The Influence of Co-action on a Simple Attention Task: A Shift Back to the Status Quo

Abstract

There is a growing consensus among researchers that a complete description of human attention and action should include information about how these processes are informed by social context. When we actively engage in co-action with others, there are characteristic changes in action kinematics, reaction time, search behavior, as well as other processes (see Sebanz et al., 2003; Becchio et al., 2010; Wahn et al., 2017). It is now important to identify precisely what is shared between co-actors in these joint action situations. One group recently found that participants seem to withdraw their attention away from a partner and toward themselves when co-engaged in a line bisection judgment task (Szpak et al., 2016). This effect runs counter to the typical finding that attention is drawn toward social items in the environment (Birmingham et al., 2008, 2009; Foulsham et al., 2011). As such, the result suggests that joint action can uniquely lead to the withdrawal of covert attention in a manner detectable by a line bisection task performed on a computer screen. This task could therefore act as a simple and elegant measure of interpersonal effects on attention within particular pairs of participants. For this reason, the present work attempted to replicate and extend the finding that attention, as measured by a line-bisection task, is withdrawn away from nearby co-actors. Overall our study found no evidence of social modulation of covert attention. This suggests that the line bisection task may not be sensitive enough to reliably measure interpersonal attention effects - at least when one looks at overall group performance. However, our data also hint at the possibility that the effect of nearby others on the distribution of attention may be modulated by individual differences.

Keywords: covert attention; joint action; joint attention; line bisection; replication; social presence.

FIGURE 1

A sample trial sequence.

FIGURE 2

Curves fitted to mean results from all thirty-one participants. Note that this is for illustrative purposes only and does not represent the inferential tests, which were performed on per-participant threshold values.

FIGURE 3

Mean line bisection thresholds across partner locations. Error bars represent within-subject 95% confidence intervals (Cousineau, 2005; Morey, 2008). Note that thresholds are not different based on partner position.

FIGURE 4

Distribution of attentional shifts across the sample. For each participant, Social Influence Score (SIS) with 95% confidence interval is shown.