Format

Send to

Choose Destination
See comment in PubMed Commons below
Behav Brain Res. 2013 Feb 1;238:265-72. doi: 10.1016/j.bbr.2012.10.011. Epub 2012 Oct 18.

Early sensory cortex is activated in the absence of explicit input during crossmodal item retrieval: evidence from MEG.

Author information

  • 1Brain Imaging and Modeling Section, National Institute on Deafness and other Communication Disorders, National Institutes of Health, Bethesda, MD 20892, United States.

Abstract

Crossmodal associations form a fundamental aspect of our daily lives. In this study we investigated the neural correlates of crossmodal association in early sensory cortices using magnetoencephalography (MEG). We used a paired associate recognition paradigm in which subjects were tested after multiple training sessions over a span of four weeks. Subjects had to learn 12 abstract, nonlinguistic, pairs of auditory and visual objects that consisted of crossmodal (visual-auditory, VA; auditory-visual, AV) and unimodal (visual-visual, VV; auditory-auditory, AA) paired items. Visual objects included abstract, non-nameable, fractal-like images, and auditory objects included abstract tone sequences. During scanning, subjects were shown the first item of a pair (S1), followed by a delay, then the simultaneous presentation of a visual and auditory stimulus (S2). Subjects were instructed to indicate whether either of the S2 stimuli contained the correct paired associate of S1. Synthetic aperture magnetometry (SAMspm), a minimum variance beamformer, was then used to assess source power differences between the crossmodal conditions and their corresponding unimodal conditions (i.e., AV-AA and VA-VV) in the beta (15-30 Hz) and low gamma frequencies (31-54 Hz) during the S1 period. We found greater power during S1 in the corresponding modality-specific association areas for crossmodal compared with unimodal stimuli. Thus, even in the absence of explicit sensory input, the retrieval of well-learned, crossmodal pairs activate sensory areas associated with the corresponding modality. These findings support theories which posit that modality-specific regions of cortex are involved in the storage and retrieval of sensory-specific items from long-term memory.

Copyright © 2012 Elsevier B.V. All rights reserved.

[PubMed - indexed for MEDLINE]
Free PMC Article
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Elsevier Science Icon for PubMed Central
    Loading ...
    Write to the Help Desk