Eroded monomode optical fiber for whispering-gallery mode excitation in fused-silica microspheres.

We demonstrate the efficient excitation of high-Q whispering-gallery modes in near-spherical fused-silica microparticles in the size range 60-450 microm by the use of an eroded monomode optical fiber. When the sphere is placed in the evanescent field of the guided fiber mode, light is resonantly coupled from the fiber into the microparticle. We report a broadening of resonance modes and a shift of the resonance central frequency as the coupling strength is increased by reduction of the gap between the sphere and the fiber.

Gender differences in schizophrenia.

Lewine (Psychol. Bull., 90: 432-444, 1981) has proposed sex differences, specific to schizophrenics, in age at first psychiatric hospitalization, age at first reported symptoms, and premorbid social competence. To evaluate Lewine's hypothesis we collected data on 64 schizophrenic and 30 nonschizophrenic psychiatric outpatients. As no interaction between sex and diagnostic groups was found, our data failed to demonstrate sex differences specific and unique to schizophrenia. It is possible that Lewine's evidence is due to a cultural artifact.

The use of temporal and amplitude cues by schizophrenics, psychiatric controls, and aged normals in auditory lateralization.

The present study investigated the ability of paranoid and nonparanoid schizophrenics, psychiatric controls, and aged controls to use temporal and amplitude cues to make judgments about the direction of auditory stimuli on an auditory lateralization task. Twelve subjects in each group were tested on three lateralization conditions: temporal--fixed, temporal--shifted, and amplitude. The subjects' task was to identify the apparent direction (left or right) of a train of clicks presented binaurally through headphones. In the temporal conditions interaural click onset differences provided the lateralization cues, while in the amplitude condition interaural amplitude differences provided the cues. In the temporal--fixed condition, onset asynchrony was constant for the duration of each stimulus. In the temporal--shifted condition, onset asynchrony was introduced midway through each stimulus presentation. A forced-choice random staircase method was used to determine each subject's 70 per cent correct response threshold. Results indicated that paranoids had particular difficulty with the temporal--fixed condition relative to the temporal--shifted condition. The opposite was true for the nonparanoids. Both control groups showed no significant difference in performance on the two temporal conditions. Psychiatric controls performed significantly better than aged controls in both the fixed and shifted conditions. There were no significant differences among groups on the amplitude condition. The data were discussed in terms of schizophrenics' clinical symptoms and previous perceptual research with schizophrenics.

Proprioception in schizophrenia.

B. Ritzler (J. Abnorm. Psychol., 86: 501-504, 1977) failed to replicate previous weight-lifting studies showing a proprioceptive deficit in schizophrenics. However, Ritzler did not use the same standard weights that the previous studies employed. Could this difference in procedure have caused his failure to replicate? Two experiments were completed to provide additional information about this question and related issues. In Experiment I, chronic hospitalized schizophrenics and normals were tested with light and heavy weights. Rosenbaum's original modified method of limits and the method of constant stimuli were utilized. Both methods provided comparable results, which, like Ritzler's data, failed to show a differential impairment in the discrimination of the light weights for paranoid schizophrenics. In Experiment II, outpatient paranoid schizophrenics, outpatient nonparanoid schizophrenics, outpatient psychiatric patients, and aged normals were evaluated utilizing the same psychophysical procedure and standard weights employed in the original studies. No differential impairment was found for the light weights for any group. These results provide strong support for Ritzler's position that a proprioceptive deficit is not unique to schizophrenia.

A study of schizophrenics' ability to localize the source of a sound.

Twelve process, nonparanoid schizophrenics, 12 nonschizophrenic psychiatric controls, and 12 normal controls were given an auditory localization task. Performance was measured by the number of correct localizations and was studied as a function of three variables: diagnosis, position of the apparatus in relation to the subject's median plane (right or left), and the degree of displacement of the auditory stimulus from a fixation point (4.5 degrees, 3.0 degrees, and 1.5 degrees). A three-way analysis of variance with two repeated measures resulted in a significant main effect for each of the three independent variables. Orthogonal comparisons indicated no difference in performance between normal and psychiatric controls but a significant difference between schizophrenics and the combined controls. The degree of displacement of the auditory stimulus resulted in a significant linear trend in performance. There were no significant interactions. The present findings strongly suggest that process, nonparanoid schizophrenics suffer from a specific deficit in auditory localization.

A multivariate analysis and modification of a preattentive, perceptual dysfunction in schizophrenia.

Preattentive information processing was examined in matched samples of process nonparanoid schizophrenics, reactive paranoid schizophrenics, and nonschizophrenic psychiatric inpatients. Three measures of visual preattentive processing were administered under standard conditions and also enriched conditions in which preattentive discriminability was enhanced through increased perceptual grouping and segregation. Nonparanoid schizophrenics displayed a differential performance deficit under standard conditions on each measure. Under conditions of enhanced preattentive discriminability, nonparanoid schizophrenics differentially improved to the extent that no significant differences were found between groups on two of the measures. Paranoid schizophrenics and psychiatric controls did not differ significantly across measures or conditions.

A test of the schizophrenic's ability to process information in one or two sensory modes.

Twenty-three schizophrenics, ten psychiatric controls, and 17 normal controls were used to test the hypothesis that schizophrenics suffer a deficit in their ability to integrate information from different sensory modes. The task involved identifying auditory, visual, or mixed (auditory and visual) patterns which had previously been equated in difficulty for normal subjects. Mean error scores were greatest for schizophrenics and least for normals with psychiatric controls in between. Moreover, the schizophrenics did equally well whether the task was visual, auditory, or mixed. Thus, schizophrenics showed no deficit specific to the synthesis of information from two different sensory modes.

Psychotherapy: theory, experience, and personalized actuarial tables.

This paper addresses the issue of the role of theory in the actual application of psychotherapeutic operations. Within the present framework, psychotherapeutic effectiveness is seen as an empirical, actuarial process which occurs in an interpersonal setting separate from theoretical considerations. The role of theory is discussed and a rationale for the coexistence of equally 'effective' contradictory theories is presented. Suggestions for future research in the area of behaviour change are made and an argument for the eventual development of a 'therapeutic cookbook' is presented.

The effect of distractor strength versus rate of item presentation on retention in schizophrenics.

Predictions made from Chapman & McGhie's attentional dysfunction theory of schizophrenia were compared with those made from Yates' slow information processing theory. Retention in a free-recall, short-term memory task was studied with 20 chronic nonparanoid schizophrenics and 20 psychiatric controls matched on age, educational level and intelligence as subjects. Schizophrenics performed consistently poorer than controls, but no differences between groups were found as a function of either variation in distractor strength or in item presentation rate. Thus, neither theory was supported, but several uncontrolled aspects of the task variable were suggested as possible reasons for some of these conflicting findings.