Altered subjective fear responses in Huntington's disease

Patients with Huntington's disease (HD) have been shown to exhibit impairment in the recognition of facial expressions such as disgust, as well as deficits in disgust responses to olfactory and gustatory stimuli. The present study investigated whether HD is associated with changes in emotional responses to a variety of visual and verbal stimuli selected to elicit core disgust, moral disgust, fear and happiness. Thirteen patients with HD and twelve controls provided emotional ratings after both reading emotion eliciting scenarios and viewing pictures from the International Affective Picture System database. Patients with HD exhibited executive dysfunction. In comparison to controls, they gave similar ratings for happy stimuli and did not differ significantly in response to core disgust or moral disgust stimuli. However, they did exhibit lower fear ratings in response to both sets of fear stimuli (pictures and scenarios), and higher anger ratings than controls in response to fear pictures. These differences in fear response could reflect dysfunction within frontostriatal pathways involving the amygdala. Changes to fear responses in HD may impair decision making and lead to increased risk-taking behaviour with significant personal or social consequences.     

Disgust and Huntington's disease

The disproportionate impairment for the recognition of facial expressions of disgust in patients with Huntington's disease (HD) forms a double dissociation with the impaired recognition of fear that has been reported in amygdala patients. The dissociation has generated discussion regarding the potential existence of neural substrates dedicated to the recognition of facial signals of specific emotions. The aim of this study was to establish whether the impairment for disgust in HD was restricted solely to the domain of facial perception, or whether HD patients also demonstrate impairment in other kinds of disgust. Fourteen HD patients and fourteen age and education matched healthy controls participated in seven disparate emotion processing tasks. (1) A measure of knowledge for the situational determinants of distinct emotions; (2) recognition of emotion expressed in nonverbal vocalisations; (3) recognition of the emotional content of explicit lexical stimuli; (4) recognition of emotional content in pictures of emotion scenes; (5) a disgust experience questionnaire; (6) a measure of olfactory hedonic responsiveness; (7) a measure of gustatory perception. While verbal aspects of disgust processing were preserved, parallel impairments were revealed for olfactory disgust, vocal disgust expressions, the classification of disgusting pictures, and declarative knowledge of disgust elicitors. The finding of impaired perception of disgust signalled through different input domains suggests that the inability to recognise the facial expression in this population reflects a fundamental problem with disgust processing.     

Impaired facial expression recognition in children with temporal lobe epilepsy: impact of early seizure onset on fear recognition

The amygdala has been implicated in the recognition of facial emotions, especially fearful expressions, in adults with early-onset right temporal lobe epilepsy (TLE). The present study investigates the recognition of facial emotions in children and adolescents, 8–16 years old, with epilepsy. Twenty-nine subjects had TLE (13 right, 16 left) and eight had fronto-central epilepsy (FCE). Each was matched on age and gender with a control subject. Subjects were asked to label the emotions expressed in pictures of children's faces miming five basic emotions (happiness, sadness, fear, disgust and anger) or neutrality (no emotion). All groups of children with epilepsy performed less well than controls. Patterns of impairment differed according to the topography of the epilepsy: the left-TLE (LTLE) group was impaired in recognizing fear and neutrality, the right-TLE (RTLE) group was impaired in recognizing disgust and, the FCE group was impaired in recognizing happiness. We clearly demonstrated that early seizure onset is associated with poor recognition of facial expression of emotion in TLE group, particularly for fear. Although right-TLE and left-TLE subjects were both impaired in the recognition of facial emotion, their psychosocial adjustment, as measured by the CBCL questionnaire [Achenbach, T. M. (1991). Manual for the Child Behavior Checklist and Youth Self-report. Burlington, VT: University of Vermont Department of Psychiatry], showed that poor recognition of fearful expressions was related to behavioral disorders only in children with right-TLE. Our study demonstrates for the first time that early-onset TLE can compromise the development of recognizing facial expressions of emotion in children and adolescents and suggests a link between impaired fear recognition and behavioral disorders.     

Evidence for altered amygdala activation in schizophrenia in an adaptive emotion recognition task

Deficits in social cognition seem to present an intermediate phenotype for schizophrenia, and are known to be associated with an altered amygdala response to faces. However, current results are heterogeneous with respect to whether this altered amygdala response in schizophrenia is hypoactive or hyperactive in nature. The present study used functional magnetic resonance imaging to investigate emotion-specific amygdala activation in schizophrenia using a novel adaptive emotion recognition paradigm. Participants comprised 11 schizophrenia outpatients and 16 healthy controls who viewed face stimuli expressing emotions of anger, fear, happiness, and disgust, as well as neutral expressions. The adaptive emotion recognition approach allows the assessment of group differences in both emotion recognition performance and associated neuronal activity while also ensuring a comparable number of correctly recognized emotions between groups. Schizophrenia participants were slower and had a negative bias in emotion recognition. In addition, they showed reduced differential activation during recognition of emotional compared with neutral expressions. Correlation analyses revealed an association of a negative bias with amygdala activation for neutral facial expressions that was specific to the patient group. We replicated previous findings of affected emotion recognition in schizophrenia. Furthermore, we demonstrated that altered amygdala activation in the patient group was associated with the occurrence of a negative bias. These results provide further evidence for impaired social cognition in schizophrenia and point to a central role of the amygdala in negative misperceptions of facial stimuli in schizophrenia.     

Perception of emotional facial expressions at different intensities in early-symptomatic Huntington's disease

BACKGROUND: While there is abundant evidence that patients with Huntington's disease (HD) have an impairment in the recognition of the emotional facial expression of disgust, previous studies have only examined emotion perception using full-blown facial expressions. OBJECTIVE: The current study examines the perception of facial emotional expressions in HD at different levels of intensity to investigate whether more subtle deficits can be detected, possible also in other emotions. METHOD: We compared early symptomatic HD patients with healthy matched controls on emotion perception, presenting short video clips of a neutral face changing into one of the six basic emotions (happiness, anger, fear, surprise, disgust and sadness) with increasing intensity. Overall face perception ability as well as depressive symptoms were taken into account. RESULTS: A specific impairment in recognizing the emotions disgust and anger was found, which was present even at low emotion intensities. CONCLUSION: These results extend previous findings and support the use of more sensitive emotion perception paradigms, which enable the detection of subtle neurobehavioral deficits even in the pre- and early symptomatic stages of the disease.     

Impaired recognition of facial expressions of anger in Parkinson's disease patients acutely withdrawn from dopamine replacement therapy

We have previously reported that acute dopaminergic blockade in healthy volunteers results in a transient disruption of the recognition of facial expressions of anger, whilst leaving intact the recognition of other facial expressions (including fear and disgust) and facial identity processing. Parkinson's disease (PD) is characterised by cell loss in dopaminergic neuronal populations, and hence we predicted that PD would be associated with impaired anger recognition. We reasoned that treatment with dopamine replacement therapy (DRT) could mask any deficit present in PD, and therefore studied facial expression recognition in a group of PD patients transiently withdrawn from DRT. Seventeen PD patients were compared to 21 age- and IQ-matched controls on the Ekman 60 task, which required the forced-choice labelling of 10 exemplars of each of six facial expressions (anger, disgust, fear, sadness, happiness, surprise). In line with our predictions, PD patients showed a selective impairment in the recognition of facial expressions of anger. This deficit was not related to the PD patients' performance on the Benton unfamiliar-face matching task, which was normal, nor was the deficit related to overall disease severity, or to depression symptoms. However, as predicted by simulation theories, impaired anger recognition in PD was related to reduced levels of the anger-linked temperament trait, exploratory excitability. The results extend our previous findings of a role for dopamine in the processing of facial expressions of anger, and demonstrate the power of adopting a phylogenetic, comparative perspective on emotions.     

Seeing happy emotion in fearful and angry faces: qualitative analysis of facial expression recognition in a bilateral amygdala-damaged patient

Neuropsychological studies reported that bilateral amygdala-damaged patients had impaired recognition of facial expressions of fear. However, the specificity of this impairment remains unclear. To address this issue, we carried out two experiments concerning the recognition of facial expression in a patient with bilateral amygdala damage (HY). In Experiment 1, subjects matched the emotion of facial expressions with appropriate verbal labels, using standardized photographs of facial expressions illustrating six basic emotions. The performance of HY was compared with age-matched normal controls (n = 13) and brain-damaged controls (n = 9). HY was less able to recognize facial expressions showing fear than normal controls. In addition, the error pattern exhibited by HY for facial expressions of fear and anger were distinct from those exhibited by both control groups, and suggested that HY confused these emotions with happiness. In Experiment 2, subjects were presented with morphed facial expressions that blended happiness and fear, happiness and anger, or happiness and sadness. Subjects were requested to categorize these expressions by two-way forced-choice selection. The performance of HY was compared with age-matched normal controls (n = 8). HY categorized the morphed fearful and angry expressions blended with some happy content as happy facial expressions more frequently than normal controls. These findings support the idea that amygdala-damaged patients have impaired processing of facial expressions relating to certain negative emotions, particularly fear and anger. More specifically, amygdala-damaged patients seem to give positively biased evaluations for these negative facial expressions.     

Emotion recognition and experience in Huntington's disease: is there a differential impairment?

Findings on affective processing deficits in Huntington's disease (HD) have been inconsistent. It is still not clear whether HD patients are afflicted by specific deficits in emotion recognition and experience. We tested 28 symptomatic HD patients and presented them with pictures depicting facial expressions of emotions (Karolinska-Set) and with affective scenes (International Affective Picture System; IAPS). The faces were judged according to the displayed intensity of six basic emotions, whereas the scenes received intensity ratings for the elicited emotions in the viewer. Patients' responses were compared with those of 28 healthy controls. HD patients gave lower intensity ratings for facial expressions of anger, disgust and surprise than controls. Patients' recognition deficits were associated with reduced functional capacity, such as problems with social interactions. Moreover, their classification accuracy was reduced for angry, disgusted, sad and surprised faces. When judging affective scenes for the elicitation of happiness, disgust and fear, HD patients had a tendency to estimate them as more intense than controls. This finding points to a differential impairment in emotion recognition and emotion experience in HD. We found no significant correlations between emotion experience/recognition ratings and CAG repeats, symptom duration and UHDRS Motor Assessment in the patient group.     

Selective Impairment of Basic Emotion Recognition in People with Autism: Discrimination Thresholds for Recognition of Facial Expressions of Varying Intensities

Autism spectrum disorders (ASD) are characterized by early onset qualitative impairments in reciprocal social development. However, whether individuals with ASD exhibit impaired recognition of facial expressions corresponding to basic emotions is debatable. To investigate subtle deficits in facial emotion recognition, we asked 14 children diagnosed with high-functioning autism (HFA)/AS and 17 typically developing peers to complete a new highly sensitive test of facial emotion recognition. The test stimuli comprised faces expressing increasing degrees of emotional intensity that slowly changed from a neutral to a full-intensity happiness, sadness, surprise, anger, disgust, or fear expression. We assessed individual differences in the intensity of stimuli required to make accurate judgments about emotional expressions. We found that, different emotions had different identification thresholds and the two groups were generally similar in terms of the sequence of discrimination threshold of six basic expressions. It was easier for individuals in both groups to identify emotions that were relatively fully expressed (e.g., intensity >?50%). Compared with control participants, children with ASD generally required stimuli with significantly greater intensity for the correct identification of anger, disgust, and fear expressions. These results suggest that individuals with ASD do not have a general but rather a selective impairment in basic emotion recognition.     

Defective emotion recognition in early HD is neuropsychologically and anatomically generic

Huntington's disease (HD) is an inherited neurodegenerative disorder that classically presents with motor, cognitive and psychiatric symptoms. However, other abnormalities also occur in this condition, notably deficient recognition of facial emotional expressions. Deficits in emotion recognition impact significantly on the lives of HD patients and their families and thus it is important to clarify the onset and pattern of impairment. This study investigated facial emotion recognition in a large cohort of early HD patients, and premanifest gene-carriers. We used voxel-based morphometry (VBM) to examine the neuroanatomical correlates of emotion recognition performance. Forty patients with early HD, 21 premanifest gene carriers and 20 controls were assessed using 24 faces from the Ekman Pictures of Facial Affect, and volumetric brain MRI. The HD group was significantly worse than controls at recognising, surprise, disgust, anger and fear, and worse than the premanifest group at recognising disgust and anger. When patient data were expressed as z-scores, recognition of anger was significantly worse than disgust in the early HD group. In the VBM analysis, these deficits were associated with common regional atrophy: impaired recognition of surprise, disgust, anger and fear were all associated with striatal volume loss. Fear was associated with additional atrophy of the right insula and left and right lateral orbitofrontal cortex. Even in early HD there is a wide-ranging impairment in recognition of negative emotions denoting 'threat'. Our findings implicate a generic fronto-subcortical network in the pathogenesis of these emotion recognition deficits.     

Impaired recognition of facial emotions from low-spatial frequencies in Asperger syndrome

The theory of 'weak central coherence' [Happe, F., & Frith, U. (2006). The weak coherence account: Detail-focused cognitive style in autism spectrum disorders. Journal of Autism and Developmental Disorders, 36(1), 5-25] implies that persons with autism spectrum disorders (ASDs) have a perceptual bias for local but not for global stimulus features. The recognition of emotional facial expressions representing various different levels of detail has not been studied previously in ASDs. We analyzed the recognition of four basic emotional facial expressions (anger, disgust, fear and happiness) from low-spatial frequencies (overall global shapes without local features) in adults with an ASD. A group of 20 participants with Asperger syndrome (AS) was compared to a group of non-autistic age- and sex-matched controls. Emotion recognition was tested from static and dynamic facial expressions whose spatial frequency contents had been manipulated by low-pass filtering at two levels. The two groups recognized emotions similarly from non-filtered faces and from dynamic vs. static facial expressions. In contrast, the participants with AS were less accurate than controls in recognizing facial emotions from very low-spatial frequencies. The results suggest intact recognition of basic facial emotions and dynamic facial information, but impaired visual processing of global features in ASDs.     

Differential deficits in expression recognition in gene-carriers and patients with Huntington's disease

Previous studies in symptomatic patients and asymptomatic gene-carriers of Huntington's disease (HD) reported a differential deficit in the recognition of facial expressions of disgust. This impairment may point to involvement of the basal ganglia in the recognition of disgust. In this study, we compared the performance of 20 patients with symptoms of HD, 20 gene-carriers of HD and 20 healthy controls on two tests of facial expressions in order to further investigate the role of the basal ganglia in disgust recognition. Recognition of fear, rather than disgust, was most severely impaired in the patients, who were also impaired at recognising expressions of anger, disgust and sadness. Direct testing for a differential deficit in disgust at the group level (and at the level of individual HD cases) revealed that the patients were in fact significantly more impaired on the other negative expressions than on disgust. The gene-carriers were not impaired on any expression, although there was a trend for the gene-carriers to be poorer at recognising fearful faces than the controls. We argue that the expression recognition performance of the patients and gene-carriers simply reflects differences in task difficulty, rather than dysfunction of any mechanisms dedicated to specific emotions. In contrast to previous studies in patients or gene-carriers of HD, our findings provide no evidence for a role of the basal ganglia in the recognition of disgust and cast doubt on whether results from HD patients and gene-carriers can be used in support of a double dissociation between recognition of disgust and fear.     

Lateralisation effect in comprehension of emotional facial expression: A comparison between EEG alpha band power and behavioural inhibition (BIS) and activation (BAS) systems

Asymmetry in comprehension of facial expression of emotions was explored in the present study by analysing alpha band variation within the right and left cortical sides. Second, the behavioural activation system (BAS) and behavioural inhibition system (BIS) were considered as an explicative factor to verify the effect of a motivational/emotional variable on alpha activity. A total of 19 participants looked at an ample range of facial expressions of emotions (anger, fear, surprise, disgust, happiness, sadness, and neutral) in random order. The results demonstrated that anterior frontal sites were more active than central and parietal sites in response to facial stimuli. Moreover, right and left side responses varied as a function of emotional types, with an increased right frontal activity for negative, aversive emotions vs an increased left response for positive emotion. Finally, whereas higher BIS participants generated more right hemisphere activation for some negative emotions (such as fear, anger, surprise, and disgust), BAS participants were more responsive to positive emotion (happiness) within the left hemisphere. Motivational significance of facial expressions was considered to elucidate cortical differences in participants' responses to emotional types.     

Fear recognition is impaired by subthalamic nucleus stimulation in Parkinson's disease

Behavioural disturbances such as disorders of mood, apathy or indifference are often observed in Parkinson's disease (PD) patients with chronic high frequency deep brain stimulation of subthalamic nucleus (STN DBS). Neuropsychological modifications causing these adverse events induced by STN DBS remain unknown, even if limbic disturbances are hypothesised. The limbic system supports neural circuits processing emotional information. The aim of this work is to evaluate changes of emotional recognition in PD patients induced by STN DBS. Thirty PD patients were assessed using a computerised paradigm of recognition of emotional facial expressions [Ekman, P., & Friesen, W. V. (1976). Pictures of facial affect. Palo Alto, CA: Consulting Psychologists Press], 15 before STN DBS and 15 after. The two patients groups were compared to a group of 15 healthy control subjects. One series of 55 pictures of emotional facial expressions was presented to each patient. Patients had to classify the pictures according to seven basic emotions (happiness, sadness, fear, surprise, disgust, anger and no emotion). The intact ability to percept faces was firstly assured using the Benton Recognition Test. Recognition of fear expressions was significantly and selectively reduced in the post-operative group in comparison to both pre-operative and control groups. Our results demonstrate for the first time a selective reduction of recognition of facial expressions of fear by STN DBS. This impairment could be the first neuropsychological marker of a more general limbic dysfunction, thought to be responsible for the behavioural disorders reported after STN DBS.     

Recognition of facial emotion in nine individuals with bilateral amygdala damage.

Findings from several case studies have shown that bilateral amygdala damage impairs recognition of emotions in facial expressions, especially fear. However, one study did not find such an impairment, and, in general, comparison across studies has been made difficult because of the different stimuli and tasks employed. In a collaborative study to facilitate such comparisons, we report here the recognition of emotional facial expressions in nine subjects with bilateral amygdala damage, using a sensitive and quantitative assessment. Compared to controls, the subjects as a group were significantly impaired in recognizing fear, although individual performances ranged from severely impaired to essentially normal. Most subjects were impaired on several negative emotions in addition to fear, but no subject was impaired in recognizing happy expressions. An analysis of response consistency showed that impaired recognition of fear could not be attributed simply to mistaking fear for another emotion. While it remains unclear why some subjects with amygdala damage included here are not impaired on our task, the results overall are consistent with the idea that the amygdala plays an important role in triggering knowledge related to threat and danger signaled by facial expressions.     

The misclassification of facial expressions in generalised social phobia

The aim of this study was to investigate facial expression recognition (FER) accuracy in social phobia and in particular to explore how facial expressions of emotion were misclassified. We hypothesised that compared with healthy controls, subjects with social phobia would be no less accurate in their identification of facial emotions (as reported in previous studies) but that they would misclassify facial expressions as expressing threatening emotions (anger, fear or disgust). Thirty individuals with social phobia and twenty-seven healthy controls completed a FER task which featured six basic emotions morphed using computer techniques between 0 percent (neutral) and 100 percent intensity (full emotion). Supporting our hypotheses we found no differences between the groups on measures of the accuracy of emotion recognition but that compared with healthy controls the social phobia group were more likely both to misclassify facial expressions as angry and to interpret neutral facial expressions as angry. The healthy control group were more likely to misclassify neutral expressions as sad. The importance of the role of these biases in social phobia needs further replication but may help in understanding the disorder and provide an interesting area for future research and therapy.     

Recognition of emotion from moving facial and prosodic stimuli in depressed patients

BACKGROUND: It has been suggested that depressed patients have a "negative bias" in recognising other people's emotions; however, the detailed structure of this negative bias is not fully understood. OBJECTIVES: To examine the ability of depressed patients to recognise emotion, using moving facial and prosodic expressions of emotion. METHODS: 16 depressed patients and 20 matched (non-depressed) controls selected one basic emotion (happiness, sadness, anger, fear, surprise, or disgust) that best described the emotional state represented by moving face and prosody. RESULTS: There was no significant difference between depressed patients and controls in their recognition of facial expressions of emotion. However, the depressed patients were impaired relative to controls in their recognition of surprise from prosodic emotions, judging it to be more negative. CONCLUSIONS: We suggest that depressed patients tend to interpret neutral emotions, such as surprise, as negative. Considering that the deficit was seen only for prosodic emotive stimuli, it would appear that stimulus clarity influences the recognition of emotion. These findings provide valuable information on how depressed patients behave in complicated emotional and social situations.     

Effects of diazepam on facial emotion recognition

OBJECTIVE: There have been few studies of the pharmacologic modulation of facial emotion recognition. The present study aimed to replicate and extend the finding that recognition of facial anger was selectively impaired by diazepam. The hypothesis was that, in comparison with placebo, diazepam would impair the recognition of facial anger in healthy volunteers, but not the recognition of 5 other basic emotions: happiness, surprise, fear, sadness and disgust. DESIGN: A randomized, counterbalanced, double-blind, placebo-controlled, within-subjects comparison of diazepam with placebo. SETTING: A university psychopharmacology research unit. PARTICIPANTS: Healthy male (n = 6) and female (n = 22) volunteers, aged 18-45 years. PROCEDURES: Subjects were tested on 2 tasks following the administration of diazepam, 15 mg, and placebo on separate occasions. In the first "multimorph" task, images of facial expressions were morphed to produce continua between the neutral and full expressions of 6 basic emotions. Accuracy and identification thresholds were assessed for stimuli in which the intensity of expression gradually increased. In the second "emotional hexagon" task, facial expressions were morphed between pairs of emotions. Single images were presented, and accuracy and speed of response were assessed. RESULTS: Diazepam produced broad impairments in response accuracy, recognition thresholds and response speed on the facial emotion tasks that were not limited to angry expressions. CONCLUSIONS: The present study found that diazepam, 15 mg, impaired facial emotion recognition, but not selectively. In the emotional hexagon task, a reaction-time analysis suggested that the identification of facial anger might be differentially sensitive to variations in stimulus duration, complicating the interpretation of this paradigm.     

Amygdala damage impairs emotion recognition from scenes only when they contain facial expressions

Bilateral damage to the human amygdala impairs recognition of negatively valenced emotions from facial expressions, but it is unclear if this finding generalizes to richer visual stimuli that contain cues in addition to faces. We investigated this issue in 4 subjects with bilateral amygdala damage, 23 with unilateral amygdala damage, 22 brain-damaged controls and 16 normal individuals. Subjects were shown two blocks of complex social scenes; all stimuli in the two blocks were identical, except that the first block had all facial expressions in the image erased. While control subjects were more accurate in recognizing emotions when facial expressions were present, subjects with bilateral amygdala damage did not show the same benefit for negative emotions, often performing equivalently across the two conditions. Most striking, subjects with bilateral amygdala damage were more accurate in recognizing scenes showing anger with faces erased than with faces present, an effect resulting in part from highly abnormal recognition of certain angry facial expressions. All four subjects with bilateral amygdala damage were impaired in recognizing angry faces shown in isolation, and frequently mistook expressions of anger for smiles, a mistake never made by any control subject. Bilateral amygdala damage thus disproportionately impairs recognition of certain emotions from complex visual stimuli when subjects utilize information from facial expressions.     

Identifying the components of facial emotion and schizophrenia

Schizophrenics, anxiety neurotics, and nonpatient control subjects were asked to identify the emotion expressed in partial (upper-middle-lower) and full facial expression of four negative emotions: sadness, fear, anger and disgust. Groups did not differ in the ability to identify emotions from partial facial expressions, however, schizophrenics were significantly poorer than anxiety neurotics and controls in identifying emotions from full facial expressions.