The Brain Uses Single-Trial Multisensory Memories to Discriminate without Awareness
Poster Presentation

Glenn Wylie
The Cognititve Neurophysiology Lab, The Nathan Kline Institute

John Foxe
The Cognititve Neurophysiology Lab, The Nathan Kline Institute

Micah Murray
Division Autonome de Neuropsychologie & Service Radiodiagnostique et Radiologie Interventionnelle Centre Hospitalier Universitaire Vaudois

     Abstract ID Number: 68
     Full text: Not available
     Last modified: March 18, 2005
     Presentation date: 06/07/2005 3:00 PM in MART Auditorium
     (View Schedule)

Abstract
Multisensory experiences enhance perceptions and facilitate memory retrieval processes, even when only unisensory information is available for accessing such memories. Using fMRI, we identified human brain regions involved in discriminating visual stimuli according to past multisensory versus unisensory experiences. Subjects performed a completely orthogonal task, discriminating repeated from initial image presentations intermixed within a continuous recognition task. Half of initial presentations were multisensory, and all repetitions were exclusively visual. Despite only single-trial exposures to initial image presentations, accuracy in indicating image repetitions was significantly improved by past auditory-visual multisensory experiences over images only encountered visually. Similarly, regions within the lateral-occipital complex – areas typically associated with visual object recognition processes – were more active to visual stimuli with multisensory than unisensory pasts. Additional differential responses were observed in the anterior cingulate and frontal cortices. Multisensory experiences are registered by the brain even when of no immediate behavioral relevance and can be used to categorize memories. These data reveal the functional efficacy of multisensory processing.