The effect of semantic memory degeneration on creative thinking: A voxel-based morphometry analysis.

Area of Science:

• Neuroscience
• Cognitive Psychology
• Neurology

Background:

• Neuroimaging studies dominate creativity research, but lesion studies offer essential insights into brain regions critical for cognitive functions.
• Divergent thinking, a key component of creativity, involves generating multiple unique ideas.

Purpose of the Study:

• To investigate the neurocognitive mechanisms of divergent thinking in semantic dementia (SD).
• To compare divergent thinking abilities in SD patients, behavioral variant frontotemporal dementia (bvFTD) patients, and healthy controls.
• To identify brain regions essential for divergent thinking using a lesion approach.

Main Methods:

• Assessed divergent thinking in 10 SD patients, 15 bvFTD patients, and 20 healthy controls using a standardized task.
• Administered comprehensive neuropsychological tests and structural MRI scans to all participants.
• Utilized voxel-based morphometry to analyze grey matter correlates of divergent thinking performance.

Main Results:

• Both SD and bvFTD groups exhibited significantly reduced response fluency compared to controls, with SD patients showing disproportionate impairment.
• Patient groups generated less original and flexible ideas than controls.
• In SD, fluency correlated with semantic association, and originality with semantic naming/comprehension. In bvFTD, originality correlated with verbal fluency and response inhibition.
• Voxel-based morphometry identified left anterior hippocampus and left middle frontal gyrus clusters associated with reduced fluency.

Conclusions:

• Semantic dementia severely impacts divergent thinking, underscoring the pivotal role of semantic knowledge in creative cognition.
• Distinct temporal (hippocampus) and prefrontal (middle frontal gyrus) regions are crucial for divergent thinking.
• Lesion studies provide valuable converging evidence for understanding the neural basis of creativity.