Title
Hippocampal involvement in processing of indistinct visual motion stimuli
Abstract
Perception of known patterns results from the interaction of current sensory input with existing internal representations. It is unclear how perceptual and mnemonic processes interact when visual input is dynamic and structured such that it does not allow immediate recognition of obvious objects and forms. In an fMRI experiment, meaningful visual motion stimuli depicting movement through a virtual tunnel and indistinct, meaningless visual motion stimuli, achieved through phase scrambling of the same stimuli, were presented while participants performed an optic flow task. We found that our indistinct visual motion stimuli evoked hippocampal activation, whereas the corresponding meaningful stimuli did not. Using independent component analysis, we were able to demonstrate a functional connectivity between the hippocampus and early visual areas, with increased activity for indistinct stimuli. In a second experiment, we used the same stimuli to test whether our results depended on the participants' task. We found task-independent bilateral hippocampal activation in response to indistinct motion stimuli. For both experiments, psychophysiological interaction analysis revealed a coupling from posterior hippocampus to dorsal visuospatial and ventral visual object processing areas when viewing indistinct stimuli. These results indicate a close functional link between stimulus-dependent perceptual and mnemonic processes. The observed pattern of hippocampal functional connectivity, in the absence of an explicit memory task, suggests that cortical-hippocampal networks are recruited when visual stimuli are temporally uncertain and do not immediately reveal a clear meaning.
Year
DOI
Venue
2012
10.1162/jocn_a_00226
J. Cognitive Neuroscience
Keywords
Field
DocType
optical flow,explicit memory,independent component analysis
XML Encryption,Efficient XML Interchange,Streaming XML,Information retrieval,XML validation,Computer science,Document Structure Description,XML database,XML schema,XML Schema Editor
Journal
Volume
Issue
ISSN
24
6
0898-929X
Citations 
PageRank 
References 
0
0.34
5
Authors
5
Name
Order
Citations
PageRank
Eva M. Fraedrich100.34
Virginia L. Flanagin201.01
Jeng-Ren Duann338439.19
Thomas Brandt414416.15
Stefan Glasauer5899.46