Neural processes underlying the"same"-"different" judgment of two simultaneously presented objects--an EEG study

PLoS One. 2013 Dec 12;8(12):e81737. doi: 10.1371/journal.pone.0081737. eCollection 2013.

Abstract

The present study investigated the neural processes underlying "same" and -"different" judgments for two simultaneously presented objects, that varied on one or both, of two dimensions: color and shape. Participants judged whether or not the two objects were "same" or "different" on either the color dimension (color task) or the shape dimension (shape task). The unattended irrelevant dimension of the objects was either congruent (same-same; different-different) or incongruent (same-different). ERP data showed a main effect of color congruency in the time window 190-260 ms post-stimulus presentation and a main effect of shape congruency in the time window 220-280 ms post-stimulus presentation in both color and shape tasks. The interaction between color and shape congruency in the ERP data occurred in a later time window than the two main effects, indicating that mismatches in task-relevant and task-irrelevant dimensions were processed automatically and independently before a response was selected. The fact that the interference of the task-irrelevant dimension occurred after mismatch detection, supports a confluence model of processing.

MeSH terms

  • Attention
  • Color Perception / physiology
  • Discrimination, Psychological*
  • Electroencephalography
  • Female
  • Humans
  • Judgment / physiology*
  • Male
  • Pattern Recognition, Visual / physiology*
  • Reaction Time
  • Space Perception / physiology
  • Stroop Test
  • Young Adult

Grants and funding

This study was supported by the National Natural Science Foundation of China (NSFC 31170982) and Royal Society (IE121122) International Cooperation and Exchanges NSFC (31311130123. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.