Posed prosodic emotional expression in unilateral stroke patients: recovery, lesion location, and emotional perception.

Recovery of emotional functioning following stroke has received limited attention in the neuropsychological literature. By emotional functioning, we refer to a range of processing modes, including perception, expression, experience, and behavior. The aim of the current study was to evaluate the course of prosodic emotional expression over time in individuals with stroke. Posed prosodic expression tasks from the New York Emotion Battery were administered to right brain-damaged (RBD), left brain-damaged (LBD), and demographically matched normal control (NC) participants at two separate testing times (median interval of 25 months). Posers (i.e., individuals producing the emotional expressions) were required to produce neutral-content sentences using four different emotional tones (happiness, sadness, anger, and fear). Raters judged poser output for accuracy, intensity, and confidence. For accuracy ratings, RBDs and LBDs were impaired relative to NCs at baseline. In terms of recovery, there was a tendency for LBDs to improve over time, and there was a significant decline for RBDs. Inspection of the group mean data suggested that frontal lesions had a negative impact on prosodic emotional expression in RBDs and that lesion extent did not systematically influence performance at baseline or over time. Participants maintained their relative standing on the NYEB expression tasks over time. Finally, no significant relationships were found between participant performance on prosodic emotional perception and expression tasks at either testing time, suggesting that these two processing modes are relatively independent.     

Is the right hemisphere involved in idiom comprehension? A neuropsychological study

Nonambiguous idiom comprehension was assessed in 15 right brain-damaged (RBD) and 12 left brain-damaged (LBD) aphasic patients by means of a string-to-picture matching task. Idiom comprehension was found to be severely impaired with a bias toward literal interpretation. The RBD patients, though impaired, performed significantly better than LBD patients; their performance was correlated with visuospatial abilities and was significantly affected by lesion site. The results of this study suggest that the performance of RBD patients in the comprehension of idiomatic sentences may be affected by (a) an involvement of the frontal lobe and/or (b) visuospatial deficits that may impair their performance on the picture-matching task.     

Effects of emotion and semantic relatedness on recognition memory: Behavioral and electrophysiological evidence

Some aspects of our memory are enhanced by emotion, whereas others can be unaffected or even hindered. Previous studies reported impaired associative memory of emotional content, an effect termed associative “emotional interference”. The current study used EEG and an associative recognition paradigm to investigate the cognitive and neural mechanisms associated with this effect. In two experiments, participants studied negative and neutral stimulus-pairs that were either semantically related or unrelated. In Experiment 1 emotions were relevant to the encoding task (valence judgment) whereas in Experiment 2 emotions were irrelevant (familiarity judgment). In a subsequent associative recognition test, EEG was recorded while participants discriminated between intact, rearranged, and new pairs. An associative emotional interference effect was observed in both experiments, but was attenuated for semantically related pairs in Experiment 1, where valence was relevant to the task. Moreover, a modulation of an early associative memory ERP component (300–550 ms) occurred for negative pairs when valence was task-relevant (Experiment 1), but for semantically related pairs when valence was irrelevant (Experiment 2). A later ERP component (550–800 ms) showed a more general pattern, and was observed in all experimental conditions. These results suggest that both valence and semantic relations can act as an organizing principle that promotes associative binding. Their ability to contribute to successful retrieval depends on specific task demands.     

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.     

Startle Reflex Modification: Emotion or Attention?

Alternative interpretations of startle probe modulation by a pictorial foreground were tested: Either reflex amplitude varies as a function of modality-determined attention allocation, or, regardless of probe modality, reflex amplitude varies with the emotional valence of the foreground content. Thirty-six subjects viewed a series of 54 slides, divided into two 27-slide blocks. Each block consisted of nine exemplars of three independently rated emotional content categories--pleasant, neutral, and unpleasant. Startle probes, half visual (flashgun) and half acoustic (white noise), were presented unpredictably during and between slide presentations. Eyeblink reflexes, corrugator and orbicularis oculi muscle tension, heart rate, and skin conductance were recorded during a 6-s slide interval. Subjects subsequently rated the slides for emotional valence and arousal, and interest value. Free-viewing times were also recorded. Analysis of reflex response and all ancillary measures supported the hypothesis that the primary determinant of startle modulation was the emotional valence of foreground content.     

Local (focussed) and global (distributed) visual processing in hemispatial neglect

In the present study we set out to investigate deficits of focussed and distributed attention (and their interaction) in brain-damaged patients. To this purpose, four left brain damaged (LBD) patients without signs of hemispatial neglect and six right brain damaged (RBD) patients with variable signs of hemispatial neglect were tested by means of an experimental paradigm comprising two embedded tasks performed on the same visual array. The first task (i.e. counting the number of shapes, 1–4, briefly displayed) mainly involved distributed attention rather than focussed attention. The second task was a typical target detection task, which emphasized the detailed analysis of each element in the array, thus mainly tapping focussed attention. Results clearly showed that: (1) LBD patients are slightly impaired at directing focussed attention to the contralesional visual hemifield; (2) in comparison to LBD patients, RBD patients with mild neglect show an exaggerated difficulty in orienting focussed attention toward the contralesional side, while they are similarly unimpaired in the deployment of distributed attention, i.e. in global processing; (3) RBD patients with the most severe neglect suffer from a deficit of both local and global visual processing, i.e. of both focussed and distributed attention. Taken together, these observations indicate that focussed and distributed components of visual attentional processing may be differentially affected in left and right brain-damaged patients with and without neglect.     

Total amount learned versus learning rate of verbal and nonverbal information, in differentiating left-from right-brain injured patients.

Twenty Left-Brain Damaged (LBD), 20 Right-Brain Damaged (RBD), and 20 control subjects were compared on three different learning tasks: (a) verbal, the Paired Associate Learning subtest of the Wechsler Memory Scale; (b) figural, the Gollin Incomplete Figures task, which can be easily verbalized, and (c) spatial, the Stylus Maze. When learning ability was measured, by assessing the total amount learned (sum of items learned in all trials), the results showed that, on all three tasks, the control group's performance significantly surpassed that of the patient groups. The RBD group performed better than the LBD group on the verbal learning task, while LBD subjects performed better than their RBD counterparts on the spatial learning task. No significant difference between the two patient groups was detected on the figural task, suggesting that a task using visually and verbally codable stimuli is not useful in differentiating between LBD and RBD groups. When the learning rate was measured, similar results were obtained in the verbal and figural task. However, in the spatial task, the learning rates of the three groups did not significantly differ, probably because the specific task used required procedural learning, which is normally preserved in amnesics.     

Heart rate response is longer after negative emotions than after positive emotions

Summary. Recent ambulatory findings showing comparable cardiovascular effects of positive and negative emotions are not consistent with the assumed etiological role of negative affect in stress-related diseases. We tested the hypothesis that regardless of initial reactivity, responses associated with negative emotions would be prolonged compared to responses associated with positive emotions. During 8 h, 33 healthy subjects from a general population reported their emotional arousal, emotional valence and physical activity and recorded their heart rates (HR) after a beep at each 60th min (‘initial HR’; T0), followed by two ‘prolonged activation’ recordings, respectively 5 min later (T1) and 10 min later (T2). While emotional arousal and activity predicted initial HR, prolonged activation at T1 was solely predicted by emotional valence (negative affect) at T0, independent of emotional recovery. The results lend support to the hypothesis that cardiovascular activation after negative emotions last longer than after positive emotions. This finding is consistent with the view that prolonged activation, and not so much reactivity, might be a mechanism underlying the etiological role of negative emotions (‘stress’) in somatic disease. Perseverative cognition (worry, rumination) might be responsible for this prolonged activation.     

Effects of unrecognized physiological residual arousal on emotional experience

This study investigated the effect of residual arousal on perceived positive and negative emotion, and the relationship between the valence of emotion and cardiovascular and cardiorespiratory reactivity. A total of 74 participants were randomly assigned to either a Residual Arousal (exercise‐induced) group or a No Residual Arousal (no exercise) group. Following the arousal manipulation, participants watched a video that elicited positive emotion and a video that elicited negative emotion. Within‐person differences revealed greater discrepancies between participants’ reports of positive and negative emotions in response to the videos, indicating that residual arousal caused stronger positive and negative emotions. With regard to physiological reactivity, participants in the No Residual Arousal group exhibited lower heart rate, respiration amplitude, and heart rate variability (LF /HF ratio) during the negative video than during the positive video, suggesting that the positive and negative videos had different influences on physiology. These results support the hypothesis that autonomic activation may be nonspecific with regard to the genesis of emotion, but once a person becomes emotional, physiological reactivity may differ between emotions.     

Lateralization of emotional expression under a neuroleptic drug

Sixteen student volunteers were administered placebo and 50 mg of chlorpromazine (CPZ) in tablet form, on separate occasions, two hours before testing. Whilst volunteers related pleasant and unpleasant personal life events, the frequency and intensity of expressions on the left and right sides of the face were rated by independent observers. Subsequently the valence of the narration was also rated. Similar to a previous study facial expressions during negative emotions were expressed more often and intensely in the left face but positive emotions were bilaterally represented. CPZ neutralised the emotion on both sides of the face, irrespective of whether it was positive or negative. However, because negative emotions were almost completely lateralised to the left face the drug's effect on this emotion was most pronounced on this side. Independent ratings of the narration of the life events showed CPZ made them more pleasant. It is suggested that emotional arousal increases the asymmetry of behaviours when these are unilaterally represented or controlled. CPZ may equalize the symmetry of behaviour by reducing emotional arousal rather than by blocking all behaviour.     

Unilateral spatial neglect: biases in contralateral search and fine spatial attention.

Contralateral search and fine spatial attentional asymmetries, two aspects of hemispatial neglect, were examined in a total of 91 right brain damaged (RBD) and 40 non-aphasic left brain damaged (LBD) stroke rehabilitation inpatients. Fine spatial attentional asymmetries within a hemispace were found in both RBD and LBD patients on the LAVA figure-match test. This finding is in contrast to Gainotti's hypothesis that such problems in extracting contralateral visual information are uniquely characteristic of RBD patients. Furthermore, the study suggests that the gross search and fine attentional aspects of neglect are dissociable and may reflect different underlying mechanisms of hemispatial neglect.     

Revisiting the James versus Cannon debate on emotion: startle and autonomic modulation in patients with spinal cord injuries

James' hypothesis that impaired peripheral physiology in patients with spinal cord injuries (SCI) impairs emotional processing, as manifested in the modulation of physiological responses and in the subjective component of emotions, was examined in the present study. A pilot study confirmed the utility of Lang's picture viewing paradigm in a group of 78 students using the Spanish norms of the International Affective Picture System. In the main study, 19 patients with SCI and 19 well controls matched for sex, age and education were examined. Results showed: (1) no differences between SCI and control participants in the valence and arousal ratings of the pictures; (2) similar heart rate modulation in both groups, i.e. the unpleasant pictures produced greater deceleration than the pleasant ones; and (3) no decrease in emotional experience in the SCI group compared with the control group. The implications of the results for the James versus Cannon controversy on the theory of emotions are discussed.     

Attention interference for emotional stimuli in cardiac interoceptive awareness

Previous research has shown that individuals with good perception of cardiac signals, referred to as cardiac interoceptive awareness, experience emotions more intensely. To investigate if emotional experience in high cardiac interoceptive awareness arises from biases in attention, we compared the performance of participants with high versus regular cardiac interoceptive awareness in an emotional Stroop task. Participants with high cardiac interoceptive awareness showed attention interference for negative words, whereas participants with regular cardiac interoceptive awareness showed attention facilitation for positive words. Our data provide further evidence for the emotion information process associated with cardiac interoceptive awareness. The results support the notion that better access to cardiac changes accompanying negative emotional conditions results in automatic vigilance for negative information and may interfere with cognitive processing.     

Facial expression recognition and emotional regulation in narcolepsy with cataplexy

Cataplexy is pathognomonic of narcolepsy with cataplexy, and defined by a transient loss of muscle tone triggered by strong emotions. Recent researches suggest abnormal amygdala function in narcolepsy with cataplexy. Emotion treatment and emotional regulation strategies are complex functions involving cortical and limbic structures, like the amygdala. As the amygdala has been shown to play a role in facial emotion recognition, we tested the hypothesis that patients with narcolepsy with cataplexy would have impaired recognition of facial emotional expressions compared with patients affected with central hypersomnia without cataplexy and healthy controls. We also aimed to determine whether cataplexy modulates emotional regulation strategies. Emotional intensity, arousal and valence ratings on Ekman faces displaying happiness, surprise, fear, anger, disgust, sadness and neutral expressions of 21 drug‐free patients with narcolepsy with cataplexy were compared with 23 drug‐free sex‐, age‐ and intellectual level‐matched adult patients with hypersomnia without cataplexy and 21 healthy controls. All participants underwent polysomnography recording and multiple sleep latency tests, and completed depression, anxiety and emotional regulation questionnaires. Performance of patients with narcolepsy with cataplexy did not differ from patients with hypersomnia without cataplexy or healthy controls on both intensity rating of each emotion on its prototypical label and mean ratings for valence and arousal. Moreover, patients with narcolepsy with cataplexy did not use different emotional regulation strategies. The level of depressive and anxious symptoms in narcolepsy with cataplexy did not differ from the other groups. Our results demonstrate that narcolepsy with cataplexy accurately perceives and discriminates facial emotions, and regulates emotions normally. The absence of alteration of perceived affective valence remains a major clinical interest in narcolepsy with cataplexy, and it supports the argument for optimal behaviour and social functioning in narcolepsy with cataplexy.     

Affective and physiological responses to environmental noises and music.

Research suggests that respiratory patterns may reflect general dimensions of emotional response. In this study, we investigated the relationships between judgments of affective valence (pleasantness) and arousal and respiratory responses to acoustic stimuli. Sixteen environmental noises and 16 musical fragments of 30 s duration were presented to 31 participants, while respiration, skin conductance level and heart rate were recorded. Judgments of valence and arousal were registered using the 9-point Self-Assessment Manikin. For noises, breathing accelerated and minute ventilation augmented with decreases in pleasantness for low-arousal stimuli and with increases in arousal for positive stimuli. For music, breathing accelerated and minute ventilation augmented with increases both in rated valence and arousal. Skin conductance level increased with arousal ratings for music but not for noises, whereas mean heart rate increased with rated arousal for noises but not for music. Although both noises and music are sound-vibrations, differences in the relationships between affective judgments and physiological responses were found suggesting differences in the processing of the two types of acoustic stimuli.     

Overnight emotional adaptation to negative stimuli is altered by REM sleep deprivation and is correlated with intervening dream emotions

Rapid eye movement (REM) sleep and dreaming may be implicated in cross-night adaptation to emotionally negative events. To evaluate the impact of REM sleep deprivation (REMD) and the presence of dream emotions on a possible emotional adaptation (EA) function, 35 healthy subjects randomly assigned to REMD ( n  = 17; mean age 26.4 ± 4.3 years) and control ( n  = 18; mean age 23.7 ± 4.4 years) groups underwent a partial REMD and control nights in the laboratory, respectively. In the evening preceding and morning following REMD, subjects rated neutral and negative pictures on scales of valence and arousal and EA scores were calculated. Subjects also rated dream emotions using the same scales and a 10-item emotions list. REMD was relatively successful in decreasing REM% on the experimental night, although a mean split procedure was applied to better differentiate subjects high and low in REM%. High and low groups differed – but in a direction contrary to expectations. Subjects high in REMD% showed greater adaptation to negative pictures on arousal ratings than did those low in REMD% ( P  < 0.05), even after statistically controlling sleep efficiency and awakening times. Subjects above the median on EA_valence had less intense overall dream negativity ( P  < 0.005) and dream sadness ( P  < 0.004) than subjects below the median. A correlation between the emotional intensities of the morning dream and the morning picture ratings supports a possible emotional carry-over effect. REM sleep may enhance morning reactivity to negative emotional stimuli. Further, REM sleep and dreaming may be implicated in different dimensions of cross-night adaptation to negative emotions.     

Emotional Modulation of the Ability to Inhibit a Prepotent Response During Childhood

The present study examined the bottom-up influence of emotional context on response inhibition, an issue that remains largely unstudied in children. Thus, 62 participants, aged from 6 to 13 years old, were assessed with three stop signal tasks: one with circles, one with neutral faces, and one with emotional faces (happy and sad). Results showed that emotional context altered response inhibition ability in childhood. However, no interaction between age and emotional influence on response inhibition was found. Positive emotions were recognized faster than negative emotions, but the valence did not have a significant influence on response inhibition abilities.     

What's the meaning of this? A behavioral and neurophysiological investigation into the principles behind the classification of visual emotional stimuli

Two experiments were performed to investigate the principles by which emotional stimuli are classified on the dimensions of valence and arousal. In Experiment 1, a large sample of healthy participants rated emotional stimuli according to both broad dimensions. Hierarchical cluster analyses performed on these ratings revealed that stimuli were clustered according to their semantic content at the beginning of the agglomerative process. Example semantic themes include food, violence, nudes, death, and objects. Importantly, this pattern occurred in a parallel fashion for ratings on both dimensions. In Experiment 2, we investigated if the same semantic clusters were differentiated at the neurophysiological level. Intracerebral EEG was recorded from 18 patients with intractable epilepsy who viewed the same set of stimuli. Not only did electrocortical responses differentiate between these data‐defined semantic clusters, they converged with the behavioral measurements to highlight the importance of categories associated with survival and reproduction. These findings provide strong evidence that the semantic content of affective material influences their classification along the broad dimensions of valence and arousal, and this principle of categorization exerts an effect on the evoked emotional response. Future studies should consider data‐driven techniques rather than normative ratings to identify more specific, semantically related emotional images.     

Emotion and motivated behavior: postural adjustments to affective picture viewing

Thirty-six participants (18 female, 18 male) viewed affective pictures to investigate the coupling between emotional reactions and motivated behavior. Framed within the biphasic theory of emotion, the three systems approach was employed by collecting measures of subjective report, expressive physiology, and motivated behavior. Postural adjustments associated with viewing affective pictures were measured. Results indicated sex-differences for postural responses to unpleasant pictures; an effect not found for pleasant and neutral picture contents. Females exhibited increased postural movement in the posterior direction, and males exhibited increased movement in the anterior direction, for unpleasant pictures. Subjective report of valence and arousal using the self-assessment manikin (SAM), and the startle eye-blink reflex were collected during a separate session, which replicated previous picture-viewing research. Specifically, participants rated pleasant pictures higher in valence and exhibited smaller startle responses compared to unpleasant pictures. Females also reported lower valence ratings compared to males across all picture contents. These findings extend our knowledge of motivated engagement with affective stimuli and indicate that postural responses may provide insight into sex-related differences in withdrawal behavior.     

Age differences in perception and awareness of emotion

We investigated the effects of age and gender on emotional perception and physiology using electrodermal skin conductance response (SCR) and examined whether SCR is related to subjective perceptions of emotional pictures. Older adults found pictures to be more positive and arousing than younger participants. Older women rated pictures more extremely at both ends of the valence continuum: they rated positive pictures more positively and negative pictures more negatively. Elders were less likely to show measurable SCRs. However, magnitude of SCRs when a response occurred did not differ between young and old. Subjective ratings of emotion correlated with physiological responses in younger participants, but they were unrelated in older participants. Thus, in older adults the perception of emotional events was disconnected from the physiological state induced by emotion.