title: The role of the frontal cortex in memory: an investigation of the Von Restorff effect.
abstract: Evidence from neuropsychology and neuroimaging indicate that the pre-frontal cortex (PFC) plays an important role in human memory. Although frontal patients are able to form new memories, these memories appear qualitatively different from those of controls by lacking distinctiveness. Neuroimaging studies of memory indicate activation in the PFC under deep encoding conditions, and under conditions of semantic elaboration. Based on these results, we hypothesize that the PFC enhances memory by extracting differences and commonalities in the studied material. To test this hypothesis, we carried out an experimental investigation to test the relationship between the PFC-dependent factors and semantic factors associated with common and specific features of words. These experiments were performed using Free-Recall of word lists with healthy adults, exploiting the correlation between PFC function and fluid intelligence. As predicted, a correlation was found between fluid intelligence and the Von-Restorff effect (better memory for semantic isolates, e.g., isolate "cat" within category members of "fruit"). Moreover, memory for the semantic isolate was found to depend on the isolate's serial position. The isolate item tends to be recalled first, in comparison to non-isolates, suggesting that the process interacts with short term memory. These results are captured within a computational model of free recall, which includes a PFC mechanism that is sensitive to both commonality and distinctiveness, sustaining a trade-off between the two.
authors.affiliation: Department of Psychological Sciences, Birkbeck College, University of London London, UK.
authors.forename: Anat
authors.initials: A
authors.lastname: Elhalal
authors.affiliation: Department of Psychological Sciences, Birkbeck College, University of London London, UK.
authors.forename: Eddy J
authors.initials: EJ
authors.lastname: Davelaar
authors.affiliation: School of Psychological Science and Sagol School of Neuroscience, Tel Aviv University Tel Aviv, Israel ; Department of Experimental Psychology, University of Oxford and Wahadham College, University of Oxford Oxford, UK.
authors.forename: Marius
authors.initials: M
authors.lastname: Usher
keywords: PFC; categorization; computational modeling; distinctiveness; free recall; frontal lobe; semantic memory; von restorff