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Biomedical subjects

C Schulman-Galambos

Publications and source records attributed to C Schulman-Galambos.

5 recordsLinked to original sources
PubMed1979

Brain stem evoked response audiometry in newborn hearing screening.

Brain stem evoked response audiometry (BERA) has been used as an auditory screening procedure in three groups of newborn infants. Group 1 consisted of 220 normal-term infants who were tested within 72 hours of birth; no hearing abnormalities were uncovered (386 ears), and their threshold responses (for clicks) lay between a 10- and 20-dB hearing level (re: adult). Group 2 consisted of 75 newborns who were treated in an intensive care unit for one to 14 weeks; four were found to have severe sensorineural hearing loss (seven ears) at the time of discharge. Group 3 consisted of a group of 325 infants, 1 year or older, who had previously been discharged from the same intensive care unit; of these infants, an additional four showed severe sensorineural hearing loss. All abnormalities that were identified by BERA were subsequently confirmed by conventional audiometric measures. The estimate of an incidence of severe hearing loss in one of 50 infants who required intensive care in the neonatal period calls for careful testing of this population.

Audiometry↗
PubMed1978

Cortical responses from adults and infants to complex visual stimuli.

Event-related potentials (ERPs) time-locked to the onset of visual stimuli were extracted from the EEG of normal adult (N = 16) and infant (N = 23) subjects. Subjects were not required to make any response. Stimuli delivered to the adults were 150 msec exposures of 2 sets of colored slides projected in 4 blocks, 2 in focus and 2 out of focus. Infants received 2-sec exposures of slides showing people, colored drawings or scenes from Disneyland, as well as 2-sec illuminations of the experimenter as she played a game or of a TV screen the baby was watching. The adult ERPs showed 6 waves (N1 through P4) in the 140--600-msec range; this included a positive wave at around 350 msec that was large when the stimuli were focused and smaller when they were not. The waves in the 150--200-msec range, by contrast, steadily dropped in amplitude as the experiment progressed. The infant ERPs differed greatly from the adult ones in morphology, usually showing a positive (latency about 200 msec)--negative(5--600msec)--positive(1000msec) sequence. This ERP appeared in all the stimulus conditions; its presence or absence, furthermore, was correlated with whether or not the baby seemed interested in the stimuli. Four infants failed to produce these ERPs; an independent measure of attention to the stimuli, heart rate deceleration, was demonstrated in two of them. An electrode placed beneath the eye to monitor eye movements yielded ERPs closely resembling those derived from the scalp in most subjects; reasons are given for assigning this response to activity in the brain, probably at the frontal pole. This study appears to be one of the first to search for cognitive 'late waves' in a no-task situation. The results suggest that further work with such task-free paradigms may yield additional useful techniques for studying the ERP.

Adolescent↗
PubMed1975

On hemispheric differences in evoked potentials to speech stimuli.

Eight subjects listened to lists of speech sounds (pa or ba) or pure tones (250 or 600 c/sec). Within each list one of the sounds (the "frequent") occurred more often than the other (the "target") in a ratio of approximately 4:1. Subjects were required to count the targets in each list; concurrently, evoked responses to both targets and frequents were being separately averaged from electrodes at vertex at symmetrical left and right parietal locations. The evoked responses show the expected sequence of deflections at all three electrode sites, including large P3 waves (about 350 msec latency) to the target stimuli. However, the left and right hemispheric responses to speech or tones, either frequent or target, were strikingly similar, both to the eye and by statistical tests intended to reveal differences between them.

Auditory Perception↗
PubMed1975

Brain stem auditory-evoked responses in premature infants.

Brain stem auditory-evoked responses were recorded in 24 infants ranging in age from six-weeks premature to term. At a given age, the latency of the response increased with decreasing stimulus intensity. Further, as age increased, there was a systematic decrease in latency of the response at each sound intensity level. The response was shown not to be fatigue or sleep stage. It may, therefore, be of use for evaluating auditory function in high-risk newborn infants.

Acoustic Stimulation↗