Hand posture and cognitive control: The congruency sequence effect is reduced near the hands.

According to several recent articles, attentional processing seems to be modulated by the proximity of one's own hand to a stimulus. Weidler and Abrams (Psychonomic Bulletin & Review, 21, 462-469, 2014) found a significant reduction of the Eriksen flanker effect when the stimuli were presented close to the participants' hands. They interpreted this as evidence for stronger cognitive control near the hands. Using a near-by hands manipulation intended to vary distance while keeping posture of the hands constant, we found a modulation of the congruency sequence effect (CSE or Gratton effect), i.e., a larger flanker effect following incompatible trials than following compatible trials. The CSE was eliminated near the hands. Though we did not find a reduction in the flanker effect itself (which might be the result of using a near-by hand manipulation somewhat different from that of Weidler and Abrams), this result can be considered to be compatible with Weidler and Abrams' original hypothesis if the congruency sequence effect is interpreted in terms of cognitive control.