Neural Mechanisms of Episodic Retrieval Support Divergent Creative Thinking

Abstract

Prior research has indicated that brain regions and networks that support semantic memory, top-down and bottom-up attention, and cognitive control are all involved in divergent creative thinking. Kernels of evidence suggest that neural processes supporting episodic memory-the retrieval of particular elements of prior experiences-may also be involved in divergent thinking, but such processes have typically been characterized as not very relevant for, or even a hindrance to, creative output. In the present study, we combine functional magnetic resonance imaging with an experimental manipulation to test formally, for the first time, episodic memory's involvement in divergent thinking. Following a manipulation that facilitates detailed episodic retrieval, we observed greater neural activity in the hippocampus and stronger connectivity between a core brain network linked to episodic processing and a frontoparietal brain network linked to cognitive control during divergent thinking relative to an object association control task that requires little divergent thinking. Stronger coupling following the retrieval manipulation extended to a subsequent resting-state scan. Neural effects of the episodic manipulation were consistent with behavioral effects of enhanced idea production on divergent thinking but not object association. The results indicate that conceptual frameworks should accommodate the idea that episodic retrieval can function as a component process of creative idea generation, and highlight how the brain flexibly utilizes the retrieval of episodic details for tasks beyond simple remembering.

Figures

Figure 1.

Design schematic. Participants completed a within-subjects fMRI experiment in a single session. (Top) Scanning procedure. In the first segment of scanning, participants watched a short video, completed a brief filler task, and then were asked questions about the video in the form of an episodic specificity induction (ESI) or impressions control induction. Immediately following the induction manipulation, participants completed 3 fMRI runs during which they viewed 36 object cues (12 per run) and either generated unusual and creative uses for the cue (i.e., divergent thinking: Alternate Uses Task, or AUT) or typical object associates (i.e., object control: Object Association Task, or OAT). After completing these 3 runs, participants underwent a resting-state fMRI run followed by a brief filler task. They then completed the second segment where they received new stimuli in the same sequence (i.e., video, induction, and task cues). (Middle) Sample trial cycle during the fMRI main task runs. For each trial, participants viewed a screen for 20 s with the top line providing the task (i.e., uses or associates), the second line providing a reminder of instructions (i.e., Unusual and creative or typical objects), and the third line providing an object cue in capital letters (e.g., BUCKET). Participants pressed a button each time they generated a use or object during the trial window. After each trial, participants completed a task engagement rating for 4 s (i.e., on or off task), followed by a jittered odd/even baseline task for 4, 6, or 8 s. (Bottom) Postscan procedure. Participants underwent a postscan interview after completing the 2 main segments in the scanner. They viewed the 72 cues from the scanner in the same order, and trial-by-trial verbally stated what they had thought about for each cue and provided additional phenomenological ratings. Participants’ verbal output was transcribed and audio-recorded, and they labeled each divergent thinking response as an old idea from memory or new idea from imagination. Individual difference assessments for creativity, personality, imagery, memory, and language were also collected. Raters blind to hypothesis and induction later scored participants’ output to further characterize performance.

Figure 2.

fMRI main task results following each induction. Mean BOLD activation from univariate regressions exhibited for the Alternate Uses Task (AUT) > Object Association Task (OAT) following (A) the control induction and (B) the episodic specificity induction with statistical parameters that survive a significance threshold of P < 0.05 corrected for multiple voxel-wise comparisons. Results are projected onto surface and slice templates from MRIcron (Rorden et al. 2007).

Figure 3.

fMRI main task results as a function of induction. BOLD activation exhibited for the Alternate Uses Task (AUT) > Object Association Task (OAT) for the Specificity Induction > Control Induction in terms of (A) mean activation from univariate regressions and (B) between-network functional connectivity from multivariate ICA with statistical parameters that survive a significance threshold of P < 0.05 corrected for multiple voxel-wise comparisons or multiple component comparisons, respectively. Results are projected onto slice templates from MRIcron (Rorden et al. 2007). L, left and R, right.

Figure 4.

fMRI resting-state results as a function of induction. Neural connectivity profiles exhibited for the specificity induction > control induction using a univariate seed-to-voxel approach with statistical parameters that survive a significance threshold of P < 0.05 corrected for multiple voxel-wise comparisons. Results are projected onto slice templates from MRICron (Rorden et al. 2007). L, left and R, right; VLPFC, ventrolateral prefrontal cortex.