Lateralized insular activation/deactivation as a result of active learning

摘要

Learning to draw or to play music are prime examples of complex active learning that engages sensorimotor integration, working memory, perception-action associations and emotions. Recent studies have discovered striking unilateral activation in left insular cortex for listening to melodies previously rehearsed on a musical instrument but not for unrehearsed melodies. It is not known, however, if practice in visual art would have an analogous effect. Methods: Using fMRI before and after active training to draw faces and objects, we compared brain activity under i) passive image viewing, ii) active reproduction by drawing from memory, iii) copying while viewing the images, and iv) non-image drawing (scribble) as a motor-control. Results: As predicted, left insula was activated during viewing of actively practiced images. Remarkably, however, massively increased fMRI responses to practiced vs unpracticed images were found in left anterior insula during both types of image drawing - from memory, and copying (but not for scribbling, thus eliminating pure motor-related explanations). Face and object activation largely overlapped, with face activation significantly stronger and shifted anteriorly. Striking post-training deactivation developed in right insula, which has recently been assigned a critical role in switching between central-executive and default-mode networks. Conclusions. Our results provide evidence against the classic view of perception and action as two extremes of mental operations, and instead support an emerging integrated view. Because these insular regions are involved in the regulation of visceral changes related to emotional states, its differential involvement in skilled drawing and music activities suggests a role in embodied cognition. Moreover, such drawing-related behaviors are a useful model of general perception-action mechanisms, bidirectional interactions between the visual and motor systems during active learning and how they develop through training. The functional connectivity and relations of insula with the respective networks will be discussed.