Catrina M. Hacker
Visual Memory Lab, University of Pennsylvania
Identifying the neural correlates of context-dependent changes in image memorability

We have an incredible capacity for visual memory, but not all images are equally likely to be remembered. Some images are consistently better remembered than others, a phenomenon known as image memorability. The images we've most recently seen also influence how easily we remember new images. We're much less likely to remember a dog when we've just seen 10 other dogs than we are if we see that same dog after seeing 10 other objects. My project aims to understand the neural correlates of this phenomenon and to determine how changes in the neural representations of visual memories drive these changes in memory. I recently presented my work at the 2022 meeting of the Vision Science Society. Check back again later for more updates about this project.

Bottjer Songbird Lab, University of Southern California
Optogenetic Disruption of Song-Learning in Juvenile Zebra Finches
Image Understanding Lab, University of Southern California
Assesesing Proficiency for Face Memory Independent of Face Perception

Most tests of face recognition implicitly assume it to be an undifferentiated ability. Several independent components could comprise face recognition proficiency, such as those for the perceptual discrimination of faces, face memory and the ability to generalize across viewpoints. I designed a behavioral task to separate two of these potential components: proficiency for the perceptual discrimination of faces and proficiency for face memory. Using this task, I found evidence on the group level that these are two independent processes. My analyses suggest that these two proficiencies may be uncorrelated on an individual basis, challenging the generally held assumption that face recognition is a general ability that cannot be differentiated into independent components.

Watch a demo of the task or check out the poster or read the preprint!!

A Neurocomputational Account of the Difficulty of Recognizing a Face Rotated in Depth
Recognition of Stretched Faces

In 2002, Graham Hole showed that we have a remarkable capacity to recognize familiar faces that have been stretched vertically or horizontally by a factor of 2. Since this discovery, no explanation has been given for this invariance. One possibility is that familiarity with a face facilitates invariance to stretch similarly to how familiarity has been shown to facilitate invariance to rotation in depth. To test this, I designed a behavioral task to determine if familiarity with a face could also explain invariance to stretch by having subjects rate their familiarity with a number of celebrities used in the task. My results show that familiarity cannot account for stretched face recognition. After rejecting the possibility that faces are “un-stretched” by warping them to an average face we suggest that the percept of an elongated face provides a signal for the shrink-wrapping of receptive fields to conform to an attended object, a phenomenon witnessed in single unit activity in the macaque by Moran and Desimone (1985). Such a phenomenon may serve, more generally, as the underlying neural mechanism for object-based attention.

Watch a demo of the task or check out the poster or read the preprint!

Detection of Familiar Faces at RSVP Rates