Hippocampal damage impairs creativity in conceptual combination
Heather D. Lucas1, Mahima Goel2, Kara D. Federmeier2, Melissa C. Duff3, Neal J. Cohen2; 1Louisiana State University, 2University of Illinois Urbana-Champaign, 3Vanderbilt University
Much of human communication involves conceptual combination, or the integration of multiple concepts (e.g., “snow” and “man”) to form new, emergent concepts (“a snowman”). However, relatively little is known about the neural mechanisms that support conceptual combination, particularly as it applies to unfamiliar word pairs (e.g., “dress swan”), or when word pairs must be interpreted in novel or creative ways. The present study examined whether the hippocampus—a brain region traditionally associated with memory, but recently linked more broadly to creativity and cognitive flexibility—contributes to the ability to interpret novel compound phrases. We asked patients with hippocampal damage as well as healthy comparison participants to generate either a plausible or creative definition for a series of word pairs. Definitions were coded according to a set of common relational structures used in compound words, and creativity was assessed by comparing the salience of each chosen relation against normed data. For example, a high-salience/low-creativity definition of “snow cave” might use the “MADE OF” relation (a cave that is made of snow), whereas a lower-salience/higher-creativity definition might use the “FOR” relation (a cave intended for the storage of snow). Patients and comparisons used similarly-salient relations when asked to generate plausible definitions. When asked to generate creative definitions, however, comparisons’ definitions used relations that were significantly less salient than the patients’ definitions, indicating greater creativity. These results reinforce the notion that the hippocampus is involved in creative and flexible thinking, and provide specific support for the idea that hippocampal damage limits flexibility in conceptual combination.
Topic Area: LONG-TERM MEMORY: Episodic