The Relation between Gray Matter Morphology and Divergent Thinking in Adolescents and Young Adults

Adolescence and early adulthood are developmental time periods during which creative cognition is highly important for adapting to environmental changes. Divergent thinking, which refers to generating novel and useful solutions to open-ended problems, has often been used as a measure of creative cognition. The first goal of this structural neuroimaging study was to elucidate the relationship between gray matter morphology and performance in the verbal (AUT; alternative uses task) and visuo-spatial (CAT; creative ability test) domain of divergent thinking in adolescents and young adults. The second goal was to test if gray matter morphology is related to brain activity during AUT performance. Neural and behavioral data were combined from a cross-sectional study including 25 adolescents aged 15-17 and 20 young adults aged 25-30. Brain-behavior relationships were assessed without a priori location assumptions and within areas that were activated during an AUT-scanner task. Gray matter volume and cortical thickness were not significantly associated with verbal divergent thinking. However, visuo-spatial divergent thinking (CAT originality and fluency) was positively associated with cortical thickness of the right middle temporal gyrus and left brain areas including the superior frontal gyrus and various occipital, parietal, and temporal areas, independently of age. AUT brain activity was not associated with cortical thickness. The results support an important role of a widespread brain network involved in flexible visuo-spatial divergent thinking, providing evidence for a relation between cortical thickness and visuo-spatial divergent thinking in adolescents and young adults. However, studies including visuo-spatial divergent thinking tasks in the scanner are warranted

Training creative cognition: Adolescence as a flexible period for improving creativity

Creativity commonly refers to the ability to generate ideas, solutions, or insights that are novel yet feasible. The ability to generate creative ideas appears to develop and change from childhood to adulthood. Prior research, although inconsistent, generally indicates that adults perform better than adolescents on the alternative uses task, a commonly used index of creative ideation. The focus of this study was whether performance could be improved by practicing alternative uses generation. We examined the effectiveness of creative ideation training in adolescents (13-16 yrs., N=71) and adults (23-30 yrs., N=61). Participants followed one of three types of training, each comprising 8 twenty-minute practice sessions within two weeks time: 1) alternative uses generation (experimental condition: creative ideation); 2) object characteristic generation (control condition: general ideation); 3) rule-switching (control condition: rule-switching). Progression in fluency, flexibility, originality of creative ideation was compared between age-groups and training conditions. Participants improved in creative ideation and cognitive flexibility, but not in general ideation. Participants in all three training conditions became better in fluency and originality on the alternative uses task. With regard to originality, adolescents benefitted more from training than adults, although this was not specific for the creative ideation training condition. These results are interpreted in relation to a) the different underlying processes targeted in the three conditions and b) developmental differences in brain plasticity with increased sensitivity to training in adolescents. In sum, the results show that improvement can be made in creative ideation and supports the hypothesis that adolescence is a developmental stage of increased flexibility optimized for learning and explorative behavior

Spatial characteristics of brain networks included in the whole-brain RS analysis.

<p>(<b>A</b>) Default mode network including precuneus, posterior cingulate cortex, inferior parietal cortex, medial frontal gyrus, and anterior cingulate cortex. (<b>B</b>) Left frontal-parietal network including middle and superior frontal gyrus, superior parietal cortex, and middle temporal gyrus. (<b>C</b>) Right frontal-parietal including middle and superior frontal gyrus, superior parietal cortex, and meddle temporal gyrus. (<b>D</b>) Cognitive control network including middle and superior frontal gyrus, and dorsal part of anterior cingulate cortex. (<b>E</b>) Visuo-spatial attention network including precuneus, posterior parietal cortex, and posterior cingulated cortex. (<b>F</b>) Ventral visual stream including superior temporal gyrus and superior frontal gyrus. Significant clusters are overlaid on a standard MNI brain. Right side of the brain is depicted at right side.</p

The association between performance on the visuo-spatial divergent thinking task (CAT) and cortical thickness observed in the whole-brain analyses.

<p>(<b>A</b>) Positive association with <i>CAT fluency.</i> (<b>B</b>) Positive association with <i>CAT originality</i>. Note, TIV, age and sex were used as nuisance variables, FDR-corrected, <i>p</i><0.05 in both figures. (<b>C</b>) Positive association with <i>CAT originality corrected for IQ</i>. Note, TIV, age and sex were used as additional nuisance variables, FDR-corrected, <i>p</i><0.05 in all figures. Hot colors indicate cortical thickening, cool colors thinning.</p

Relationship AUT-scanner fluency at-pre-test and right middle temporal gyrus connectivity to bilateral postcentral gyrus at pre-test.

<p>Higher fluency scores at pre-test are related to stronger functional connectivity at pre-test. Scatterplot depicts relationship between fluency and individual parameter estimated of connectivity at maximum (x = 32, y = −26, z = 54) separately for the Experimental (black) and Control (gray) group. Regression line depicts this association across groups. Clusters of significant functional connectivity <i>(Z</i> >2.3, whole-brain cluster corrected at <i>p</i><0.0125) are overlaid on a standard MNI template. Right side of the brain is depicted at the right side.</p

Behavior scores during the AUT-training and LGT-training.

<p>(<b>A</b>) Mean (standard error) feasibility, fluency, and originality scores of each AUT-training session in the experimental group (n = 16). (<b>B</b>) Mean (standard error) motivation scores of each training session in the experimental group (n = 16). (<b>C</b>) Median (standard error) reaction time of local-global switch trials of each LGT-training session in the control group (n = 16). (<b>D</b>) Mean (standard error) proportion correct of local-global switch trials of each LGT-training session in the control group (n = 16). * <i>p</i><0.05, ** <i>p</i><0.001.</p

Results of the seed based RS analyses.

<p>MNI coordinates and Z-scores are shown of local maxima for each significant cluster. Statistical voxel threshold Z >2.3, critical cluster p = 0.0125 (corrected for the number of seeds). L: left. R: right. MNI: Montreal Neurological Institute. Ns.: non-significant. MTG: middle temporal gyrus. MeFG: medial frontal gyrus. SMG: supramarginal gyrus.</p><p>Results of the seed based RS analyses.</p

Brain activity for AU>OC at pretest.

<p>AU>OC at pretest resulted in activation in bilateral middle temporal gyrus, medial frontal gyrus and left supramarinal gyrus. Significant activations were observed in the bilateral middle temporal gyrus, medial frontal gyrus and left supramarinal gyrus. Significant clusters (>10 continues voxels, <i>p</i><0.05 FWE-corrected) are overlaid on a standard MNI brain. Right side of the brain is depicted at right side. AU; alternative uses. OC; ordinary characteristics.</p

Seed regions of the seed-based resting-state analysis.

<p>Seed regions and their pattern of functional connectivity during rest at pre-test across groups are depicted. Seeds were based on fMRI data collected in the same participants while performing the AUT task at pre-test (see supplement) (<b>A</b>) Seed in the left middle temporal gyrus (left MTG), significantly connected to the right middle temporal gyrus and the bilateral supramarginal gyrus, precentral gyrus, occipital cortex, superior parietal cortex, and superior frontal gyrus. (<b>B</b>) Seed in the right middle temporal gyrus (right MTG) significantly connected to the left middle temporal gyrus and bilateral occipital cortex and precuneus. (<b>C</b>) Seed in the left medial frontal gyrus (MeFG) significantly connected to the right medial frontal gyrus and the bilateral precuneus, posterior cingulate cortex, inferior parietal cortex, middle temporal gyrus, caudate nucleus, and anterior cingulate cortex. (<b>D</b>) Seed in the left supramarginal gyrus (left SMG) significantly connected to the right supramarginal gyrus and bilateral superior parietal cortex, cingulate gyrus, precentral gyrus, middle frontal gyrus, and insula. A 4 mm sphere was drawn around the 4 peak voxels in the MTG, SFG, and SMG for the main effect of AU>OC across the experimental and control group. Clusters of significant functional connectivity (<i>Z</i> >2.3, whole-brain cluster corrected at <i>p</i><0.05) are overlaid on a standard MNI template. Right side of the brain is depicted at the right side.</p

Sample characteristics and cognitive assessments at pre-test and post-test.

<p>*p<0.05 and ** p<0.001 for group comparison.^#p<0.05 and ^##p<0.001 for pre-test post-test main effect of time. AUT; Alternative Uses Test. CAT; Creative Ability Test. MCT; Mental Counters Task. LGT; Local Global Task. PC; Proportion Correct. RT; Reaction Time. SD; Standard Deviation. ¹Brick data missing from one control participant.</p><p>Sample characteristics and cognitive assessments at pre-test and post-test.</p