PubMed Health⌕ Search

Biomedical subjects

M Kohn

Publications and source records attributed to M Kohn.

At least 37 records · Page 2Linked to original sources
PubMed1980

Average evoked potentials and amplitude modulation.

Average auditory evoked potentials (AEPs) to amplitude modulated (AM) linear voltage ramps within a limited intensity range were investigated in a group of 4 subjects. Increasing linear voltage ramps evoked the familiar vertex potential; the average AEP to decreasing ramps was difficult to measure because of its small amplitude. The amplitude of the average AEP to increasing ramps depended on the tone that preceded it. The average amplitude was largest when the tone preceding the onset of the ramp was constant and decreased in amplitude when the slope of the preceding tone deviated from zero either in the positive or negative direction with the positive slope having the more marked attenuating effect. The standard deviation (S.D.) of the distributions of reaction times to stimulus onset correlated negatively with the average AEP amplitude. The attenuation of the averaged AEP appeared to be related to the uncertainty of the subjects as to when the various types of stimuli occurred. The above findings on AM ramp stimuli closely parrellel our previously reported findings on frequency modulated ramp stimuli.

Acoustic Stimulation↗
PubMed1979

Phase I trial with peptichemio.

Thirty-two patients with tumor progression, even after conventional cytostatic drug treatment, were treated with peptichemio, with increasing doses for groups of 4 patients. The maximum tolerated dose (with minimum hematological toxicity and without any other evident toxicity) with repeated administrations, was 1.2 mg/kg twice weekly. The recommended doses for phase II trials are, as shown by the detailed analysis of the results, 0.9 mg/kg, twice weekly and administered alone, and 1.3 mg/kg, once weekly combined with other cytostatic drugs, in 500 ml of infusion fluid, with 25 mg of heparin and 25 mg of hydrocortisone to minimize the freqent risk of local phlebosclerosis.

Adult↗
PubMed1979

Social-ecological assessment of environments: toward a two-factor model.

A study was conducted to test the usefulness of the two-factor model in assessing social environments. Subjects were residents and staff at a residential treatment center for emotionally disturbed and/or delinquent boys and girls. Rating instruments consisted of (a) two parallel versions of Moos' Community-Oriented Programs Enivronment Scale (COPES), each worded so as to be appropriate to the setting being measured, and (b) global ratings of satisfaction with the environment. Principal component factor analyses, carried out separately on the youths' COPES-School and the youths' COPES-Cottage, yielded two orthogonal but similar factors in each environment. In a comparison with Moos' three-dimensional formulation of the social milieu, the two factors strongly resembled two of Moos' dimensions but were more independent, had greater validity, and discriminated between the two environments at a higher level of significance. The instruments derived from the factor analyses provide a simple procedure for assessing a variety of treatment programs and populations.

Adolescent↗
PubMed1979

An adolescent symptom checklist for juvenile deliquents.

A rating instrument was developed to assess the personality functioning of problem adolescents who have a brief history of official delinquency. Subjects were 186 residents at a short-term diagnostic detention facility. The instrument that emerged from a factor analysis was tested for reliability, validity, and cross-situational generality. Two major orthogonal factors emerged, Apathy-Withdrawal (I) and Anger-Defiance (II). Each factor was found to be congruent with the corresponding dimension on behavior rating instruments that had previously yielded two orthogonal factors and that had been shown to be relevant to a large number of psychological and educational issues. Significant correlations between the factors and a series of global ratings measuring behavior and measures indicative of the frequency and seriousness of official delinquency provided further evidence of construct and discriminant validity as well as evidence of cross-setting consistency of personality functioning.

Adolescent↗
PubMed1978

Averaged evoked potentials and frequency modulation.

Frequency modulated (FM) auditory stimuli result in average vertex potentials similar to the usual auditory average evoked potential (AEP). For stepwise increase or decrease in tone frequency the AEPs are similar. For FM stimuli modulated by pulses of different durations 'on' responses are evoked by the transition of the stimulus from the longer duration to the shorter duration frequency tone while 'off' responses result when the frequency transition is from the shorter to the longer duration tone. Ramp modulation of the stimulus frequency results in average evoked responses; the amplitude of these responses is proportional to the slope of the ramp as well as the frequency of the tone that precedes the ramp. Thus, if the tone preceding the ramp is also a ramp but of smaller slope the AEP is attenuated and with sufficiently large slope the AEP can be completely extinguished. No AEPs were obtained at the offset of ramp modulated stimuli. The standard deviation (S.D.) of the reaction time (RT) distributions to stimulus onset indicate that the AEP amplitude is inversely proportional to the S.D. values. Thus, the attenuation phenomena appeared to be related to the uncertainty of the subject as to the exact time the stimulus occurred, both of which seem to be the result of sensory difficulty to the type of stimuli used. AEPs to negative ramps were smaller than AEPs to positive ramps; this may be on account of the psychological inequality between the stimuli.

Acoustic Stimulation↗
PubMed1978

Cross-situational consistency among problem adolescents: an application of the two-factor model.

A study was conducted to measure cross-situational consistency of the orthogonal dimensions of the two-factor model of social-emotional functioning. According to this model, large proportions of variance in social-emotional functioning can be accounted for by two orthogonal, highly replicable dimensions. The setting was Hawthorne-Cedar Knolls, a long-term institution for emotionally disturbed and delinquent youths; the subjects were 206 residents of varied ethnic and socioeconomic backgrounds. Cross-situational correlations between school and cottage settings were found to be .52 for Factor II (Cooperation-Compliance versus Anger-Defiance) and .42 for Factor I (Interest-Participation versus Apathy-Withdrawal). The results confirm the consistency and discriminant validity hypotheses--specifically, correlations between the corresponding factors of different instruments measuring behavior in different settings were large, whereas correlations between noncorresponding factors were very low. The value of using broad, higher order factors in personality research on the trait versus situation issue is discussed.

Adolescent↗
PubMed1975

Emotional impairment and achievement deficit in disadvantaged children--fact or myth?

This study examined the relationship between demographic and preschool social-emotional variables, on the one hand, and first grade social-emotional and intellectual achievement variables, on the other. Three hundred twenty-three children from New York City public day care centers were followed up 12 and 18 months later in elementary school. Emotional impairment in first grade was found to be a function of social class, race, and preschool emotional impairment. Two major dimensions of social-emotional functioning showed same-factor stability but not cross-factor correlation over time; one of the dimensions (Apathy-Withdrawal) predicted to first grade underachievement.

Affective Symptoms↗