The effects of stimulus intensity, duration, and risetime on the autonomic and behavioral components of orienting, startle, and defense responses were investigated. Six groups of 10 students were presented with 15 white noise stimuli at either 60 or 100 dB, with controlled risetimes of either 5 or 200 ms, and at stimulus durations of 1 or 5 s (1 s only in the case of the 60-dB groups). A dishabituation stimulus consisting of a 1000 Hz tone was also presented. Measures consisted of skin conductance and heart rate, together with ratings of facial expressions and upper torso movement obtained using video recording. Increased intensity resulted in greater amplitudes and frequencies of electrodermal and behavioral responses, and a change from cardiac deceleration to acceleration. Faster risetimes elicited larger electrodermal responses, greater frequencies of eye-blinks, head and body movements, and larger cardiac accelerations. The effects of duration for the 100-dB stimuli were less clear-cut. Overall, the results are discussed in relation to the differentiation of orienting, startle, and defense responses.

The present study examined the hemodynamics underlying blood pressure elevations for evidence of a shift in the control of blood pressure during prolonged mental stress. Mean arterial pressure (MAP), cardiac output (CO), and total peripheral resistance (TPR) were measured at rest, during a 28-min mental arithmetic stress task, and during recovery, in 30 young healthy men and women. The stress task elicited a sustained increase in MAP: CO rose during the first half of the task but returned to baseline levels during the last quarter of the task, whereas TPR increased as the task progressed. When participants' hemodynamic reactions were classified as cardiac, vascular, or neither, there were more cardiac reactors early relative to late in the task, whereas there were more vascular reactors late relative to early. Thus, the sustained pressor response was initially supported mainly by cardiac mechanisms but subsequently by predominantly vascular mechanisms.

The ability to identify unaffected gene carriers within families may be crucial to the success of schizophrenia genetics studies. Data collected from three family samples (N = 365) demonstrated that poor antisaccade performance is an exceptionally promising indicator of liability for schizophrenia. A particular antisaccade task version provides large separations (5–6 sigma) between proband and normal groups. Poor antisaccade performance alone correctly identified 70% of patients in California, Utah, and Micronesia schizophrenia samples. Twenty-five to 50% of these patients' nonpsychotic first-degree relatives also had poor antisaccade performance, yielding risk ratios around 20:1 for simplex and 50:1 for multiplex schizophrenia families. Poor antisaccade performance is associated with dorsolateral prefrontal cortex pathology, suggesting that dysfunction of this circuitry also may predispose individuals to developing this disease.

Blood pressure, heart rate, and changes in facial and finger blood flow were monitored in 24 male Chinese and 24 male Caucasians while they described anger-provoking incidents and read out neutral material, either loudly and rapidly or softly and slowly. Describing the incidents loudly and rapidly heightened anger ratings and enhanced digital vasoconstriction but not blood pressure or heart rate; however, anger enhanced blood pressure during soft, slow speech. Facial blood flow increased during anger expression, irrespective of speech style, but decreased when neutral material was read out. The findings suggest that an increase in facial blood flow reduces peripheral vascular resistance during anger expression, and that baroreflexes attenuate increases in heart rate and blood pressure. Racial background did not influence subjective reports or physiological responses, possibly because the procedure did not draw strongly enough on cultural taboos.

We investigated the influence of sympathetic nervous system processes on mucosal immunity by comparing the effects of beta-adrenoceptor blockade with 40 mg propranolol and placebo on secretory immunoglobulin A (sIgA) at rest and during paced serial arithmetic, cold pressor, and submaximal cycling. These tasks produced patterns of cardiovascular activity indicative of combined alpha- and beta-adrenergic, alpha-adrenergic, and beta-adrenergic activation, respectively. The effectiveness of the beta blockade was confirmed by the attenuation under propranolol of the shortening of the cardiac preejection period and the tachycardia elicited by mental arithmetic and exercise. The cold pressor test did not affect sIgA under either the placebo or the propranolol. Mental arithmetic increased sIgA concentration, and this increase was not blocked by propranolol. Exercise elicited increases in both sIgA concentration and sIgA secretion rate, which were not diminished by beta blockade. These data suggest that sIgA is not regulated by beta-adrenergic mechanisms.

Performance on heartbeat counting tasks is usually interpreted in terms of cardiac sensitivity. We tested the hypothesis that heartbeat counting is influenced by beliefs about heart rates by dissociating beliefs about heart rates and actual heart rates. In a within-subjects design, heart rates of 50 patients with cardiac pacemakers were set to a low (50 bpm), medium (75 bpm), or high (110 bpm) pacing rate unknown to the patients via remote control while they performed a heartbeat tracking task. Results showed that patients' heartbeat counting did not follow the shifts in their actual heart rates adequately, although their overall performance was comparable to that of young and healthy control participants. As a result, tracking scores decreased significantly in the high pacing rate condition where beliefs about heart rates and actual heart rates were most extremely dissociated. The findings suggest that tracking scores reflect beliefs about heart rates rather than cardiac sensitivity.

Two experiments compared finger plethysmograph (FP) to electrocardiogram (ECG) in providing accurate heart periods for use in heart rate variability (HRV) calculations. In Experiment 1, simultaneous ECG and FP recordings were taken from 16 healthy subjects at rest. In Experiment 2, 10 additional healthy subjects were recorded at rest and during the Stroop Color-Word Test. In both studies, high correlations were found between FP-derived and ECG-derived band variance for high and low frequency HRV at rest. But, during the Stroop task, correlations were strongly diminished. In addition, under both conditions, HRV measures were significantly higher using the FP signal. Thus, FP may be adequate for determining HRV at rest, but, for experimental use, ECG may still be recommended. Nonetheless, further studies that include test–retest reliability assessment of both data collection techniques are warranted before a more certain determination can be made.

To examine associations between heart period variability (HPV) and psychopathology in young urban boys at risk for delinquency, a series of 69 7–11-year-old younger brothers of adjudicated delinquents received a standardized psychiatric evaluation and an assessment of heart period variability (HPV). Psychiatric symptoms were rated in two domains: externalizing and internalizing psychopathology. Continuous measures of both externalizing and internalizing psychopathology were associated with reductions in HPV components related to parasympathetic activity. These associations could not be explained by a number of potentially confounding variables, such as age, ethnicity, social class, body size, or family history of hypertension. Although familial hypertension predicted reduced HPV and externalizing psychopathology, associations between externalizing psychopathology and HPV were independent of familial hypertension. Psychiatric symptoms are associated with reduced HPV in young urban boys at risk for delinquency.

In the present study it was investigated whether the smaller P3s in attention-deficit hyperactivity disorder (ADHD) children are caused by a shortage of capacity underlying P3 processes or whether they are due to a capacity allocation problem. Also, effects of methylphenidate on these processes were investigated. Performance and event-related potentials (ERPs) of 14 ADHD and 14 control children were measured using an irrelevant-probe technique. Three types of task irrelevant visual probes (standards, deviants, and novels) were presented against the background of two visual tasks that varied in task difficulty. The parietal P3 wave was measured in response to task stimuli and probes. ADHD subjects made significantly fewer correct detections than normal controls in both the easy and the hard tasks. Controls showed an enhanced P3 to task-relevant stimuli in the hard task, whereas ADHD children did not. Probe (novel) P3 amplitudes decreased from the easy to the hard task to the same extent in both groups. Methylphenidate enhanced the percentage of correct responses and task P3 amplitudes in both the easy and the hard task but probe P3 amplitudes were not influenced by methylphenidate. It was concluded that ADHD children do not suffer from a shortage in attentional capacity; rather, the evidence is in favor of a problem with capacity allocation. Furthermore, methylphenidate had enhancing effects on performance and ERPs, but did not improve the capacity-allocation deficit.

Hyperventilation (HV) is often considered part of a defense response, implying an unpleasant emotion (negative valence) combined with a strong action tendency (high arousal). In this study, we investigated the importance of arousal and valence as triggers for HV responses. Forty women imagined eight different scripts varying along the arousal and valence dimensions. The scripts depicted relaxation, fear, depressive, action, and desire situations. After each trial, the imagery was rated for valence, arousal, and vividness. FetCO2, inspiratory and expiratory time, tidal volume, and pulse rate were measured in a nonintrusive way. FetCO2 drops and decreases in inspiratory and expiratory time occurred in all but the depressive and the relaxation scripts, suggesting that a defense conceptualization of hyperventilation is not always appropriate.

Many studies have been carried out to assess the variability of sleep parameters. The first night effect is one of the most important factors in this variability and has been extensively studied. However, the readaptation phenomenon when subjects returned to the sleep laboratory after spending a certain period of time at home has been not systematically evaluated. To investigate this phenomenon across multiple sleep laboratory sessions, polysomnographic data from 12 healthy young subjects for 12 nights (three periods each of 4 consecutive nights, with a minimum of 1 month between them) were collected. The first night effect was present only in the first night of the first period (“very first night”) and was significant only for REM sleep-related variables. We conclude that the results from the first nights of consecutive periods within a specific protocol with healthy young subjects need not be discarded in subsequent analyses.

Studies in psychophysiology and behavioral medicine have uncovered associations among psychological processes, behavior, and lung function. However, methodological issues specific to the measurement of mechanical lung function have rarely been discussed. This report presents an overview of the physiology, techniques, and experimental methods of mechanical lung function measurements relevant to this research context. Techniques to measure lung volumes, airflow, airway resistance, respiratory resistance, and airflow perception are introduced and discussed. Confounding factors such as ventilation, medication, environmental factors, physical activity, and instructional and experimenter effects are outlined, and issues specific to children and clinical groups are discussed. Recommendations are presented to increase the degree of standardization in the research application and publication of mechanical lung function measurements in psychophysiology.

Fourteen children with attention-deficit hyperactivity disorder (ADHD) and 14 normal control children were compared with respect to stimulus- and response-related processes. Subjects with ADHD took part in two additional sessions under methylphenidate or placebo. In both experiments, performance and electrophysiological measures such as the P2, N2, and P3 components of event-related potential and electromyogram (EMG) activity were measured during an Eriksen flanker task. In both groups of children, reaction times (RTs) to arrow stimuli incongruent with the target were longer than those to neutral stimuli (response interference), which were again slower than RTs to target-alone stimuli (perceptual interference). Children with ADHD made more errors to incongruent stimuli and showed more response interference. For correct responses, no differences between the groups in response interference effects on reaction time, P2, N2, and P3 latency, or EMG onset were found. Methylphenidate had a general enhancing effect on accuracy but did not specifically reduce interference from the flanking stimuli. Methylphenidate had no effects on RT, N2 and P2 latency, P3 amplitude or latency, or EMG activity. The conclusion that methylphenidate did not influence response processes contrasts sharply with findings reported by authors using the Sternberg memory search task.

Previous studies demonstrated distinct cardiovascular patterns associated with threat and challenge appraisals for groups of participants. We extend these results by assessing whether appraisals continue to be associated with these cardiovascular response patterns within an individual as appraisals change. Participants completed four verbal mental arithmetic tasks for which they made appraisals before and after each task. Cardiac reactivity and total peripheral resistance (TPR) were calculated for the first and last minutes of each task, and the number of responses and percent correct were measured for each task. In line with our prediction, pretask appraisals were related to some task-related cardiac responses across the four tasks. In addition, task-related cardiovascular reactivity and behaviors both influenced appraisals following the task. Our findings suggest that an idiographic analysis of appraisals, cardiovascular physiology, and task-related behaviors provides a richer understanding of the appraisal process and reveals sex differences deserving further assessment.

This study examined the acute immunological effects of two laboratory stressors, expected to evoke distinct patterns of cardiac autonomic activity; namely an “active coping” time-paced memory test, and a “passive coping” stressful video showing surgical operations. We measured salivary S-IgA, IgA-subclasses (IgA1, IgA2), and secretory component (SC). SC is responsible for the transport of S-IgA across the epithelium, and thus a rate-determining step in S-IgA secretion. Thirty-two male undergraduates were subjected to both stressors and a control video (a didactic television program). The memory test induced a typical “fight-flight” response, characterized by increases in heart rate and blood pressure in association with a decrease in cardiac preejection period (PEP) and vagal tone. The surgical video produced a “conservation-withdrawal”-like response, characterized by an enhanced vagal tone, a decrease in heart rate, and a moderate sympathetic coactivation (as indicated by a shortened PEP and an increased systolic pressure). The memory test induced an increase in the concentration and, to a lesser extent, in the output of S-IgA, IgA1, and SC. The output of IgA2 was not significantly affected. For the surgical video, a different pattern emerged: During stressor exposure S-IgA remained unaffected, against the background of a small increase in SC output. However, 10 min after the surgical video S-IgA levels had decreased. This decrease in S-IgA was paralleled by a decrease in IgA1, but not IgA2. We conclude that acute stress can have both enhancing and suppressive effects on secretory immunity, the IgA1 subclass in particular. The mechanisms that underlie these divergent responses may include stressor-specific patterns of autonomic activation.

The effects on performance of unattended stimulus–response spatial relationships in choice reaction time tasks (i.e., the Simon effect) have been attributed to automatic activation of the response ipsilateral to stimulus location. We tested this assumption using the lateralized readiness potential (LRP). The response key labels changed randomly from trial to trial and were presented either 400 ms before (immediate-reaction trials) or 400 ms after (delayed-reaction trials) stimulus. The critical test for the automatic activation hypothesis was on delayed-reaction trials, in which LRP deflections were expected in the interval between stimulus and response-key labels. Contrary to this prediction, there were no LRP signs of response activation within that interval.

The effects on performance of unattended stimulus–response spatial relationships in choice reaction time tasks (i.e., the Simon effect) have been attributed to automatic activation of the response ipsilateral to stimulus location. We tested this assumption using the lateralized readiness potential (LRP). The response key labels changed randomly from trial to trial and were presented either 400 ms before (immediate-reaction trials) or 400 ms after (delayed-reaction trials) stimulus. The critical test for the automatic activation hypothesis was on delayed-reaction trials, in which LRP deflections were expected in the interval between stimulus and response-key labels. Contrary to this prediction, there were no LRP signs of response activation within that interval.

Event-related potentials (ERPs) provide a noninvasive method to evaluate neural activation and cognitive processes in schizophrenia. The pathophysiological significance of these findings would be greatly enhanced if scalp-recorded ERP abnormalities could be related to specific neural circuits and/or regions of the brain. Using quantitative approaches in which scalp-recorded ERP components are correlated with underlying neuroanatomy in schizophrenia, we focused on biophysical and statistical procedures (partial least squares) to relate the auditory P300 component to anatomic measures obtained from quantitative magnetic resonance imaging. These findings are consistent with other evidence that temporal lobe structures contribute to the generation of the scalp-recorded P300 component and that P300 amplitude asymmetry over temporal recording sites on the scalp may reflect anatomic asymmetries in the volume of the superior temporal gyrus in schizophrenia.

Research has indicated that performance on heartbeat counting tasks may be influenced by beliefs about heart rate. Sixty male subjects were administered the Schandry heartbeat counting task after viewing fast, slow, or no heart rate feedback. Subjects were also administered the Whitehead signal-detection type task. Results indicated that subjects who received fast or no heartbeat feedback performed better on the Schandry task than subjects who received slow feedback. Feedback presentation did not affect performance on the Whitehead task. These results suggest that the Schandry task is influenced by external variables (expectations, beliefs) beyond pure awareness of “discrete” visceral sensations and, thus, may not be as powerful a method for determining awareness of individual heartbeats as some other paradigms.

Task and modality effects on P3 latency, amplitude, and scalp topography were studied during parallel versions of visual (VCPT) and auditory (ACPT) continuous performance tasks using a Go/NoGo paradigm (A-X CPT). Both the ACPT and VCPT incorporated five conditions including Go and NoGo stimulus sequences as well as three other nontarget conditions. The goal was to evaluate the functional significance and modality specificity of the P300 response and the NoGo P3. Analyses were performed using both raw and normalized data to make comparisons across modalities. For both modalities, the Target X (Go) and three nontarget conditions elicited maximum P3 amplitudes over the posterior scalp sites and qualified as classical P300 responses. The NoGo condition was associated with an increase in central-frontal amplitude compared to the Target X condition. The scalp topography of the P300/P3 for Go and NoGo conditions, as well as all other conditions, was the same for both modalities, supporting the modality independent nature of both P300 and the NoGo P3. Min-Max normalization of P3 amplitudes did not change the condition-topography relationships.