Towards a genetics of semantics? False memories and semantic memory organization in Williams syndrome.

Williams syndrome (WS) is a rare genetic neurodevelopmental disorder caused by microdeletion of a critical region on chromosome 7q11.23. At the cognitive level, it is usually characterized by moderate intellectual disability and deficits in visuospatial skills, while showing relative strengths in verbal skills and nonverbal reasoning. Despite their apparent good performance with verbal skills, previous studies have suggested that the structure of semantic memory may be altered in people diagnosed with WS. In this study, we explored the organization of semantic memory in WS through the Deese-Roediger-McDermott (DRM) paradigm, a task in which participants are induced to produce false memories through semantic associations. 24 participants with WS and 24 controls matched for gender and verbal mental age participated in the study. Results showed that the WS group, compared to the control group, had less false memories of critical lures, and made associations with words less related to the items studied. Taken together, these results suggest that semantic memory organization may be atypical in WS. We discuss how certain genes usually associated with the WS cognitive phenotype, GTF2I and GTF2IRD1, might modulate the development of brain areas responsible for semantic processing, ultimately producing atypical associations between words in the semantic networks of the mental lexicon.