PMID- 29924710 OWN - NLM STAT- MEDLINE DCOM- 20190801 LR - 20190901 IS - 1522-1598 (Electronic) IS - 0022-3077 (Print) IS - 0022-3077 (Linking) VI - 120 IP - 3 DP - 2018 Sep 1 TI - Auditory modulation of spiking activity and local field potentials in area MT does not appear to underlie an audiovisual temporal illusion. PG - 1340-1355 LID - 10.1152/jn.00835.2017 [doi] AB - The timing of brief stationary sounds has been shown to alter the perceived speed of visual apparent motion (AM), presumably by altering the perceived timing of the individual frames of the AM stimuli and/or the duration of the interstimulus intervals (ISIs) between those frames. To investigate the neural correlates of this "temporal ventriloquism" illusion, we recorded spiking and local field potential (LFP) activity from the middle temporal area (area MT) in awake, fixating macaques. We found that the spiking activity of most MT neurons (but not the LFP) was tuned for the ISI/speed (these parameters covaried) of our AM stimuli but that auditory timing had no effect on that tuning. We next asked whether the predicted changes in perceived timing were reflected in the timing of neuronal responses to the individual frames of the AM stimuli. Although spiking dynamics were significantly, if weakly, affected by auditory timing in a minority of neurons, the timing of spike responses did not systematically mirror the predicted perception of stimuli. Conversely, the duration of LFP responses in beta- and gamma-frequency bands was qualitatively consistent with human perceptual reports. We discovered, however, that LFP responses to auditory stimuli presented alone were robust and that responses to audiovisual stimuli were predicted by the linear sum of responses to auditory and visual stimuli presented individually. In conclusion, we find evidence of auditory input into area MT but not of the nonlinear audiovisual interactions we had hypothesized to underlie the illusion. NEW & NOTEWORTHY We utilized a set of audiovisual stimuli that elicit an illusion demonstrating "temporal ventriloquism" in visual motion and that have spatiotemporal intervals for which neurons within the middle temporal area are selective. We found evidence of auditory input into the middle temporal area but not of the nonlinear audiovisual interactions underlying this illusion. Our findings suggest that either the illusion was absent in our nonhuman primate subjects or the neuronal correlates of this illusion lie within other areas. FAU - Kafaligonul, Hulusi AU - Kafaligonul H AD - National Magnetic Resonance Research Center, Bilkent University , Ankara , Turkey. AD - Interdisciplinary Neuroscience Program, Bilkent University , Ankara , Turkey. FAU - Albright, Thomas D AU - Albright TD AD - Vision Center Laboratory, The Salk Institute for Biological Studies , La Jolla, California. FAU - Stoner, Gene R AU - Stoner GR AD - Vision Center Laboratory, The Salk Institute for Biological Studies , La Jolla, California. LA - eng PT - Journal Article PT - Research Support, N.I.H., Extramural PT - Research Support, Non-U.S. Gov't DEP - 20180620 PL - United States TA - J Neurophysiol JT - Journal of neurophysiology JID - 0375404 MH - Acoustic Stimulation MH - *Action Potentials MH - Animals MH - Auditory Pathways/physiology MH - Auditory Perception/*physiology MH - Illusions/*physiology MH - Macaca mulatta MH - Male MH - Motion Perception/*physiology MH - Neurons/*physiology MH - Photic Stimulation MH - Temporal Lobe/*physiology MH - Visual Pathways/physiology PMC - PMC6171057 OTO - NOTNLM OT - audiovisual interactions OT - motion processing OT - multisensory OT - temporal ventriloquism OT - visual area MT EDAT- 2018/06/21 06:00 MHDA- 2019/08/02 06:00 PMCR- 2019/09/01 CRDT- 2018/06/21 06:00 PHST- 2018/06/21 06:00 [pubmed] PHST- 2019/08/02 06:00 [medline] PHST- 2018/06/21 06:00 [entrez] PHST- 2019/09/01 00:00 [pmc-release] AID - JN-00835-2017 [pii] AID - 10.1152/jn.00835.2017 [doi] PST - ppublish SO - J Neurophysiol. 2018 Sep 1;120(3):1340-1355. doi: 10.1152/jn.00835.2017. Epub 2018 Jun 20.