Abnormal semantic knowledge in a case of developmental amnesia.

Authors

Anna Blumenthal, Department of Psychology, University of Western Ontario, London, Ontario, Canada; The Brain and Mind Institute, University of Western Ontario, London, Ontario, CanadaFollow
Devin Duke, Department of Psychology, University of Western Ontario, London, Ontario, Canada; The Brain and Mind Institute, University of Western Ontario, London, Ontario, Canada
Ben Bowles, Department of Psychology, University of California Berkeley, Berkeley, California, USA
Asaf Gilboa, Rotman Research Institute, Baycrest, Toronto, Canada
R Shayna Rosenbaum, Rotman Research Institute, Baycrest, Toronto, Canada; Department of Psychology and Centre for Vision Research, York University, Toronto, Canada
Stefan Köhler, Department of Psychology, University of Western Ontario, London, Ontario, Canada; The Brain and Mind Institute, University of Western Ontario, London, Ontario, Canada; Rotman Research Institute, Baycrest, Toronto, Canada
Ken McRae, Department of Psychology, University of Western Ontario, London, Ontario, Canada; The Brain and Mind Institute, University of Western Ontario, London, Ontario, Canada

Document Type

Article

Publication Date

7-28-2017

Journal

Neuropsychologia

Volume

102

First Page

237

Last Page

247

URL with Digital Object Identifier

10.1016/j.neuropsychologia.2017.06.018

Abstract

An important theory holds that semantic knowledge can develop independently of episodic memory. One strong source of evidence supporting this independence comes from the observation that individuals with early hippocampal damage leading to developmental amnesia generally perform normally on standard tests of semantic memory, despite their profound impairment in episodic memory. However, one aspect of semantic memory that has not been explored is conceptual structure. We built on the theoretically important distinction between intrinsic features of object concepts (e.g., shape, colour, parts) and extrinsic features (e.g., how something is used, where it is typically located). The accrual of extrinsic feature knowledge that is important for concepts such as chair or spoon may depend on binding mechanisms in the hippocampus. We tested HC, an individual with developmental amnesia due to a well-characterized lesion of the hippocampus, on her ability to generate semantic features for object concepts. HC generated fewer extrinsic features than controls, but a similar number of intrinsic features than controls. We also tested her on typicality ratings. Her typicality ratings were abnormal for nonliving things (which more strongly depend on extrinsic features), but normal for living things (which more strongly depend on intrinsic features). In contrast, NB, who has MTL but not hippocampal damage due to surgery, showed no impairments in either task. These results suggest that episodic and semantic memory are not entirely independent, and that the hippocampus is important for learning some aspects of conceptual knowledge.

Notes

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