The intrinsic value of
visual information affects saccade velocities
Xu, Zee, and Shadmehr (2009) Experimental
Brain Research.
Abstract Let us assume that the purpose of any
movement is to position our body in a more advantageous or rewarding
state. For example, we might make a
saccade to foveate an image because our brain assigns an intrinsic value to the
information that it expects to acquire at the endpoint of that saccade. Different images might have different
intrinsic values. Optimal control
theory predicts that the intrinsic value that the brain assigns to targets of
saccades should be reflected in the trajectory of the saccade. That is, in anticipation of foveating a
highly valued image, our brain should produce a saccade with a higher velocity
and shorter duration. Here, we
considered four types of images: faces, objects, inverted faces, and
meaningless visual noise. Indeed,
we found that reflexive saccades that were made to a laser light in
anticipation of viewing an image of a face had the highest velocities and
shortest durations. The intrinsic
value of visual information appears to have a small but significant influence
on the motor commands that guide saccades.