If you need an accessible version of this item please contact JSTOR User Support

A Subcortical Pathway to the Right Amygdala Mediating "Unseen" Fear

J. S. Morris, A. Ohman and R. J. Dolan
Proceedings of the National Academy of Sciences of the United States of America
Vol. 96, No. 4 (Feb. 16, 1999), pp. 1680-1685
Stable URL: http://www.jstor.org/stable/47262
Page Count: 6
  • Download PDF
  • Cite this Item

You are not currently logged in.

Access your personal account or get JSTOR access through your library or other institution:

login

Log in to your personal account or through your institution.

If you need an accessible version of this item please contact JSTOR User Support
A Subcortical Pathway to the Right Amygdala Mediating
Preview not available

Abstract

Neuroimaging studies have shown differential amygdala responses to masked ("unseen") emotional stimuli. How visual signals related to such unseen stimuli access the amygdala is unknown. A possible pathway, involving the superior colliculus and pulvinar, is suggested by observations of patients with striate cortex lesions who show preserved abilities to localize and discriminate visual stimuli that are not consciously perceived ("blindsight"). We used measures of right amygdala neural activity acquired from volunteer subjects viewing masked fear-conditioned faces to determine whether a colliculo-pulvinar pathway was engaged during processing of these unseen target stimuli. Increased connectivity between right amygdala, pulvinar, and superior colliculus was evident when fear-conditioned faces were unseen rather than seen. Right amygdala connectivity with fusiform and orbitofrontal cortices decreased in the same condition. By contrast, the left amygdala, whose activity did not discriminate seen and unseen fear-conditioned targets, showed no masking-dependent changes in connectivity with superior colliculus or pulvinar. These results suggest that a subcortical pathway to the right amygdala, via midbrain and thalamus, provides a route for processing behaviorally relevant unseen visual events in parallel to a cortical route necessary for conscious identification.

Page Thumbnails

  • Thumbnail: Page 
1680
    1680
  • Thumbnail: Page 
1681
    1681
  • Thumbnail: Page 
1682
    1682
  • Thumbnail: Page 
1683
    1683
  • Thumbnail: Page 
1684
    1684
  • Thumbnail: Page 
1685
    1685