Visual asymmetry biases assessment of conjugate lateral eye movement

Abstract

This paper reports a serendipitous observation. Prior research led to the expectation that equal numbers of right-movers and left-movers would be found in a study aimed at exploring individual differences in conjugate lateral eye movement. Instead, most subjects were found to be right-movers (p < .001). Scrutiny ofthe study's procedures revealed that the subjects had inadvertently been placed next to the left wall of the room. Apparently asymmetrical visual stimulation during the assessment of conjugate lateral eye movement can affect the right versus left directionality of such movement, an interpretation consistent with earlier formulations and findings of the sensorytonic theory of perception. This paper reports a serendipitous observation that seems to indicate that asymmetrical positioning of a subject in a testing room during assessment of conjugate lateral eye movement (CLEM) biases the right versus left directionality of CLEM. To put this issue into appropriate perspective, the CLEM phenomenon is described and some earlier CLEM findings reviewed. Then, after the report of the study, the implications and interpretation of this finding are considered.If two people are facing each other while sharing eye gaze and if the first asks the second a question that requires some reflective thinking, the second person will typically avert his/her eyes to the right or left before beginning to reply . This shift in eye gaze has been called conjugate lateral eye movement.Based on clinicalobservations, Day (1964) was the first to call attention to CLEM . He reported that most people can be described as either "right-movers" (i.e. , a person who shows mostly right CLEMs) or "left-movers. " This description turned out to be somewhat oversimplified: it implies a bimodal distribution of CLEM scores, whereas in fact the distribution is relatively flat (cf. Ehrlichman & Weinberger, 1978, Figure 1). This flat distribution indicates that although many people show predominantly right CLEM and many others show predominantly left CLEM, there are a number who fall in the middle, showing more nearly equal amounts of right and left CLEM . In terms of the issues involved in the present paper, it should be added, however, that if one categorizes a number of people into two groups-those who show more right CLEM versus those who show more left CLEM-the two groups should be approximately equal in size.

Cognitive Consequences of Asymmetrical Visual Distraction

“…However, many different influences can affect looking behavior. For example, Baker (1989) demonstrated that visual asymmetry influenced direction of gaze, with participants consistently making eye movements away from the closest wall in the room. Rodin and Singer (1976) found that even if people predominately look to the right, they will stop doing so if another person is standing there.…”