Ocular movements and spontaneous blink rate as functions of personality.

Abstract

Although the importance of both deliberate and spontaneous blinking and eye movements in the study of certain perceptual phenomena has been stressed repeatedly, the circumstances surrounding the relative contributions for these two variables remain open to question. The Merediths (1962) suggested that differential eye movements and blink rates may be associated with different types of viewing instructions. This could partially account for recently reported differences among Necker cube fluctuation data obtained under different viewing instructions (Franks & Lindahl, 1963). In this study, in which eye movements per se were not investigated, blinking was unrelated either to extraversion or to fluctuation. In a subsequent invesrrg3rron eye movemenrs and blink rates were related ro the extraversion scores of 39 normal adult males. Spontaneous blinking was recorded photoelectrically while Ss sat in a sound proof room gazing at a 600-rpm rotating spiral for rare I-min, viewing periods, separated by a 3-min. interval. Extraversion scores were then obtained by having Ss complete the E scale of the Maudsley Personality Inventory ( M P I ) . Spontaneous eye movements were investigated by a technique which required Ss to keep their heads still and report any fleering obtruding upon the otherwise uniform grey appearance at the same high speed (Holland, 1960) . This effect, which also occurs when certain blinks occur, is supposed to be stable and reliable. After a brief explanation and practice period Ss were given rwo trials of 1 min. separated by a 3-min. interval, all flashes being recorded by a light touch on a silent telegraph key attached to a counter. For 2 0 Ss the blink test followed the questionnaire. The order of presentation was found to produce no pertinent differences in either rate of blinking or report of flashes. Pearson product-moment testretest correlations were .72 and .84 for the blinks and flashes, respectively. Correlations among mean blink rate, mean flash rate and E were as follows: blink-E, r = .lo; blink-flash, I = .22; E-flash, r = .42. If flash rate does indeed measure certain eye movements, then these data suggest that eye movements may be of greater pertinence than eye blinks in studies involving visuaI fixation and extraversion. These data also provide some support for Eysenck's contention that extraverts are poorer at. visual fixation than are introverts (see Holland, 1960).