Respiratory responses associated with affective processing of film stimuli

We investigated respiratory responses during film clip viewing and their relation to the affective dimensions of valence and arousal. Seventy-six subjects participated in a study using a between groups design. To begin with, all participants viewed an emotionally neutral film clip. Then, they were presented with one out of four emotional film clips: a positive high-arousal, a positive low-arousal, a negative high-arousal and a negative low-arousal clip. Respiration, skin conductance level, heart rate, corrugator activity and affective judgments were measured. Expiratory time was shorter and inspiratory duty cycle, mean expiratory flow and minute ventilation were larger during the high-arousal clips compared to the low-arousal clips. The pleasantness of the stimuli had no influence on any respiratory measure. These findings confirm the importance of arousal in respiratory responding but also evidence differences in comparison to previous studies using visual and auditory stimuli.     

Parallel processing of affective visual stimuli

Event-related potential (ERP) studies of affective picture processing have demonstrated an early posterior negativity (EPN) for emotionally arousing pictures that are embedded in a rapid visual stream. The present study examined the selective processing of emotional pictures while systematically varying picture presentation rates between 1 and 16 Hz. Previous results with presentation rates up to 5 Hz were replicated in that emotional compared to neutral pictures were associated with a greater EPN. Discrimination among emotional and neutral contents was maintained up to 12 Hz. To explore the notion of parallel processing, convolution analysis was used: EPNs generated by linear superposition of slow rate ERPs explained 70%–93% of the variance of measured EPNs, giving evidence for an impressive capacity of parallel affective discrimination in rapid serial picture presentation.     

Expectation enhances event-related responses to affective stimuli

Extensive practice is associated with a higher level of learning than practice until performance stabilization. This is partially attributable to the changes in the variability of the structure that control the motor skill that occur during practice. However, because both conditions result in performance stabilization, the error in the task performance does not decrease further, and it is necessary to introduce higher demands (e.g., unpredictable perturbations) into the task for differences between the two conditions to arise. This study aimed to investigate whether extensive practice contributes to adaptation to unpredictable perturbations in a sequential motor skill task as compared to practice until performance stabilization. Thirty-four self-reported right handed young adults performed a sequential coincident timing task and were assigned to two groups during the first phase of experiment: the stabilization group (SG) or the extensive practice group (EG), which differs with respect to the quantity of practice. In the second phase, both groups performed under equal conditions and the subjects practiced the same task performed in the first phase, but unpredictable changes in the velocity of the visual stimulus were occasionally introduced. The results suggest that extensive practice improves adaptation to unpredictable perturbations better than practice until performance stabilization and indicates that the motor learning process continues after performance stabilization.     

Expectation enhances event-related responses to affective stimuli

How the expectation of forthcoming emotional events influences individuals’ behaviors and brain responses to such events remains controversial. The present study addressed this issue using event-related potentials (ERPs) to overcome limitations in research techniques. In addition, a no cue condition was adopted as the unexpected condition to make the research paradigm closer to real life situations for ecological validity. Behavioral results showed that positive stimuli were experienced more pleasantly and negative ones were experienced more unpleasantly during the expected condition than the unexpected one. ERPs results also displayed larger P2, N2 and LPP amplitudes in the expected condition, regardless of stimulus valence. The finding that expected emotional events evoke enhanced behavioral and brain responses than the unexpected ones do provides a strong piece of evidence for the effect of expectation on emotion processing.     

Autonomic, neuroendocrine, and subjective responses to emotion-inducing film stimuli.

The aim of the present study was to investigate differential emotional response patterns to film stimuli by multimodal assessment of subjective, autonomic and endocrine variables. Scenes of two films, chosen to induce different affective states, were presented to 20 male subjects. Changes in mood and perceived bodily sensations, autonomic activity (heart rate and skin conductance) and one endocrine parameter (salivary cortisol) were measured. Analyses revealed that the films elicited differential mood patterns. The cartoon film, which induced a pleasant, amused state, was accompanied by very few changes in bodily sensations, a temporary decrease in heart rate, and a rapid decrease in electrodermal activity. The suspense film, which elicited a marked reduction in joyfulness and relaxation together with an enhancement in irritation, differed from that pattern primarily by marked changes in several bodily sensations, an increase in electrodermal activity, and a temporary decrease in heart rate. There were no film-dependent cortisol changes. The results together with evidence from other emotion induction experiments support the usefulness of film segments in eliciting mild to moderate affective states and their concomitances. They particularly point to the relevance of bodily sensations as an emotional response component.     

Cerebral processing of nonverbal affective stimuli: differential effects of cognitive and affective sets on hemispheric asymmetry

The cerebral processing of emotion has been the subject of a number of recent studies, but results relating to hemispheric asymmetry have been quite mixed. The present study attempted to clarify and extend findings in this area by examining the differential effects of cognitive and affective sets on hemisphere asymmetry under conditions of nonverbal emotional stimulation. Electroencephalographic (EEG) data, recorded bilaterally, showed that differential hemispheric processing interacted with emotion (positive or negative), condition (cognitive or affective), and sex. In those emotion/condition combinations where hemispheric asymmetry was observed, there was greater activity in the left hemisphere than in the right. In addition, positive affect produced greater asymmetry than negative, and females showed greater activity in response to positive emotional stimuli than did males. Further, affective conditions yielded higher levels of activity than did cognitive. Finally, electrodermal activity showed lateralization effects as a differential function of cognitive and affective conditions.     

Early life stress and psychiatric disorder modulate cortical responses to affective stimuli

Altered affective processing has been proposed as mediating between early life stress (ELS) and subsequent psychopathology. The present study examined whether ELS influences affective cortical processing differently in psychiatric patients and healthy subjects. The number of stressful experiences before onset of puberty was assessed in 50 inpatients with diagnoses of Major Depressive Disorder, schizophrenia, drug addiction, or Borderline Personality Disorder and in 20 healthy comparison subjects. Subjects monitored pleasant, neutral, and unpleasant pictures during magnetoencephalographic recording. Suppression of right-posterior activity 160–210 ms after stimulus onset was associated with certain diagnoses and high ELS. Results confirmed specific contributions of ELS versus adult stress, comorbid posttraumatic stress disorder, or depression.     

Alcoholism and judgments of affective stimuli

This study sought to differentiate alcoholism-related changes in judgments of emotional stimuli from those of other populations in which such changes have been documented. Two sets of visual stimuli, one containing words and the other containing drawings of faces (representing a range of emotional content), were presented to abstinent alcoholic adults with and without Korsakoff's syndrome, as well as to a healthy control group and four groups of patients with other neurobehavioral disorders: Parkinson's disease, schizophrenia, depression, and posttraumatic stress disorder. Participants rated the stimuli according to emotional valence and intensity of emotion. Results implicated bi-hemispheric frontal and subcortical involvement in the abnormalities of emotion identification associated with alcoholism, and they also support the notion of age-related vulnerabilities in conjunction with alcoholism.     

Defensive responses to phobic stimuli.

Physiological recordings were made while nine females who were afraid of spiders (group P) and nine who were not (group N) viewed a random series of spider and neutral slides. Group P's responses to the spider slides included heart rate (HR) acceleration, cephalic vasoconstriction and an increase in palmer skin conductance (SC), a pattern considered to be part of a defensive response (DR). Group N's responses, on the other hand, were indicative of an orienting response (OR), and included HR deceleration, cephalic vasodilation and an increase in palmar SC. The neutral slides elicited little in the way of responses from group N. However, they elicited the cardiovascular and electrodermal components of an OR from group P, presumably because of their contrast with the feared spider slides. Although the DR pattern observed in group P was often accompanied by increased somatic activity, HR acceleration and cephalic vasoconstriction still occurred even when somatic activity did not appear to increase.     

Suppression and enhancement of emotional responses to unpleasant pictures

Despite the prominence of emotional dysfunction in psychopathology, relatively few experiments have explicitly studied emotion regulation in adults. The present study examined one type of emotion regulation: voluntary regulation of short-term emotional responses to unpleasant visual stimuli. In a sample of 48 college students, both eyeblink startle magnitude and corrugator activity were sensitive to experimental manipulation. Instructions to suppress negative emotion led to both smaller startle eyeblinks and decreased corrugator activity. Instructions to enhance negative emotion led to larger startle eyeblinks and increased corrugator activity. Several advantages of this experimental manipulation are discussed, including the use of both a suppress and an enhance emotion condition, independent measurement of initial emotion elicitation and subsequent regulation of that emotion, the use of a completely within-subjects design, and the use of naturalistic emotion regulation strategies.     

Prolonged marital stress is associated with short‐lived responses to positive stimuli

Marital stress is associated with a higher incidence of psychiatric disorders, in particular major depression. One pathway through which marital stress may impact emotional health is by compromising emotion‐responding processes. We examined a longitudinal sample of adults (N = 116; 59 males; 39–84 years) to verify how marital stress predicts reactivity to, and recovery from, emotional provocation. Individuals watched positive, neutral, and negative pictures while an objective measure of affective state, corrugator supercilii muscle activity, was recorded continuously. Our results indicate that marital stress is associated with short‐lived responses to positive pictures, indexed by a less persistent decrease in corrugator activity after picture offset. Extending beyond the prior focus on negative emotional processes, these results suggest that social stress may impact health by influencing the time course of responding to positive events.     

Action-induced blindness with lateralized stimuli and responses

Previous dual-task studies showed that the selection and/or execution of a response interfere with concurrent visual encoding (action-induced blindness). Four experiments examined how the lateralization of stimuli and responses might affect action-induced blindness. Participants responded to tones (S1) by pressing keys with the left or right hand (R1), and simultaneously identified stimuli (S2) presented to the left or right visual field. Results revealed a complex pattern of cross-talk effects between response preparation and visual encoding. Firstly, preparing a response generally impaired concurrent visual encoding. Secondly, action-induced blindness was equally present for ipsilaterally and contralaterally presented stimuli. Thirdly, response preparation facilitated processing of visual stimuli at ipsilateral locations, probably a case of action-centered attention. Finally, the facilitatory effect of R1–S2 correspondence on visual encoding was complemented by a S2–R1 correspondence effect on response execution. Thus, acting while seeing can have both beneficial and detrimental effects on identification performance at the same time.     

Patient-centered interviewing is associated with decreased responses to painful stimuli: An initial fMRI study

Objective

To identify the functional magnetic resonance imaging (fMRI) changes associated with a patient-centered interview (PCI) and a positive provider–patient relationship (PPR).

Methods

Nine female patients participated, five randomly selected to undergo a replicable, evidence-based PCI, the other four receiving standard clinician-centered interviews (CCI). To verify that PCI differed from CCI, we rated the interviews and administered a patient satisfaction with the provider–patient relationship (PPR) questionnaire. Patients were then scanned as they received painful stimulation while viewing pictures of the interviewing doctor and control images (unknown doctor).

Results

Interview ratings and questionnaire results confirmed that PCIs and CCIs were performed as planned and PCIs led to a much more positive PPR. We found significantly reduced pain-related neural activation in the left anterior insula region in the PCI group when the interviewing doctor's picture was shown.

Conclusion

This study identifies an association between a PCI that produced a positive PPR and reduced pain-related neural responses in the anterior insula. This is an initial step in understanding the neural underpinnings of a PCI.

Practice implications

If confirmed, our results indicate one neurobiological underpinning of an effective PCI, providing an additional scientific rationale for its use clinically.     

Brain potentials in affective picture processing: covariation with autonomic arousal and affective report

Emotionally arousing picture stimuli evoked scalp-recorded event-related potentials. A late, slow positive voltage change was observed, which was significantly larger for affective than neutral stimuli. This positive shift began 200-300 ms after picture onset, reached its maximum amplitude approximately 1 s after picture onset, and was sustained for most of a 6-s picture presentation period. The positive increase was not related to local probability of content type, but was accentuated for pictures that prompted increased autonomic responses and reports of greater affective arousal (e.g. erotic or violent content). These results suggest that the late positive wave indicates a selective processing of emotional stimuli, reflecting the activation of motivational systems in the brain.     

Enhanced perceptual responses during visual processing of facial stimuli in young socially anxious individuals

The present study investigated whether social anxiety modulates the processing of facial expressions. Event-related potentials were recorded during an oddball task in young adults reporting high or low levels of social anxiety as evaluated by the Liebowitz Social Anxiety Scale. Repeated pictures of faces with a neutral expression were infrequently replaced by pictures of the same face displaying happiness, anger, fear or disgust. For all participants, response latencies were shorter in detecting faces expressing disgust and happiness as compared to fear or anger. Low social anxiety individuals evoked enhanced P1 in response to angry faces as compared to other stimuli while high socially anxious participants displayed enlarged P1 for all emotional stimuli as compared to neutral ones, and general higher amplitudes as compared to non-anxious individuals. Conversely, the face-specific N170 and the task-related decision P3b were not influenced by social anxiety. These results suggest increased pre-attentive detection of facial cues in socially anxious individuals and are discussed within the framework of recent models of anxiety.     

Neural responses elicited by stimuli associated with masking of low-frequency, monaural tonal signals by noise

The responses of low-frequency, primary-like neurons of the ventral cochlear nucleus were measured as a function of signal-to-noise ratio for gated tonal signals and noise maskers that were varied in bandwidth and duration. For a given signal-to-noise ratio, each of the maskers is known to produce the same amount of masking in psychophysical experiments. The neural discharge rates measured in the present experiment were different, however, for each of the maskers for each signal-to-noise ratio. In contrast, all three maskers produced the same orderly relationship between signal-to-noise ratio and the degree of neural synchrony to the signals. It is concluded that information concerning the presence and relative strength of a low-frequency tonal signal in a background of masking noise is carried by the nervous system as the degree to which responses are synchronized to the phase of the signal.     

Immunological variability associated with experimentally-induced positive and negative affective states.

Functional and phenotypic immunological parameters were examined immediately before, after, and 30 minutes after experimentally-induced short-term positive (happiness) and negative (anxiety, depression) affective states and a neutral state, in five healthy subjects. Results indicated that all affective states induced more immune fluctuations (regardless of the direction) than the neutral state. Furthermore, among the affective states, anxiety induced the most immunological variability and depression the least.     

Face-selective processing and the effect of pleasant and unpleasant emotional expressions on ERP correlates.

Previous studies have revealed that decoding of facial-expressions starts very early in the brain ( approximately 180 ms post-stimulus) and might be processed separately from the basic stage of face perception. In order to explore brain potentials (ERPs) related to decoding of facial-expressions and the effect of emotional valence of the stimulus, we analyzed 18 normal subjects. Faces with five basic emotional expressions (fear, anger, surprise, happiness, sadness) and neutral stimulus were presented in random order. The results demonstrated that an emotional face elicited a negative peak at approximately 230 ms (N230), distributed mainly over the posterior site for each emotion. The electrophysiological activity observed may represent specific cognitive processing underlying the decoding of emotional facial-expressions. Nevertheless, differences in peak amplitude were observed for high-arousal negative expressions compared with positive (happiness) and low-arousal expressions (sadness). N230 amplitude increased in response to anger, fear and surprise, suggesting that subjects' ERP variations are affected by experienced emotional intensity, related to arousal and unpleasant value of the stimulus.     

Sex differentiated responses to intranasal trigeminal stimuli.

The aim of the study was to address sex-related hemispheric differences in trigeminal event-related potentials while controlling for the subjects' olfactory sensitivity. Event-related potentials to lateralized stimulation using the trigeminal stimulant CO(2) were recorded in 28 healthy young subjects (16 women). There was no sex-related difference in olfactory sensitivity. Results indicated a sex-differentiated response to trigeminally induced pain. Women were found to have generally higher amplitudes and shorter latencies of the late positive component than men. Moreover, men and women exhibited different hemispheric activations in that women expressed shorter latencies over the left hemisphere than men. The pronounced sex-related difference of the late positive component suggests a cognitive/emotional impact on the processing of intranasal pain as indicated by others.     

Neural activities for negative priming with affective stimuli: an fMRI study

Cytokines are soluble proteins secreted mainly by immune cells and are key players in the induction and maintenance of pain. Pro-inflammatory cytokines are mostly algesic, while anti-inflammatory cytokines have analgesic properties. After the role of cytokines was shown in diverse animal models of pain, interest arose in the systemic and local regulation of cytokines in human pain states. Most clinical studies give evidence for an imbalance between pro- and anti-inflammatory cytokines in neuropathic and other pain states with pronounced pro-inflammatory cytokine profiles. Anti-cytokine treatment gives encouraging preliminary results and supports the notion of a crucial role of cytokines also in human pain states. Further research is needed for a better understanding of the mechanisms linking altered cytokine profiles to the sensation of pain.