Ambient Light Modulation of Exogenous Attention to Threat

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• 作者：Luis Carretié ; Elisabeth Ruiz-Padial
• 关键词：Exogenous attention ; Ambient light ; Threat ; Event ; related potentials ; Photoreceptors
• 刊名：Brain Topography
• 出版年：2016
• 出版时间：November 2016
• 年：2016
• 卷：29
• 期：6
• 页码：847-855
• 全文大小：1,032 KB
• 刊物类别：Biomedical and Life Sciences
• 刊物主题：Biomedicine
  Neurosciences
  Psychiatry
  Neurology
  
• 出版者：Springer New York
• ISSN：1573-6792
• 卷排序：29

文摘

Planet Earth’s motion yields a 50 % day–50 % night yearly balance in every latitude or longitude, so survival must be guaranteed in very different light conditions in many species, including human. Cone- and rod-dominant vision, respectively specialized in light and darkness, present several processing differences, which are—at least partially—reflected in event-related potentials (ERPs). The present experiment aimed at characterizing exogenous attention to threatening (spiders) and neutral (wheels) distractors in two environmental light conditions, low mesopic (L, 0.03 lx) and high mesopic (H, 6.5 lx), yielding a differential photoreceptor activity balance: rod > cone and rod < cone, respectively. These distractors were presented in the lower visual hemifield while the 40 participants were involved in a digit categorization task. Stimuli, both targets (digits) and distractors, were exactly the same in L and H. Both ERPs and behavioral performance in the task were recorded. Enhanced attentional capture by salient distractors was observed regardless of ambient light level. However, ERPs showed a differential pattern as a function of ambient light. Thus, significantly enhanced amplitude to salient distractors was observed in posterior P1 and early anterior P2 (P2a) only during the H context, in late P2a during the L context, and in occipital P3 during both H and L contexts. In other words, while exogenous attention to threat was equally efficient in light and darkness, cone-dominant exogenous attention was faster than rod-dominant, in line with previous data indicating slower processing times for rod- than for cone-dominant vision.