Alvin S. Bernstein

The orienting response and direction of stimulus change

Following habituation to a given stimulus intensity, rearousal of the GSR OR was significantly greater to a stimulus change involving an increase in intensity than to an equal absolute amount of change involving a decrease in intensity. This was true both in normal and chronic schizophrenic samples. Thus, both the direction in which stimulus change occurs as well as the degree of change involved are important variables in triggering the OR.

The galvanic skin response orienting reflex among chronic schizophrenics

Regressed schizophrenics showed marked reduction in both OR frequency and amplitude in relation to both controls and remitted schizophrenics. However, initial response frequency increased virtually to control levels when a more intense stimulus was used. All schizophrenics in common habituated faster than controls. Increased hospitalization was itself associated with reduced overall OR reactivity though phenothiazine medication had no significant effect. All results were supported on re-test some two months later.

The autonomic orienting response and CT scan findings in schizophrenia

CT scan measures of prefrontal sulcal prominence, parieto-occipital sulcal prominence, ventricle-brain ratio (VBR), and third ventricle width (TVW) were examined in 24 schizophrenic patients who were grouped on the basis of their autonomic orienting response (OR) status. A two-component definition of the OR was used that required concordance across both electrodermal and finger pulse volume components for response status assignment. The nine OR responders had significantly greater TVW than the 15 OR nonresponders. Although OR responders had higher values also on the other CT scan measures, these differences were not significant. These findings are consistent with the possibility that OR responsiveness and nonresponsiveness are related to different pathological dimensions of schizophrenia.

Differing patterns of electrodermal and finger pulse responsivity in schizophrenia and depression

Non-response of the autonomic orienting response (OR), as indexed jointly by deficient skin conductance (SCR) and finger pulse amplitude responding (FPAR), has been shown to occur with excessive frequency in the schizophrenic population. The present study is an attempt to replicate earlier evidence that SCR-OR and FPAR-OR, when measured in concert, could distinguish schizophrenic from depressed patients (Bernstein et al. 1988). This issue is critical of the question of diagnostic specificity of OR non-responding, since reduced SCR has been found repeatedly in depression as well as in schizophrenia. We examined SCR and FPAR concurrently in 69 schizophrenic, 45 depressed, and 67 normal subjects. SCR non-responding was more frequent in both schizophrenics and depressives than in normal controls, while only the schizophrenics displayed excessive FPAR non-responding. Moreover, among SCR non-responders, concordant OR non-responding--defined as non-responding indexed simultaneously in both the SCR and FPAR components--was most common in the schizophrenic sample. These findings support our previous conclusion that OR non-responding in depression, may have distinct peripheral origins. Our results also suggest that measuring multiple biochemically distinct components of the OR may be more sound methodologically than obtaining a single channel recording.

The relationship of the skin conductance and finger pulse amplitude components of the orienting response to season of birth in schizophrenia and depression

Schizophrenia is said to be associated with a modest excess of winter births. We examined relations of season of birth (SOB) to the skin conductance response (SCR) and finger pulse amplitude response (FPAR) components of the orienting response (OR) in 83 schizophrenic patients, 59 depressed patients, and 81 normal controls. SCR-OR nonresponding was more prevalent among depressed patients regardless of SOB, whereas only winter-born schizophrenics showed significantly more frequent electrodermal nonresponding than controls. However, this latter relation was not confirmed with log linear analysis. No other relations of SOB to SCR-OR or FPAR-OR nonresponding were significant. Our data do not support the view that nonresponding in the SCR or FPAR components of the OR is associated with winter birth either in schizophrenia or depression.

The orienting response in schizophrenia and mania

We examined skin conductance (SCR) and finger pulse amplitude response (PULSE) in 53 schizophrenic, 30 manic, and 28 control subjects to provide information on orienting response (OR) dysfunction in severe psychiatric disorders. SCR and PULSE to neutral and task-relevant tones were measured in acutely ill inpatients and normal control subjects on two occasions separated by a 3-week interval. There were no significant group differences in proportions of SCR and PULSE non-responders to neutral tones. PULSE frequency to task-relevant tones in both the schizophrenic and manic patients was lower than that for the control subjects in both OR sessions, but did not differ significantly between patient groups. Although PULSE frequency was inversely related to neuroleptic dose in the schizophrenia sample, reanalysis of unmedicated patients did not change our results. OR frequency to task-relevant but not to neutral tones exhibited test-retest reliability. Certain aspects of OR dysfunction may overlap in schizophrenia and bipolar disorder. Our failure to demonstrate excessive OR non-responding to neutral tones in schizophrenia patients is inconsistent with many previous studies but may be due to a high proportion of OR non-responders among the control subjects.

Autonomic reactivity in manic and schizophrenic patients

tionships between duration and side effects of neuroleptic treatment and NSS. These findings suggest that neuroleptic treatment may only play a partial role in the development of NSS in patients with schizophrenia and NSS may be one of the biological markers of this disorder. To confirm the fmdings of this study, data on a prospective follow-up design of neuroleptic-naive patients after neuroleptic treatment will be presented. and 25 patients with trypanosomiasis (sleeping sickness). Our results show that Bal I allelic frequencies in the D3 gene display ethnic variations, even though schizophrenia is present in all human cultures. This suggests that, if the Bal I locus is associated with schizophrenia, it might not be causative per se but instead be a marker which is linked to another causative mutation in some populations.

Clinical correlates of nonresponsiveness of the autonomic orienting response in patients with schizophrenia

Eye blinks and movements (EOG) can seriously contaminate topographic maps of EEG and event-related potentials (ERP) especially in psychiatric populations. We have thus employed an offline regression-based algorithm (Semlitsch et al., 1986) to remove EOG signals while leaving brain electrical topography intact. To determine the validity of corrected-EEG (c-EEG) in our patient studies, we performed two studies which compared c-EEG versus artifact-free EEG (af-EEG). The first study showed that the spectral rms voltage (delta band) of c-EEG (5.8 pV) from ten normal subjects in frontal leads was significantly smaller (p .90, paired t-values (lldf) between 0.0 0.4).