Improved Motion Perception and Impaired Spatial Suppression following Disruption of Cortical Area MT/V5
Open Access
- 26 January 2011
- journal article
- Published by Society for Neuroscience in Journal of Neuroscience
- Vol. 31 (4), 1279-1283
- https://doi.org/10.1523/jneurosci.4121-10.2011
Abstract
As stimulus size increases, motion direction of high-contrast patterns becomes increasingly harder to perceive. This counterintuitive behavioral result, termed “spatial suppression,” is hypothesized to reflect center–surround antagonism—a receptive field property ubiquitous in sensory systems. Prior research proposed that spatial suppression of motion signals is a direct correlate of center–surround antagonism within cortical area MT. Here, we investigated whether human MT/V5 is indeed causally involved in spatial suppression of motion signals. The key assumption is that a disruption of neural mechanisms that play a critical role in spatial suppression could allow these normally suppressed motion signals to reach perceptual awareness. Thus, our hypothesis was that a disruption of MT/V5 should weaken spatial suppression and, consequently, improve motion perception of large, moving patterns. To disrupt MT/V5, we used offline 1 Hz transcranial magnetic stimulation (TMS)—a method that temporarily attenuates normal functioning of the targeted cortex. Early visual areas were also targeted as a control site. The results supported our hypotheses and showed that disruption of MT/V5 improved motion discrimination of large, moving stimuli, presumably by weakening surround suppression strength. This effect was specific to MT/V5 stimulation and contralaterally presented stimuli. Evidently, the critical neural constraints limiting motion perception of large, high-contrast stimuli involve MT/V5. Additionally, our findings mimic spatial suppression deficits that are observed in several patient populations and implicate impaired MT/V5 processes as likely neural correlates for the reported perceptual abnormalities in the elderly, patients with schizophrenia and those with a history of depression.Keywords
This publication has 46 references indexed in Scilit:
- GABA Concentration Is Reduced in Visual Cortex in Schizophrenia and Correlates with Orientation-Specific Surround SuppressionJournal of Neuroscience, 2010
- Safety, ethical considerations, and application guidelines for the use of transcranial magnetic stimulation in clinical practice and researchClinical Neurophysiology, 2009
- The Role of the Parietal Lobe in Visual Extinction Studied with Transcranial Magnetic StimulationJournal of Cognitive Neuroscience, 2009
- Comparison of Spatial Summation Properties of Neurons in Macaque V1 and V2Journal of Neurophysiology, 2009
- Enhanced Visual Motion Perception in Major Depressive DisorderJournal of Neuroscience, 2009
- Baseline Cortical Excitability Determines Whether TMS Disrupts or Facilitates BehaviorJournal of Neurophysiology, 2008
- Contrast Dependence of Suppressive Influences in Cortical Area MT of Alert MacaqueJournal of Neurophysiology, 2005
- Motion Perception Getting Better with Age?Neuron, 2005
- Enhanced visual spatial attention ipsilateral to rTMS-induced 'virtual lesions' of human parietal cortexNature Neuroscience, 2001
- Segregation of Object and Background Motion in Visual Area MT: Effects of Microstimulation on Eye MovementsNeuron, 2000