Visual Perception and Attention

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My lab studies the interface between human visual perception, social-emotional processing, and action kinematics. The methods are behavioral (psychophysics, eye tracking, limb movement, self-report, third-person observation, questionnaire) and are strongly informed by theories based on physiology (electrophysiology, imaging) and neuropsychology (brain injury, disease). Two representative lines of research are outlined briefly as examples of the projects ongoing in the UBC Vision Lab. An exciting recent discovery from our group is that when human observers are trying to predict the next moves of an actor, they are sensitive to the attentional control state of the actor. One consequence of this sensitivity is that observers are better able to predict the actor's next moves when the actor is choosing freely to move than when they are being directed by an external force. We call this the “choice advantage” in person perception (Pesquita et al., 2016 PNAS) and have shown that (a) it is visible in the very early kinematics of the actor, (b) it is outside the conscious awareness of the observer, (c) the kinematic signal is distributed over the torso and limbs of the actor, and (d) that sensitivity to the signal is correlated with the overall social aptitude of the observer. We conclude that humans are sensitive to an implicit kinematic process linked to empathy and that social perception involves the predictive modeling of others' attentional states. The proposed work now examines in greater detail how the kinematic signals received by individuals differs as a function of their ability to empathize with others. The proposed work also examines how sensitivity to an actor's attentional state influences the observer's ability to engage in collaborative tasks with the actor. A second important discovery of the past round of funding is that the so-called “autopilot” of the dorsal visual stream (i.e., the circuitry that enables us to press an elevator button while moving, to catch a ball with our hands, to pass a baton to a runner in a relay) seems to operate independently from the ventral visual stream circuitry that informs us about the emotional meaning of the objects we are reaching for (e.g., a spider crawling on a pen). Central to this discovery was the development of an experimental method that disentangled the contents of consciousness from the directions needed to make a visually guided pointing movement (Enns et al., 2017, Progress in Brain Research). The proposed research will extend this methodology to study of how the two visual systems (dorsal and ventral) are guided by dissociable selective mechanisms. In short, this work is an effort to break away from the bias in our field to invoke a monolithic attentional network; arguing instead that the mechanisms of selectivity are as different in the two visual streams as are the representations that are formed by each of them.