A salient and task-irrelevant collinear structure hurts visual search

PLoS One. 2015 Apr 24;10(4):e0124190. doi: 10.1371/journal.pone.0124190. eCollection 2015.

Abstract

Salient distractors draw our attention spontaneously, even when we intentionally want to ignore them. When this occurs, the real targets close to or overlapping with the distractors benefit from attention capture and thus are detected and discriminated more quickly. However, a puzzling opposite effect was observed in a search display with a column of vertical collinear bars presented as a task-irrelevant distractor [6]. In this case, it was harder to discriminate the targets overlapping with the salient distractor. Here we examined whether this effect originated from factors known to modulate attentional capture: (a) low probability-the probability occurrence of target location at the collinear column was much less (14%) than the rest of the display (86%), and observers might strategically direct their attention away from the collinear distractor; (b) attentional control setting-the distractor and target task interfered with each other because they shared the same continuity set in attentional task; and/or (c) lack of time to establish the optional strategy. We tested these hypotheses by (a) increasing to 60% the trials in which targets overlapped with the same collinear distractor columns, (b) replacing the target task to be connectivity-irrelevant (i.e., luminance discrimination), and (c) having our observers practice the same search task for 10 days. Our results speak against all these hypotheses and lead us to conclude that a collinear distractor impairs search at a level that is unaffected by probabilistic information, attentional setting, and learning.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Attention / physiology*
  • Discrimination, Psychological
  • Humans
  • Learning / physiology
  • Models, Statistical
  • Pattern Recognition, Visual / physiology*
  • Photic Stimulation
  • Reaction Time / physiology
  • Task Performance and Analysis
  • Visual Perception / physiology*

Grants and funding

Dr. Li Jingling was supported by Taiwan National Science Council (NSC-100-2627-B-039-004 and NSC101-2410-H-039-001-MY2) (http://www.most.gov.tw/) and a travel grant by HKU China Affair Office (http://www.als.hku.hk/hkucao/). Dr. Chia-huei Tseng was supported by the Hong Kong Grant Research Council and HKU Seed Funding Programme for Basic Research. (http://www.ugc.edu.hk and http://www.rss.hku.hk/). NTT Research Lab in Japan supported Dr. Tseng during completion of this manuscript. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.