• Top page
  • Timetable
  • Per session
  • Per presentation
  • How to
  • Meeting Planner



Visual System

開催日 2014/9/12
時間 11:00 - 12:00
会場 Poster / Exhibition(Event Hall B)

Neural correlates of change blindness in human early visual cortex

  • P2-149
  • Li-Feng Yeh:1 Justin L Gardner:1,2 
  • 1:RIKEN Brain Science Institute, Wako, Japan 2:Dept Psych, Stanford Univ, Stanford, USA 

Detecting changes in visual scenes is a critical function of our visual system. Despite this, human subjects can fail to detect highly salient changes if they coincide with other visual disruptions, such as flickering distractors, a phenomenon known as change blindness. We asked what the fate of early visual cortical neural responses to salient changes in image contrast was when these changes were rendered imperceptible by flickering distractor stimuli. The visual stimuli consisted of 38 high-contrast natural images of soccer balls scattered across a gray screen. In two third of trials a single change occurred in the peripheral visual field, namely, a ball emerged from the background. Subjects were cued to indicate whether they detected the change by pressing a button, and maintained fixation during the task. When these changes happened with simultaneous flickering of distractor stimuli, the subjects´ performance was profoundly impaired (d-prime = 1.175; compared to no flickering: d-prime = 3.384; t(5) = 14.005, p<0.0001). Simultaneously, we employed functional magnetic resonance imaging (fMRI) and extracted the BOLD response from retinotopically-mapped voxels which responded to the stimulus change. In V1 and V3, we found the response to the change in trials with flickering distractors was significantly lower when subjects failed to identify the transient increment in contrast, compared to correct detection. Control analyses confirmed that the difference could not be attributed to the difference of visual inputs or eye movements. Our findings indicate that local neuronal activity in early visual cortex reflects changes in awareness in the ever-changing world.

Copyright © Neuroscience2014. All Right Reserved.