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OBJECT - This study was undertaken to assess the reliability of observations of postoperative photographs in assigning House-Brackmann scores as outcome measures for patients following resection of vestibular schwannomas.
METHODS - Forty pictures of differing facial expressions typically elicited from patients for assigning House-Brackmann scores were individually evaluated by neurosurgery residents and faculty members at the University of Alabama at Birmingham; a score was assigned to each picture by the individual raters. The interrater reliability was measured using the Spearman correlation coefficient, Kendall coefficient of concordance, and kappa statistic; internal consistency was calculated using the Cronbach alpha reliability estimate.
RESULTS - The Spearman correlation coefficients showed strong positive association among raters, with a range of values of 0.66 to 0.90. Internal consistency measured by the Cronbach alpha coefficient was excellent (α = 0.97). The Kendall coefficient of concordance for the ordinal grades suggested a substantial degree of agreement among the raters (w = 0.76, p < 0.001).
CONCLUSIONS - Static postoperative photographs are a reliable outcome measure for determining facial nerve function after vestibular schwannoma resection and may serve as a surrogate for the dynamic patient interview.
Although facial expressions are thought to vary in their functional impact on perceivers, experimental demonstration of the differential effects of facial expressions on behavior are lacking. In the present study, we examined the effects of exposure to facial expressions on visual search efficiency. Participants (n = 31) searched for a target in a 12 location circle array after exposure to an angry, disgusted, fearful, happy, or neutral facial expression for 100 ms or 500 ms. Consistent with predictions, exposure to a fearful expression prior to visual search resulted in faster target identification compared to exposure to other facial expressions. The effects of other facial expressions on visual search did not differ from each other. The fear facilitating effect on visual search efficiency was observed at 500-ms but not at 100-ms presentations, suggesting a specific temporal course of the facilitation. Subsequent analysis also revealed that individual differences in fear of negative evaluation, trait anxiety, and obsessive-compulsive symptoms possess a differential pattern of association with visual search efficiency. The experimental and clinical implications of these findings are discussed.
The study of adaptation aftereffects has been used as a tool to investigate the neural events that give rise to face perception. Recent adaptation studies suggest that face processing does not occur outside of awareness since identity- and gender-specific face aftereffects cannot be induced when the adapting face is rendered perceptually invisible using interocular suppression. However there is substantial evidence suggesting that facial expression, unlike identity and gender, is an attribute of faces that may recruit processes that are engaged automatically and independent of observers' awareness and attention. Therefore we investigated whether adaptation aftereffects specific to facial expressions could arise under continuous flash suppression (CFS). Our results show that adaptation to facial expressions is virtually abolished, when faces are suppressed from awareness. Moreover, this loss in aftereffect strength cannot be attributed to contrast adaptation exclusively, since results show only modest changes in perceived contrast following face adaptation. When observers endogenously attend to the location of the suppressed adapting stimulus, expression-specific aftereffects are enhanced. Our findings suggest that neural activity specifying affective information of facial expressions is highly vulnerable to the disruptive effect of interocular suppression, but that allocation of attentional resources can partially counteract suppression's effect.
Schizophrenia patients exhibit deficits in recognition and identification of facial emotional expressions, but it is unclear whether these deficits result from abnormal affective processing or an impaired ability to process complex visual stimuli such as faces. Participants comprised 16 outpatients with schizophrenia and 22 matched healthy control subjects who performed two computerized visual matching tasks (facial emotional expression and orientation). Accuracy and reaction time were recorded. Clinical symptoms were assessed in the patients using the Brief Psychiatric Rating Scale (BPRS), Scale for the Assessment of Positive Symptoms (SAPS), and Scale for the Assessment of Negative Symptoms (SANS). Social functioning as measured by the Zigler social competence scale was indexed in all participants. Patients with schizophrenia were less accurate than control participants on both facial emotion and orientation matching tasks, but there was no diagnosis-by-task interaction. Clinical symptoms of the patients were associated with deficits on emotion and orientation matching tasks. Worse social functioning was correlated with facial emotion matching errors across both groups. Patients with schizophrenia show general deficits in processing of faces, which is in turn associated with worse symptoms and reduced social functioning.
The social significance of imitation is that it provides internal tools for understanding the actions of others by simulating or forming internal representations of these actions. Imitation plays a central role in human social behavior by mediating diverse forms of social learning. However, imitation and simulation ability in schizophrenia has not been adequately addressed. The major aim of the present study was to investigate imitation ability in schizophrenia patients and healthy individuals by examining simple motor imitation that involved the replication of meaningless manual and oral gestures, and the imitation of emotional facial expressions, which has implications for mentalizing. A secondary aim of the present study was to investigate the relationships among imitation ability, social functioning, and working memory. Subjects were asked to mimic hand gestures, mouth movements, and facial expressions of others, online. Clinical symptoms, social competence, and working memory were also assessed. Patients with schizophrenia were significantly impaired on all imitation tasks. Imitation errors were significantly correlated with reduced social competence and increased negative symptoms. However, imitation ability was only weakly associated with working memory. To summarize, the present study examined the ability of patients with schizophrenia to imitate the behaviors demonstrated by others. The results indicate a fundamental impairment in imitation ability in schizophrenia and implicate a possible difficulty in simulation. Further research to determine the neural and developmental origins of this difficulty could be extremely helpful in elucidating the role of simulation in schizophrenia and to establish the complex relationships among mental representation, imitation, and social cognition.
Rapid evaluation of ecologically relevant stimuli may lead to their preferential access to awareness. Continuous flash suppression allows assessment of affective processing under conditions in which stimuli have been rendered invisible due to the strongly suppressive nature of dynamic noise relative to static images. The authors investigated whether fearful expressions emerge from suppression into awareness more quickly than images of neutral or happy expressions. Fearful faces were consistently detected faster than neutral or happy faces. Responses to inverted faces were slower than those to upright faces but showed the same effect of emotional expression, suggesting that some key feature or features in the inverted faces remained salient. When using stimuli solely representing the eyes, a similar bias for detecting fear emerged, implicating the importance of information from the eyes in the preconscious processing of fear expressions.
BACKGROUND - Higher levels of facial processing, such as recognition of the individuality and emotional expression of faces, are abnormal in schizophrenia. It is unknown, however, whether the visual detection of a face as face is impaired as well.
METHODS - We examined the performance of schizophrenia patients (n=29) and normal controls (n=28) in locating a line-drawn face on the left or the right side of a larger line drawing. To prevent the normal formation of general facial impressions, stimulus presentations were brief (13-104 ms). The face stimuli were either displayed upright or inverted in order to study the face inversion effect, ie, the specific effect of stimulus inversion on face processing.
RESULTS - Schizophrenia patients showed a significantly reduced face inversion effect, resulting primarily from significantly lower accuracy in detecting upright faces than normal controls. In tree detection, a comparison task that was also administered, the stimulus inversion effect was similarly small in both groups.
CONCLUSION - Given the primitive nature and brief duration of the stimuli, and the simplicity of the task, these results indicate that at the initial visual detection stage, facial processing is inefficient in schizophrenia. By isolating face detection from other aspects of face recognition, this study identifies a face-specific visual deficit in schizophrenia, which may ultimately contribute to impaired face-related cognitive and emotional processing and social interaction.
INTRODUCTION - Patients with schizophrenia show deficits in facial affect and facial identity recognition and exhibit structural and neurophysiological abnormalities in brain regions known to mediate these processes. Functional neuroimaging studies of neural responses to emotional facial expressions in schizophrenia have reported both increases and decreases in medial temporal lobe (MTL) activity in schizophrenia. Some of this variability may be related to the tasks performed and the baseline conditions used. Here we tested whether MTL responses to human faces in schizophrenia are abnormal when unconstrained by a cognitive task and measured relative to a low-level baseline (fixation) condition.
METHODS - 15 patients with schizophrenia and 16 healthy control subjects underwent functional magnetic resonance imaging (fMRI) while passively viewing human faces displaying fearful, happy, and neutral emotional expressions.
RESULTS - Relative to control subjects, the patients demonstrated (1) significantly greater activation of the left hippocampus while viewing all three facial expressions and (2) increased right amygdala activation during the initial presentation of fearful and neutral facial expressions.
CONCLUSIONS - In schizophrenia, hippocampal and amygdala activity is elevated during the passive viewing of human faces.
The extent to which the brain regions associated with face processing are selective for that specific function remains controversial. In addition, little is known regarding the extent to which face-responsive brain regions are selective for human faces. To study regional selectivity of face processing, we used functional magnetic resonance imaging to examine whole brain activation in response to human faces, dog faces, and houses. Fourteen healthy right-handed volunteers participated in a passive viewing, blocked experiment. Results indicate that the lateral fusiform gyrus (Brodmann's area 37) responds maximally to both dog and human faces when compared with other sites, followed by the middle/inferior occipital gyrus (BA 18/19). Sites that were activated by houses versus dog and human faces included the medial fusiform gyrus (BA 19/37), the posterior cingulate (BA 30), and the superior occipital gyrus (BA 19). The only site that displayed significant differences in activation between dog and human faces was the lingual/medial fusiform gyrus. In this site, houses elicited the strongest activation, followed by dog faces, while the response to human faces was negligible and did not differ from fixation. The parahippocampal gyrus/amygdala was the sole site that displayed significant activation to human faces, but not to dog faces or houses.