Dissociating the Neural Correlates of Intra-Item and Inter-Item Working-Memory Binding

Carinne Piekema, Mark Rijpkema, Guillén Fernández, Roy P. C. Kessels, André Aleman
2010 PLoS ONE  
Integration of information streams into a unitary representation is an important task of our cognitive system. Within working memory, the medial temporal lobe (MTL) has been conceptually linked to the maintenance of bound representations. In a previous fMRI study, we have shown that the MTL is indeed more active during working-memory maintenance of spatial associations as compared to non-spatial associations or single items. There are two explanations for this result, the mere presence of the
more » ... atial component activates the MTL, or the MTL is recruited to bind associations between neurally non-overlapping representations. Methodology/Principal Findings: The current fMRI study investigates this issue further by directly comparing intrinsic intraitem binding (object/colour), extrinsic intra-item binding (object/location), and inter-item binding (object/object). The three binding conditions resulted in differential activation of brain regions. Specifically, we show that the MTL is important for establishing extrinsic intra-item associations and inter-item associations, in line with the notion that binding of information processed in different brain regions depends on the MTL. Conclusions/Significance: Our findings indicate that different forms of working-memory binding rely on specific neural structures. In addition, these results extend previous reports indicating that the MTL is implicated in working-memory maintenance, challenging the classic distinction between short-term and long-term memory systems.
doi:10.1371/journal.pone.0010214 pmid:20419095 pmcid:PMC2856674 fatcat:kacpcxxmjbh6njmyuiiwkke5d4