Expectations generated by predictive cues increase the efficiency of perceptual processing for complex stimuli (e.g., faces, scenes); however, the impact this has on working memory (WM) and long-term memory (LTM) has not yet been investigated. Here, healthy young adults performed delayed-recognition tasks that differed only in stimulus category expectations, while behavioral and functional magnetic resonance imaging data were collected. Univariate and functional-connectivity analyses were used to examine expectation-driven, prestimulus neural modulation, networks that regulate this modulation, and subsequent memory performance. Results revealed that predictive category cueing was associated with both enhanced WM and LTM for faces, as well as baseline activity shifts in a face-selective region of the visual association cortex [i.e., fusiform face area (FFA)]. In addition, the degree of functional connectivity between FFA and right inferior frontal junction (IFJ), middle frontal gyrus (MFG), inferior frontal gyrus, and intraparietal sulcus correlated with the magnitude of prestimulus activity modulation in the FFA. In an opposing manner, prestimulus connectivity between FFA and posterior cingulate cortex, a region of the default network, negatively correlated with FFA activity modulation. Moreover, whereas FFA connectivity with IFJ and the precuneus predicted enhanced expectation-related WM performance, FFA connectivity with MFG predicted LTM improvements. These findings suggest a model of expectancy-mediated neural biasing, in which a single node (e.g., FFA) can be dynamically linked or disconnected from different brain regions depending on prestimulus expectations, and the strength of distinct connections is associated with WM or LTM benefits.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3006446 | PMC |
http://dx.doi.org/10.1523/JNEUROSCI.1547-10.2010 | DOI Listing |
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