Watching emotional movies: Affective reactions and gender differences

Previous studies have found that unpleasant film clips depicting mutilated bodies or injuries evoke a sustained heart rate deceleration which has been interpreted as reflecting a stimulus-specific aversive response or as increased orienting and attentional processing that varies with stimulus significance. Few studies, however, have examined cardiac changes during the viewing of high arousal pleasant films. To clarify this issue, the present study assessed evaluative, facial and autonomic reactions in both men and women during the viewing of highly arousing pleasant, as well as unpleasant, films. Results indicated a similar skin conductance increase and heart rate deceleration which were greater than those observed during the viewing of a neutral film. Compared to men, women rated both films as less pleasant and rated the unpleasant film as more arousing. The present findings suggest that sustained exposure to pleasant and unpleasant stimuli elicit similar cardiac orienting when stimuli are equated for subjective report of emotional arousal.     

Loss of emotional experience after traumatic brain injury: findings with the startle probe procedure

The authors used affective modulation of the eyeblink startle response to examine the impact of traumatic brain injury (TBI) on emotional reactions to pictures. Participants were 13 individuals with severe TBI and 24 controls. Participants were presented with pictures that differed in affective valence (e.g., mutilated bodies, erotic couples, and household objects) while the eyeblink startle response to an acoustic probe was measured. Startle amplitude was used to assess valence of emotional response, and startle latency was used to index interest in the pictures. Subjective ratings of the affect and arousal elicited by the various pictures were also obtained. TBI impaired startle potentiation to unpleasant pictures but not startle attenuation to pleasant pictures. Further, subjective ratings indicated that TBI participants found unpleasant pictures less arousing than did controls. The results are consistent with recent evidence of differential impairment in negative versus positive emotions after TBI and are discussed in relation to 2 competing explanations of startle modulation.     

Autonomic and neural correlates of dysregulated arousal in severe traumatic brain injury

Severe traumatic brain injury (TBI) in adults is associated with abnormalities in arousal and emotional responsivity, which are observed physiologically, behaviourally and via self-report measures. While an accurate measure of physiological arousal is debated, ,  and  have consistently shown an inverse relationship between skin conductance level (SCL), and mean alpha power (alpha) during an eyes-closed resting condition (EC), accompanied by an increase in SCL and corresponding decrease in alpha during eyes-open (EO). Thus, alpha may provide a novel index of autonomic arousal. This study aimed to elucidate the neural and autonomic correlates of arousal disturbances in TBI.     

Emotional reactivity of the airways in asthma: Consistency across emotion-induction techniques and emotional qualities

Considerable individual differences exist in asthma patients’ airway responses to emotional stimuli, but little is known about the generalization of such responses across situations or states of airways constriction. Fifty-four asthma patients and 25 healthy controls viewed in two separate sessions, films and blocks of pictures from each of three emotional qualities, pleasant, unpleasant, and neutral. At the beginning of each session, patients received a placebo or anti-cholinergic bronchodilator (ipratropium bromide), respectively, in a randomized double-blind design. Respiratory resistance, reactance and impedance were recorded throughout stimulus presentations with impulse oscillometry. Resistance increases showed a moderate degree of generalization across unpleasant films and pictures, unpleasant and pleasant pictures, as well as cholinergic blockade and placebo. Thus, the intensity of airway responses to unpleasant emotional stimuli is a moderately stable characteristic of asthma patients. In addition to the central airway, peripheral and extrathoracic airways may also contribute the consistency of such responses.     

Arousal and valence effects on event-related P3a and P3b during emotional categorization

Due to the adaptive value of emotional situations, categorizing along the valence dimension may be supported by critical brain functions. The present study examined emotion–cognition relationships by focusing on the influence of an emotional categorization task on the cognitive processing induced by an oddball-like paradigm. Event-related potentials (ERPs) were recorded from subjects explicitly asked to categorize along the valence dimension (unpleasant, neutral or pleasant) deviant target pictures embedded in a train of standard stimuli. Late positivities evoked in response to the target pictures were decomposed into a P3a and a P3b and topographical differences were observed according to the valence content of the stimuli. P3a showed enhanced amplitudes at posterior sites in response to unpleasant pictures as compared to both neutral and pleasant pictures. This effect is interpreted as a negativity bias related to attentional processing. The P3b component was sensitive to the arousal value of the stimulation, with higher amplitudes at several posterior sites for both types of emotional pictures. Moreover, unpleasant pictures evoked smaller amplitudes than pleasant ones at fronto-central sites. Thus, the context updating process may be differentially modulated by the affective arousal and valence of the stimulus. The present study supports the assumption that, during an emotional categorization, the emotional content of the stimulus may modulate the reorientation of attention and the subsequent updating process in a specific way.     

Probe P3 and blinks: Two measures of affective startle modulation

Two concurrent measures of the evoked startlé response, the elicited blink reflex and the event-related potential, were measured while individuals viewed pictures that varied in pleasure and arousal. Replicating previous findings, the blink response was modulated by picture pleasantness, with larger reflexes elicited in the context of viewing unpleasant versus pleasant pictures. However, the probe P3 was primarily modulated by picture arousal, with smaller P3 responses elicited when viewing affective (pleasant or unpleasant) than when viewing neutral pictures. Both modulatory effects were sustained for probes presented in a subsequent picture imagery period. These data suggest that two measurable responses to the same startle probe are differentially modified by emotional context, with blink magnitude varying with pleasure and probe P3 varying with stimulus arousal.     

Emotional effects on time-to-contact judgments: arousal,threat, and fear of spiders modulate the effect of pictorial content

Recently, responses to looming visual stimuli have been shown to depend on the emotional content of the stimulus. A threatening stimulus is judged to arrive sooner compared to a neutral stimulus, possibly buying the organism time to prepare defensive actions. Here, we explored the underlying mechanism. We found that time-to-contact judgments of threatening pictures did not differ from those of highly arousing pleasant pictures (Experiment 1), suggesting that arousal, not fear, modulates the perception of looming. Specific fear modulated the effects of arousal (Experiment 2): Spider-fearful participants’ judgments showed a threat advantage effect, while non-fearful participants’ judgments were less affected by emotional content. In Experiment 3, arrival times were less overestimated when pictures induced arousal. However, this effect interacted with the valence of the stimulus: For unpleasant stimuli, arousal induced shorter time-to-contact judgments, whereas for pleasant stimuli, an inverted U-shaped relation was found. We propose a general content effect to explain the overestimation with neutral pictures: Pictorial content may draw visual attention to inner contours instead of to the outer edges of the picture. This could delay time-to-contact judgments according to the known size-arrival effect. Our results add to the growing literature examining affective influences on visual perception.     

Facial Electromyography: A Measure of Affective Processes During Sexual Arousal

Forty female volunteers participated in a study to investigate whether facial EMGs could be used as measures of affect during sexual arousal. Audiotaped narratives were used to induce the following affect-sexual states: 1) pleasant affect + sexual arousal, 2) unpleasant affect + sexual arousal, 3) pleasant affect + no sexual arousal, and 4) unpleasant affect + no sexual arousal. EMG activity was recorded bilaterally from the corrugator and zygomatic muscle regions. Corrugator muscle activity was significantly greater in response to the unpleasant stimulus conditions. This relationship held for both the non-sexual and sexual conditions, suggesting that corrugator muscle activity may provide a reliable index of negative affect during sexual arousal. Zygomatic activity was significantly greater during the sexual as compared to the non-sexual stimuli, but did not increase as a function of pleasant affect. Greater left than right corrugator muscle activity was observed in response to the sexual stimuli. Left muscle superiority was also noted for zygomatic muscle activity, in response to the sexual unpleasant stimulus. Issues related to the interpretation of lateralized muscle activity are discussed.     

Autonomic arousal explains social cognitive abilities in high-functioning adults with autism spectrum disorder

Empirical research into behavioural profiles and autonomic responsivity in individuals with autism spectrum disorders (ASDs) is highly variable and inconsistent. Two preliminary studies of children with ASDs suggest that there may be subgroups of ASDs depending on their resting arousal levels, and that these subgroups show different profiles of autonomic responsivity. The aim of the present study was to determine whether (i) adults with high-functioning ASDs may be separated into subgroups according to variation in resting arousal; and (ii) these ASD arousal subgroups differ in their behavioural profiles for basic emotion recognition, judgements of trustworthiness, and cognitive and affective empathy. Thirty high-functioning adults with ASDs and 34 non-clinical controls participated. Resting arousal was determined as the average skin conductance (SCL) across a 2 min resting period. There was a subgroup of ASD adults with significantly lower resting SCL. These individuals demonstrated poorer emotion recognition, tended to judge faces more negatively, and had atypical relationships between SCL and affective empathy. In contrast, low cognitive empathy was a feature of all ASD adults. These findings have important implications for clinical interventions and future studies investigating autonomic functioning in ASDs.     

Affective visual event-related potentials: arousal, repetition, and time-on-task

Affective stimulus pictures that differed in valence (unpleasant, neutral, and pleasant) were repeated as targets in an oddball task to elicit event-related potentials (ERPs) in young female adults. Each picture target was repeated consecutively four times, with picture order counterbalanced and time-on-task influences assessed across subjects. Response time decreased from the first to second stimulus presentation and remained stable. Stimulus repetition was associated with voltage increases for N1, P2, N2, and P3, from initial to subsequent presentations. Arousal effects did not interact with stimulus repetition at any latency range. Time-on-task was associated with decreased voltages for the N2 and P3 potentials but was unaffected by stimulus valence. The findings suggest affective arousal, stimulus repetition, and time-on-task independently modulate ERP outcomes at overlapping time ranges. Theoretical implications are discussed.     

Heart rate response after emotional picture presentation is modulated by interoceptive awareness.

The perception of visceral signals plays a crucial role in many theories of emotions. The present study was designed to investigate the relationship between interoceptive awareness, emotional experience and heart rate responses in an emotional stimulation paradigm. Based on their performance in a heartbeat perception task 38 participants (16 males, 22 females) were classified as subjects with either high (n=19; 8 males) or low interoceptive awareness (n=19; 8 males). 120 pictures (40 pleasant, 40 unpleasant, 40 neutral slides) from the International Affective Picture System served as emotional stimuli. Heart rate changes were recorded during baseline and during slide presentation. After each slide, the subjects had to rate emotional valence and arousal on a 9-point self-report scale. Statistical analyses revealed significantly stronger heart rate responses to pleasant and unpleasant stimuli in subjects with high interoceptive awareness. Furthermore, subjects with high interoceptive awareness rated pleasant and unpleasant slides as significantly more arousing; no differences were found in the emotional valence ratings. Heartbeat perception scores correlated significantly positive with both the mean arousal rating and with the mean heart rate changes. Our results demonstrate a strong relationship between the perception of cardiac signals and the peripheral processing of emotional stimuli.     

Affective startle modulation in anticipation and perception

Startle modulation was investigated as participants first anticipated and then viewed affective pictures in order to determine whether affective modulation of the startle reflex is similar in these different task contexts. During a 6-s anticipation period, a neutral light cue signaled whether the upcoming picture would portray snakes, erotica, or household objects; at the end of the anticipatory period, a picture in the signaled category was viewed for 6 s. Male participants highly fearful of snakes were recruited to maximize emotional arousal during anticipation and perception. Results indicated that the startle reflex was potentiated when anticipating either unpleasant (phobic) or pleasant (erotic) pictures, compared to neutral stimuli, whereas during perception, reflexes were potentiated when viewing unpleasant stimuli, and reduced when viewing pleasant pictures. The startle reflex is modulated by hedonic valence in picture perception, and by emotional arousal in a task context involving picture anticipation.     

The influence of attention and arousal on emotion perception in adults with severe traumatic brain injury

Many people with traumatic brain injury (TBI) have poor emotion recognition, with negative emotions more frequently impaired. They can also display abnormal affective responses to emotionally charged material, however, the mechanisms underpinning such deficits are unclear. This study examined whether affective responsivity can be improved by focusing attention and whether responsivity is associated with perception accuracy. Eighteen adults with moderate-to-severe TBI and 18 control participants viewed facial expressions while skin conductance (SCR) and evoked cardiac deceleration (ECD) (used as indices of orientation) and skin conductance levels (SCL) (used as an index of phasic arousal) were monitored. They viewed two blocks of faces (8 angry and 8 happy per block), passively in the first block and with the instruction to identify the emotional expression in the second. No differences between conditions, emotions or groups were found using SCR. Both groups demonstrated increasing ECD for the attend condition relative to the passive condition. For the passive task the control group showed increasing SCL (sensitisation) over trials when viewing angry faces and decreasing SCL (habituation) to happy faces. No differences between emotions were shown for the TBI group who rapidly habituated to both expressions. For the attend task, there was no evidence of habituation for either expression for either the control or TBI participants. Physiological measures did not correlate to accuracy in recognising emotions. The results suggest that increasing attentional demands improves orientation and emotional engagement (arousal) to emotional faces following TBI. However, the relationship to this and emotion perception accuracy remains unclear.     

Blood pressure changes highlight gender differences in emotional reactivity to arousing pictures

The current study was aimed at investigating the effects of gender on the magnitude and patterning of blood pressure responses to specific pleasant and unpleasant, arousing visual stimuli. Systolic and diastolic blood pressure (SBP and DBP), as well as heart rate (HR) and skin conductance (SCR) responses were investigated during picture viewing in 21 female and 25 male students. The pattern of SCR and HR reactivity across emotional categories was found to be similar for men and women. Gender was found to be an effective moderator of BP responses specifically to sexual stimulus content, which prompted greater reactivity in men than in women. These findings extend prior research on gender differences in autonomic responding to emotional visual stimuli and suggest that BP changes might reflect sexual peripheral arousal more than other autonomic measures.     

Emotional & electroencephalographic responses during affective picture viewing after exercise

We examined the effects of 30 min of cycling exercise at a moderate intensity of 50% peak oxygen uptake, compared to 30 min of rest, on changes in emotional responses to pictorial foreground stimuli that reliably elicit unpleasant, neutral, and pleasant affect. Emotional responses were measured by self-reports of valence (unpleasant to pleasant) and arousal (low to high) and by hemispheric asymmetry (R-L) of frontal and parietal brain electroencephalographic (EEG) activity in 13 females and 21 males (24+/-3 y). Compared to after rest, self-reports of arousal in response to unpleasant slides were diminished after exercise, but self-reports of valence and frontal asymmetry of alpha frequencies were generally unchanged. Even so, there were differential responses in asymmetry in the beta frequencies in the frontal region and for alpha and beta frequencies in the parietal region, indicative of decreased activity in the left frontal and right parietal regions after exercise compared to after rest. We conclude that moderately intense cycling exercise generally does not alter emotional responding to pleasant and neutral pictures, but may reduce emotional arousal during exposure to unpleasant stimuli.     

Music and emotion: electrophysiological correlates of the processing of pleasant and unpleasant music

Human emotion and its electrophysiological correlates are still poorly understood. The present study examined whether the valence of perceived emotions would differentially influence EEG power spectra and heart rate (HR). Pleasant and unpleasant emotions were induced by consonant and dissonant music. Unpleasant (compared to pleasant) music evoked a significant decrease of HR, replicating the pattern of HR responses previously described for the processing of emotional pictures, sounds, and films. In the EEG, pleasant (contrasted to unpleasant) music was associated with an increase of frontal midline (Fm) theta power. This effect is taken to reflect emotional processing in close interaction with attentional functions. These findings show that Fm theta is modulated by emotion more strongly than previously believed.     

Facial EMG and heart rate responses to emotion-inducing film clips in boys with disruptive behavior disorders

We examined aspects of emotional empathy across different physiological response systems in boys with disruptive behavior disorders (DBD) and normal controls. Heart rate (HR) and electromyographic (EMG) reactivity in zygomaticus major and corrugator supercilii muscles were monitored during sadness-, anger-, or happiness-inducing film clips. Relative to controls, DBD boys showed significantly less HR reduction during sadness, and a smaller increase in corrugator EMG activity both during sadness and anger. No significant group differences emerged in HR and zygomaticus EMG responsivity during happiness. We also examined cardiac activity at rest and found higher resting HR and lower respiratory sinus arrhythmia in DBD boys compared to controls. Findings give evidence for a selective impairment in empathy with sadness and anger (not happiness) among DBD boys who exhibit relatively high levels of anxiety and poor emotional control.     

Event related potentials to emotional adjectives during reading

We investigated to what extent emotional connotation influences cortical potentials during reading. To this end, event-related potentials (ERPs) were recorded during reading of high arousal pleasant and unpleasant and low arousal neutral adjectives that were presented at rates of 1 Hz and 3 Hz. Enhanced processing of both pleasant and unpleasant emotional compared to neutral adjectives was first reflected in an amplified early posterior negativity (EPN) starting from 200 ms after word onset. Later potentials (>300 ms), as analyzed in the slower 1 Hz condition, revealed facilitated processing selectively for pleasant adjectives that were associated with a reduced N400 and an enhanced late positive potential (LPP). Pleasant adjectives were also better remembered in an incidental memory test. Thus, emotionally relevant adjectives are processed spontaneously and selectively. Initially, emotional arousal drives attention capture (EPN). Healthy subjects may have a natural bias toward pleasant information facilitating late ERPs (N400, LPP) to pleasant adjectives as well as their superior recall.     

Gender differences in emotional responses: A psychophysiological study

Gender differences in emotional responses have been investigated in two groups of students, 22 males and 21 females. Participants watched a set of sixty emotional standardized slides divided into pleasant, neutral and unpleasant, while Startle reflex, Evoked Potentials, Heart Rate, facial EMG and Skin Conductance were recorded. Startle reflex amplitude, an index modulated by amygdala and orbitofrontal cortex and sensitive to aversive emotional stimuli, was overall larger in women. In addition, startle emotion modulation was greater in women with respect to men. Slow Evoked Potentials (400–800 ms), a measure representing the cognitive component of the emotional response, revealed gender differences in the left prefrontal site, with women showing greater positivity to unpleasant compared with pleasant slides while men had greater positivity to pleasant vs. neutral slides. Women, compared with men, perceived all slides as less pleasant and reported greater arousal to unpleasant condition. Results are in line with known functional brain differences, at level of limbic and paralimbic structures, between men and women, and point to biologically grounded greater sensitivity and vulnerability of women to adverse/stressful events.     

Event-related beta oscillations are affected by emotional eliciting stimuli

According to previous results, negative emotional facial expressions elicit oscillatory beta responses. The present study analyzes event-related beta oscillations upon presentation of International Affective Picture System (IAPS) and aims to show whether behavior of beta in response to negative IAPS pictures also have similar dynamics. IAPS pictures (unpleasant, pleasant, and neutral) were presented as a block and random passive viewing to 14 healthy subjects (8 male). Only with pictures with similar luminance level were selected as stimuli. Event-Related Potentials (ERPs) were recorded from 30 different scalp locations, and adaptive digital filtering was used for analysis in different frequency windows. The maximum peak-to-peak amplitudes were measured for each subject's averaged beta responses (15–30 Hz) in the 0 and 300 ms time window. Beta responses were significantly higher for unpleasant pictures than for pleasant and neutral pictures (average 50%). Beta responses were significantly higher for unpleasant than for pleasant pictures over frontal, central and parietal electrode sides (p < 0.05). Furthermore, beta responses were significantly higher for unpleasant than for neutral pictures over parietal and occipital electrodes (p < 0.04). In addition, the pleasant pictures elicited higher beta responses than neutral pictures over occipital electrode sites (p < 0.04). The results of the present study indicate that negative emotions are related to increased beta responses in humans, independent of stimulus types (facial expression or IAPS pictures). Accordingly, beta responses to negative emotions are possibly a common phenomenon. The standardization of luminance in pictures may reduce divergences between results from different laboratories.