People

Geoffrey Karl Aguirre, MD, PhD
Assistant Professor of Neurology
University of Pennsylvania
aguirreg@mail.med.upenn.edu

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Alison Harris, PhD
Post-doctoral Fellow
alisonmh@mail.med.upenn.edu

Biosketch - PDF :: Search PubMed

My research examines the neural correlates of face and object perception using a variety of techniques, including magnetoencephalography (MEG) and functional magnetic resonance imaging (fMRI). Using MEG, I have quantified the properties of the M170 response, an early "face-selective" component, both in normal adults and in developmental prosopagnosics, individuals with behavioral impairments in face recognition (in collaboration with Dr. Brad Duchaine). More recently, in my work with Dr. Geoffrey Aguirre, I have been using fMRI to explore the nature of representations within "face- selective" regions of interest (ROIs). Together, the results from these two lines of inquiry suggest that the neural encoding of faces includes not only global or holistic information about the entire face, as has been previously proposed, but also representation of individual face features or parts.

Research Publications, peer reviewed (papers & editorials)

A Harris, GK Aguirre. (2008) The Effects of Parts, Wholes, and Familiarity on Face-Selective Responses in MEG. Journal of Vision, In Press.
A Harris, GK Aguirre. (2008) The Representation of Parts and Wholes in Face-Selective Cortex. Journal of Cognitive Neuroscience, 20(5), 863-78.
A Harris, K Nakayama. (2008)Rapid adaptation of the M170 response: Importance of face parts. Cerebral Cortex, 18(2), 467-76.
A Harris, GK Aguirre. (2007). Prosopagnosia. Current Biology, 17, 7-8.
A Harris, K Nakayama. (2007). Rapid face-selective adaptation of an early extrastriate component in MEG. Cerebral Cortex, 17, 63-70.
A Harris, B Duchaine, K Nakayama. (2005). Normal and abnormal face selectivity of the M170 response in developmental prosopagnosics. Neuropsychologia, 43, 2125-2136.
J Liu, A Harris, N Kanwisher. (2002). Stages of processing in face perception: An MEG study. Nature Neuroscience, 5(9), 910-916.
R Epstein, A Harris, D Stanley, N Kanwisher. (1999). The parahippocampal place area: Recognition, navigation, or encoding? Neuron, 23, 115-125.
N Kanwisher, D Stanley, A Harris. (1999). The fusiform face area is selective for faces not animals. Neuroreport, 10, 183-187.

Daniel Drucker
Psychology Graduate Student

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I am broadly interested in the neural bases of object and concept similarity spaces. Currently, I am exploring the focal and distributed representations of visual similarity of parameterized shape spaces in human object recognition cortex.

Amy Thomas
Research Technician

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I am involved in a variety of facial perception studies including the development of a neuropsychological battery of face perception and many other fMRI and behavioral studies.

Petya Radoeva
Neuroscience Graduate Student

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I am interested in characterizing the organization of the visual system of patients with occipital cortex damage, and in establishing if remapping of retinotopic organization can occur visual cortex lesions. I have been studying the residual visual functioning, both behaviorally and on a neural level (using fMRI), of a patient with Blindsight, as well as the representation of the ipsilateral visual field in healthy control subjects. In the long run, I hope to examine ways of improving vision after stroke (eg, through perceptual training), and the neural basis of recovery.

Sashank Prasad, MD
Neurology Resident

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I have a blossoming interest in higher-order visual processing. Currently, I am using functional imaging to investigating the mechanisms of cross-modal plasticity of the visual cortex in early-blind subjects. Specifically, I am assessing the relative contribution of the "visual" cortex to a spoken-language semantic categorization task. I collaborate on another project studying a subject with intact motion perception within a scotoma due to a discrete lesion of the primary visual cortex. At the completion of residency training, I will pursue a clinical neuro-ophthalmology fellowship at Penn, followed by a two-year cognitive research fellowship in Dr. Aguirre's lab.

Summer Students

David Yaron - Johns Hopkins Undergrad
Jeff Ratliff - Syracuse School of Medicine
Wesley Kerr - University of Pennsylvania Undergrad
Ben Tseng - Drexel University School of Medicine