Effects of Saccades and Response Type on the Simon Effect: If you Look at the Stimulus, the Simon Effect May be Gone

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.

Pointing out mechanisms underlying joint action

“…These conclusions are supported by a recent study by Buetti and Kerzel (2010), in which the authors tested in a standard Simon task the influence of eye movements (or fixed gaze) as a function of two types of responses. Crucially, in the scenario comparable to the present study-the pointing response combined with a fixed gaze-a spatial compatibility effect was observed.…”

“…In a previous study, Buetti and Kerzel (2010) investigated the impacts of different response modes (a finger lift and a pointing gesture) and gaze conditions (fixed gaze, free eye movements, and a saccade toward the stimulus) on a standard Simon task. They observed that the pointing gesture systematically caused a spatial compatibility effect in the fixed-gaze and free-eye-movement conditions, but not in the saccade condition.…”

“…Adapting the experimental logic of Buetti and Kerzel (2010) to the JST, in the present study, we aimed to investigate whether indirectly varying the degree of attention by means of pointing gestures in two individuals could elicit a compatibility effect in the individual condition and modulate the joint condition. Toward this aim, we emphasized the discrepancy between the compatible and incompatible responses by asking participants to perform a pointing gesture toward their respective compatible side, regardless of the stimulus location.…”

Dissociation between Goal-directed and Discrete Response Localization in a Patient with Bilateral Cortical Blindness

“…His hands lay on the screen, just below the boxes where stimuli were displayed ( Figure 1B). This finger-lift action was shown to be comparable with more common button-press responses (Buetti & Kerzel, 2010; see also Buetti & Kerzel, 2009).…”

A reach-to-touch investigation on the nature of reading in the Stroop task

“…For instance, in the Simon task literature, the reach-to-touch paradigm has already been used to investigate temporal properties of the effect (Porcu et al, 2016;Buetti & Kerzel, 2010;Finkbeiner & Heathcote, 2016). In a typical design, participants may be presented with a cognitive task that requires a speeded choice between two or more response alternatives.…”