Both Physical Exercise and Progressive Muscle Relaxation Reduce the Facing-the-Viewer Bias in Biological Motion Perception

Abstract

Biological motion stimuli, such as orthographically projected stick figure walkers, are ambiguous about their orientation in depth. The projection of a stick figure walker oriented towards the viewer, therefore, is the same as its projection when oriented away. Even though such figures are depth-ambiguous, however, observers tend to interpret them as facing towards them more often than facing away. Some have speculated that this facing-the-viewer bias may exist for sociobiological reasons: Mistaking another human as retreating when they are actually approaching could have more severe consequences than the opposite error. Implied in this hypothesis is that the facing-towards percept of biological motion stimuli is potentially more threatening. Measures of anxiety and the facing-the-viewer bias should therefore be related, as researchers have consistently found that anxious individuals display an attentional bias towards more threatening stimuli. The goal of this study was to assess whether physical exercise (Experiment 1) or an anxiety induction/reduction task (Experiment 2) would significantly affect facing-the-viewer biases. We hypothesized that both physical exercise and progressive muscle relaxation would decrease facing-the-viewer biases for full stick figure walkers, but not for bottom- or top-half-only human stimuli, as these carry less sociobiological relevance. On the other hand, we expected that the anxiety induction task (Experiment 2) would increase facing-the-viewer biases for full stick figure walkers only. In both experiments, participants completed anxiety questionnaires, exercised on a treadmill (Experiment 1) or performed an anxiety induction/reduction task (Experiment 2), and then immediately completed a perceptual task that allowed us to assess their facing-the-viewer bias. As hypothesized, we found that physical exercise and progressive muscle relaxation reduced facing-the-viewer biases for full stick figure walkers only. Our results provide further support that the facing-the-viewer bias for biological motion stimuli is related to the sociobiological relevance of such stimuli.

Tactile input and empathy modulate the perception of ambiguous biological motion

“…Therefore, a facing-the-viewer bias was manifested. This replicates several studies reported on in the literature (Vanrie et al, 2004 ; Brooks et al, 2008 ; Miller and Saygin, 2013 ; Van de Cruys et al, 2013 ; Heenan and Troje, 2014 ). However, there was no main effect of group.…”

What causes the facing-the-viewer bias in biological motion?

“…Recently, Heenan and Troje (2014) presented data that support the theory that the facing-the-viewer bias is at least in parts modified by the social relevance of biological motion stimuli. The authors show that individuals with high anxiety levels demonstrate a higher degree of facing-the-viewer bias than individuals with low levels of anxiety.…”

Sex and gender affect the social brain: Beyond simplicity

“…Deficient BM processing has been reported in a wide range of neuropsychiatric diseases including ASD (Klin et al, ; Koldewin et al, ; Nackaerts et al, ; Alaerts et al, ; Cleary et al, ; Kröger et al, ; for review see Pavlova, ), schizophrenia (Kim et al, ; van den Stock et al, ; Hasting et al, ; Spencer et al, ; Hashimoto et al, 2016; Vaskinn et al, ), schizotypal personality disorder (Hur et al, ), ADHD (Kröger et al, ), anxiety disorders (van de Cruys et al, ; Heenan and Troje, ), obsessive compulsive disorders (Kim et al, ). BM processing is also impaired in individuals with autistic traits (Actis‐Grosso et al, ), and in individuals born preterm who suffer congenital brain lesions (Pavlova et al, ; Taylor et al, ; for review see Pavlova and Krägeloh‐Mann, ).…”