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Biomedical subjects

A Fishbach

Publications and source records attributed to A Fishbach.

3 recordsLinked to original sources

Auditory edge detection: a neural model for physiological and psychoacoustical responses to amplitude transients.

Primary segmentation of visual scenes is based on spatiotemporal edges that are presumably detected by neurons throughout the visual system. In contrast, the way in which the auditory system decomposes complex auditory scenes is substantially less clear. There is diverse physiological and psychophysical evidence for the sensitivity of the auditory system to amplitude transients, which can be considered as a partial analogue to visual spatiotemporal edges. However, there is currently no theoretical framework in which these phenomena can be associated or related to the perceptual task of auditory source segregation. We propose a neural model for an auditory temporal edge detector, whose underlying principles are similar to classical visual edge detector models. Our main result is that this model reproduces published physiological responses to amplitude transients collected at multiple levels of the auditory pathways using a variety of experimental procedures. Moreover, the model successfully predicts physiological responses to a new set of amplitude transients, collected in cat primary auditory cortex and medial geniculate body. Additionally, the model reproduces several published psychoacoustical responses to amplitude transients as well as the psychoacoustical data for amplitude edge detection reported here for the first time. These results support the hypothesis that the response of auditory neurons to amplitude transients is the correlate of psychoacoustical edge detection.

Animals↗

Counteractive self-control in overcoming temptation.

How do anticipated short-term costs affect the likelihood of engaging in an activity that has long-term benefits. Five studies investigated the factors that determine (a) how anticipated short-term costs elicit self-control efforts and (b) how self-control efforts eventually diminish the influence of short-term costs on behavior. The studies manipulated short-term costs (e.g., painful medical procedures) and assessed a variety of self-control strategies (e.g., self-imposed penalties for failure to undergo a test). The results show that short-term costs elicit self-control strategies for self rather than others, before rather than after behavior. when long-term benefits are important rather than unimportant and when the costs are moderate rather than extremely small or large. The results also show that the self-control efforts help people act according to their long-term interests.

Blood Glucose↗

Cystic fibrosis heterozygote screening in 5,161 pregnant women.

A screening program for cystic fibrosis (CF) heterozygotes was conducted in a large HMO prenatal population, to evaluate the level of interest among eligible patients, the effectiveness of prescreening education, attitudes toward the screening process, psychological effects, and utilization of prenatal diagnosis and its outcomes. The heterozygote identification rate and frequency of specific CFTR mutations were also assessed. Identified carriers were offered genetic counseling and testing of male partners. Prenatal diagnosis was offered if both parents were identified as carriers. A total of 5,161 women underwent carrier testing; 947 others completed survey instruments only. The acceptance rate of screening was high (78%), and pretest education by videotape was generally effective. Adverse psychological effects were not reported. Participants generally found screening to be desirable and useful. Screening identified 142 female heterozygotes, 109 couples in which the male partner was not a carrier, and 7 high-risk couples. The incidence of R117H mutations was much higher than expected. The number of identified carriers was much lower in Hispanics than in Caucasians. We conclude that large-scale prenatal screening for CF heterozygotes in the absence of a family history of CF is an acceptable method for identifying couples at risk for affected fetuses. Sufficient pretest education can be accomplished efficiently, test insensitivity is well accepted, adverse psychological events are not observed, and general patient satisfaction is high.

Adult↗