Speaker: Aina Puce PhD --- Eleanor Cox Riggs Professor in Social Justice & Ethics, Psychological & Brain Sciences, Indiana University; Bachelor and Master of Applied Science, Swinburne Institute of Technology, Melbourne, Australia; PhD Medicine, University of Melbourne; Post-doctoral Fellow Neurosurgery, Yale University (Email: ainapuce@indiana.edu) (Sponsored By: Robert Yee MD)(ID: 1916)
The human brain's visual system is a mosaic of brain regions with different specializations, which can manifest as selective visual deficits in focal brain injury. Non-invasive brain mapping methods can study these specialized brain regions in detail in healthy people and patients alike. It is possible to measure changes in focal brain blood flow [functional MRI] and magnetic fields or electrical activity at the scalp surface [magnetoencephalography and electroencephalography]. Electrical activity may also be recorded invasively from inside the brains of neurosurgical patients. Studying the functions of the brain's "grey matter" are only part of the story: the information carrying pathways formed by the brain's "white matter" help ferry the grey matter's communications to other parts of the brain. Dr. Puce will present examples from all of these methods to discuss how our brains make sense of the face and body movements of others.
Program: Live and Zoom:
Seeing Your Way Around the Brain, Brain Mapping
Speaker: Aina Puce, PhD, Eleanor Cox Riggs Professor in Social Justice & Ethics, Psychological & Brain Sciences, Indiana University
Introduced By: Robert Yee
Attendance: NESC: 110, Zoom: 34
Guest(s): Pat Lawler, Bob Chreist, Bob Shinge, Christine Baldwin, Kim Fletter
Scribe: Benny Ko
Editor: Ed Nitka
View a Zoom recording of this talk at: Today's Program 111824
The human brain's visual system is a mosaic of brain regions that can manifest as selective visual deficits in focal brain injury. Non-invasive brain mapping methods can study these specialized brain regions. It is possible to measure changes in local brain blood flow and magnetic fields or electrical activity at the scalp surface. Electrical activity may also be recorded invasively from inside the brains of neurosurgical patients.
Studying the functions of the brain's "grey matter" is only part of the story: the information-carrying pathways formed by the brain's "white matter" help ferry the grey matter's communications to other parts of the brain. Dr. Puce presented examples from all of these methods and discussed how our brains make sense of the face and body movements of others.
Perception of an object such as a face involves the occipital region of the brain. However, recognition of whose face it belongs to, what the face is expressing, and what kind of motions/movements the various facial parts are performing involve specific brain areas; most are anterior to the occipital cortex in the brain's temporal lobe and parietal lobe. Studying the function of these brain areas and locating them is known as brain mapping, and it is the research Dr. Puce engages in. Her tools include functional and structural magnetic resonance imaging, infrared eye tracking, high-density encephalography, and transcranial magnetic stimulation. Pioneering research in this field was performed on monkeys.
Traditionally, two "pathways" are recognized in processing visual information. One is considered to be the "what" pathway and the other, the "where" pathway. From the inferior occipital gyri, visual information goes through the superior temporal sulcus reaching respectively a) the intraparietal sulcus where the spatial direction is recognized, b) the amygdala, insula, and the limbic system where the information is transformed into emotions and initiates autonomic responses, and, c) liaison with the auditory cortex. In another direction, visual information reaches the lateral fusiform gyrus where the perception of a unique identity is formed. Generally speaking, perception of the "whole" is generated in the temporal lobe, for the "part", in the parietal lobe.
A third visual pathway has now been proposed. Termed the dorsal pathway, it specializes in "social perception", and much research is ongoing.
The brain's white matter is the superhighways that link up different parts of the cortical brain.
Here are some examples of unique visual deficits that have been clinically encountered. Together they prove the perception of objects, in whole or in parts, static or in motion, as friend or foe. All have specific locations for their function and processing.
Prosopaphasia----inability to recognize faces. Achromatopsia----inability to recognize colors. akinetopsia---inability to recognize motion. Acalculia----inability to recognize numbers. Alexia---inability to recognize words or text. Amusia---inability to recognize music.
Aina Puce
