Research
Philosophy
Each time we engage in a moderately complex task,
we likely enlist the help of an untold number of simpler visuo-motor
operations that exist largely outside of our conscious awareness.
Consider for instance the steps involved in preparing a cup of
coffee. For the sake of simplicity, assume that the coffee has
already been brewed and is waiting in the pot, and that all of the
essential accessories, an empty cup, a spoon, a carton of cream, and
a tin of sugar, are sitting on a countertop in front of you. What is
your first step toward accomplishing this goal? The very first thing
that you might do is to move your eyes to the handle of the coffee
pot, followed shortly thereafter by the much slower movement of your
preferred hand to the same target. Because the coffee pot is hot and
the handle is relatively small, this change in fixation is needed to
guide your hand to a safe and useful place in which to grasp the
object. After lifting the pot, your eye may then dart over to the
cup. This action is needed, not only to again guide the pot to a
very specific point in space directly over the cup, but also to
provide feedback to the pouring operation so as to avoid a spill.
After sitting the pot back on the counter (an act that may or may
not require another eye movement), your gaze will likely shift to
the spoon. Lagging shortly behind this behavior may be simultaneous
movements of your hands, with your dominant hand moving toward the
sugar tin and your non-preferred hand moving to the spoon. The spoon
is a relatively small and slender object that again requires
assistance from foveal vision for grasping; the tin is a rather
bulky and indelicate object that does not require precise Visual
information to inform the grasping operation. Once the spoon is in
hand and the lid to the tin is lifted, gaze can then be directed to
the tin in order to help scoop out the correct measure of sugar. To
ensure that the spoon is kept level, a tracking operation may be
used to keep your gaze on the loaded spoon as it moves slowly to the
cup. After receiving the sugar, and following a few quick turns of
the spoon, your coffee would finally be ready to drink (see Land et
al., 1998, for a similarly framed example).
Projects
Developing a neurocomputational model of eye movements during Visual search
Exploring memory for rejected distractors in a Visual search task
Understanding the role of target memory in a search task
Developing a neurocomputational model of change detection
Using eye movements to reveal memory for objects in scenes
Using eye movements to reveal the spatio-temporal dynamics of Visual search
Demonstrating set size effects in the absence of Visual search
Using eye movements to study scene-based change detection
Specifying linguistic constraints on Visual processing