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Biomedical subjects

J A Stern

Publications and source records attributed to J A Stern.

10 recordsLinked to original sources
PubMed1992

Effect of task difficulty and interstimulus interval on blink parameters.

The effects of task difficulty and interstimulus interval (ISI) on blink rate, blink latency and blink duration, were studied in a modified Sternberg memory task in which either two or six characters were to be memorized. Stimuli were presented in ISI blocks at either 5.3 or 9.3 s (SOAs of 6 or 10 s). While blink rate and blink duration declined prior to each stimulus, the difficulty of the expected task (the length of the memory set) did not affect the rate of decline or the final prestimulus level. Concerning ISI, blink rate declined more rapidly during shorter ISIs but the final prestimulus level, as was the case with task difficulty, was unaffected by the ISI duration. Presentation of the 6-character memory set produced a marked immediate inhibition of blinking. The data suggest that the encoding of visual stimuli is more akin to processes invoked in preparation for input than to ensuing processing stages since both encoding as well as preparation are accompanied by inhibition of blinking.

Adolescent↗
PubMed1991

Distribution and metabolism of doxorubicin in rats undergoing testicular circulatory isolation.

Several hundred thousand men receive chemotherapy each year; many are sterilized by this treatment. Temporary testicular circulatory isolation (TCI), a regional drug delivery approach to circumvent this, decreases doxorubicin-induced testicular injury in the rat and provides partial protection from doxorubicin-related infertility. We evaluated the distribution of doxorubicin and its metabolites (doxorubicinol and doxorubicin aglycone) in rats treated with TCI. In each of 56 male Sprague-Dawley rats, the left spermatic cord and gubernaculum were mechanically clamped for 45 minutes. Immediately after clamp application, these rats received doxorubicin (6 mg/kg, intravenous bolus) and were killed at seven time points after doxorubicin administration, ranging from 30 minutes to 48 hours. Twenty-one control rats were treated identically but did not receive TCI. Doxorubicin and its metabolites were extracted from tissue (left testis, right testis, left kidney, heart, left lung, liver) and serum and analyzed by high-performance liquid chromatography. In the TCI group, the distribution of the parent drug and doxorubicinol in tissue and serum closely approximated levels from doxorubicin-treated controls not receiving TCI in all organs except left testis. No anthracycline was detected at any time point in the left testis of the TCI group. These results indicate that TCI completely protects the testis from doxorubicin exposure in this model and that TCI does not affect distribution of doxorubicin in other organs.

Animals↗
PubMed1976

Attention and distractibility during reading in hyperactive boys.

Nonhyperactive and clinically defined hyperactive boys were administered reading tasks under "quiet" and "distracting" conditions. Hyperactive boys were less attentive to task relevant stimuli and more attentive to task irrelevant stimuli than their controls. Our results demonstrate that the previous findings of inattentiveness among hyperactive boys on laboratory tasks can be generalized to more typical school activities such as reading.

Attention↗
PubMed1976

Electrodermal response configuration as a function of rated psychopathology in children.

Electrodermally labile children of schizophrenic, manic-depressive, and normal parents were identified as either uniphasic or biphasic responders, in each of three phases of a psychophysiological experiment. Psychological disturbance ratings, based upon test protocols, were determined independently. Analysis of the relationship between electrodermal response configuration and rated psychological pathology showed that biphasic responders were evaluated as more disturbed than uniphasic responders. The results were interpreted within a framework provided by Edelberg's work on the information content of the electrodermal recovery limb, and were seen as relevant to notions regarding schizophrenic information processing. It was hypothesized that in this situation, uniphasic responding reflected an adaptive defense against stimuli perceived as potentially threatening, whereas biphasic responding indicated overprocessing and inappropriate goal orientation.

Age Factors↗