Effects of saccades and response type on the Simon effect: if you look at the stimulus, the Simon effect may be gone

Q J Exp Psychol (Hove). 2010 Nov;63(11):2172-89. doi: 10.1080/17470211003802434. Epub 2010 Jun 3.

Abstract

The Simon effect has most often been investigated with key-press responses and eye fixation. In the present study, we asked how the type of eye movement and the type of manual response affect response selection in a Simon task. We investigated three eye movement instructions (spontaneous, saccade, and fixation) while participants performed goal-directed (i.e., reaching) or symbolic (i.e., finger-lift) responses. Initially, no oculomotor constraints were imposed, and a Simon effect was present for both response types. Next, eye movements were constrained. Participants had to either make a saccade toward the stimulus or maintain gaze fixed in the screen centre. While a congruency effect was always observed in reaching responses, it disappeared in finger-lift responses. We suggest that the redirection of saccades from the stimulus to the correct response location in noncorresponding trials contributes to the Simon effect. Because of eye-hand coupling, this occurred in a mandatory manner with reaching responses but not with finger-lift responses. Thus, the Simon effect with key-presses disappears when participants do what they typically do--look at the stimulus.

MeSH terms

  • Adult
  • Analysis of Variance
  • Attention / physiology*
  • Female
  • Fixation, Ocular / physiology*
  • Humans
  • Male
  • Photic Stimulation / methods*
  • Reaction Time / physiology
  • Saccades / physiology*
  • Students / psychology
  • Task Performance and Analysis
  • Visual Perception / physiology*
  • Young Adult