Subthreshold auditory inputs to extrastriate visual neurons are responsive to parametric changes in stimulus quality: Sensory-specific versus non-specific coding

Abstract A new subthreshold form of multisensory processing has been recently identified that results from the convergence of suprathreshold excitatory inputs from one modality with subthreshold inputs from another. Because of the subthreshold nature of the second modality, descriptive measures of s...

Full description

Saved in:
Bibliographic Details
Published in:Brain research 2008-11, Vol.1242, p.95-101
Main Authors: Allman, Brian L, Keniston, Leslie P, Meredith, M. Alex
Format: Article
Language:English
Subjects:
Acoustic Stimulation
Animals
Arousal
Auditory Perception - physiology
Bimodal
Cats
Cross-modal
Modulation
Multisensory
Neurology
Neurons - physiology
Non-specific sensory activation
Photic Stimulation
Visual Cortex - physiology
Visual Perception - physiology
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Abstract A new subthreshold form of multisensory processing has been recently identified that results from the convergence of suprathreshold excitatory inputs from one modality with subthreshold inputs from another. Because of the subthreshold nature of the second modality, descriptive measures of sensory features such as receptive field properties or location are not directly apparent as they are for traditional bimodal neurons. This raises the question of whether or not subthreshold signals actually convey sensory-specific receptive field information as seen in their bimodal counterparts, or if they represent non-specific effects such as arousal. The present experiment addressed this issue in visually-responsive neurons from the cat posterolateral lateral suprasylvian cortex (PLLS). Single-unit electrophysiological techniques were used to record neuronal responses to visual, auditory and combined visual–auditory stimuli while the intensity of stimulation in the subthreshold auditory modality was systematically altered. The results showed that subthreshold multisensory neurons were sensitive to changes in auditory stimulus intensity. These receptive field sensitivities are similar to those observed in bimodal neurons and thereby represent sensory-specific, not arousal-related responses. In addition, these results provide further support for the notion that multisensory processing occurs along a dynamic continuum of neuronal convergence patterns from bimodal to purely sensory-specific.
ISSN:0006-8993
1872-6240
DOI:10.1016/j.brainres.2008.03.086