Inefficient face detection in schizophrenia

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.     

Early-stage face processing dysfunction in patients with schizophrenia

OBJECTIVE: Deficits in emotional processing are evident in patients with schizophrenia. Since recent studies have indicated dysfunctions in cortical areas involved in face processing, this study investigated the early processing of faces in schizophrenia patients through the use of event-related potentials. METHOD: Event-related potential responses were obtained from 24 schizophrenia patients and 28 healthy comparison subjects who were presented with pictures of faces and pictures of buildings (control stimuli). RESULTS: Schizophrenia patients displayed significantly lower differences in the face-specific N170 component between the face and building pictures than did the healthy comparison subjects. CONCLUSIONS: This finding suggests a dysfunction of early-stage visual processing of faces in patients with schizophrenia.     

Hippocampal underactivation in an fMRI study of word and face memory recognition in schizophrenia

Schizophrenia is a major mental disorder which is characterized by several cognitive deficits. Investigations of the neural basis of memory dysfunctions using neuroimaging techniques suggest that the hippocampus plays an important role in declarative memory impairment. The goal of this study was to investigate possible dysfunctions in cerebral activation in schizophrenic patients during both word and face recognition memory tasks. We tested 22 schizophrenics and 24 controls matched by gender, age, handedness and parental socioeconomic status. Compared to healthy volunteers, patients with schizophrenia showed decreased bilateral hippocampal activation during word and face recognition tasks. The whole brain analysis also showed a pattern of cortical and subcortical hypoactivation for both verbal and non-verbal recognition. This study provides further evidence of hippocampal involvement in declarative memory impairments of schizophrenia.     

Facial expression and emotional face recognition in schizophrenia and depression

Summary Twenty-three acute schizophrenics, 21 acute major depressives (Research Diagnostic Criteria), and 15 normal controls participated in a study on facial expression and emotional face recognition. Under clinical conditions, spontaneous facial expression was assessed according to the affective flattening section of the Scale for the Assessment of Negative Symptoms. Under experimental laboratory conditions involuntary (emotioneliciting interview) and voluntary facial expression (imitation and simulation of six basic emotions) were recorded on videotape, from which a raterbased analysis of intensity or correctness of facial activity was obtained. Emotional face recognition was also assessed under experimental conditions using the same stimulus material. All subjects were assessed twice (within 4 weeks), controlling for change of the psychopathological status in the patient groups. In schizophrenics, neuroleptic drug influence was controlled by random allocation to treatment with either haloperidol or perazine. The main findings were that schizophrenics and depressives are characterized by different quantitative, qualitative, and temporal patterns of affect-related dysfunctions. In particular, schizophrenics demonstrated a trait-like deficit in affect recognition and in their spontaneous and voluntary facial activity, irrespective of medication, drug type and dosage, or extrapyramidal side-effects. In depressives a stable deficit could be demonstrated only in their involuntary expression under emotion-eliciting interview conditions, whereas in the postacute phase a reduction in their voluntary expression became apparent. Differences in patterns of affect-related behavioral deficits may reflect dysfunctions in different underlying psychobiological systems.     

Sensory contributions to impaired prosodic processing in schizophrenia.

BACKGROUND: Deficits in affect recognition are prominent features of schizophrenia. Within the auditory domain, patients show difficulty in interpreting vocal emotional cues based on intonation (prosody). The relationship of these symptoms to deficits in basic sensory processing has not been previously evaluated. METHODS: Forty-three patients and 34 healthy comparison subjects were tested on two affective prosody measures: voice emotion identification and voice emotion discrimination. Basic auditory sensory processing was measured using a tone-matching paradigm and the Distorted Tunes Test (DTT). A subset of subjects was also tested on facial affect identification and discrimination tasks. RESULTS: Patients showed significantly impaired performance on all emotion processing tasks. Within the patient group, a principal components analysis demonstrated significant intercorrelations between basic pitch perception and affective prosodic performance. In contrast, facial affect recognition deficits represented a distinct second component. Prosodic affect measures correlated significantly with severity of negative symptoms and impaired global outcome. CONCLUSIONS: These results demonstrate significant relationships between basic auditory processing deficits and impaired receptive prosody in schizophrenia. The separate loading of auditory and visual affective recognition measures suggests that within-modality factors may be more significant than cross-modality factors in the etiology of affect recognition deficits in schizophrenia.     

Eye movements reflect impaired face processing in patients with schizophrenia.

BACKGROUND: Impaired processing of faces in patients with schizophrenia may underlie aspects of disturbance in their social interaction. This study examined patterns of eye fixation in subjects with schizophrenia and non-psychiatric controls, while processing a high resolution picture of a neutral face and a nonbiological complex geometric stimulus. METHODS: Ten-second sequences of eye movement were recorded video-oculographically (50 samples/sec) while subjects were "free-viewing" the stimuli. An essential element of the study was customized software that ensured stimulus presentation on a video display only after subjects were fixated upon a centre-screen cue, so that all subjects began stimulus processing from the same point. RESULTS: Compared with the control group, subjects with schizophrenia exhibited reduced scanpath lengths and a tendency toward fewer fixations for the face stimulus. They also showed an initial relative right spatial hemineglect (for the first voluntary fixation) when viewing the Rey figure, but not when viewing the face stimulus. Overall, there were no significant differences between the schizophrenia and control groups in the lateral distribution of subsequent fixations for either stimulus. CONCLUSIONS: Disturbed spatial and temporal patterns of eye movement in some people with schizophrenia may reflect sub-optimal processing of face stimuli, that may predispose these individuals to dysfunctional interpretation of facial communication cues.     

Representational demands modulate involvement of perirhinal cortex in face processing

The classic view holds that the medial temporal lobes (MTL) are dedicated to declarative memory functioning. Recent evidence, however, suggests that perirhinal cortex (PrC), a structure within the anterior MTL, may also play a role in perceptual discriminations when representations of complex conjunctions of features, or of gestalt‐characteristics of objects must be generated. Interestingly, neuroimaging and electrophysiological recordings in nonhuman primates have also revealed a face patch in the anterior collateral sulcus with preferential responses to face stimuli in various task contexts. In the present fMRI study, we investigated the representational demands that influence PrC involvement in different types of judgments on human faces. Holding stimulus complexity constant, we independently manipulated the nature of the task and the orientation of the stimuli presented (through face inversion). Aspects of right PrC showed increased responses in a forced‐choice recognition‐memory and a perceptual‐oddity task, as compared to a feature‐search task that was included to probe visual detection of an isolated face feature. Effects of stimulus orientation in right PrC were observed when the recognition‐memory condition for upright faces was compared with all other experimental conditions, including recognition‐memory for inverted faces‐a result that can be related to past work on the role of PrC in object unitization. Notably, both effects in right PrC paralleled activity patterns in broader networks of regions that also included the right fusiform gyrus and the amygdala, regions frequently implicated in face processing in prior research. As such, the current findings do not support the view that reference to a prior study episode clearly distinguishes the role of PrC from that of more posterior ventral visual pathway regions. They add to a growing body of evidence suggesting that the functional role of specific MTL structures may be best understood in terms of the representations that are required by the task and the stimuli at hand. © 2013 Wiley Periodicals, Inc.     

EEG correlates of face recognition in patients with schizophrenia spectrum disorders: A systematic review

ObjectiveTo systematically assess EEG studies and evaluate neuropsychological changes of face recognition in the context of neutral face stimuli in individuals with schizophrenia spectrum disorders.MethodsA literature search was conducted using the PubMed database from inception to March 2018. Studies included in the review measured any event-related potentials, neural oscillations, or phase synchrony.ResultsA total of 113 articles were identified. Twenty-nine studies were included for the review. The majority of the studies focused on the N170 component. Smaller N170 amplitudes were consistently reported in schizophrenia patients compared to the healthy control group. Significant correlations between N170 amplitudes and social functioning scales were reported. Other results were quite inconsistent; however, group differences were more prominent for tasks with specific conditions.ConclusionsOlder patients with longer disease duration show more consistent neuropsychological correlations. Alterations of event-related potentials are likely to be linked to higher severity of symptoms. The N170 component seems to be the most promising event-related potential to be used for evaluation of present status and for dynamic control of cognitive impairments, social functioning, and rehabilitation effectiveness.SignificanceThis systematic review provides evidence of (1) neuropsychological alterations of face processing outside an emotional context, and (2) a potential role of N170 as a diagnostic and treatment monitoring biomarker.     

No global processing deficit in the Navon task in 14 developmental prosopagnosics

Faces are represented in a more configural or holistic mannerthan other objects. Substantial evidence indicates that thisrepresentation results from face-specific mechanisms, but somehave argued that it is produced by configural mechanisms thatcan be applied to many objects including words. The face-specifichypothesis predicts that non-face configural processes willoften be normal in prosopagnosic subjects, whereas the domain-generalconfigural hypothesis predicts they will be deficient on allconfigural tasks. Although the weight of the evidence favorsthe face-specific hypothesis, a recent study reopened this issuewhen it was found that three out of five developmental prosopagnosicsshowed a larger local processing bias than controls in a global-localtask (i.e. a Navon task). To examine this issue more thoroughlywe tested a significantly larger sample of prosopagnosics (14participants) who had severe face memory and face perceptiondeficits. In contrast to the previous report, the developmentalprosopagnosics performed normally in the global–localtask. Like controls, they showed a typical global advantageand typical global-to-local consistency effects. The resultsdemonstrate that the configural processing required by the Navontask is dissociable from face configural processing.     

Abnormal visual motion processing in schizophrenia: a review of research progress

Motion processing represents a perceptual domain in which dynamic visual information is encoded to support the perception of movement. Research over the last decade has found a variety of abnormalities in the processing of motion information in schizophrenia. The abnormalities span from discrimination of basic motion features (such as speed) to integration of spatially distributed motion signals (such as coherent motion). Motion processing involves visual signals across space and time and thus presents a special opportunity to examine how spatial and temporal information is integrated in the visual system. This article surveys the behavioral and neuroimaging studies that probe into the spatial integration of motion information in schizophrenia. An emerging theme from these studies points to an imbalanced regulation of spatial interaction processes as a potential mechanism mediating different levels of abnormal motion processing in schizophrenia. The synthesis of these mechanism-driven studies suggests that further investigation of the neural basis and functional consequences of this abnormal motion processing are needed in order to render a basic biomarker for assessment and intervention of cognitive dysfunction in this mental disorder.     

Dysfunction of early-stage visual processing in schizophrenia.

OBJECTIVE: Schizophrenia is associated with deficits in higher-order processing of visual information. This study evaluated the integrity of early visual processing in order to evaluate the overall pattern of visual dysfunction in schizophrenia. METHOD: Steady-state visual-evoked potential responses were recorded over the occipital cortex in patients with schizophrenia and in age- and sex-matched comparison volunteers. Visual-evoked potentials were obtained for stimuli composed of isolated squares that were modulated sinusoidally in luminance contrast, number of squares, or chromatic contrast in order to emphasize magnocellular or parvocellular visual pathway activity. RESULTS: Responses of patients to magnocellular-biased stimuli were significantly lower than those of comparison volunteers. These lower response levels were observed in conditions using both low luminance contrast and large squares that biased processing toward the magnocellular pathway. In contrast, responses to stimuli that biased processing toward the parvocellular pathway were not significantly different between schizophrenia patients and comparison volunteers. A significant interaction of group and stimulus type was observed in the condition using low luminance contrast. CONCLUSIONS: These findings suggest a dysfunction of lower-level visual pathways, which was more prominent for magnocellular than parvocellular biased stimuli. The magnocellular pathway helps in orienting toward salient stimuli. A magnocellular pathway deficit could contribute to higher-level visual cognitive deficits in schizophrenia.     

Negative emotional face perception is diminished on a very early level of processing in autism spectrum disorder

Deficits in facial affect recognition (FAR) are often reported in autism spectrum disorder (ASD) due to inappropriate visual search strategies. It is unclear, however, whether or not deficits in subliminal FAR are still present in autism when visual focus is controlled. Thirteen persons with ASD and 13 healthy participants took part in this experiment. Supraliminal FAR was assessed using a standardized, computer-aided test. Subliminal FAR was obtained by an emotional face priming paradigm. By using an eye-tracking technique, it was assured that the initial visual focus was on the eyes of the prime. Persons with ASD showed worse FAR in supraliminal face recognition. Although controlled for initial gaze direction, participants also showed reduced negative face priming. These data confirm that FAR is disturbed already on a pre-attentive level in autism.     

Featural versus configural face processing in a rare genetic disorder: Williams syndrome

Background Williams syndrome (WMS) is a rare genetic disorder with an estimated prevalence of 1 in 20 000 live births. Among other characteristics, WMS has a distinctive cognitive profile with spared face processing and language skills that contrasts with impairment in the cognitive domains of spatial cognition, problem solving and planning. It remains unclear whether individuals with WMS process faces using a featural strategy that focuses on features or a configural strategy that takes into consideration the contour of a face and spatial relations between features. Methods To investigate face processing in WMS, the tasks specifically probe unfamiliar face matching by using a design that includes manipulations in face presentation (thatcherised and non‐thatcherised), face orientation (upright and inverted) and face valence (happy and neutral expression) in a match‐to‐target face recognition design. The sample consisted of 20 participants with WMS, 10 participants with non‐specific developmental delay (IQ‐matched) and 10 normal control participants (chronological age‐matched). Results Similar to normal controls, WMS performed best when faces were presented upright. The results show while the WMS group did not perform as well as their typically developing counterparts, they did significantly better than the IQ‐matched developmentally delayed group. WMS did not show an accuracy advantage for inverted faces commonly understood as an index for featural face processing, nor did they perform better on thatcherised inverted face conditions whereby featural processing is forced. Furthermore, no accuracy advantage was observed for positively valenced (happy) faces in the WMS group. Conclusion These results are consistent with previous work showing a configural face processing approach in WMS, a strategy that is also utilised by normal controls.     

Developmental prosopagnosia with normal configural processing

The configural processing hypothesis proposes that prosopagnosia results from a domain-general impairment in configural processing, and so predicted that all prosopagnosics would have impaired configural processing. In order to test this prediction, tests of face recognition and configural processing were presented to a developmental prosopagnosic. He was severely impaired in face recognition, but his normal performance on three tests of configural processing disconfirmed the configural processing hypothesis. Additional tests of low-level vision and object recognition found no evidence of impairments with material other than faces. The pattern of spared and impaired face recognition indicates that this case of developmental prosopagnosia is caused by a domain-specific inability to match novel views of faces with previously derived representations.     

Neurophysiological correlates of face gender processing in humans

Event-related potentials (ERPs) were recorded while subjects were involved in three gender-processing tasks based on human faces and on human hands. In one condition all stimuli were only of one gender, preventing any gender discrimination. In a second condition, faces (or hands) of men and women were intermixed but the gender was irrelevant for the subject's task; hence gender discrimination was assumed to be incidental. In the third condition, the task required explicit gender discrimination; gender processing was therefore assumed to be intentional. Gender processing had no effect on the occipito-temporal negative potential at approximately 170 ms after stimulation (N170 component of the ERP), suggesting that the neural mechanisms involved in the structural encoding of faces are different from those involved in the extraction of gender-related facial features. In contrast, incidental and intentional processing of face (but not hand) gender affected the ERPs between 145 and 185 ms from stimulus onset at more anterior scalp locations. This effect was interpreted as evidence for the direct visual processing of faces as described in Bruce and Young's model [Bruce, V. & Young, A. (1986) Br. J. Psychol., 77, 305-327]. Additional gender discrimination effects were observed for both faces and hands at mid-parietal sites around 45-85 ms latency, in the incidental task only. This difference was tentatively assumed to reflect an early mechanism of coarse visual categorization. Finally, intentional (but not incidental) gender processing affected the ERPs during a later epoch starting from approximately 200 ms and ending at approximately 250 ms for faces, and approximately 350 ms for hands. This later effect might be related to attention-based gender categorization or to a more general categorization activity.     

Modulation of neuromagnetic responses to face stimuli by preceding biographical information

When we encode faces in memory, we often do so in association with biographical information regarding the person. To examine the neural dynamics underlying such encoding processes, we devised a face recognition task and recorded cortical activity using magnetoencephalography. The task included two conditions. In the experimental condition, face stimuli were preceded by biographical information regarding the person whose face was to be memorized, whereas in the control condition, nonsense syllables were presented before face stimuli. Behavioral results indicated that the biographical information about a person facilitated the recognition memory of their face. Magnetoencephalography signals showed clear visually evoked magnetic fields mainly in the occipitotemporal cortex, in response to the face stimuli that were to be encoded. The phasic peak was observed at 100-200 ms after onset of a face stimulus, which was followed by late latency deflections (200-400 ms). Comparison of the signal between conditions revealed that the preceding semantic information does modulate the neuromagnetic responses to the face stimuli. This modulation occurred primarily at the late latency component in the sensors over the occipitotemporal cortex. In addition, the effects of conditions were also observed in the signals from more anterior sensors, which occurred earlier than the effects in the occipitotemporal cortex. These results provide insights into the neural dynamics underlying the encoding of faces in association with their biographical information.     

A comparative case study of face recognition: The contribution of configural and part-based recognition systems, and their interaction

Understanding the interaction between the configural and part-based systems in face recognition is the major aim of this study. Specifically, we established whether configural representation of faces contribute to aspects of face recognition that depend on part-based processes, such as identifying inverted or fractured faces. Using face recognition tasks that require part-based or configural processing, we compared the results of CK—a man who has object agnosia and alexia [Moscovitch, M., Winocur, G., & Behrmann, M. (1997). What is special about face recognition? Nineteen experiments on a person with visual object agnosia and dyslexia but normal face recognition. Journal of Cognitive Neuroscience, 9(5), 555–604] but normal upright face recognition, to those of DC—a man who has prosopagnosia but normal object recognition. CK was normal at recognizing faces if configural processing was sufficient, but poor at recognizing faces that were modified so as to alter their gestalt, and require part-based processing (Moscovitch et al.). DC was impaired at recognizing upright faces and his performance declined in all tasks involving recognition of modified faces, including those that depend on part-based and on configural processing. Nevertheless, DC was normal on tasks involving perception of generic faces and face imagery. These results show that although configural face perception can proceed without part-based processing, the reverse is not the case. Our results suggest that the configural system is always necessary for face recognition, and appears to support what remains of face identification even in prosopagnosic people who have an intact part-based system.