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Biomedical subjects

S R Steinhauer

Publications and source records attributed to S R Steinhauer.

At least 19 recordsLinked to original sources
PubMed2000

Mood and behavioral symptoms in individuals with chronic solvent exposure.

Psychiatric symptoms have been reported for individuals who experience chronic exposure to low levels of organic solvents. However, it is not known what proportion of such individuals experience psychiatric disorder; which specific disorders may be characteristic of this population; or whether bioaccumulation of lead contributes to the relationship between solvent exposure and psychiatric symptoms. Twenty-nine male journeymen painters and 32 male non-painter control subjects were administered semi-structured diagnostic interviews for DSM-III-R Axis I and Axis II disorders. Career solvent exposure and blood lead levels were also measured. Painters and control subjects did not differ significantly with respect to age, intelligence, or demographic characteristics. Results showed that the probability of being diagnosed with a mood disorder differed significantly in painters (41%) and control subjects (16%). Painters (66%) and control subjects (50%) did not differ for substance use diagnoses. Groups also did not differ for personality disorders involving an onset before 25 years of age. In contrast, painters exhibited a sub-clinical pattern of personality dysfunction involving symptomatology that was measured allowing for late onset (after age 25). Finally, a significant dose-response relationship was observed between career solvent exposure, blood lead level, and personality symptoms. In summary, these data showed an increased rate of psychological disturbance in a significant and substantial number of painters. However, not all painters were so characterized. This overall pattern raises a question regarding a potential role for differential vulnerability, which requires empirical validation.

Adult↗
PubMed2000

Cognitive modulation of midbrain function: task-induced reduction of the pupillary light reflex.

The activation of processing resources has widespread effects in the nervous system. A model of pupillary control systems (Steinhauer S.R. , Hakerem G., 1992. The pupillary response in cognitive psychophysiology and schizophrenia. Ann. N.Y. Acad. Sci. 658, 182-204) had predicted that ongoing cognitive activation should result in inhibition of the light reaction at the level of the oculomotor nucleus, n. III, in the midbrain. In this study, modification of parameters of the pupillary reaction to light were examined during varying task demands. The averaged light reaction was recorded from 33 male and female healthy volunteers during the performance of a serial 7 subtraction task and compared to a 'no task' condition. For 13 subjects, an additional verbalization task with little processing demand (add 1) also was presented. Two types of effects were observed. Firstly, the tonic pupil diameter increased from the no task to the easy (add 1) task, and increased further in the more demanding condition (subtract 7). Secondly, the extent of the phasic light reaction was significantly reduced and the latency at the end of the contraction was significantly decreased in the 'subtract 7' condition compared to both the no task and easy conditions (which did not differ from each other). The locus of interference with the light reaction was the Edinger-Westphal complex of the oculomotor nucleus, which is the motor center for the pupillary sphincter muscles. Descending cortical influences inhibited the activity of the Edinger-Westphal complex. Thus, increasing activation had a tonic inhibitory effect on this center, while higher levels of processing complexity produced a separate component of inhibition that interacted with dynamic activation at this midbrain site. It was suggested that the variation in the light reaction is quantitatively responsive to varying processing loads, and may be utilized as a sensitive metric for a wide variety of cognitive operations.

Adolescent↗
PubMed1999

Developmental delay in P300 production in children at high risk for developing alcohol-related disorders.

BACKGROUND: Reduction of P300 amplitude in children and adolescents at high risk for developing alcoholism has frequently been reported. It has been hypothesized that this reduction represents a developmental delay in reaching age-appropriate levels in P300 amplitude. Using latent growth analysis of longitudinal data obtained at yearly intervals, this study seeks to define normal growth, and determine if the pattern seen in high-risk children differs from that obtained in normal low-risk controls. METHODS: A total of 156 children from either high or low-risk families have been assessed multiple times (two-thirds more than 4 times) using both a clinical assessment (K-SADS) and ERP evaluation performed on the same day. A total of 635 separate assessments were available for modeling. RESULTS: Quadratic growth curves revealed a slower rate of change in P300 amplitude in high-risk than low-risk males. High-risk girls showed reduced visual P300 amplitude only when the presence of a K-SADS diagnosis was considered. No differences were seen for P300 latency. CONCLUSIONS: This study confirms the hypothesis that when reduction of P300 amplitude is seen in males at high risk for developing alcoholism, it is due to a developmental delay.

Adolescent↗
PubMed1999

Absence of visual and auditory P300 reduction in nondepressed male and female alcoholics.

BACKGROUND: The P300 component of the event-related potential has been extensively studied as a possible neurobiological risk marker for the development of alcoholism. Although P300 amplitude reduction has frequently been documented in high-risk children, studies of adult alcoholics are inconsistent. METHODS: P300 amplitude from 121 adult alcoholics was compared to 68 controls utilizing event-related potential paradigms from the auditory and visual modalities. All participants were evaluated clinically with psychiatric interviews and administered the MMPI. RESULTS: Male alcoholics did not show a reduction in amplitude in either the auditory or visual modality. Female alcoholics showed reduced P300 amplitude, but only when a comorbid lifetime diagnosis of depression was present. Similar results were found using current depressed mood (Scale 2 from the MMPI). CONCLUSIONS: No differences in P300 amplitude were found between alcoholics and controls unless comorbid depression was present. Therefore, P300 amplitude reduction seen in children at high-risk for developing alcoholism seems to represent a neurodevelopmental delay that normalizes by adulthood.

Adult↗
PubMed1999

Modulation of language processing in schizophrenia: effects of context and haloperidol on the event-related potential.

BACKGROUND: Disturbances in language associations were among the first clinical symptoms reported for individuals described as schizophrenic (Bleuler 1911/1950). Currently, associative language disturbance is a diagnostic feature of schizophrenia (American Psychiatric Association 1994); however, the mechanisms that produce this symptom remain unknown. In the present study, two candidate psychological functions were examined: sensitivity to semantic context and expectancy (attention). METHODS: Visual event-related potentials were recorded during a lexical decision task in which semantic relationship and expectancy (relatedness proportions) were varied. Semantic priming processes were compared between 34 male normal control subjects tested once and 37 male schizophrenic inpatients evaluated during their participation in a double-blind haloperidol maintenance therapy and placebo replacement protocol. RESULTS: Schizophrenic patients failed to discriminate between associated and unassociated words, as measured by the amplitude of the N400 component (i.e., absence of the N400 priming effect); however, the overall mean amplitude of N400 did not differ between patients and control subjects. In addition, patients and control subjects did not differ significantly in the amplitude of N400 elicited to associated words or to unassociated words. Finally, the effect of expectancy-based processing on the magnitude of the N400 priming effect did not differ between patients and control subjects. CONCLUSIONS: On the basis of these findings, a tentative hypothesis is suggested that schizophrenic patients are characterized by a pattern of indiscriminate or random spread of activation in their semantic network during the processing of single-word semantic contexts.

Acoustic Stimulation↗
PubMed1998

Genetic association between reduced P300 amplitude and the DRD2 dopamine receptor A1 allele in children at high risk for alcoholism.

BACKGROUND: There is evidence that both reduction in P300 amplitude and the presence of the A1 allele are risk markers for alcoholism. We hypothesized that demonstration of a relationship between the marker and the trait in young children who had not begun to drink regularly would provide evidence for dopaminergic mediation of the reduction in P300 often seen among high-risk children. A previous association between the A1 and the P300 amplitude in screened controls supports the hypothesis that this association occurs in the general population. METHODS: Children were assessed using both visual and auditory paradigms to elicit event-related potentials (ERPs). The P300 component of the ERP was investigated with respect to the genetic variation of the Taq1A D2 receptor in these children. RESULTS: Genetic association between a marker locus (Taq1 A RFLP near the D2 receptor locus) and the amplitude of P300 was found to be present in 58 high-risk children and their relatives (a total of 100 high-risk individuals). CONCLUSIONS: A higher proportion of children from alcoholic families may exhibit lower P300 because more of these children carry the A1 allele than is seen in the normal population.

Acoustic Stimulation↗
PubMed1998

Preparing the heart, eye, and brain: foreperiod length effects in a nonaging paradigm.

Psychophysiological "preparatory" responses may or may not depend on a focused expectation of when a stimulus will occur. Changes in heart rate, pupillary diameter, and brain potentials were examined during trials in which foreperiod of a simple reaction time (RT) task was fixed or unpredictable. Trials were also included in which stimuli for the speeded motor reaction were triggered by psychophysiological changes occurring spontaneously in the foreperiod. Thirty-two college-aged volunteers equally divided by gender participated in the experiment. Reducing expectancy, by using nonaging foreperiods, eliminated transient prestimulus psychophysiological responses but failed to eliminate slow changes over the foreperiod--slowing of heart rate, dilation of the pupil, and cortical surface negativity. Triggering the reaction stimulus by physiological changes did not influence RT. Correlations between psychophysiological changes in the foreperiod and between these changes and RT were generally low. The results were consistent with a multiprocess view of preparation.

Adult↗
PubMed1998

Predictors of involvement in P300 latency in solvent-exposed adults.

Persons with a history of exposure to organic solvents have been shown to have cognitive and personality changes, as well as abnormalities on measures of neurophysiology (e.g., delays in P300 latency). Studies assessing long-term sequelae in exposed persons have been limited, especially those using neurophysiologic measures. This study assessed cognitive event-related potentials (ERPs) in 16 persons with a history of organic solvent exposure at two testings, separated, on average, by 1.5 years. The sample was divided into persons who showed improvement on P300 latency (e.g., reduction in latency of 1.5 SD of control group) and those who did not. Sixty-three percent showed no improvement, whereas 37% showed significant improvement. Recency of exposure and the interaction of exposure duration and history of peak exposure significantly predicted group membership. That is, persons with shorter duration of exposure coupled with no peak exposures and longer time from exposure to test were more likely to fall in the improved group. Substituting age for duration of exposure in the interaction term improved classification of the two groups. The results support previous findings that most exposed persons do not show significant improvements over time. The results further suggest that there is a need to assess factors, such as aging, which may make one more vulnerable to the neurotoxic effects of solvents.

Adult↗
PubMed1997

Vigilance and iconic memory in children at high risk for alcoholism.

OBJECTIVE: Previous studies report reduced visual event-related potential (ERP) amplitudes in young males at high risk for alcoholism. These findings could involve difficulties at several stages of visual processing. This study was aimed at examining vigilance performance and iconic memory functions in children at high risk or low risk for alcoholism. METHOD: Sustained vigilance and retrieval from iconic memory were evaluated in 54 (29 male) white children at high risk and 47 (25 male) white children at low risk for developing alcoholism. Children were also grouped according to gender and age (younger: 8-12 years; older: 13-18 years). RESULTS: No differences is visual sensitivity, response criterion or reaction time were associated with risk status on the degraded visual stimulus version of the Continuous Performance Test. For the Span of Apprehension, no differences were found due to risk status when only 1 or 5 distractors were presented, although with 9 distractors a significant effect of risk status was found when it was tested as an interaction with gender and age (decreased accuracy for older high-risk boys compared to older low-risk boys). CONCLUSIONS: These findings suggest that ERP deviations are not attributable to stages of visual processing deficits, but represent difficulty involving more complex utilization of information. Implications of these results are that the differences between high- and low-risk children that have been reported previously for visual ERP components (e.g., P300) are not attributable to deficits of attentional or iconic memory mechanisms.

Adolescent↗
PubMed1997

Neuropsychological performance of journeymen painters under acute solvent exposure and exposure-free conditions.

Journeymen painters were evaluated with a comprehensive battery of neuropsychological tests and compared to demographically similar nonexposed controls. For painters, a cumulative exposure to solvents was estimated from a structured interview that derived an index based on lifetime exposure and exposure in the past year. Painters were tested either shortly after having painted or after an exposure-free interval. Significant between-group differences were found on a cluster of tests measuring learning and memory. Within the painter group, scores on the learning and memory tests were significantly related to the interaction of condition and exposure. That is, those painters who were tested soon after painting and who also had a higher overall lifetime exposure, performed worst on tests of learning and memory. These results are consistent with the view that neuropsychological function--particularly learning and memory--may be compromised in active workers with a history of chronic solvent exposure. Furthermore, both the chronicity of solvent exposure, as well as the acuteness of the exposure, are significant factors in cognitive performance.

Adult↗
PubMed1996

Working memory capacity predicts language comprehension in schizophrenic patients.

The association between language comprehension and working memory capacity was evaluated in 25 male DSM-III-R schizophrenic patients (14 inpatients; 11 outpatients), and in 11 male normal controls (no lifetime DSM-III-R disorder). Patients and controls did not differ significantly on age and education. Language comprehension was examined as a function of two types of processing demand: grammatical complexity (complex versus simple sentences) and presentation rate (accelerated versus conversational). Schizophrenic patients showed significantly reduced language comprehension and decreased working memory capacity for language, compared with controls. Patients showed general difficulty in comprehending accurately, rather than exhibiting problems with specific grammatical structures. Subject groups were highly accurate and did not differ in their ability to perceive the individual words in sentences presented at the accelerated rate (intelligibility). Presentation rate and grammatical complexity affected comprehension accuracy in all groups, however, with increases in rate and complexity producing decreases in understanding. Of most importance, theoretically, is the finding that working memory capacity predicted language comprehension accuracy in both schizophrenic patients and normal controls. Results suggest that language comprehension deficits in schizophrenic patients may involve a general dysfunction that is associated with working memory capacity for language.

Adult↗
PubMed1996

A preliminary neuropsychological study of Persian Gulf veterans.

A neuropsychological investigation of 21 Persian Gulf veterans and 38 demographically matched controls was conducted in order to make a preliminary determination concerning presence of neuropsychological deficits associated with the Persian Gulf War experience. The neuropsychological test battery consisted of measures of complex attention, memory, and motor skills previously shown to be sensitive to exposure to environmental toxins. It was found that the Persian Gulf veteran group did not demonstrate substantial impairment, but an impairment index derived from 14 test variables was statistically significantly different from controls in the direction of poorer performance.

Adult↗
PubMed1996

Differential associations of P300 amplitude and latency with cognitive and psychiatric function in solvent-exposed adults.

Cognitive and mood changes are central components of solvent encephalopathy. This study examined event-related potentials in relation to neuropsychological and psychiatric function in solvent-exposed adults. Results revealed that longer P300 latency was associated with poorer cognitive test scores, whereas reduced P300 amplitude was related to increased psychiatric symptomatology. The findings suggest that the cognitive deficits and the psychiatric disturbance following solvent exposure may have different neurophysiological bases.

Adult↗
PubMed1995

Language comprehension in schizophrenia: trait or state indicator?

Language comprehension, measured by the Luria-Nebraska Relational Concepts Factor Scale, was evaluated twice in 15 male DSM-III-R schizophrenic patients during a controlled double-blind haloperidol maintenance (without anticholinergics) and placebo replacement protocol. Fifteen male normal controls were tested once. Patients and controls were matched on age and education. Language comprehension was significantly reduced in patients under both pharmacologic conditions, as compared with controls. Patients' comprehension accuracy did not differ significantly between neuroleptic-treatment and placebo replacement conditions. Patients' comprehension accuracy was independent of positive symptoms, anxiety-depression, measures of clinical course, and CSF and plasma monoamines. Comprehension accuracy was also not associated with patients' educational level or WAIS-R measures of their intellectual and short-term memory functioning. Patients' comprehension performance was significantly associated only with the negative symptom anhedonia-asociality during haloperidol maintenance. Thus, language comprehension in schizophrenic patients was independent of changes in pharmacologic treatment and the positive symptoms of psychosis. Results suggest language comprehension may represent a stable or trait characteristic in schizophrenia.

Adult↗
PubMed1995

Alterations in heart rate and pupillary response in persons with organic solvent exposure.

Cardiac and pupillary reactivity were examined in 25 persons with a history of exposure to organic solvents and 19 nonexposed controls during performance of a counting and a choice reaction task. The solvent-exposed group demonstrated an atypical pattern of responding across tasks. While control subjects showed a decline in heart rate across the two conditions (e.g., habituation), exposed persons had an increase in heart rate. Initial pupil diameter was similar for both groups, but only the control subjects exhibited habituation across the two tasks. In the exposed group, higher heart rate was not associated with higher levels of self-reported anxiety. Anticipatory cardiac deceleration preceding unpredictable events was significantly less in the exposed group, but there were no significant group differences on poststimulus acceleration. The results suggest that persons with solvent exposure have a deficiency in the allocation of attention (reduced anticipatory deceleration and decreased pupillary dilation). It is further suggested that difficulty in the allocation of attention produces an increase in tonic sympathetic levels when confronted with a cognitively challenging task. In this experiment, in which the choice reaction task was purposely presented last, and was apparently more challenging for exposed persons, a failure to exhibit autonomic habituation over the course of the session characterized the solvent-exposed group.

Adult↗
PubMed1993

Postural sway in children from pedigrees exhibiting a high density of alcoholism.

A total of 98 children participated in a study of the neurobehavioral characteristics of individuals from pedigrees in which there was a high density of alcoholism. Two groups of children were evaluated (High and Low Risk) using a sensitive movement platform and a variety of methods to challenge the motor system. High-Risk children showed a greater decrement in postural steadiness when visual input was removed than did Low-Risk children. Additionally, the monopedal stances revealed hemispheric differences in postural sway as a function of risk status. The amount of sway exhibited was correlated with the latency of P300 recorded using a visual task. Both appear to be indicators of neuropathological changes. The present results suggest that postural sway may be a neurobehavioral marker for alcoholism risk.

Adult↗
PubMed1993

Assessment of prepubertal and postpubertal boys and girls at risk for developing alcoholism with P300 from a visual discrimination task.

A total of 86 children (45 male) between the ages of 8-18 who were from families that were either at high- or low-risk for developing alcoholism were evaluated in a visual event-related potential paradigm. The children responded to two target conditions (hard and easy) and a blank condition by pressing an appropriate button. P300 amplitude was reduced in prepubescent boys who were at high-risk for developing alcoholism. Reaction time data for type of target indicated that, while latency was longer for the hard condition compared to the easy one, no significant differences by risk status were found. Performance accuracy did not differ by group status. These behavioral findings suggest that P300 amplitude is an electrophysiological marker of alcoholism risk in young boys.

Adolescent↗