Extramission, Attribution, and the Speed of the Implicit Gaze Beam

Abstract

The human brain devotes a notable amount of effort to process the gaze of other social agents as it is a fundamental aspect of social interactions and the prediction of other’s behavior. Eyes have been regarded as the “window into the soul” and have been associated with an ancient theory of vision, called extramission, whereby an invisible substance emanating from eyes interacts with objects before returning to the eyes spawning vision. Recent research has shown that the brain may implicitly and automatically model a social agent’s attention in a physically inaccurate representation as if it were emanating from the agent’s eyes and flowing through space towards an attended object while additionally shown to enact a pushing effect which biases the perceived weight of that object. This thesis will review the known mechanisms by which eye directed social attention is facilitated and will analyze the attention given to eyes from a historical and evolutionary perspective in addition to elucidating properties of the attribution and speed of the implicit gaze beam model of social attention. In Chapter 1, I review social attention and indicate the vital importance that eyes and eye gaze have on the communicative nature of humans before explaining the known neural mechanisms of eye gaze processing, followed by a review of the vast quantity of information that humans attribute to eyesight – including notions of the evil eye and theory of mind – before providing a historical review of the pervasive belief in extramission and its implications on social attention. In Chapter 2 – I describe two novel experiments performed using a tube-tilt paradigm where participants rate the angle at which a tube will topple over to determine that humans may model the mind of a group distinctly from that of an individual. In Chapter 3, I describe four novel experiments performed using a dot-motion paradigm where the effects of motion adaptation generated by facial stimuli reveal that humans likely model the minds of non-human species in a manner very similar to that of humans in addition to the determination that the speed at which the implicit gaze beam propagates is approximately 1.4 visual degrees per second. In Chapter 4, I will conclude this thesis and provide ideas for further experimentation to further elucidate the unknown properties of the implicit gaze beam model of social attention.