Role of oscillations in multisensory enhancement of auditory processing
Multiple Paper Presentation

Peter Lakatos
Cognitive Neuroscience & Schizophrenia Program, Nathan Kline Institute

Monica N. O'Connell
Cognitive Neuroscience & Schizophrenia Program, Nathan Kline Institute

Aimee Mills
Cognitive Neuroscience & Schizophrenia Program, Nathan Kline Institute

George Karmos
Inst. Psychology, Hungarian Acad. Sci., Budapest, Hungary

Charles Schroeder
Cognitive Neuroscience & Schizophrenia Program, Nathan Kline Institute

     Abstract ID Number: 208
     Last modified: April 7, 2006
     Presentation date: 06/18/2006 2:00 PM in Hamilton Building, McNeil Theatre
     (View Schedule)

Abstract
EEG oscillations reflect cyclical variation in the excitability of neuronal ensembles. Cortical response amplitudes thus depend on the oscillatory phase under which inputs arrive. Critically, oscillations in delta, theta and gamma bands are coupled hierarchically, and overall phase can be re-set by sensory input. We tested the possibility that oscillatory phase re-setting contributes to multisensory enhancement of auditory processing in A1, by recording laminar profiles of synaptic activity and action potentials in awake monkeys. Somatosensory stimulation alone caused no ‘classical’ evoked response, but triggered oscillatory phase concentration (re-setting) weighted towards the supragranular layers, and beginning earlier than the local auditory response. Bimodal stimulation enhanced the auditory responses. Manipulation of SOA (between a sound and a preceding somatosensory stimulus) revealed a complex pattern of enhancement peaking within 1/2 gamma cycle (~15 ms SOA), with additional peaks near -30, -180 and -800 ms SOA (full gamma, theta and delta cycles). Collectively, these findings strongly support phase re-setting of ambient neuronal rhythms as a key process in multisensory integration. The fact that heteromodal inputs can use this mechanism to promote multisensory enhancement in primary cortical regions may explain many of the effects reported in both human and nonhuman species.

To be Presented at the Following Symposium:
multisensory processing in and near primary auditory cortex
Other papers in this Symposium:

• Michael Brosch
  Institute of Neurobiology, Magdeburg
  Representation of non-auditory events in monkey auditory cortex
• Troy Hackett
  Dept. Psychology, Vanderbilt University
  John Smiley
  Cognitive Neuroscience & Schizophrenia Program, Nathan Kline Inst.
  George Karmos
  Inst. Psychology, Hungarian Acad. Sci., Budapest, Hungary
  Istvan Ulbert
  Inst. Psychology, Hungarian Acad. Sci., Budapest, Hungary
  Peter Lakatos
  Cognitive Neuroscience & Schizophrenia Program, Nathan Kline Inst.
  Charles Schroeder
  Cognitive Neuroscience & Schizophrenia Program, Nathan Kline Inst.
  Sources of somatic sensory input to auditory cortex in monkeys
• Asif Ghazanfar
  Princeton University
  Face/voice integration in monkey auditory cortex