Showing papers in "Psychophysiology in 1989"

Modern Mind‐Brain Reading: Psychophysiology, Physiology, and Cognition

Abstract: This paper reviews the actual and potential benefits of a marriage between cognitive psychology and psychophysiology. Psychophysiological measures, particularly those of the event-related brain potential, can be used as markers for psychological events and physiological events. Thus, they can serve as "windows" on the mind and as "windows" on the brain. These ideas are illustrated in the context of a series of studies utilizing the lateralized readiness potential, a measure of electrical brain activity that is related to preparation for movement. This measure has been used to illuminate presetting processes that prepare the motor system for action, to demonstrate the presence of the transmission of partial information in the cognitive system, and to identify processes responsible for the inhibition of responses. The lateralized readiness potential appears to reflect activity in motor areas of cortex. Thus, this measure, along with other psychophysiological measures, can be used to understand how the functions of the mind are implemented in the brain.

Premenopausal and postmenopausal women differ in their cardiovascular and neuroendocrine responses to behavioral stressors.

Abstract: Middle-aged (45-51 years) women performed four tasks while their heart rate, blood pressure, and plasma catecholamines were measured. The tasks were serial subtraction, mirror image tracing, speech, and postural tilt. The speech task was considered to be particularly relevant to women because of its emphasis on social skills. Fifteen premenopausal women reported menstruating regularly and were tested in the early follicular phase. Sixteen postmenopausal women reported not menstruating for at least 12 months and their hormonal status was verified by serum levels of follicle-stimulating hormone. Results showed that postmenopausal women exhibited greater increases from baseline in heart rate during all tasks, relative to premenopausal women, with a particularly pronounced increase during the speech task. Postmenopausal women exhibited greater increases from baseline in systolic blood pressure and epinephrine, relative to premenopausal women, during the speech task only. Explanations for the stressor-specific effect of menopausal status were discussed. The results suggest that reproductive hormones may interact with stressor characteristics to determine middle-aged women's physiological responses to stress.

Sleep on the Night Shift: 24-Hour EEG Monitoring of Spontaneous Sleep/Wake Behavior

Abstract: The present study sought to objectively describe the spontaneous sleep/wakefulness pattern of shift workers during a 24-hour period. Portable Medilog tape-recorders were used for ambulatory EEG monitoring of 25 male papermill workers (25-55 years) during days with night and afternoon work. The results showed that sleep after night work was two hours shorter than after afternoon work. The sleep reduction affected mainly Stage 2 and REM sleep while slow wave sleep was unchanged. In connection with night work 28% of the workers took a nap in the afternoon. These naps contained a large proportion of slow wave sleep and were, apparently, caused by the sleep deficit after the short main sleep period. The EEG recordings also revealed that 20% of the participants had sleep episodes during night work. These naps were as long as the afternoon naps, were experienced as "dozing offs" rather than naps, occurred at the time of the trough of the circadian wakefulness rhythm, and were concomitant with extreme subjective sleepiness and low rated work load. It was concluded that not only the sleep of shift workers was disturbed, but also the wakefulness--to the extent that sleepiness during night work sometimes reached a level where reasonable wakefulness could not be maintained. The latter observation is probably of special importance in work situations demanding a great responsibility for human lives or for great economic values.

Developmental Evidence for Modality‐Dependent P300 Generators: A Normative Study

Abstract: The behavior of the early and late components of the event-related brain potential (ERP) elicited by auditory and visual stimuli was studied in 40 normal females between the ages of 7 and 20. The ERPs were collected using two different tasks (i.e.,count and reaction time) in an oddball paradigm. Analysis of the early component (i.e., N1, P2, N2) latencies revealed small but significant decreases with age in the visual modality but no change in the auditory modality. Except for the visual N1, early component amplitudes did not change significantly over this age range. The results showed that auditory and visual P300 latencies, but not amplitudes, changed at significantly different rates over this age range. P300 latencies in the auditory modality showed a relatively abrupt change around age 12, after which P300 latencies changed little and were essentially at their adult levels. The latencies of visual P300s showed a much smaller and more steady decrease with age. Thus visual P300 latencies were shorter than auditory P300s in young children but longer than auditory P300s in older children. Significantly different scalp distributions were found for auditory and visual P300s. Although all P300 activity was maximal over parietal scalp, visual P300s were significantly larger than auditory P300s over central and frontal scalp. The developmental differences, combined with the presence of significantly different scalp topographies for auditory and visual P300s, provide convergent evidence that P300 activity is not independent of the modality of the eliciting stimulus.

Laboratory and ambulatory monitoring of menopausal hot flashes.

Abstract: A large increase in skin conductance activity recorded from the sternum was found during menopausal hot flashes and corresponded well with patient self-reports. The magnitude and time course of this skin conductance change was similar during spontaneous hot flashes recorded in the laboratory, during heat-induced hot flashes, and during those recorded by ambulatory monitoring techniques. This pattern of sternal skin conductance change did not occur in premenopausal women during body heating or ambulatory monitoring. These methods should be useful in research on the etiology and treatment of menopausal hot flashes.

The autonomic differentiation of emotions revisited: convergent and discriminant validation.

Abstract: The convergent and discriminant validity of three models of physiological emotion specificity were compared, Forty-two female students served as subjects in a 2 (Context of emotional inductions: real-life, imagery) × 3 (Emotion: fear, anger, control) + 1 (Happiness induced in real-life context) repeated measures design. The dependent measures included self-reports of emotion, Gottschalk-Gleser affect scores, back and forearm extensor EMG activity, body movements, heart period, respiration period, skin conductance, skin temperatures, pulse transit time, pulse volume amplitude, and blood volumes. Self-report data confirmed the generation of affective states in both contexts, as intended. Planned multivariate comparisons between physiological profiles established discriminant validity for fear and anger in the real-life context, whereas under imagery, emotion profiles were essentially equal. Convergent validity could not be substantiated. Implications for models of physiological specificity of emotion were discussed.

Effects of smoking/nicotine on anxiety, heart rate, and lateralization of EEG during a stressful movie.

Abstract: The effects of smoking cigarettes with differing FTC nicotine deliveries on anxiety and EEG activity were evaluated in 40 smokers who were compared with 40 non-smokers, matched for age and gender. Following smoking (sham-smoking in the case of the non-smokers), the participants viewed a stress-inducing movie. Smoking higher-nicotine delivery cigarettes during the movie, as compared to smoking low-nicotine control cigarettes, was associated with reductions in anxiety and right hemisphere activation, increased heart rate, and enhancement of the ratio of left-hemisphere parietal EEG activation to right-hemisphere activation. These results are interpreted as indicating that the anxiolytic effects of nicotine may be mediated by the right hemisphere. The EEG activity and emotional responses of non-smokers were more like those of smokers who smoked the lower-nicotine cigarettes than those of smokers of the higher-nicotine cigarettes.

Auditory and visual P300s in temporal lobectomy patients: evidence for modality-dependent generators.

Abstract: The P300 component of the event-related brain potential (ERP) was studied in epileptic patients with unilateral resections of medial temporal lobe areas of the brain. The patients and controls were tested in an oddball paradigm in two conditions: counting and reaction time. Both auditory and visual stimuli were used to elicit ERP activity in different blocks. Despite the reported presence of locally-generated auditory and visual P300-like potentials in these areas, no evidence was found of any surgically-related hemispheric asymmetries in the scalp distribution of the P300 or Slow Wave for stimuli in either modality. Moreover, compared to normal controls, there were no significant reductions in overall P300 amplitude in the patients. The patients did show a double dissociation in their frontal ERP activity: the left temporal lobectomy patients showed apparent decreased frontal auditory P300 amplitudes but normal visual P300 amplitudes, whereas the right temporal lobectomy patients showed the opposite pattern. These results appeared to be due to the presence of a long-duration slow wave rather than to alterations in P300 amplitude. These data do not support the presence of a significant contribution by a hippocampal/amygdala generator to the activity of the scalp-recorded P300 in the oddball paradigm. Topographic comparisons on normalized amplitudes revealed significantly different scalp distributions as a function of stimulus modality, event probability, and task for both the P300 and Slow Wave components. These data indicate that the amplitude variations associated with each experimental variable are due to the activity of a separate underlying neural source. The sources of task and probability effects on P300 and Slow Wave amplitude each appeared to be modality-independent generators. The nature of the third, modality-related generator is less clear. These results uphold the tenets of the model of P300 amplitude proposed by Johnson (1986) and argue against the idea that the P300 is a unitary phenomenon.

Patterns of autonomic response during laboratory stressors.

Abstract: The present study was designed to include an index reflecting the influence of parasympathetic nervous system activity on the heart, respiratory sinus arrhythmia, in addition to measures reflecting primarily sympathetic nervous system activity. The inclusion of the parasympathetic index was considered important for two reasons: (a) Past studies have suggested different patterns of autonomic response to qualitatively different laboratory stressors but have had to infer parasympathetic influences more indirectly, and (b) there is evidence that borderline hypertensives may have reduced vagal tone at rest when compared to normotensives. This last point is important for the study of individual differences in cardiovascular reactivity because excessive responsiveness in young normotensives (beta-adrenergic reactors) has been suggested as a model for studying the precursors of some types of hypertension. Fifty-one male college students were given a reaction time task, a mental arithmetic task, a cold pressor task, and graded bicycle exercise. A variety of cardiovascular and respiratory measures were collected on each subject. Results indicated significant differences in levels of respiratory sinus arrhythmia during the three tasks and the rest period, giving additional evidence for parasympathetic differences (along with sympathetic differences) in these conditions. Additionally, high beta-adrenergic reactors did not differ in mean level of respiratory sinus arrhythmia from low reactors either at rest or during the task periods. These results are discussed in the context of previous research.

Brain potentials during selective attention, memory-search, and mental rotation

Abstract: Event-related potentials were measured in a task that combined the classic selective attention paradigm with memory search and mental rotation paradigms. Subjects were required to attend to stimulus letters in one color and to ignore stimuli in a different color. Within the attended category subjects searched for target letters from a prememorized set (the memory set) and indicated whether they were presented normally or in mirror-image. Letters in all stimulus categories were presented randomly in either their upright position or rotated over 60 degrees, 120 degrees, or 180 degrees. The event-related potentials showed that the earliest effect of attending to color was a positivity at the anterior electrodes and a negativity at Oz (onset about 150 ms), followed by the enhancement of a central N2 component (N2b, onset about 220 ms). The early effect is thought to reflect selective processing of elementary stimulus features, the later N2b the covert orienting of attention. A later, prolonged central negativity elicited by attended stimuli covaried with the duration of the memory search process. Target detection resulted in a parietal P3b component, and also in an earlier negativity (in the range approximately 200-300 ms) to both attended and unattended targets, suggesting an early preattentive target classification. There were two effects of the rotation of stimuli. First there was an early occipital effect (about 200-300 ms), irrespective of attention and stimulus categories. It was argued that this effect reflected the preattentive identification of the orientation of the stimulus letters. A later (onset about 350-400 ms) parietal effect consisted of an increase in negativity as a function of the angle over which letters were rotated. This prolonged negativity had a later onset latency than the search-related negativity, and was restricted to the event-related potentials to target letters in the attended input channel. It was suggested that this component is the manifestation of a mental rotation process. It was argued that rotation-related negativity and memory search-related activity reflect operations in distinct working memory subsystems.

Bootstrapping: applications to psychophysiology.

Abstract: This paper presents the statistical technique known as the bootstrap to the general audience of psychophysiologists. The bootstrap, introduced by Efron (1979), allows data analysts to study the distribution of sample statistics that might otherwise be too complicated to consider. The technique, which requires simple calculations, involves drawing repeated samples (with replacement) from the empirical--or the actual--data distribution and then building a distribution for a statistic by calculating a value of the statistic for each sample. The bootstrap can be used to obtain confidence intervals, standard errors, and even higher moments for the statistic. It is similar to the well-known jackknife of Quenouille and Tukey. After discussing the history and theory of both the bootstrap and the jackknife, we illustrate the use of the bootstrap in the statistical analysis of correlation coefficients and the general linear model.

Assessment of baroreceptor reflex function during mental stress and relaxation.

Abstract: This paper describes a method of measuring baroreceptor cardiac reflex sensitivity noninvasively from spontaneous patterns of blood pressure and interbeat interval, and the application of this technique in psychophysiology. Baroreflex function was assessed in 24 female volunteers during relaxation and performance of the cold pressor test and a non-verbal mental arithmetic task. Blood pressure and interbeat interval were monitored continuously from the finger using the vascular unloading technique. Sequences of three or more cardiac cycles were identified over which systolic blood pressure increased progressively in conjunction with lengthening interbeat interval, or systolic blood pressure decreased as interbeat interval was reduced. The regression between systolic blood pressure and interbeat interval was computed as an index of baroreflex sensitivity. Relaxation was associated with a small prolongation of interbeat interval, whereas baroreflex sensitivity increased from 17.1 to 19.8 ms/mmHg. Baroreflex sensitivity was reduced significantly during mental arithmetic (mean 14.2 ms/mmHg) but not during the cold pressor test (mean 17.4 ms/mmHg). The difference between mental arithmetic and the cold pressor test may be related to the relative intensity of cardiac and vascular responses in the two situations. The implications of these results for the understanding of behavioural influences on haemodynamic function are discussed and the advantages of noninvasive methods are considered.

Modulation of event-related potentials by word repetition: the effects of inter-item lag.

Abstract: The modulation of event-related potentials by word repetition was investigated in two experiments. In both experiments, subjects responded to occasional nonwords interspersed among a series of words. A proportion of the words were repetitions of previously presented items. Words were repeated after 0 or 6 intervening items in Experiment 1 and after 6 or 19 items in Experiment 2. Event-related potentials to repeated words were characterised by a sustained, widespread positive-going shift with an onset of approximately 300 ms. This effect did not vary significantly as a function of lag in either experiment. When words were repeated immediately, this repetition-evoked positive shift was preceded by a transient negative deflection (onset ca. 200 ms) which was absent in event-related potentials to words repeated at longer lags. These results suggest that the modulation of event-related potentials by word repetition is influenced by at least two processes. One of these processes acts relatively early during the processing of a repeated word, but subsides rapidly as inter-item lag between first and second presentations increases. The second process occurs later in time, but is considerably more robust over variations in inter-item lag.

A Psychometric Study of Surface Electrode Placements for Facial Electromyographic Recording: I. The Brow and Cheek Muscle Regions

Abstract: Despite the burgeoning literature using facial electromyography (EMG) to study cognitive and emotional processes, the psychometric properties of facial EMG measurement have received little attention Two experiments were conducted to assess the reliability and validity of facial EMG as a measure of specific facial actions In Experiment 1, two recording sites in the brow region were compared for their ability to differentiate facial actions hypothesized to be due to the activation of the corrugator supercilii from facial actions presumed to be due to the activation of proximate muscles (eg depressor supercilii, procerus, frontalis, levator labii superioris alaeque nasi, orbicularis oculi), and four sites in the infraorbital triangle were compared for their ability to differentiate facial actions hypothesized to be due to the activation of the zygomaticus major from facial actions presumed to be due the activation of proximate muscles (eg zygomaticus minor, risorius, buccinator, orbicularis oculi, orbicularis oris) Fifteen subjects were instructed to pose a series of facial actions while EMG activity was sampled simultaneously at all sites In Experiment 2, 5 subjects returned to the laboratory for a more extensive investigation of surface EMG activity over the zygomaticus major muscle region The results of this experiment confirmed the findings of Experiment 1 Overall, the results demonstrate that certain recording sites located over specific facial muscle regions are more sensitive and valid indices of particular facial actions than other nearby sites

Attention to color: an analysis of selection, controlled search, and motor activation, using event-related potentials.

Abstract: In this study the organization of information processing in a selective search task was examined by analyzing event-related potentials. This task consisted of searching for target letters in a relevant (attended) color. The ERPs revealed two different effects of attention: an early occipital negativity (+/- 150 ms) reflecting feature-specific attention, and a later, central N2b component (+/- 240 ms) reflecting covert orienting of attention. A later, prolonged negativity (search-related negativity) (+/- 300 ms), maximal at Cz, was related to controlled search to letters in the attended color. Detection of relevant targets resulted in a parietal P3b component. Depending on stimulus presentation conditions an earlier response to both attended and unattended targets was found: an N2 component (+/- 250 ms). In these same conditions, C'3-C'4 asymmetries (Corrected Motor Asymmetries--CMA) suggested motor activation at +/- 300 ms, in the same time range as search-related negativity. It was argued that N2 and CMA suggest the existence of a preattentive target detection system, operating in parallel with a slower serial attentive system, as reflected by N2b and search negativity.

Is elicitation of the autonomic orienting response associated with allocation of processing resources

Abstract: Two experiments investigated whether elicitation of the autonomic orienting response is associated with active allocation of processing resources as indexed by the slowing of reaction time to secondary task probes. In Experiment 1, 75 college student subjects performed a dual task consisting of a primary auditory orienting task and a concurrent secondary visual reaction time task. The primary orienting task included task-relevant tones presented to one ear and task-irrelevant tones presented to the other ear. The last trial of the primary task included an unexpected novel tone presented binaurally. The secondary task consisted of a series of brief light flashes presented at critical times throughout the primary task; the reaction time of the subjects' motor responses to these flashes was measured. Consistent with the resource allocation view of orienting, the results demonstrated that resources were allocated during the primary task tones and the novel tone, and this allocation was greater during the early trials than the late trials of the primary task. However, a directional dissociation was observed in that resource allocation was greater during the task-irrelevant tone whereas autonomic orienting responses were larger to the task-relevant tone. Experiment 2 replicated all of these effects and demonstrated that the directional dissociation was sensitive to the predictability and ease of discrimination between the task-relevant and task-irrelevant tones. Taken together, these findings indicate that the relationship between resource allocation and autonomic orienting is a reliable but complex one in need of further research.

Acute Emotional and Psychophysiological Effects of Aerobic Exercise

Abstract: An experiment was conducted to examine the acute emotional and psychophysiological effects of a single bout of aerobic exercise. Forty active and 40 inactive college students were randomly assigned to an aerobic exercise or a waiting-period control condition. Self-report measures of mood and cardiovascular response measures to challenging cognitive tasks were collected before and after the 20-min exercise/control period to examine any exercise-induced changes. The results indicated that mood was significantly altered by the exercise activity, with reductions in tension and anxiety specifically evident. Exercise was not found to have any effects on cardiovascular reactivity. A test of aerobic fitness confirmed fitness differences between active and inactive participants, but no mood or reactivity effects related to activity status were obtained. These results suggest that both active and inactive individuals experience acute reductions in anxiety following single bouts of exercise, even in the absence of changes in cardiovascular reactivity. Implications for the continued investigation of the acute effects of exercise are discussed.

Event-related brain potentials reflecting processing of relevant and irrelevant stimuli during selective listening.

Abstract: Event-related brain potentials were recorded from the human scalp during selective listening to tone pips differing in location and/or pitch from irrelevant tones. The subjects' task was to discriminate infrequent deviant tones of lower intensity appearing among designated (relevant) tones. A large processing negativity was observed in the event-related potentials to relevant tones differing from the irrelevant tones in location even when both tones randomly varied in pitch. Similarly, a large processing negativity was elicited by the relevant tones differing from the irrelevant tones in pitch even when the location of both tones varied randomly. The results support the theory that the processing negativity to relevant stimuli reflects a match of these stimuli with an "attentional trace," an actively maintained neuronal representation of the physical feature(s) of relevant stimuli that distinguish these stimuli from the irrelevant stimuli. Furthermore, the infrequent lower-intensity tones appearing among irrelevant tones elicited a mismatch negativity similar to the mismatch negativity elicited by target tones, equivalent lower-intensity tones appearing among relevant tones. This indicates that these infrequent stimulus changes were automatically discriminated by the generator mechanism associated with mismatch negativity.

The contingent negative variation in psychopaths.

Abstract: There have been persistent claims that the contingent negative variation (CNV) is absent or greatly attenuated in psychopaths. However, these claims are based on a few studies with serious methodological and diagnostic problems. The present study attempted to avoid these problems. The subjects were male prison inmates divided into psychopaths and nonpsychopaths on the basis of scores on the Psychopathy Checklist. CNV was recorded while the subject performed a forewarned reaction time task with a relatively long interval (6 s) between the warning stimulus and the imperative stimulus. Motivation to perform well was ensured by having reaction times to the imperative stimulus determine how much money would be won or lost on a given trial. The early CNV of psychopaths was significantly larger than was that of the nonpsychopaths. There were no group differences in the late CNV or in reaction time. To the extent that the early CNV reflects processing of the warning stimulus and attention to task demands, the results are consistent with the hypothesis that psychopaths are proficient at focusing attention on events that interest them.

Event‐Related Potentials During Memory Search and Selective Attention to Letter Size and Conjunctions of Letter Size and Color

Abstract: The analysis of event-related potentials was used in two experiments to investigate the structure of information processing in a task in which subjects selectively attended to letter size (Experiment 1) or a conjunction of letter size and color (Experiment 2) and searched for target letters within the attended stimulus category. The event-related potentials showed that selective attention to letter size resulted in the enhancement of a central N2b component (onset about 200 ms), which was assumed to reflect feature nonspecific orienting of attention. When attention was directed to conjunctions of letter size and color an earlier effect was found (onset about 150 ms) consisting of positivity at the anterior electrodes and negativity at Oz. This earlier effect was assumed to reflect feature-specific selective processing. Although the early effect showed a hierarchical pattern of results, in which the effect of attending to size was contingent on the relevance of the color attribute, the N2b showed a more independent pattern of results, in which the relevance of either the color or the size attribute resulted in an enhancement of this component, independent of the relevance of the other attribute. An increase in the duration of the memory search process resulted in a prolonged negativity with an onset of about 200 ms which was maximal at Cz. In both experiments the initial phase of this negativity was also found in the event-related potentials to the unattended stimulus categories, suggesting that the search process was initiated nonselectively and terminated after the selection cues were identified. Detection of attended target letters resulted in a parietal P3b component. In both experiments there was an earlier effect discriminating targets and nontargets in the range 200–300 ms.

The relationship between the type A behavior pattern and physiological responsivity: a quantitative review.

Abstract: Researchers have attempted to specify the process linking Type A behavior to coronary artery disease. Increased cardiovascular and neuroendocrine reactivity in Type A individuals has been proposed as the intervening mechanism. There have been several previous reviews of the research relating Type A behavior to physiological reactivity. The authors' conclusions have been equivocal; some assert that Type A persons are more reactive, whereas others find no evidence for such a conclusion. In this report, meta-analysis, an alternative to the traditional narrative review, was employed to provide a quantitative evaluation of the relationship between Type A behavior and physiological reactivity. Results indicated that: 1) Type As respond to cognitive and psychomotor stimulus situations with greater heart rate and systolic blood pressure responses, 2) this relationship is not evident in females, 3) the relationship is more evident for some cognitive tasks than for others, and 4) the strength of the relationship depends upon the instrument used to assess Type A behavior.

Event-Related Potentials, Spatial Orienting, and Reading Disabilities

Abstract: Event-related potentials (ERPs) were used to investigate the effects of visual-spatial orienting on selective neural processing in boys with learning disabilities. Twenty-seven 8-12 year old boys were classified into four groups depending on whether or not they had a reading disability or attention deficit disorder. Event-related potentials were recorded over the left and right occipital, central, and frontal cortical regions. The behavioral task required the subjects 1) to rapidly switch their attention from the center to the periphery of the visual field (spatial component), and 2) to selectively respond to a target versus a nontarget flash when the target was presented in the relevant visual field (nonspatial component). The amplitude of two ERP components was enhanced in response to relevant as compared to irrelevant stimuli. The enhancement of an early negative occipital-central component, which peaked 180-200 ms following targets (N1), indicated that selective neural processing associated with spatial attention could be switched in 600 ms. This enhancement of N1 was greater in boys with than without a reading disability, which implies that reading disability is associated with enhanced spatial attention. The enhancement of a later positive component, which peaked 300-340 ms following targets (P3), suggested that nonspatial target selection was reduced in boys with a reading disability, particularly over the left occipital hemisphere. Target relevance and reading disability also influenced trial-to-trial variability in the ERP waveform. The effects of reading disability on event-related potentials did not vary as a function of attention deficit disorder, indicating that these two disorders are distinct.

Effects of motivation and verbal-response type on psychophysiological detection of information.

Abstract: Two independent experiments were designed to investigate the effects of motivation to deceive and the type of verbal response on psychophysiological detection using the Guilty Knowledge Technique. The first was a field experiment in which 72 subjects were randomly assigned to 8 experimental conditions. These conditions were created by a 2 x 4 factorial design (two motivational states crossed with four verbal response modes--affirming, denying, repeating, or no verbal response to questions about personal information). The second experiment was a laboratory experiment in which 160 students were assigned to the same 8 conditions. Results of both experiments indicated that highly motivated subjects were detected better than less motivated subjects. The act of lying was associated with enhanced differential responsivity, but no effects were obtained for verbal response versus no response or for variable versus standard verbal response. Differential responsivity tended to decline when questions were repeated. The first experiment revealed a clear advantage of electrodermal measures over respiration and cardiovascular measures. The results were discussed in relation to previous findings, a new theoretical formulation, and practical implications.

Race, parental history of hypertension, and patterns of cardiovascular reactivity in women.

Abstract: This study examined the interaction of race and parental history of hypertension on patterns of cardiovascular responses among women. Two stressors were used that produce different patterns of cardiovascular reactivity: mental arithmetic, primarily a beta-adrenergic stimulus, and the cold face stimulus, which evokes alpha-adrenergic (i.e. vascular) activity. Systolic and diastolic blood pressure, heart rate, forearm blood flow, and forearm vascular resistance were assessed before, during, and after arithmetic and cold face stimulus. Both tasks produced the expected patterns of cardiovascular adjustment, although no Black-White differences occurred during arithmetic. However, Black subjects did show a slower recovery of diastolic blood pressure following arithmetic. The cold face stimulus produced significantly greater changes in systolic blood pressure in the Black than in the White women. Parental history of hypertension did not relate significantly to reactivity. The results provide limited support for the idea that Black females exhibit a greater pressor response than White females to a stimulus that produces primarily vascular rather than cardiac changes. These findings are discussed in relation to previous findings with males and with respect to their implications for the role of reactivity in Black-White differences in hypertension prevalence.

Development and Stability in Visual Sustained Attention in 14, 20, and 26 Week Old Infants

Abstract: Infants were studied at 14, 20, and 26 weeks of age in a longitudinal design. They were presented with varying and complex patterns on a TV screen. Two-thirds of the presentations were accompanied by a stimulus in the periphery delayed in time from the onset of fixation on the central stimulus. As in previous research, the infants were not as easily distracted by the interrupting stimulus when the presentation occurred at the point of maximal heart rate deceleration as when the presentation occurred at the end of the heart rate response. Infants with large amounts of respiratory sinus arrhythmia (i.e., heart rate variability) in a baseline recording were less distractible during the deceleration-defined trials than were infants with low amounts of respiratory sinus arrhythmia. Intra-individual patterns of development in respiratory sinus arrhythmia over the testing ages were closely paralleled by patterns of heart rate responding during sustained attention. Individual differences in baseline levels of heart rate and respiratory sinus arrhythmia were more stable than individual differences in sustained attention. The stability of attention responses over age may be mediated by the stability of the physiological system (e.g., heart rate, respiratory sinus arrhythmia, etc.), and by the within-age relation of attention to heart rate variability.

Aerobic fitness and the cardiovascular response to stress.

Abstract: The observation that aerobically fit persons react to physical load with a smaller sympathetic response than do less fit subjects suggests that their response to psychological stress might also be reduced. The evidence for this, however, is far from consistent. It was argued that this inconsistency might be due to the incomplete measurement of the response system involved. In the present experiment two groups, which differed strongly in maximal aerobic power, were compared with respect to their cardiovascular response to a laboratory stressor. In addition to the traditional heart rate and blood pressure measurements, pre-ejection period, cardiac output, and peripheral resistance were assessed. Since only the part of the stress response that is not accounted for by metabolic needs might have pathological significance, the so-called "additional" responses were also measured. Fitness was shown to be associated with smaller sympathetic effects on both heart and vessels. The decrement in pre-ejection period and the heart rate response were smaller in the high fit group. The total peripheral resistance and diastolic blood pressure responses pointed to a much stronger vascular reactivity in the low fit group. Unexpectedly cardiac output did not increase during stress. The strong heart rate response in the low fit group was compensated by a reduction in stroke volume, which probably originated in an increased peripheral resistance. The largest discrepancy between the effects of sympathetic activation during stress and exercise occurred in the vessels, as demonstrated by the large "additional" response in total peripheral resistance during stress. The data point to the often neglected role of vascular processes in experiments of this kind. Furthermore, it seems necessary to take the effect of fitness into account when comparing subjects with respect to their cardiovascular stress response.

Human brainstem auditory evoked potentials fail to provide evidence of efferent modulation of auditory input during attentional tasks.

Abstract: Efferent modulation of auditory input at the level of the brainstem during attention-demanding tasks has been described in animal studies. Attempts to demonstrate these effects in humans have produced conflicting results, however. These studies are reviewed with particular reference to those animal experiments that have demonstrated peripheral effects. The human experiments have used a number of attentional conditions which have not been related either to each other or to the successful animal work. Two of the most important conditions in these studies–the use of an intermodal attention task and the manipulation of attentional states–have been examined rarely or not at all in the human research. Two experiments were conducted to investigate the possibility of attention-related effects on the human brainstem auditory evoked potential. These experiments were designed to examine experimental conditions common to both successful and unsuccessful attempts to demonstrate attention-driven efferent modulation at the periphery in humans. Also examined was the gradation of attention effects on efferent modulation demonstrated in animals but never studied in humans. No significant changes in either the latency or the amplitude of the brainstem auditory evoked potential were found in any of the attention-demanding conditions. Results are discussed in terms of psychophysiological theories of attention. Also, the interpretation of the most recent animal work is questioned.

Does the heart know what the eye sees? A cardiac/pupillometric analysis of motor preparation and response execution.

Abstract: Autonomic response measures are well suited for the study of preparation because they allow the analysis of covert aspects of performance This is illustrated by an experiment in which task-evoked cardiac and pupillary responses were compared during a disjunctive (Go/No Go) reaction task The motoric demands of the task were varied by manipulating foreperiod length (4 and 8 s) and probability of response (25%, 50%, and 75%) Reaction time increased with foreperiod length and decreased with probability of response The depth of anticipatory heart rate deceleration was affected only by foreperiod length Analysis of the beats during, and directly preceding and following the imperative stimulus revealed that interbeat intervals increased with probability of responding and foreperiod duration The effect of stimulus timing relative to the R-wave of the ECG was also analyzed Early occurring stimuli prolonged the cycle of their occurrence more than late occurring stimuli The cycle time effect was somewhat more pronounced for No Go stimuli than for Go stimuli The subsequent cycle was shorter for early occurring stimuli compared to late stimuli This effect was stronger for Go compared to No Go trials Both Go and No Go reactions elicited significant pupil dilations The No Go dilation peaked earlier than the Go dilation and its amplitude was smaller Probability of responding affected the latency of the No Go dilation but not that of the Go dilation The current results justify an interpretation of preparation in terms of a timing mechanism (indexed by heart rate deceleration during the foreperiod) and a mechanism allocating processing resources to stimulus encoding (indexed by cardiac slowing just prior to stimulus occurrence) and response preparation (indexed by continued cardiac deceleration and pupillary dilation)

Self-Report During Feedback Regulation of Slow Cortical Potentials

Abstract: Subjects received exteroceptive feedback for bidirectional changes in slow cortical potentials or alpha power measured from the vertex. The slow potential group succeeded in shifting slow potentials toward negativity and positivity on feedback and transfer trials requiring these changes, after two sessions of training. Differentiation of negativity and positivity was accompanied by verbal reports of somatomotor activation that occurred on trials on which negative slow potentials were required (p < .01). Vertical and lateral eye movements, chin and frontalis electromyogram, and heart rate did not differentiate between negativity and positivity trials in the slow potential group. However, heart rate acceleration correlated between-subjects with slow potential negativity during feedback. Although the alpha power group did not succeed at controlling changes in alpha, evidence of a training effect appeared in verbal reports of emotional arousal (p< .05) and focused vision (p< .08) on alpha suppression trials in this group. We discuss the findings from the viewpoint that biofeedback tasks involving electrocortical responses are problems in the organization of action that subjects seek to solve.

Stimulus Miscuing, Electrodermal Activity, and the Allocation of Processing Resources

Abstract: The present research investigated the effects of stimulus miscuing on electrodermal responding, dishabituation, stimulus expectancy, and the allocation of processing resources as assessed by reaction time to a secondary task probe stimulus. In both experiments, a control group received 33 S1-S2 pairings intermixed with 33 S3-alone presentations. For the experimental group, S2 was miscued by its presentation following S3 on 4 trials. Experiment 1 (N = 24) demonstrated reliable electrodermal responding when S2 was miscued by S3 and subsequent dishabituation when S2 was re-presented following S1 on the next trial. A continuous measure of S2 expectancy revealed that S2 was not expected to follow S3 on miscuing trials. On re-presentation trials, S2 was not expected to follow S1. Experiment 2 (N = 24) employed probe reaction time as the dependent variable. White noise probe stimuli of 500-ms duration were presented 300 ms following the onset of S2 on miscued trials and on re-presentation trials. Reaction time to probes presented during miscued presentations of S2 was slower in the experimental group than in the control group. Reaction time on S2 re-presentation trials was also slower in the experimental group than in the control group. The results are interpreted to indicate that both the miscuing of S2 by S3 and its re-presentation following S1 on the next trial command processing resources. The results are discussed in terms of current theories of associative learning.