Age-related structural and functional changes in the cardiovascular, sympathoadrenomedullary (SAM), and hypothalamic-pituitary-adrenocortical (HPA) systems may affect the ability to reliably identify individual differences in response to stress. Heart rate, preejection period, respiratory sinus arrhythmia, respiratory rate, norepinephrine, epinephrine, adrenocorticotropic hormone, and cortisol were assessed in 64 healthy older women (mean = 67 years) in response to a mental arithmetic and public-speaking task. All cardiovascular and endocrine measures changed significantly during the tasks. All measures were consistent across the two tasks (rss = .50 to .97). Moreover, a majority of women in this sample exhibited cross-task consistency in the relative activation of the autonomic, SAM, and HPA systems (i.e., response profiles). Further research is recommended to examine the significance of consistent individual differences in response profile.

Stimulus-preceding negativity (SPN) was recorded to investigate the effect of positive and negative emotion on the SPN preceding feedback stimuli. In the time-estimation task in which an acoustic stimulus was presented 3 s after a voluntary movement, (1) the negative valence (aversive band noise and pure tone) and (2) the positive valence (reward and no-reward) of feedback stimuli were manipulated. During noise conditions, participants received the band noise as a feedback stimulus except when their time estimations were accurate. They received a monetary reward for accurate time estimations under the reward conditions. The prefeedback SPN was larger under reward than no-reward conditions. In addition, the prefeedback SPN in the noise condition was larger compared with the pure tone condition. Our results appear to suggest that emotional anticipation is important in eliciting the prefeedback SPN.

Hemodynamic responses to an anger interview and cognitive and physical stressors were compared, and the stability of associated hemodynamic reactions examined. Participants experienced control, handgrip, counting, and mental arithmetic tests and an anger interview on two occasions. Systolic and diastolic blood pressure, heart rate, stroke volume, and cardiac output were measured. Total peripheral resistance was also derived. The anger interview produced larger, more sustained changes in blood pressure in both sessions than the other stressors. These changes were largely a consequence of increased peripheral resistance. Consistent with previous findings, handgrip was associated with a resistance-type reaction whereas arithmetic was associated with a cardiac output-type reaction. There was low-to-modest stability of hemodynamic reactions to the interview. Further research is necessary to optimize its utility in studies of cardiovascular function. Nevertheless, the findings underscore the ability of ecologically relevant stressors to provoke unique configurations of cardiovascular activity.

Evidence from both hypertensive and normotensive individuals indicate that elevated blood pressure is associated with decreased pain sensitivity. The current study sought to experimentally raise blood pressure using 250 mg caffeine, and investigate its effects on the cold pressor pain experiences of 25 men and 25 women. In a placebo-controlled repeated-measures experiment, caffeine increased systolic and diastolic blood pressure, as well as producing more clearheaded and energetic feelings. Caffeine produced higher pain threshold and pain tolerance levels compared to placebo, and women had a lower tolerance to pain than men. Finally, a significant association was found between caffeine-related increase in systolic blood pressure and caffeine-related increase in pain tolerance. Furthermore, this association was the strongest in women. These results are discussed in light of future directions for pain and hypertension research.

This study examined the effects of visual selective attention and stimulus discriminability on phasic heart rate changes. Grating stimuli consisting of four vertical bars were presented left or right from fixation. Participants attended to one side of the screen and responded with a button press to attended target stimuli that were defined by shorter middle bars. Stimulus discriminability was manipulated by increasing the length of the middle bars of targets. To examine the time course of response inhibition, participants had to respond to auditory probe stimuli that were presented occasionally and unpredictably at varying intervals following the visual stimulus. Responses to targets and probes following attended nontargets were slower in the difficult condition. Heart rate slowed in anticipation of a target and accelerated back to baseline afterwards. Phase-dependent cardiac slowing was larger for attended nontargets compared to unattended nontargets and was more pronounced in the difficult condition. These findings were interpreted vis-à-vis inhibition accounts of phase-dependent cardiac slowing.

Previous research has shown that warning signals can speed the onset of the startle-blink reflex. To relate this phenomenon to warning effects on voluntary reaction time (RT), the latencies of both reflexive and voluntary responses were measured for nine factorial combinations of warning and reflexogenic stimulus modalities. Previous failures to use factorial manipulations of warning (S1) and reaction (S2) stimulus modalities have led to conflicting results in both the reflex and RT literatures. Using psychophysically matched warning signals, we found a facilitation of reflex latency that was nonspecific with regard to S1 and S2 modality. Furthermore, there was no support for the widely held assumption that visual stimuli are inherently less alerting than auditory and cutaneous stimuli. A between-group comparison showed that simultaneous voluntary reactions do not distort the reflex facilitation effect. These results support the validity of reflex facilitation as a simple model system for studying warning effects on sensorimotor reactions.

Brain activity was monitored while 36 participants produced facial configurations denoting anger, disgust, fear, joy, and sadness. EEG alpha power was analyzed during each facial pose, with facial conditions grouped according to the approach/withdrawal motivational model of emotion. This model suggests that “approach” emotions are associated with relatively greater left frontal brain activity whereas “withdrawal” emotions are associated with relatively greater right frontal brain activity. In the context of a bilateral decrease in activation, facial poses of emotions in the withdrawal condition resulted in relatively less left frontal activation in the lateral-frontal, midfrontal and frontal-temporal-central region, but not in the parietal region, as predicted. Findings in the approach condition were less consistently supportive of predictions of the approach/withdrawal model. Implications for the approach/withdrawal model and for the emotion eliciting potential of voluntary facial movement are discussed.

Two experiments investigated the neural mechanisms of Gestalt grouping by recording high-density event-related brain potentials (ERPs) during discrimination tasks. In Experiment 1, stimulus arrays contained luminance-defined local elements that were either evenly spaced or grouped into columns or rows based on either proximity or similarity of shape. Proximity grouping was indexed by a short-latency positivity (110–120 ms) over the medial occipital cortex and a subsequent right occipitoparietal negativity. Grouping by similarity was reflected only in a long-latency occipitotemporal negativity. In Experiment 2, proximity grouping was examined when local elements were defined by motion cues, and was again associated with a medial occipital positivity. However, the subsequent long-latency negativity was now enhanced over the left posterior areas. The implications of these results to the neural substrates subserving different grouping processes are discussed.

Previous studies on aversive learning have suggested a right hemispheric advantage for eliciting autonomic reactions to a masked conditioned facial stimulus (CS) depicting anger. The present study investigated the effects of visual field (VF), stimulus awareness, and emotional valence of the CSs on indicators of conditioning (bilateral SCRs, HR) using a differential conditioning paradigm (N = 41). In Group 1, four different negatively valenced facial expressions (CS+) but not four positively valenced CS− were associated with an unconditioned stimulus (US, aversive vocalization, 97 dB, 3 s) during acquisition. Group 2 received a treatment reversal with positive CS+ associated with the US. In a repeated measures design, CSs were presented with or without awareness during extinction (two weeks interval, order counterbalanced). SOAs were adapted for each subject and condition prior to the experiment so that identification performance was approaching chance level. The results revealed that both negative and positive facial expressions could be aversively conditioned providing evidence for a generalization of learning in the valence dimension. During extinction, preattentive negative CS+ presented to the left VF showed a trend towards greater electrodermal and cardiac reactions. However, no such effect emerged under full awareness of the CSs. These results confirm and further specify the nature of hemispheric asymmetries in emotional associative learning.

Latent growth curve methodology was used to model systolic blood pressure reactivity and recovery from the cold pressor test. A piecewise regression approach permitted the separate but simultaneous modeling of the two components (reactivity and recovery) of the stress process. Data came from a study of 99 participants classified on the basis of gender, ethnicity, and family history of hypertension. Their systolic blood pressure was assessed at rest, during the cold pressor test, and during a task recovery period. A measure of task appraisal and readings from ambulatory blood pressure monitoring during a workday were also examined. The article illustrates a step-by-step approach to modeling reactivity and recovery. Results indicated that both reactivity and recovery were associated with subsequent systolic blood pressure at work.

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.

This study examined whether 7–9-year-old children preattentively build memories of constancy for individual stimulus features, and if these representations are affected by variability of other stimulus features. This was achieved by looking at the mismatch negativity (MMN) event-related potential to a duration deviant occurring in a stimulus environment in which one or two other features constantly changed. Performance data were also collected, to look at the correspondence between the effects of this manipulation on preattentive and intentional deviance detection. MMN data indicated that the children built a preattentive feature-based memory of constancy that was not affected by the number of varying features. In contrast, intentional deviance detection was considerably impaired by the introduction of feature variability. This dissociation is at variance with previous studies that usually report close association between MMN and behavior.

The present study assessed alertness, memory, and performance following three schedules of ∼8 hr of sleep loss (slow, intermediate, and rapid accumulation) in comparison to an 8-hr time in bed (TIB) sleep schedule. Twelve healthy individuals aged 21–35 completed each of four conditions according to a Latin Square design: no sleep loss (8-hr TIB for 4 nights; 2300–0700), slow (6-hr TIB for 4 nights; 0100–0700), intermediate (4-hr TIB for 2 nights; 0300–0700), and rapid (0-hr TIB for 1 night) sleep loss. On each day, participants completed a multiple sleep latency test (MSLT), a probed-recall memory task, a psychomotor vigilance task, a divided attention task, and the Profile of Mood States. “Rapid” sleep loss produced significantly more impairment on tests of alertness, memory, and performance compared to the “slow” accumulation of a comparable amount of sleep loss. The impairing effects of sleep loss vary as a function of rate, suggesting the presence of a compensatory adaptive mechanism operating in conjunction with the accumulation of a sleep debt.

Two studies examined the effects of breast-feeding on maternal cardiovascular function. In the first experiment, groups of breast-feeding and bottle-feeding women were compared on preejection period (PEP), heart rate (HR), cardiac output (CO), and total peripheral resistance (TPR) recorded for 1-min periods before and during standard laboratory stressors. Compared with bottle-feeders, breast-feeders had higher CO throughout the session, and greater decreases in CO and increases in TPR during cold pressor. In the second experiment, HR and blood pressure (BP) were compared before and after one breast-feeding and one bottle-feeding session in a within-subjects design. Both feeding methods increased BP but decreased HR, and systolic BP was higher for the breast-feeding than the bottle-feeding condition. Both studies support the notion that breast-feeding alters maternal cardiovascular function, possibly through the actions of oxytocin.

The n-back task was hypothesized to be a dual task, permitting the imposition of parametrically increasing attentional and working memory demands, while keeping constant the demands of an embedded matching subtask. Visual targets were presented for 200 ms every 2.2 s at pseudorandomly varying positions on a computer screen. Participants were required to remember the most recent 0, 1, 2, or 3 positions and responded with a choice button push to whether the current target position matched the position presented n items previously. P300 peak latency was constant across n-back tasks, reflecting constant perceptual and cognitive demands of the matching subtask. P300 peak amplitude decreased with increasing memory load, reflecting reallocation of attention and processing capacity away from the matching subtask to working memory activity. These data support a dual-task nature of the n-back, which should be considered when employing this paradigm.