Out of sight but not out of mind: the neurophysiology of iconic memory in the superior temporal sulcus

Abstract

Iconic memory, the short-lasting visual memory of a briefly flashed stimulus, is an important component of most models of visual perception. Here we investigate what physiological mechanisms underlie this capacity by showing rapid serial visual presentation (RSVP) sequences with and without interstimulus gaps to human observers and macaque monkeys. For gaps of up to 93 ms between consecutive images, human observers and neurones in the temporal cortex of macaque monkeys were found to continue processing a stimulus as if it was still present on the screen. The continued firing of neurones in temporal cortex may therefore underlie iconic memory. Based on these findings, a neurophysiological vision of iconic memory is presented.

The first two authors contributed equally.

Acknowledgments

This work was supported by the BBSRC, the Wellcome Trust, the Boehringer Ingelheim Fond, and the Studienstiftung des deutschen Volkes. We thank E. Kohler and A. Perrett for critical comments, Mary Potter for suggesting that persistence might have an important role for higher brain functions, and the Sony Corporation for providing technical information about the GDM-20D11 computer screen.

Notes

The first two authors contributed equally.