Pupillographic assessment of sleepiness in sleep-deprived healthy subjects

Medical research frequently involves the statistical comparison of >2 groups, often using data obtained through the application of complex experimental designs. Fortunately, inferential statistical methodologies exist to address these situations. Analysis of variance (ANOVA) in its many forms is used to simultaneously test the equality of all groups in a study. One-way (with 1 independent variable), 2-way (with 2 independent variables), and repeated-measures (patients serve as their own controls) ANOVAs are forms of this technique. Each form has been developed to analyze data from a specific experimental design. Analysis of covariance (ANCOVA) allows the researcher to control for confounding variables that may influence the response of the dependent variable. Finally, multivariate analysis of variance (MANOVA) evaluates the simultaneous responses of multiple dependent variables to > or = 1 independent variable. Whereas ANOVA is the correct alternative to statistically inappropriate multiple t-tests, MANOVA is the correct alternative to statistically inappropriate multiple univariate ANOVA calculations. Use of each of these statistical methods requires an appropriate experimental design and data meeting a number of assumptions. When used properly, each of these methods provides a powerful statistical analysis technique.     

Empathic ability in normals and schizophrenics.

"Normals and schizophrenics were asked to predict on a rating scale the responses of three Ss: an associate, a normal, and a psychotic, the latter two persons known only through an observed interview situation. Individuals in each group had previously made self-ratings in terms of the same scale. Deviation scores for members of each group provided a measure of accuracy of prediction (empathy) and the tendency to assume a similarity between oneself and another person (assumed similarity). The control group revealed generally greater empathic ability and greater assumed similarity than did the schizophrenic group." (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Biogenic amine-related enzymes and personality variations in normals

Altered activities of biogenic amine-related enzymes have been reported in some studies of patients with affective disorders and chronic schizophrenia. To evaluate whether any relationship between personality variations, including non-diagnosed psychopathology, and these enzymes might occur in non-psychiatric patients, 95 young adult volunteers were studied. Higher MMPI and Zuckerman sensation--seeking scale scores were found in male, but not female, volunteers with lower platelet and plasma amine oxidase activities. Males generally exhibited negative correlations, while females had positive correlations between the psychological test scores and amine oxidase activities. In contrast to the amine oxidase results, no associations were observed between plasma dopamine beta-hydroxylase activities and the personality variables.     

Two types of conditioning in psychotics and normals.

The conditionality of 2 groups of schizophrenics (chronic paranoids and chronic nonparanoids) and a normal (male nurses) was tested via 2 methods of conditioning: visual (stimulus)—eyelid (response), and auditory (stimulus)—handpress (response). The results indicated no difference between the groups re: eyelid conditioning, but the paranoid group took significantly longer to condition on the verbal procedure. Suggested reasons for the results are discussed, and the results are compared with that of previous research. 18 refs. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Critical interstimulus interval in delusional schizophrenics and normals.

The critical interstimulus interval, the minimum interval between presentation of a test and mask stimulus at which the mask no longer interferes with processing of the test stimulus, was calculated for 10 schizophrenics with delusional symptoms and 10 normal college students. All Ss had previous experience with the masking procedure. Each S's critical interstimulus interval was obtained 4 times in 4 separate sessions. Results indicate a larger critical interstimulus inteval for the schizophrenics. All Ss also showed less masking with practice. Results are consistent with A. J. Yates's (see record 1966-05514-001) hypothesis of a schizophrenic deficit prior to cortical levels of information processing but were inconsistent with A. J. Yates and P. Korboot's (see record 1971-06730-001) findings that slow information processing is unique to chronic nonparanoid schizophrenics. Post hoc analysis suggests the possibility of an additional schizophrenic deficit in preattentive filtering. Directions for future research are discussed. (22 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Fabrication of delusional thinking in normals.

Tested a learning model for paranoid development by requiring Ss in the laboratory to fabricate ideation under conditions approximating those thought to be conducive to actual clinical delusions. Measures used on the 92 male undergraduate Ss included the Parent Attitude Research Instrument, the Parent–Child Interaction Rating Scales, and the Adjective Check List. Ss proposed to be susceptible to paranoid ideation, that is, late-adolescent males who have adopted an open style of adapting to the aversive-maternal-control experience, demonstrated the proposed signs of delusional thinking in their belief systems. Ss were required to formulate a rationale for the view that they believed others held concerning them. The open-style group, relative to control groups, provided beliefs that were more extensive, less credible, more concerned with negative information, and, for the more extended beliefs, better integrated and more presumptive of outside social influence. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

GSR conditioning and personality factors in alcoholics and normals.

Alcoholic and nonalcoholic introversive and extroversive Ss were placed in a GSR conditioning situation. Significant differences in conditionability were not found between alcoholics and the nonalcoholic group with regard to the intro-extroversion dimension. The results were seen as confirming aspects of Eysenck's (1957) theory of personality. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Recall in normals and subnormals of like mental age.

Normal children and young adult imbeciles were matched for mental age and were given sets of 6 pairs of words to learn by association. The words were recorded on tape, and presented to subgroups at a sound intensity of 90 db. or 55 db. Each subgroup was further subdivided—? the Ss being given 10 and ? given 20 repetitions. 1 minute, 2 days, and 1 month later they heard the stimulus word of each pair and were asked to give the appropriate response word. It was shown that there was no difference in learning or memory scores between normals and imbeciles. Frequency of presentation affected immediate recall scores of both groups, with intensity level contributing to a lesser degree. Memory over longer time intervals was determined by the amount initially learned, rather than by the conditions under which such learning had occurred. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Impression management ability in psychiatric hospital samples and normals.

As a partial test of the view that schizophrenia is essentially a manipulatory phenomenon, the abilities of normal, neurotic, alcoholic-character disorder, and single and married schizophrenic groups (N = 180) to manage the impressions they make on others were compared. Ss were administered a semistructured interview twice-once each under instructions to make as bad and as good impressions as possible. All groups proved capable of managing the impressions they made to some degree. However, the single schizophrenics produced higher scores than any of the patient samples. Results argue against the hypothesis that schizophrenics are peculiarly capable impression managers. Moreover, the impression management scores of the groups did not change differentially in response to threat, casting some doubt on the view that schizophrenics are peculiarly inclined to produce spurious abnormal behavior to escape painful stress. Results contradict the view that the behaviors characterized as schizophrenic arise from special impression management tendencies rather than cognitive deficits. (15 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Mismatch negativity during objective and subjective sleepiness

The mismatch negativity (MMN) and P3 of auditory event-related potentials were studied during subjectively and objectively (physiologically) defined sleepiness under optimal stimulus conditions for MMN elicitation. The MMN and P3 were elicited by either small or large unattended auditory deviants presented to the left ear. The participant's task was to detect either rare auditory targets presented to the right ear or rare changes in the light flashes. Eleven young adults served as participants in a nighttime experiment. The MMN declined especially at Fz and Cz but not so markedly at the right mastoid as either subjective or objective alertness decreased. The amplitude of P3 also decreased during sleepiness. The attenuation of the MMN was paralleled by a decline in behavioral performance. The results show that the MMN is attenuated by a decrease in alertness even before an actual sleep state is reached.     

Word association repertoires of schizophrenics and normals.

The work association repertoires of 3 association responses of 20 poor and 20 good premorbid nonparanoid schizophrenics were not more deviant than those of 20 normals. There was significantly greater commonality in the 1st association response than in the 2nd response which, in turn, showed greater commonality than the 3rd response. These results suggest that schizophrenic language disorders are not due to overall language deficiency and partially support the disturbance viewpoint. A 3rd viewpoint is proposed, based on a 2-stage process involving nondeviant associations with inadequate cognitive controls as differentiating schizophrenics from normals. The hierarchical order for frequency given by the Russell-Jenkins norms obtains for both discrete and extended word association responses. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Automatic detection of K-complexes: validation in normals and dysthymic patients

A model-based automatic K-complex (Kc) detector was applied to all-night single-channel sleep electroencephalographic (EEG) recordings from normal and dysthymic patients. The performance of the detector was analyzed in the two groups, and the differences obtained were discussed. The results showed that the detection rate of Kc in the normal group was around 92% through all stages of non-rapid eye movement (NREM) sleep, but with high numbers of "false" positives in stage 4 NREM, which reached 57%. In the dysthymic patients "true" detection included 85% of the Kc, but the percentage of "false" positives dropped to 25% in stage 4 NREM. Most of the "false" detections in the normal group were due to sharp delta activity during slow wave sleep (SWS). The results in the patient group were expected, because sleep in dysthymics showed a reduction in SWS when compared to normals. The behavior and automatic artifact rejection mechanisms of the detector are briefly presented. The model-based Kc detector performed significantly better than other automatic detectors described in the literature; it was found to be a useful tool for routine sleep EEG studies.     

Organization in memory: A comparison of psychotics and normals.

15 acute schizophrenics, 11 acute psychotic depressives, and 15 normal Ss completed a multitrial free-recall task. The 30 to-be-remembered nouns from 6 conceptual categories were printed, 1 on each card. During self-paced presentation, the nouns were sorted into S-determined categories. Patient recall was inferior. The extent to which successive categorizations of the words during sorting were similar and reflected norms of category membership was measured. No significant group differences were realized. Patient recall clustering, defined both by norms of category membership and subjective sorting categorizations, was inferior. On no measure did schizophrenics and depressives differ. Results indicate that with lists of relatively high semantic content, the recall impairment displayed by schizophrenics and depressives stems mainly from an inability to completely use perceived structuring of the list during recall. (20 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Childhood social competence in functionally disordered psychiatric patients and in normals.

Assessed childhood social competence in 71 male and 70 female schizophrenics, personality disordered patients, psychotic depressives, neurotics, and normals. The results indicate that children eventually hospitalized for schizophrenia are characterized by their poor interpersonal skills long before symptom onset; academic competence failed to differentiate the various groups. Not all serious psychiatric disorder is preceded by poor social competence, as indicated by the psychotic depressives whose competence scores were not significantly different from the normals'. Analysis of sex and Sex?×?Diagnosis effects revealed that females were more competent than males regardless of psychiatric status. This may reflect primarily greater conformity to teacher expectations for appropriate school behavior. The absence of significant interaction effects suggests that previously reported sex differences in premorbid social competence are not specific to schizophrenic disorders. (27 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Stimulus and social cues in concept identification of schizophrenics and normals.

162 Ss were tested to investigate the effects of combinations of stimulus and social cues on concept identification (CI) of normals and schizophrenics. 6 major conditions were designed to evaluate positive and negative effects of these cues. Social cues inhibited CI when they were randomly reinforced in contrast to the effect of the nonreinforced stimulus cues. Inhibitive effect of social cues had greater influence than its positive effect for both populations. When both social and stimulus cues were reinforced, CI performance did not differ from conditions when only one or the other of these cues was reinforced. (27 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Attitudes of schizophrenics and normals toward success and failure.

The purpose of this study was to test the hypothesis that schizophrenics, as compared with normals, are relatively more highly motivated to avoid failure than to achieve success. A total of 291 Ss, including 136 hospitalized male schizophrenics, 103 normals, and--as a contrast group--52 neurotics, were administered the Success-Failure Inventory (SFI), a 22-item True-False instrument designed to assess attitudes toward success attainment and failure avoidance. As predicted, the schizophrenic samples manifested greater relative failure avoidance than the normals. Further, active schizophrenics evidenced greater relative failure avoidance than did remitted schizophrenics. Remitted schizophrenics and neurotics were not significantly different. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Evaluative feedback and aspiration statements of schizophrenics and normals.

Elicited aspiration statements from 30 male schizophrenics and 30 normal adult males in 3 treatment conditions: response-contingent praise, response-contingent censure, and no evaluation. Task "performance scores" were predetermined by E and were identical for all Ss. 2 dependent measures were examined: frequency of increased aspiration statements and magnitude of aspiration changes compared with prior "performance." Response-contingent censure resulted in greater frequency of increased aspiration statements for both diagnostic groups. However, censure differentially effected the magnitude of performance-aspiration differences, with schizophrenics showing greater magnitude of response. Results support previous findings on attitudes of schizophrenics and normals toward success and failure and are congruent with theories of schizophrenic behavior emphasizing development of withdrawal patterns to avoid punishment. It is also indicated that schizophrenics' sensitivity to the aversive may be used constructively. (23 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Exercise fitness, cardiac work and blood viscosity factors in patients and normals

A study of 41 cardiovascular patients and normals showed significant correlations between physical fitness (as expressed by a fitness index based on work output) and high shear rate blood viscosity (p less than 0.01); between the cardiac work expressed as double product (= myocardial oxygen demand) and aggregation of red cells (p less than 0.05); between the triple term of cardiac work (fitness index divided by double product) and high shear rate blood viscosity (p less than 0.005) or aggregation of red cells (p less than 0.05), in all cases correlations being negative i.e., higher cardiac work or higher fitness being related to low blood viscosity or lower aggregation of red cells. Significant differences were found between high-fitness and low-fitness groups, the high-fitness group showing from plasma viscosity (p less than 0.0005), lower fibrinogen level (p less than 0.05), and higher albumin/fibrinogen ratio (p less than 0.01).