness and Competitiveness Personality Scale: Score for Cooperativeness dimension	The Cooperativeness and Competitiveness Personality Scale measures the level of cooperativeness and competitiveness of an individual as two distinct traits. Within the scale, 13 items belong to the Cooperativeness dimension, which can be further subdivided into the subscales of Cognition, Behaviour and Affect. Test-takers have to respond on a 7-point Likert scale that ranges from 1 as 'Do not agree at all' to 7 as 'Totally agree'. The total possible score ranges from 13 to 91, with higher scores indicating higher levels of cooperative trait.	Baseline (pre-intervention and within two weeks prior to pre-MRI scan) and Post-intervention (within two weeks after post-MRI scan)
Social Orientation Outcome 3 - Cooperativeness and Competitiveness Personality Scale: Score for Competitiveness dimension	The Cooperativeness and Competitiveness Personality Scale measures the level of Cooperativeness and Competitiveness of an individual as two distinct traits. Within the scale, 10 items belong to the Competitiveness dimension, which can be further subdivided into the subscales of Cognition, Behaviour and Affect. Test-takers have to respond on a 7-point Likert scale that ranges from 1 as 'Do not agree at all' to 7 as 'Totally agree'. The total possible score ranges from 10 to 70, with higher scores indicating higher levels of competitive trait.	Baseline (pre-intervention and within two weeks prior to pre-MRI scan) and Post-intervention (within two weeks after post-MRI scan)
Tolerance of Uncertainty Outcome 1 - Receptiveness to Opposing Views: Score from Questionnaire	The Receptiveness to Opposing Views Scale is an 18-item self-report scale that measures one's willingness to take in and think about information that does not align with their personal opinions. There are four distinct dimensions in the scale - Intellectual curiosity, Derogation of opponents, Taboo issues, and Negative emotions, each with 4 to 5 items. Test-takers rate their responses on a 7-point Likert scale, where 1 is 'strongly disagree' and 7 is 'strongly agree'. The total receptiveness index is computed by reverse coding 13 items and averaging the total score. Hence, the possible total receptiveness index ranges from 1 to 7, with higher score indicating higher levels of receptiveness to opposing views.	Baseline (pre-intervention and within two weeks prior to pre-MRI scan) and Post-intervention (within two weeks after post-MRI scan)
Tolerance of Uncertainty Outcome 2 - Need for Closure Scale (Short): Score from Questionnaire	The Need for Closure Scale measures the level of desire for cognitive closure, an answer or an outcome. There are five distinct dimensions in the scale - Predictability, Close-Mindedness, Ambiguity, Order, and Decisiveness. The abridged version containing 15 items, 3 items each for the dimensions, is used. Test-takers provided their responses on a 6-point Likert scale where 1 is 'strongly disagree' and 6 is 'strongly agree'. Both a total score ranging from 15 to 90 and subscale scores ranging from 1 to 18 is computed by adding up the items. Higher scores indicate greater need for closure.	Baseline (pre-intervention and within two weeks prior to pre-MRI scan) and Post-intervention (within two weeks after post-MRI scan)
Tolerance of Uncertainty Outcome 3 - Tolerance for Ambiguity Scale	This 12-item scale measures individual differences in the tendency to perceive ambiguous situations as desirable. Participants have to respond on a 5-point Likert scale, where 1 is 'strongly disagree' and 5 is 'strongly agree'. Higher score indicates a greater tendency to find ambiguity desirable.	Baseline (pre-intervention and within two weeks prior to pre-MRI scan) and Post-intervention (within two weeks after post-MRI scan)
Tolerance of Uncertainty Outcome 4 - Dispositional Resistance to Change	This questionnaire measures the individual's dispositional resistance to change whereby individuals who are dispositionally resistant to change are less likely to voluntarily initiate changes and more likely to form negative attitudes towards the changes they encounter. It consists of subscales such as routine seeking, emotional reaction, short-term focus and cognitive rigidity. It contains 17 items in total. Participants have to respond on a 6-point Likert scale, where 1 is 'strongly disagree' and 6 is 'strongly agree'. Higher score indicates a greater dispositional resistance to change.	Baseline (pre-intervention and within two weeks prior to pre-MRI scan) and Post-intervention (within two weeks after post-MRI scan)
Tolerance of Uncertainty Outcome 5 - Intolerance of Uncertainty	Intolerance of uncertainty (IUS) is the tendency of an individual to consider the possibility of a negative event occurring unacceptable, irrespective of the probability of occurrence. IUS-12 is a shorter version that measures this tendency via two factors - prospective anxiety and inhibitory anxiety. Participants respond on a Likert-scale from 1 'not at all characteristic of me' to 5 'entirely characteristic of me'. Higher score indicates a greater tendency to consider the possibility of a negative event occurring as unacceptable.	Baseline (pre-intervention and within two weeks prior to pre-MRI scan) and Post-intervention (within two weeks after post-MRI scan)
Multilingualism Outcome 1 - Contextual Linguistic Profile Questionnaire (CLiP-Q)	The CLiP-Q provides a comprehensive language profile of participants across different contexts and includes demographic information, participants' general language background, participants' language history, use and proficiency in up to three languages as chosen by participants, and the Contextual and Individual Linguistic Diversity Questionnaire (CILD-Q). The CILD-Q measures contextual linguistic diversity and consists of 20 items across three factors (Multilingualism in Context, Multilingualism in Practice, and Linguistic Diversity Promotion). Items in the CILD-Q are scored on a five-point Likert scale ranging from 1 (strongly disagree) to 5 (strongly agree) with high scores reflecting higher levels of contextual linguistic diversity.	Post-intervention (within two weeks after post-MRI scan)
Perceived Social Support Outcome 1 - Multidimensional Scale of Perceived Social Support: Score from Questionnaire	The Multidimensional Scale of Perceived Social Support measures one's perception of their level of social support from family, friends and a significant other. Test-takers rate their response on a 7-point Likert scale, where 1 is 'Very strongly disagree' and 7 is 'Very strongly agree'. Three distinct subscale scores are calculated from averaging the 4 item scores for each source of social support. Possible subscale score ranges from 1 to 7, where higher score indicates higher perceived social support from that particular group of people/individual.	Post-intervention (within two weeks after post-MRI scan)
Personality Outcome 1 - Big Five Inventory: Score from Questionnaire	The Big Five Inventory reflects an individual's personality on 5 dimensions - Extraversion, Neuroticism, Openness, Agreeableness, & Conscientiousness. Each dimension comprises 2 items, one of which is reverse coded. An additional reverse-coded item is added for the Openness to experience dimension due to test-takers misunderstanding the original item. Test-takers rate their response on a 5-point Likert scale, where 1 is 'Disagree strongly' and 5 is 'Agree strongly'. Five distinct subscale scores are calculated from averaging the items within each dimension. Possible subscale score ranges from 1 to 5, where higher score indicates higher level of the trait.	Post-intervention (within two weeks after post-MRI scan)
MRI Structure Learning Outcome 1 - Structure learning task inside MRI Scanner	Structure learning task measure, Performance Index (PI) quantifies how closely participants' responses match the distribution of presented targets in each context. The overall PI is averaged across contexts. PI Relative is a normalized measure that reflects participant performance relative to random guessing, providing a summary of learning performance during the task performed inside the scanner.	Pre-intervention (at pre-MRI scan) and Post-intervention (at post-MRI scan) with maximum 6-12 days scan interval
MRI Structure Learning Outcome 2 - Structure Learning: generalisation (Transfer)	A generalization task after the post-MRI is used to assess the transfer of learned structures to new symbol sets. This measure uses the same Performance Index (PI) and PI Relative metrics to determine if the intervention-induced learning generalizes to stimuli not encountered during the training or scanning sessions.	Post-intervention (immediately following the post-MRI scan)
Neurotransmitter Outcome 1 - GABA levels in left DLPFC	Tonic Gamma-aminobutyric acid (GABA) concentration in the left dorsolateral prefrontal cortex (DLPFC) in institutional units (IU) estimated from MEGA-PRESS magnetic resonance spectroscopy (MRS) data, collected with reference water while participant perform an in-scanner Structure Learning (SL) task.	Pre-intervention (at pre-MRI scan) and Post-intervention (at post-MRI scan) with maximum 6-12 days scan interval
Neurotransmitter Outcome 2 - GABA levels in right DLPFC	Tonic GABA concentration in the right DLPFC in IU estimated from MEGA-PRESS MRS data during the SL task.	Pre-intervention (at pre-MRI scan) and Post-intervention (at post-MRI scan) with maximum 6-12 days scan interval
Neurotransmitter Outcome 3 - Glutamate levels in left DLPFC	Tonic Glutamate (Glu) concentration in the left DLPFC in IU estimated from MRS data during the SL task, quantified separately from glutamine and macromolecules.	Pre-intervention (at pre-MRI scan) and Post-intervention (at post-MRI scan) with maximum 6-12 days scan interval
Neurotransmitter Outcome 4 - Glutamate levels in right DLPFC	Tonic Glu concentration in the right DLPFC in IU estimated from MRS data during the SL task, quantified separately from glutamine and macromolecules.	Pre-intervention (at pre-MRI scan) and Post-intervention (at post-MRI scan) with maximum 6-12 days scan interval
Neurotransmitter Outcome 5 - Glu/GABA Ratio in left DLPFC	Excitatory-inhibitory (E-I) balance is assessed as the ratio of Glu to GABA concentration in the left DLPFC.	Pre-intervention (at pre-MRI scan) and Post-intervention (at post-MRI scan) with maximum 6-12 days scan interval
Neurotransmitter Outcome 6 - Glu/GABA Ratio in right DLPFC	E-I balance is assessed as the ratio of Glu to GABA concentration in the right DLPFC.	Pre-intervention (at pre-MRI scan) and Post-intervention (at post-MRI scan) with maximum 6-12 days scan interval
Neurotransmitter Outcome 7 - Control Region GABA levels (Primary Visual Cortex)	Tonic GABA concentration (IU) in the Primary Visual Cortex (V1) during the SL task serving as an anatomical control for GABA measurements.	Pre-intervention (at pre-MRI scan) and Post-intervention (at post-MRI scan) with maximum 6-12 days scan interval
Neurotransmitter Outcome 8 - Control Region Glutamate levels (Primary Visual Cortex)	Tonic Glu concentration (IU) in the Primary Visual Cortex (V1) during the SL task serving as an anatomical control for Glu measurements.	Pre-intervention (at pre-MRI scan) and Post-intervention (at post-MRI scan) with maximum 6-12 days scan interval
Neurotransmitter Outcome 9 - Control Region Glu/GABA Ratio (Primary Visual Cortex)	E-I balance is assessed as the ratio of Glu to GABA concentration in the Primary Visual Cortex (V1) during the SL task serving as an anatomical control for E-I measurements.	Pre-intervention (at pre-MRI scan) and Post-intervention (at post-MRI scan) with maximum 6-12 days scan interval
Functional Connectivity Outcome 1 - Seed-Based Connectivity	fMRI data will be collected during the Inscapes paradigm. Whole-brain voxelwise connectivity maps and targeted analysis of functional coupling between seed regions and predefined ROIs within frontoparietal and striatal circuits. Seed regions will be defined based on anatomical or data derived network nodes to ensure anatomical consistency across participants.	Pre-intervention (at pre-MRI scan) and Post-intervention (at post-MRI scan) with maximum 6-12 days scan interval
Functional Connectivity Outcome 2 - Intrinsic Network Connectivity	Resting-state networks identified via Group Independent Component Analysis (Group ICA). Intrinsic connectivity is defined as the strength of connectivity of voxels within each ICA-identified network and will be indexed for each participant and session as the mean within-network connectivity strength of each ICA-defined component.	Pre-intervention (at pre-MRI scan) and Post-intervention (at post-MRI scan) with maximum 6-12 days scan interval
Functional Connectivity Outcome 3 - Extrinsic Network Connectivity	Analysis of connectivity between predefined ROIs (e.g., striatal regions) and each Group ICA-identified resting-state network. Extrinsic connectivity is represented by correlation coefficients between the ROI and ICA component time courses of the identified networks.	Pre-intervention (at pre-MRI scan) and Post-intervention (at post-MRI scan) with maximum 6-12 days scan interval
Functional Connectivity Outcome 4 - Group Functional Network Comparison	Group Independent Component Analysis (ICA) will be used to define functional cortical networks across all participants. Subject-specific spatial maps for each network will be generated and entered into group-level analyses to assess between-group and pre-post differences in network spatial patterns and strength.	Pre-intervention (at pre-MRI scan) and Post-intervention (at post-MRI scan) with maximum 6-12 days scan interval
Microstructural Outcome 1 - Whole-brain Magnetization Transfer (MT) Saturation	Whole-brain voxel-based quantification (VBQ) of Multiparameter Mapping (MPM) derived MT maps in percentage units (p.u.) is used to identify longitudinal changes in myelin content.	Pre-intervention (at pre-MRI scan) and Post-intervention (at post-MRI scan) with maximum 6-12 days scan interval
Microstructural Outcome 2 - Whole-brain Longitudinal Relaxation Rate (R1)	Whole-brain VBQ of MPM-derived Relaxation Rate (R1) maps in inverse seconds is used to identify longitudinal changes in water and myelin density.	Pre-intervention (at pre-MRI scan) and Post-intervention (at post-MRI scan) with maximum 6-12 days scan interval
Microstructural Outcome 3 - ROI-based Magnetization Transfer (MT) Saturation	Targeted quantitative analysis of MT changes in percentage units (p.u.) within predefined frontoparietal and corticostriatal Regions of Interest (ROI).	Pre-intervention (at pre-MRI scan) and Post-intervention (at post-MRI scan) with maximum 6-12 days scan interval
Microstructural Outcome 4 - ROI-based Longitudinal Relaxation Rate (R1)	Targeted quantitative analysis of R1 changes in inverse seconds within predefined frontoparietal and corticostriatal ROIs.	Pre-intervention (at pre-MRI scan) and Post-intervention (at post-MRI scan) with maximum 6-12 days scan interval
Structural Connectivity Outcome 1 - Whole-brain Fixel Fiber Density (FD)	Whole-brain Fixel-Based Analysis (FBA) using Constrained Spherical Deconvolution (CSD) to measure microscopic changes in apparent axonal density (FD) in arbitrary units within white matter fixels.	Pre-intervention (at pre-MRI scan) and Post-intervention (at post-MRI scan) with maximum 6-12 days scan interval
Structural Connectivity Outcome 2 - Whole-brain Fixel Fiber-bundle Cross-section (FC)	Whole-brain FBA using CSD to measure macroscopic morphological changes in the physical size of fiber-bundle cross-sections (FC) in log-transformed ratio.	Pre-intervention (at pre-MRI scan) and Post-intervention (at post-MRI scan) with maximum 6-12 days scan interval
Structural Connectivity Outcome 3 - Whole-brain Fixel Fiber Density and Cross-section (FDC)	Whole-brain FBA using CSD to measure the combined effect of density and morphology (FDC) in arbitrary units, representing total axonal capacity.	Pre-intervention (at pre-MRI scan) and Post-intervention (at post-MRI scan) with maximum 6-12 days scan interval
General Cognitive Abilities Outcome 1 - Raven's Advanced Progressive Matrices (RAPM): Total correct	The Raven's Advanced Progressive Matrices provide a nonverbal estimate of fluid intelligence and measures ability to perform inductive and abstract reasoning. Each correct response is scored 1 while incorrect response is scored 0. The total possible score is 0 to 20 with higher scores indicating higher fluid intelligence. This is used for matching at baseline for group assignment of participants into Training or Control.	Baseline (pre-intervention and within two weeks prior to pre-MRI scan) and Post-intervention (within one week after post-MRI scan)
General Cognitive Abilities Outcome 2 - Raven's Advanced Progressive Matrices (RAPM): Change in accuracy score	The Raven's Advanced Progressive Matrices provide a nonverbal estimate of fluid intelligence and measures ability to perform inductive and abstract reasoning. Each correct response is scored 1 while incorrect response is scored 0. For both pre-intervention and post-intervention, the total possible score is 0 to 20 with higher scores indicating higher fluid intelligence. The change in accuracy score is calculated as the difference in score between the two administration time points (post-pre). A higher change in accuracy score may reflect improvement in abstract reasoning after the intervention.	Baseline (pre-intervention and within two weeks prior to pre-MRI scan) and Post-intervention (within one week after post-MRI scan)
General Cognitive Abilities Outcome 3 - Wechsler Abbreviated Scale of Intelligence Vocabulary (WASI-V): Vocabulary score	The WASI vocabulary is used to measure the participant's word knowledge and verbal concept formation. It includes 3 picture items and 28 verbal items. Possible total scores range from 0 to 59 with higher scores indicating better verbal intelligence ability. This is used for matching at baseline for group assignment of participants into Training or Control and raw vocabulary score will be standardised to a T-score.	Baseline (pre-intervention and within two weeks prior to pre-MRI scan)
Creativity & Generation Outcome 1 - Verbal Fluency Test (VFT): Mean fluency score (Category)	Number of correct words generated for a given category.	Pre-intervention (within one week before pre-MRI scan) and Post-intervention (within one week after post-MRI scan)
Creativity & Generation Outcome 2 - Verbal Fluency Test (VFT): Mean fluency score (Letter)	Number of correct words generated for a given letter.	Pre-intervention (within one week before pre-MRI scan) and Post-intervention (within one week after post-MRI scan)
Creativity & Generation Outcome 3 - Verbal Fluency Test (VFT): Clustering coefficient	Parameter extracted from a Semantic Network Model.	Pre-intervention (within one week before pre-MRI scan) and Post-intervention (within one week after post-MRI scan)
Creativity & Generation Outcome 4 - Verbal Fluency Test (VFT): Average shortest path length	Parameter extracted from a Semantic Network Model.	Pre-intervention (within one week before pre-MRI scan) and Post-intervention (within one week after post-MRI scan)
Creativity & Generation Outcome 5 - Verbal Fluency Test (VFT): Modularity	Parameter extracted from a Semantic Network Model.	Pre-intervention (within one week before pre-MRI scan) and Post-intervention (within one week after post-MRI scan)
Creativity & Generation Outcome 6 - Alternate Uses Task (AUT): Total fluency score	This score is the total number of valid responses given by the participant.	Post-intervention (within one week after post-MRI scan)
Creativity & Generation Outcome 7 - Alternate Uses Task (AUT): Total originality score	This score measures the statistical originality of participant's responses. A response would be deemed original if it has a low percent of occurrence in the participant pool and an unoriginal response would have a high percent of occurrence. Higher originality score would indicate higher creativity.	Post-intervention (within one week after post-MRI scan)
Creativity & Generation Outcome 8 - Alternate Uses Task (AUT): Total flexibility score	This score reflects how different the responses are. Flexibility scores are computed based on the number of distinct categories within the participants' responses.	Post-intervention (within one week after post-MRI scan)
Creativity & Generation Outcome 9 - Remote Associates Test (RAT)	The Remote Associates Test (RAT) is a measure of associative and creative problem-solving ability. In each item, participants are presented with three cue words and are required to generate a fourth word that is meaningfully associated with all three cues. Performance will be indexed by the total number of correctly solved items at post-test. Higher scores indicate stronger associative integration and flexible semantic retrieval ability.	Post-intervention (within one week after post-MRI scan)
Creativity & Generation Outcome 10 - Creative Foraging Game (CFG): Total	The Creative Foraging Game (CFG) is a paradigm in which participants explore a space of possible shapes by toggling cells in a grid to find novel, creative forms. CFG allows researchers to study the dynamics of creative search including transitions between exploitation of promising areas and exploration of new regions. The variables of interest are listed below, see Yuval et al (2017) for details: Time in exploitation is the duration spent in exploitation phase. Time in exploration is the duration spent in exploration phase. Exploitation optimality is a measure of efficiency of quality improvement during exploitation phases. Exploration optimality is a measure of effectiveness of traversing diverse regions during exploration phases. Originality score is the novelty rating of saved shapes.	Post-intervention (within one week after post-MRI scan)
Creativity & Generation Outcome 11 - Creative Mindset: Score from Questionnaire	The Creative Mindset scale reflects one's beliefs towards the malleability of creativity. Participants are presented with statements suggesting adoption of either a fixed mindset or a growth mindset to which participants then have to respond on a 5-point Likert scale, where 1 is 'definitely not' and 5 is 'definitely yes'. Two separate average scores of fixed and growth mindset are calculated from the 5 statements within each dimension. Higher score in fixed mindset suggests that individuals are more inclined to believe that creativity is innate and unchanging. Higher score in growth mindset suggests that individuals are more inclined to believe that creativity is malleable.	Baseline (pre-intervention and within two weeks prior to pre-MRI scan) and Post-intervention (within two weeks after post-MRI scan)
Exploration Outcome 1 - Maggie's Farm: behavioural choice index	Multi-armed bandit decision-making task assessing exploitation versus exploration (value-free and novelty-driven) under uncertainty. Participants repeatedly select between bandits differing in expected reward and information availability, with long and short decision horizons. Performance index 1: behavioural choice frequencies: how often participants choose high-reward, low-reward, unfamiliar, or completely new options. Choosing high-reward options more often and earning more points overall indicates effective exploitation.	Post-intervention (within one week after post-MRI scan)
Exploration Outcome 2 - Maggie's Farm: computational model parameters	Multi-armed bandit decision-making task assessing exploitation versus exploration (value-free and novelty-driven) under uncertainty. Participants repeatedly select between bandits differing in expected reward and information availability, with long and short decision horizons. Performance index 2: computational model parameters capturing random exploration tendency (ϵ-greedy), preference for new options (η; novelty bonus), reward uncertainty (prior variance, σ₀) Higher ϵ, η, and σ₀ indicate greater exploration.	Post-intervention (within one week after post-MRI scan)
Exploration Outcome 3 - Maggie's Farm: change in rewards	Multi-armed bandit decision-making task assessing exploitation versus exploration (value-free and novelty-driven) under uncertainty. Participants repeatedly select between bandits differing in expected reward and information availability, with long and short decision horizons. Performance index 3: reward measures over the round, including initial rewards, average rewards, and improvement over time Picking unfamiliar or novel options, especially in long rounds, reflects strategic exploration and the adaptive use of information.	Post-intervention (within one week after post-MRI scan)
Risk taking Outcome 1 - Iowa Gambling Task (IGT-Adult)	Decision-making task assessing sensitivity to future consequences under uncertainty. Participants select cards from four decks (A, B, C, D) with the goal of maximizing profit and avoiding loss. Choices produce a monetary reward and sometimes a penalty. Decks A and B are disadvantageous, with high immediate gains but larger long-term losses, resulting in a net loss over time. Decks C and D are advantageous, with smaller immediate gains but a net gain over time. Participants are not informed of payoff schedules and must learn through experience which decks are "good" and "bad." Performance will be indexed by net score, calculated as selections from advantageous decks minus selections from disadvantageous decks across 100 trials. Performance will also be examined across five 20-trial blocks to assess changes in deck preference over time. Higher net scores and more advantageous deck choices across blocks indicate preference for long-term gains and sensitivity to future consequences.	Post-intervention (within one week after post-MRI scan)
Risk taking Outcome 2 - Cambridge Gambling Task (CGT)	Measure of decision-making under risk assessing risk-taking, probability judgment, and deliberative decision quality when outcomes are explicitly presented. On each trial, participants view a row of coloured boxes in two colours in varying ratios, indicating the probability that a token is hidden under a box of that colour. Participants first decide which colour they believe conceals the token ("choice") and then place a proportion-based "bet" on that decision. Bets are expressed as a proportion of available points and are presented in ascending or descending order, requiring participants to make a wager reflecting both risk tolerance and confidence in their choice. Performance will be indexed using established CGT outcome variables, including risk taking, quality of decision-making, decision time, risk adjustment, delay aversion and impulsivity. Higher decision quality and appropriate risk adjustment reflect better probabilistic reasoning and adaptive risk-taking behaviour.	Post-intervention (within one week after post-MRI scan)
Planning and Problem-solving Outcome 1 - One Touch Stockings (OTS)	Computerised measure of spatial planning and working memory derived from the Stockings of Cambridge task. On each trial, participants view two displays of coloured balls arranged in vertical "stockings." They must determine the minimum number of moves required to transform the start configuration (lower display) into the target arrangement (upper display). Participants respond by selecting the minimum number of moves required to match the target pattern. Task difficulty increases as the number of required moves increases across trials. Performance will be indexed by the number of problems solved on first choice, mean choices to correct, mean latency (response speed) to first choice and mean latency to correct. Measures may be calculated across all problems, or for problems with a specified number of moves (one-move to five or six moves). More problems solved correctly and shorter decision latencies indicate stronger spatial planning ability and more efficient executive functioning.	Post-intervention (within one week after post-MRI scan)
Planning and Problem-solving Outcome 2- Crossing Valley	The Crossing Valley game is a measure of problem-solving in the context of a bridge-building game. In each level, participants are presented with a gap between two landmasses and are tasked with building a bridge using nodes and planks that is study enough to get a vehicle across. Performance will be indexed by the structural integrity of the bridge solutions. Higher scores indicate greater structural integrity that is sufficient enough for the vehicle to drive across without failure.	Post-intervention (within one week after post-MRI scan)
Scientific Reasoning Outcome 1 - Suppression of Naïve Scientific Thinking Task (true-left version)	The science sentence statement task is a measure of explanatory coexistence. In each trial, participants are presented with scientific statements from the domains of math, physics, and biology and are required to evaluate whether each statement is true or false. These statements are categorized based on whether their truth value remains consistent or conflicts across intuitive naive theories and formal scientific theories. Performance will be indexed by the mean accuracy across all trials. Higher scores indicate stronger explanatory coexistence and a superior ability to correctly apply scientific knowledge when it conflicts with intuitive misconceptions.	Post-intervention (within one week after post-MRI scan)
Socioemotional Skills Outcome 1 - Interpersonal Reactivity Index	The Interpersonal Reactivity Index is a measure of dispositional empathy that takes as its starting point the notion that empathy consists of a set of separate but related constructs. The instrument contains four seven-item subscales, each tapping a separate facet of empathy (perspective taking, fantasy, empathic concern, personal distress). Participants have to respond on a 5-point Likert scale, where 1 is 'does not describe me well' and 5 is 'describes me very well'. Higher score indicates greater empathy.	Baseline (pre-intervention and within two weeks prior to pre-MRI scan) and Post-intervention (within two weeks after post-MRI scan)
Curiosity/Exploration Outcome 1 - Five-Dimensional Curiosity Scale	This questionnaire examines different facets of curiosity including the social domain (social curiosity), which is important to human functioning. Other facets include joyous exploration, deprivation sensitivity, stress tolerance, and thrill seeking. There are a total of 24 items. Participants have to respond on a 7-point Likert scale, where 1 is 'does not describe me well' and 7 is 'completely describes me'. Higher score indicates greater curiosity.	Baseline (pre-intervention and within two weeks prior to pre-MRI scan) and Post-intervention (within two weeks after post-MRI scan)
Cognitive Flexibility Outcome 1 - Cognitive Flexibility Inventory (CFI)	The 20-item scale measures three aspects of cognitive flexibility: (a) the tendency to perceive difficult situations as controllable; (b) the ability to perceive multiple alternative explanations for life occurrences and human behaviour; and (c) the ability to generate multiple alternative solutions to difficult situations. Participants have to respond on a 7-point Likert scale, where 1 is 'strongly disagree' and 7 is 'strongly agree'. Higher scores on the scale are indicative of greater flexibility.	Baseline (pre-intervention and within two weeks prior to pre-MRI scan) and Post-intervention (within two weeks after post-MRI scan)
Emotion Regulation Outcome 1 - Emotion Regulation Questionnaire (ERQ)	This questionnaire assesses individual differences in the habitual use of two emotion regulation strategies: cognitive reappraisal and expressive suppression. It contains 10 items in total. Participants have to respond on a 7-point Likert scale, where 1 is 'strongly disagree' and 7 is 'strongly agree'. Higher score on the cognitive reappraisal items indicates greater usage of regulating one's emotional experience as an emotion regulation strategy. Higher score on the expressive suppression items indicates greater usage of regulating one's emotional expressions as an emotion regulation strategy.	Baseline (pre-intervention and within two weeks prior to pre-MRI scan) and Post-intervention (within two weeks after post-MRI scan)
Fatigue Outcome 1 - Multidimensional Fatigue Inventory	This is a self-reported 20-item scale that measures fatigue (general, mental, physical, reduced activity and motivation) rated on a five-point scale. Higher total scores correspond with more acute levels of fatigue.	Baseline (pre-intervention and within two weeks prior to pre-MRI scan)
Demographics and SES Outcome 1 - Demographics and SES (CLIP A & D, Career Related)	These items measure basic demographics that indicate an individual's socioeconomic status.	Baseline (pre-intervention and within two weeks prior to pre-MRI scan)
Cultural Identity & Orientation Outcome 1 - Multicultural Identity Integration Scale	This scale consists of 22 items that examines one's cultural identity via 3 subscales (categorization, compartmentalization, and integration). Participants respond on a Likert-scale from 1 'not at all' to 7 'exactly'.	Post-intervention (within two weeks after post-MRI scan)
Career Outcome 1 - Perceived Employability (PEMP) *	The 11-item scale measures participants' self-perceived employability within and outside their current organisation, based on their personal and occupational attributes. Participants have to respond on a 5-point Likert scale, where 1 is 'strongly disagree' and 5 is 'strongly agree'. Higher scores on the scale indicate greater perceived employability, both within the current organisation (internal) and across the broader labour market (external). *These scales will be administered only to working adults or students working part-time/an internship.	Baseline (pre-intervention and within two weeks prior to pre-MRI scan) and Post-intervention (within two weeks after post-MRI scan)
Career Outcome 2 - Future Orientation & Resilience (DMF)	The 21-item scale measures participants' future orientation skills, i.e. thoughts, ideas and feelings individuals have on their future, and resilience, i.e. the ability to resist or quickly recover strengths and energy to "set themselves in motion" while challenges are threatening stability, vitality, and development. Participants have to respond on a 5-point Likert scale, where 1 is 'it does not describe me at all' and 5 is 'it describes me very well'. Higher scores indicate a stronger future orientation and higher psychological resilience.	Post-intervention (within two weeks after post-MRI scan)
Career Outcome 3 - Career Adapt-abilities Scale (CAAS)	The 24-item scale measures participants' career adaptability across four dimensions: Concern, Control, Curiosity, Control adaptability. Participants have to respond on a 5-point Likert scale, where 1 is 'not strong' and 5 is 'strongest'. Higher scores indicate stronger career adaptability.	Post-intervention (within two weeks after post-MRI scan)
Career Outcome 4 - Protean Career Attitudes* (PCA)	The 14-item scale measures participants' self-directed career management vs. values-driven career attitude. Participants have to respond on a 5-point Likert scale, where 1 is 'to little or no extent' and 5 is 'to a great extent'. The higher the score, the more likely the individual is to shape and evaluate their career based on their own goals and values, rather than relying on employers or external norms. *These scales will be administered only to working adults or students working part-time/an internship.	Post-intervention (within two weeks after post-MRI scan)
Career Outcome 5 - Boundaryless Career Attitudes* (BCA)	The 8-item scale measures participants' "boundaryless mindset" (i.e. one's general attitude to working across organizational boundaries). Participants have to respond on a 5-point Likert scale, where 1 is 'to little or no extent' and 5 is 'to a great extent'. Higher scores indicate greater comfort with the interest in flexible and cross-boundary career experience. *These scales will be administered only to working adults or students working part-time/an internship	Post-intervention (within two weeks after post-MRI scan)
Career Outcome 6 - Proactive Career Behaviour* (PCB)	The 13-item scale measures four types of proactive career behaviour: Proactive skill development, Networking, Career consultation, and Career planning. Participants have to respond on a 5-point Likert scale, where 1 is 'strongly disagree' and 5 is 'strongly agree'. Higher scores reflect stronger initiative, future orientation, and self-directed efforts to shape one's career trajectory. *These scales will be administered only to working adults or students working part-time/an internship	Post-intervention (within two weeks after post-MRI scan)
Career Outcome 7 - Job Search Efficacy (JSE)	The 13-item scale measures to measure participants' self-confidence/self-rated skill for being able to do a good job with specific aspects of the job search. Participants have to respond on a 7-point Likert scale ranging from 1 (not at all confident) to 7 (extremely confident). Higher scores reflect stronger perceived competence and readiness to carry out effective job search behaviours.	Post-intervention (within two weeks after post-MRI scan)
Career Outcome 8 - Career Decision Ambiguity Tolerance Scale (CDAT)	The 18-item scale measures participants' evaluations of and responses to ambiguity encountered in career decision-making across three dimensions: tolerance, aversion, and preference. Participants have to respond on a 7-point Likert scale ranging from 1 (strongly disagree) to 7 (strongly agree). Higher scores indicate stronger tendencies within each respective dimension - with higher tolerance and preference scores reflecting greater openness to ambiguity, and higher aversion scores indicating greater discomfort with ambiguity.	Post-intervention (within two weeks after post-MRI scan)
Career Outcome 9 - Student Career Construction Inventory (SCCI; Students only)	The 25-item scale measures career adapting responses, which consist of vocational thoughts and behaviours, involved in constructing a career choice. It captures how adolescents and emerging adults respond to key career construction tasks during the early stages of career development. Participants have to respond on a 5-point Likert scale, where 1 is 'I have not yet thought much about it' and 5 is 'I have already done this'. Higher scores indicate greater engagement in career adapting responses, i.e. the individual has progressed further in their thinking, planning, and actions related to constructing a career choice.	Post-intervention (within two weeks after post-MRI scan)
Career Outcome 10 - Vocational Identity (VI2)	The 20-item scale measures participants' vocational identity and aims to measure how aware individuals are of their stable career goals, interests, and abilities. Participants have to respond on a 5-point Likert scale, where 1 is 'strongly disagree' and 5 is 'strongly agree'. Higher scores indicate greater clarity, confidence, and commitment regarding one's career goals, interests, and self-perceived fit with specific occupational paths.	Post-intervention (within two weeks after post-MRI scan)
Career Outcome 11 - Vocational Identity (VI1)	The 20-item scale operationalises vocational identity as a core construct in understanding career decision-making and individual readiness. Participants have to respond on a 5-point Likert scale. Higher scores indicate greater self-perceived career decision-making readiness and consistency.	Post-intervention (within two weeks after post-MRI scan)
Career Outcome 12 - Career Resilience (CCM)	The original questionnaire examines participant's commitment to their career (Career Commitment Measure). However, only the career resilience subscale, which contains 4 items is administered. Participants have to respond on a 5-point Likert scale, where 1 is 'strongly disagree' and 5 is 'strongly agree'. After reverse scoring, higher scores reflect lower perceived burden or strain associated with individual's current occupation or career path.	Post-intervention (within two weeks after post-MRI scan)

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Mood and State Outcome 1 - Self-Assessment Manikin (SAM)	Used as a control variable. This is a non-verbal pictorial assessment that measures an individual's emotional response. The original scale consists of three items rated on a nine-point scale.	Through training completion (adaptive, up to 12 days)
Mood and State Outcome 2 - Self-Assessment Manikin (SAM)	Used as a control variable. This is a non-verbal pictorial assessment that measures an individual's emotional response. The original scale consists of three items rated on a nine-point scale.	Pre-intervention (at pre-MRI scan) and Post-intervention (at post-MRI scan) with maximum 6-12 days scan interval
Mood and State Outcome 3 - Training Feedback: Task enjoyment level	Used as a control variable. Participants are asked to report how enjoyable they find the training task at the end of each training session. Possible scores range from 0 (Not at all enjoyable) to 10 (Very much enjoyable). Higher scores indicate higher enjoyment level in intervention training.	Through training completion (adaptive, up to 12 days)
Mood and State Outcome 4 - Training Feedback: Task difficulty level	Used as a control variable. Participants are asked to report how difficult they find the training task at the end of each training session. Possible scores range from 0 (Not at all difficult) to 10 (Extremely difficult). Higher scores indicate higher difficulty level of intervention training.	Through training completion (adaptive, up to 12 days)
Mood and State Outcome 5 - Patient Health Questionnaire-9 (PHQ-9): Total score	Used as a control variable. The PHQ-9 is an instrument whose 9 items are based on the Diagnostic and Statistical Manual of Mental Disorders IV (DSM-IV) diagnostic criteria. Each of the 9 items can be scored from 0 (not at all) to 3 (nearly every day). Its validity and reliability as a diagnostic measure as well as its utility in assessing depression severity and monitoring treatment response are well-established.	Post-intervention (within two weeks after post-MRI scan)
Mood and State Outcome 6 - Generalized Anxiety Disorder-7 (GAD-7): Total score	Used as a control variable. The GAD-7 items describe the most prominent diagnostic features of the Diagnostic and Statistical Manual of Mental Disorders IV (DSM-IV) diagnostic criteria for Generalized Anxiety Disorder. On the GAD-7, subjects are asked how often, during the last 2 weeks, they have been bothered by 7 core symptoms of generalized anxiety disorder. Response options are "not at all," "several days," "more than half the days," and "nearly every day".	Post-intervention (within two weeks after post-MRI scan)

Collaborators and Investigators

• Sponsor: Nanyang Technological University
• Collaborators: University of Cambridge
• Investigators: Principal Investigator: Annabel SH Chen, PhD, Nanyang Technological University

Publications and helpful links

General Publications

• Uddin LQ. Cognitive and behavioural flexibility: neural mechanisms and clinical considerations. Nat Rev Neurosci. 2021 Mar;22(3):167-179. doi: 10.1038/s41583-021-00428-w. Epub 2021 Feb 3.
• Wang R, Shen Y, Tino P, Welchman AE, Kourtzi Z. Learning predictive statistics from temporal sequences: Dynamics and strategies. J Vis. 2017 Oct 1;17(12):1. doi: 10.1167/17.12.1.
• Wang R, Shen Y, Tino P, Welchman AE, Kourtzi Z. Learning Predictive Statistics: Strategies and Brain Mechanisms. J Neurosci. 2017 Aug 30;37(35):8412-8427. doi: 10.1523/JNEUROSCI.0144-17.2017. Epub 2017 Jul 31.
• Parong, J., Mayer, R. E., Fiorella, L., MacNamara, A., Homer, B. D., & Plass, J. L. (2017). Learning executive function skills by playing focused video games. Contemporary Educational Psychology, 51, 141-151.
• Parong, J., Wells, A., & Mayer, R. E. (2020). Replicated evidence towards a cognitive theory of game-based training. Journal of Educational Psychology, 112(5), 922-937.
• Tong, K., Uchiyama, R., Fischer, N. L., Langley, C., Cheng, X., Kalaivanan, K., Melia, N., Feng, S., Fu, X., Marzuki, A. A., Talwar, A., Chan, Y. N., Fauziana, R., Hoo, N., Lee, K. M., Lee, L. L., Lee, T., Melani, I., Pei, J. Y., ... Leong, V. Cognitive flexibility: Separate shifting and strategy factors [Manuscript under review]
• Tong, K., Uchiyama, R., Feng, S., Cheng, X., Kalaivanan, K. D., Leong, V., … Robbins, T. W. (2021, December 22). Assessing cognitive flexibility, other executive functions, and learning in healthy young adults [Preregistration]. OSF.
• Tong K, Chan YN, Cheng X, Cheon B, Ellefson M, Fauziana R, Feng S, Fischer N, Gulyas B, Hoo N, Hung D, Kalaivanan K, Langley C, Lee KM, Lee LL, Lee T, Melani I, Melia N, Pei JY, Raghani L, Sam YL, Seow P, Suckling J, Tan YF, Teo CL, Uchiyama R, Yap HS, Christopoulos G, Hendriks H, Chen A, Robbins T, Sahakian B, Kourtzi Z, Leong V; CLIC Phase 1 Consortium. Study protocol: How does cognitive flexibility relate to other executive functions and learning in healthy young adults? PLoS One. 2023 Jul 20;18(7):e0286208. doi: 10.1371/journal.pone.0286208. eCollection 2023.
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Study record dates

Study Major Dates

• Study Start (Estimated): April 23, 2026
• Primary Completion (Estimated): December 31, 2026
• Study Completion (Estimated): December 31, 2026

Study Registration Dates

• First Submitted: April 7, 2026
• First Submitted That Met QC Criteria: April 22, 2026
• First Posted (Actual): April 29, 2026

Study Record Updates

• Last Update Posted (Actual): April 29, 2026
• Last Update Submitted That Met QC Criteria: April 22, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Keywords: Intervention; Neural Activation; Cognitive Flexibility; Structure Learning; Predictive statistics
• Other Study ID Numbers: IRB-2025-1325

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: All data will be uploaded to the Centre of Lifelong Learning and Individualised Cognition (CLIC) network-attached storage (NAS) database and/or REDCAP server. Researchers may apply for access to the data.
• IPD Sharing Time Frame: As soon as data collection commenced.
• IPD Sharing Access Criteria: Researchers may apply for access to data.
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP; ANALYTIC_CODE

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No