Development of cognitive control and executive functions from 4 to 13 years: evidence from manipulations of memory, inhibition, and task switching

Abstract

Predictions concerning development, interrelations, and possible independence of working memory, inhibition, and cognitive flexibility were tested in 325 participants (roughly 30 per age from 4 to 13 years and young adults; 50% female). All were tested on the same computerized battery, designed to manipulate memory and inhibition independently and together, in steady state (single-task blocks) and during task-switching, and to be appropriate over the lifespan and for neuroimaging (fMRI). This is one of the first studies, in children or adults, to explore: (a) how memory requirements interact with spatial compatibility and (b) spatial incompatibility effects both with stimulus-specific rules (Simon task) and with higher-level, conceptual rules. Even the youngest children could hold information in mind, inhibit a dominant response, and combine those as long as the inhibition required was steady-state and the rules remained constant. Cognitive flexibility (switching between rules), even with memory demands minimized, showed a longer developmental progression, with 13-year-olds still not at adult levels. Effects elicited only in Mixed blocks with adults were found in young children even in single-task blocks; while young children could exercise inhibition in steady state it exacted a cost not seen in adults, who (unlike young children) seemed to re-set their default response when inhibition of the same tendency was required throughout a block. The costs associated with manipulations of inhibition were greater in young children while the costs associated with increasing memory demands were greater in adults. Effects seen only in RT in adults were seen primarily in accuracy in young children. Adults slowed down on difficult trials to preserve accuracy; but the youngest children were impulsive; their RT remained more constant but at an accuracy cost on difficult trials. Contrary to our predictions of independence between memory and inhibition, when matched for difficulty RT correlations between these were as high as 0.8, although accuracy correlations were less than half that. Spatial incompatibility effects and global and local switch costs were evident in children and adults, differing only in size. Other effects (e.g., asymmetric switch costs and the interaction of switching rules and switching response-sites) differed fundamentally over age.

Figures

Fig. 1

Illustration of the tasks in our battery with a table summarizing the demands of each on memory and inhibition.

Fig. 2

Dots conditions: (A) accuracy, (B) reaction time and (C) anticipatory response errors.

Fig. 3

Simon effect on the Pictures task. (A) Difference in percent correct: Congruent minus Incongruent trials, (B) difference in reaction time: Incongruent minus Congruent trials and (C) percentage change in reaction time: (reaction time on Incongruent minus Congruent trials) divided by reaction time on Congruent trials.

Fig. 4

Local switch costs on the Arrows task. (a) Local switch costs in Accuracy and (b) local switch costs in reaction time.

Fig. 5

Difference between switch and nonswitch trials in the Mixed block of Dots task. (A) Percent correct and (B) reaction time.

Fig. 6

The Incongruent and Mixed conditions as percentage change from the Congruent condition of the Dots task. (A) Percentage change in accuracy and (B) percentage change in reaction time.

Fig. 7

Mixing costs on the Dots task: performance on trials in the single-task blocks compared with performance on comparable nonswitch trials in the Mixed-task block. (A) Difference in percentage of correct responses: trials in the Congruent and Incongruent blocks minus the corresponding nonswitch trials in the Mixed block and (B) difference in reaction time: nonswitch Congruent or Incongruent trials in the Mixed block minus corresponding trials in the single-task blocks.

Fig. 8

Differential accuracy cost of switching to the Congruent rule rather than the Incongruent rule. (a) Arrows test and (b) Dots-Mixed condition.

Fig. 9

Cost of switching response locations in the Arrows task on switch trials and on nonswitch trials. (A) Difference in percent correct: opposite side minus same side and (B) difference in reaction time: opposite side minus same side.

Fig. 10

Cost of switching response locations in the Dots task on switch trials and nonswitch trials. (A) Difference in percent correct: opposite side minus same side. (Across the age spectrum, and especially at 6–11 years, participants were correct on more switch trials when the response-site also switched from the previous trial.) and (B) difference in reaction time: opposite side minus same side. (The typical adult pattern of faster responding on switch trials if the response-site also switched from the previous trial, seen here and reported in numerous studies, was not evident until 13 years of age.)

Fig. 11

Comparison of Mixed conditions of Dots, Arrows and Pictures. (A) Percent correct, (B) reaction time and (C) percentage of anticipatory responses.

Fig. 12

The six-Abstract-Shapes condition as percentage change from the two-Abstract-Shapes condition. (A) Percent change in accuracy-(two-shape minus six-shapes) divided by two-shapes (in the background: Dots-Mixed as percentage change from Dots-Congruent) and (B) percent change in reaction time-(two-shape minus six-shapes) divided by two-shapes (in the background: Dots-Incongruent as percentage change from Dots-Congruent).

Fig. 13

Comparisons of the two-Abstract-Shapes conditions with each other and with all the other tasks.