Biomedical subjects

Michael L Spezio

Publications and source records attributed to Michael L Spezio.

3 recordsLinked to original sources

PubMed2007

Abnormal use of facial information in high-functioning autism.

Altered visual exploration of faces likely contributes to social cognition deficits seen in autism. To investigate the relationship between face gaze and social cognition in autism, we measured both face gaze and how facial regions were actually used during emotion judgments from faces. Compared to IQ-matched healthy controls, nine high-functioning adults with autism failed to make use of information from the eye region of faces, instead relying primarily on information from the mouth. Face gaze accounted for the increased reliance on the mouth, and partially accounted for the deficit in using information from the eyes. These findings provide a novel quantitative assessment of how people with autism utilize information in faces when making social judgments.

Adult↗

PubMed2006

Analysis of face gaze in autism using "Bubbles".

One of the components of abnormal social functioning in autism is an impaired ability to direct eye gaze onto other people's faces in social situations. Here, we investigated the relationship between gaze onto the eye and mouth regions of faces, and the visual information that was present within those regions. We used the "Bubbles" method to vary the facial information available on any given trial by revealing only small parts of the face, and measured the eye movements made as participants viewed these stimuli. Compared to ten IQ- and age-matched healthy controls, eight participants with autism showed less fixation specificity to the eyes and mouth, a greater tendency to saccade away from the eyes when information was present in those regions, and abnormal directionality of saccades. The findings provide novel detail to the abnormal way in which people with autism look at faces, an impairment that likely influences all subsequent face processing.

Adult↗

PubMed2003

Frequency-specific interaural level difference tuning predicts spatial response patterns of space-specific neurons in the barn owl inferior colliculus.

Space-specific neurons in the barn owl's inferior colliculus have spatial receptive fields (RFs) because of sensitivity to interaural time difference and frequency-specific interaural level difference (ILD). These neurons are assumed to be tuned to the frequency-specific ILDs occurring at their spatial RFs, but attempts to assess this tuning with traditional narrowband stimuli have had limited success. Indeed, tuning assessed in this manner, when processed via a linear model of spectral integration, typically explains only approximately half the variance in spatial response patterns. Here we report our findings that frequency-specific ILD tuning of space-specific neurons, when assessed from responses to broadband stimuli, predicted nearly 75% of the variance in spatial responses, using a linear model of spectral integration (p < 0.0001; n = 97 neurons). Furthermore, when we tested neurons using only those frequencies we found to be spatially relevant, we saw that their responses were similar to those elicited by broadband stimuli. When we used frequencies not identified as spatially relevant, such similarity was lacking. Furthermore, spectral components that elicited high firing rates when presented as narrowband stimuli were found in several cases to be irrelevant for or detrimental to the definition of spatial RFs. Thus, neurons achieved sharp spatial tuning by selecting for ILDs of a subset of spectral components in noise, some of which were not identified using narrowband stimuli.

Acoustic Stimulation↗