Creativity, Comprehension, Conversation and the Hippocampal Region: New Data and Theory.

Present findings indicate that hippocampal region (HR) damage impairs aspects of everyday language comprehension and production that require creativity defined as the ability to form new internal representations that satisfy relevant constraints for being useful or valuable in the real world. In two studies, seventeen people participated in extensive face-to-face interviews: sixteen normal individuals and H.M., an amnesic with cerebellar and HR damage but virtually no neocortical damage. Study 1 demonstrated deficits in H.M.'s comprehension of but not aspects of the interviews extending to the real world twelve prior demonstrations that H.M. understands routine but not novel aspects of experimentally constructed sentences, deficits that reflected his HR damage, but not his cerebellar damage, his explicit or declarative memory problems, inability to comprehend or recall the instructions, forgetting, poor visual acuity, motoric slowing, time pressure, deficits in visual scanning or attentional allocation, lack of motivation, and excessive memory load in the tasks. Study 2 demonstrated similar deficits in H.M.'s ability to creative but not routine aspects of conversational discourse, extending findings in five prior sentence production experiments to real-world creativity. We discuss conceptual frameworks for explaining relations between new-and-useful creativity and the HR.