Dissociation of Frontal and Medial Temporal Lobe Activity in Maintenance and Binding of Sequentially Presented Paired Associates

• Published in: Journal of cognitive neuroscience Vol. 21; no. 7; pp. 1244 - 1254
• Main Authors: Hales, Jena B., Israel, Sarah L., Swann, Nicole C., Brewer, James B.
• Format: Journal Article
• Language: English
• Published: One Rogers Street, Cambridge, MA 02142-1209, USA MIT Press 01.07.2009; MIT Press Journals, The
• Subjects: Analysis of Variance; Brain; Brain Mapping; Cognition & reasoning; Female; Frontal Lobe - blood supply; Frontal Lobe - physiology; Functional Laterality - physiology; Humans; Image Processing, Computer-Assisted - methods; Magnetic Resonance Imaging; Male; Memory; Neurosciences; NMR; Nuclear magnetic resonance; Oxygen - blood; Paired-Associate Learning - physiology; Pattern Recognition, Visual - physiology; Photic Stimulation - methods; Reaction Time - physiology; Recognition (Psychology) - physiology; Studies; Temporal Lobe - blood supply; Temporal Lobe - physiology; Time Factors; Young Adult
• ISSN: 0898-929X; 1530-8898
• DOI: 10.1162/jocn.2009.21096

Substructures of the prefrontal cortex (PFC) and the medial-temporal lobe are critical for associating objects presented over time. Previous studies showing frontal and medial-temporal involvement in associative encoding have not addressed the response specificity of these regions to different aspects of the task, which include instructions to associate and binding of stimuli. This study used a novel paradigm to temporally separate these two components of the task by sequential presentation of individual images with or without associative instruction; fMRI was used to investigate the temporal involvement of the PFC and the parahippocampal cortex in encoding each component. Although both regions showed an enhanced response to the second stimulus of a pair, only the PFC had increased activation during the delay preceding a stimulus when associative instruction was given. These findings present new evidence that prefrontal and medial-temporal regions provide distinct temporal contributions during associative memory formation.