Organization for Human Brain Mapping annual meeting abstract highlights

The full meeting program and all of the abstracts are available on our website at www.humanbrainmapping.org/NYC2003. Members of the press may attend the meeting at no charge by providing proper press credentials at check-in. Our registration desk will be located on the 5th floor of the Marriott Marquis Hotel and will be open 7:00-18:00 each day. If you have any questions, please contact Lori Anderson, Executive Director at 952-646-2029 or [email protected].

Scientific Poster Highlights (Embargoed until date of presentation):

Poster #410 Neural Systems Associated With Perception of One's Own Child: An fMRI Study- To be presented June

This study investigates the response to familiar faces associated with a high degree of emotional valence. Using fMRI, neurophysiological responses were measured in mothers while they were looking at pictures of their own child, friends of their child, unfamiliar children and unfamiliar adults. Probably as a result of emotional differences and differences in familiarity, effects were observed in the amygdala and fusiform gyrus, as well as other regions involved in person knowledge.

Poster #1589 Prenatal MR imaging for the study of fetus brain development – To be presented June

The study describes an MR image acquisition and processing tool capable of producing 3D images of the fetal brain while it is still in the uterus.

Poster #1568 Activation of visual cortex by electrotactile stimulation of the tongue in early-blind subjects – To be presented June

The tongue is highly sensitive, and so may be an ideal site for presenting information to those without sight. This study trained subjects for 6 hours to detect the orientation of the letter T presented in four different orientations on the tongue. Their brains were then scanned using PET. The results showed that while there was little or no activation in visual brain areas during training, significant brain activity was observed in several areas of the visual system in the blind after training. In contrast, no rCBF changes were observed in visual areas of trained normal subjects.

Brain systems related to rhythm processing were investigated in a group of young children using fMRI. While both rhythm and melody tasks resulted in general activation of the superior temporal gyrus, rhythm processing showed a bias towards the left hemisphere. This finding lends support to suggestions that the left hemisphere is specialized for temporal resolution in music, and that music may share functional substrates with language. Our follow-up studies will investigate whether or not this musical processing pattern can change with musical training.

Individuals diagnosed with autism respond atypically to social and emotional stimuli; their gaze aversion, social withdrawal and shyness are often accompanied by disturbances in social communication and interactions. This study suggests that these deficits may be related to differences in central brain mechanisms responsible for the processing of social and emotional stimuli, such as the amygdala and prefrontal cortex.

The amygdala has been shown to be involved in healthy subjects' responses to fearful stimuli. Abnormalities in this neural circuitry occur in patients with schizophrenia. Previous studies using still images may not invoke the true response to dynamic facial stimuli as seen in the real world. Using dynamic fearful facial expressions, the present study indicates specific abnormalities in the amygdalar response to threatening faces in schizophrenic patients.

There is compelling evidence that the human cerebral cortex (the sheet of brain cells that is responsible for most higher level cognitive functions) shrinks with age. The present study suggests that aging is a process that affects almost the entire cortex, yet is usually mild and corresponds to a loss of less than 0.5 mm across the age range (20-80 years) for most of the cortex. Only the frontmost part of the brain (anterior prefrontal cortex and the dorsolateral prefrontal cortex) exceed 1 mm loss across that same range. However, these are areas that are particularly important for higher level "executive" functions.

Strabismic amblyopia is one of the main visual disorders in Hong Kong in which patients suffer from misalignment of the eyes and abnormally low visual acuity. It will lead to the loss of depth and motion perception if left untreated. The purpose of this study was to investigate the possible difference in gray matter of the visual system in adults with strabismic amblyopia and in controls. The findings indicate structural changes in the primary visual cortex V1, as well as extrastriate visual areas in strabismic amblyopia. While such anatomical differences in gray matter concentration between strabismic amblyopic patients and adults without strabismic amblyopia could not be identified from MR images by simple visual inspection done, they were measurable with morphometric software.