Probing V5/MT excitability with transcranial magnetic stimulation following visual motion adaptation to random and coherent motion

Research output: Contribution to journalArticle

Researchers

  • Jessica Guzman-Lopez
  • Juha Silvanto
  • Nada Yousif
  • Sofia Nousi
  • Shamim Quadir
  • Barry M. Seemungal

Research units

  • Imperial College London

Abstract

The response to stimulating the visual cortex with transcranial magnetic stimulation (TMS) depends on its initial activation state, for example, visual motion adaptation biases perceived TMS-induced phosphene characteristics (e.g., color). We quantified this state dependence by assessing the probability of reporting a phosphene (P λ) with "threshold" TMS (i.e., the TMS intensity producingP λ= 0.5 at baseline) following visual motion adaptation to a random dot motion display. Postadaptation,P λwas increased, and this effect was confined to the adapted neuronal population. We then adapted subjects using a population of moving dots of fixed averagemotion directionwith standard deviations (SD) ranging from 1° to 128° (SD fixed for a given trial).P λwas significantly increased at all dot motion SDs except SD = 1°. Neuronal adaptation increases the susceptibility of the neuronal population to activation by threshold intensity TMS. Thus the process of neuronal adaption is not necessarily synonymous with a downmodulation of neuronal excitability.

Details

Original languageEnglish
Pages (from-to)200-207
Number of pages8
JournalAnnals of the New York Academy of Sciences
Volume1233
Issue number1
Publication statusPublished - Sep 2011
MoE publication typeA1 Journal article-refereed

    Research areas

  • Motion adaptation, Transcranial magnetic stimulation, V5/MT

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