Dynamics of alpha oscillations elucidate facial affect recognition in schizophrenia

Impaired facial affect recognition is characteristic of schizophrenia and has been related to impaired social function, but the relevant neural mechanisms have not been fully identified. The present study sought to identify the role of oscillatory alpha activity in that deficit during the process of facial emotion recognition. Neuromagnetic brain activity was monitored while 44 schizophrenia patients and 44 healthy controls viewed 5-s videos showing human faces gradually changing from neutral to fearful or happy expressions or from the neutral face of one poser to the neutral face of another. Recognition performance was determined separately by self-report. Relative to prestimulus baseline, controls exhibited a 10- to 15-Hz power increase prior to full recognition and a 10- to 15-Hz power decrease during the postrecognition phase. These results support recent proposals about the function of alpha-band oscillations in normal stimulus evaluation. The patients failed to show this sequence of alpha power increase and decrease and also showed low 10- to 15-Hz power and high 10- to 15-Hz connectivity during the prestimulus baseline. In light of the proposal that a combination of alpha power increase and functional disconnection facilitates information intake and processing, the finding of an abnormal association of low baseline alpha power and high connectivity in schizophrenia suggests a state of impaired readiness that fosters abnormal dynamics during facial affect recognition.     

Eye movement during facial affect recognition by patients with schizophrenia, using Japanese pictures of facial affect

A possible relationship between recognition of facial affect and aberrant eye movement was examined in patients with schizophrenia. A Japanese version of standard pictures of facial affect was prepared. These pictures of basic emotions (surprise, anger, happiness, disgust, fear, sadness) were shown to 19 schizophrenic patients and 20 healthy controls who identified emotions while their eye movements were measured. The proportion of correct identifications of 'disgust' was significantly lower for schizophrenic patients, their eye fixation time was significantly longer for all pictures of facial affect, and their eye movement speed was slower for some facial affects (surprise, fear, and sadness). One index, eye fixation time for "happiness," showed a significant difference between the high- and low-dosage antipsychotic drug groups. Some expected facial affect recognition disorder was seen in schizophrenic patients responding to the Japanese version of affect pictures, but there was no correlation between facial affect recognition disorder and aberrant eye movement.     

空间频率影响恐惧面孔表情加工的神经通路

恐惧情绪由于其具有威胁性而优先得到有效的加工。其中空间频率作为处理面孔信息的基础成分, 通过不同的神经通路影响恐惧面孔表情的加工。双通路观点认为在皮层下通路上, 低空间频率的恐惧面孔表情存在优先传递性, 高空间频率则主要通过皮层通路对恐惧面孔表情进行精细化加工; 而多通路则能够更加灵活地处理空间频率对情绪加工的影响。未来研究应明确脑区及其子区域在多条通路上的作用, 从而进一步验证视觉信息是如何影响情绪加工的。     

Cognitive habilitation in schizophrenia: A theoretical review and model of treatment

Evidence has accumulated for information processing deficits in schizophrenia. The functional significance of these deficits is only beginning to be understood. There are indications that these deficits may respond to intervention. Training on deficient functions has been demonstrated to relate to improvements in performance. A treatment program of cognitive rehabilitation is deduced from the literature and induced from clinical experience. The treatment is designed to impact directly on the information processing deficits of schizophrenic patients and indirectly to ameliorate functional deficits.     

Cognitive processing of multidimensional stimuli in schizophrenia: formal modeling of judgment speed and content

This article presents a formal, mathematical account of relations between response times on simple cognitive tasks and content of complex judgments involving multiple stimulus dimensions for people with schizophrenia. Changes in multidimensional judgments were viewed as the result of interference from increased stages of encoding with respect to the individual dimensions. Information on dimensional properties encoded earlier in a judgment trial was considered to be more susceptible to loss over the rest of the trial, because of a larger number of encoding stages applied to the remaining dimensional properties. Model predictions were tested with samples of paranoid and nonparanoid schizophrenic participants and controls. Unidimensional encoding speed was assessed by reaction times in an explicit similarity ratings task, and multidimensional judgment content was assessed by the relative importance of different stimulus dimensions to participants' ratings in an implicit similarity ratings task. Results support validity of the model.     

Gibsonian representations and connectionist symbol processing: Prospects for unification

Summary Not long ago the standard view in cognitive science was that representations are symbols in an internal representational system or language of thought and that psychological processes are computations defined over such representations. This orthodoxy has been challenged by adherents of functional analysis and by connectionists. Functional analysis as practiced by Marr is consistent with an analysis of representation that grants primacy to a stands for conception of representation. Connectionism is also compatible with this notion of representation; when conjoined with functional analysis, it provides a means of analyzing psychological systems in term of rules and representations without becoming committed to symbolism. Direct theorists, who rejected the orthodox symbolist conception of representation because it violated their strictures against cognitive mediational mechanisms, should find it possible to accept rules-and-representations and information-processing analyses of the mechanisms of information pickup couched in terms of functional analysis.     

Symbolically speaking: a connectionist model of sentence production

The ability to combine words into novel sentences has been used to argue that humans have symbolic language production abilities. Critiques of connectionist models of language often center on the inability of these models to generalize symbolically (Fodor & Pylyshyn, 1988; Marcus, 1998). To address these issues, a connectionist model of sentence production was developed. The model had variables (role‐concept bindings) that were inspired by spatial representations (Landau & Jackendoff, 1993). In order to take advantage of these variables, a novel dual‐pathway architecture with event semantics is proposed and shown to be better at symbolic generalization than several variants. This architecture has one pathway for mapping message content to words and a separate pathway that enforces sequencing constraints. Analysis of the model's hidden units demonstrated that the model learned different types of information in each pathway, and that the model's compositional behavior arose from the combination of these two pathways. The model's ability to balance symbolic and statistical behavior in syntax acquisition and to model aphasic double dissociations provided independent support for the dual‐pathway architecture.     

Recognition of facial affect in depression

25 depressed patients recognized a sad face with more errors than 25 normal persons and labeled other expressions as sadness when affective content was not recognized. Correct recognitions for 6 affects were related to the portion of the face depicted. Comparisons of responses of 25 patients diagnosed as having anxiety neuroses showed differences in responses from the depressed patients and normal persons.     

The face wins: Stronger automatic processing of affect in facial expressions than words in a modified Stroop task

Affective words and faces each seem to be evaluated automatically, but it is unclear if they differ from one another in perceptual salience as measured by automaticity. The current study examined a possible hierarchy among affective stimuli using a modified photo–word Stroop task. Positive and negative words were superimposed across faces expressing positive (happy) and negative (angry, sad) emotions. Participants categorised the valence of faces and words. Across two experiments, interference effects were seen for both stimulus types. However, larger interference effects occurred during judgements of words than expressions, suggesting affective faces are processed more automatically than affective words. When the strength of positive and negative expressions is compared, angry expressions resulted in a larger interference effect than sad, and happy expressions produce interference similar to that of angry faces. The latter result contrasts with research suggesting potential threat stimuli are processed more automatically than positive stimuli. Implications are discussed.     

ALCOVE: an exemplar-based connectionist model of category learning.

ALCOVE (attention learning covering map) is a connectionist model of category learning that incorporates an exemplar-based representation (Medin & Schaffer, 1978; Nosofsky, 1986) with error-driven learning (Gluck & Bower, 1988; Rumelhart, Hinton, & Williams, 1986). Alcove selectively attends to relevant stimulus dimensions, is sensitive to correlated dimensions, can account for a form of base-rate neglect, does not suffer catastrophic forgetting, and can exhibit 3-stage (U-shaped) learning of high-frequency exceptions to rules, whereas such effects are not easily accounted for by models using other combinations of representation and learning method.     

Interacting neighbors: A connectionist model of retrieval in single-digit multiplication

For most adults, retrieval is the most common way to solve a single-digit multiplication problem (Campbell & Xue, 2001). Many theories have been proposed to describe the underlying mechanism of arithmetical fact retrieval. Testing their validity hinges on evaluating how well they account for the basic findings in mental arithmetic. The most important findings are the problem size effect (small multiplication problems are easier than larger ones; cf. 3 x 2 and 7 x 8), the five effect (problems with 5 are easier than can be accounted for by their size), and the tie effect (problems with identical operands are easier than other problems; cf. 8 x 8 and 8 x 7). We show that all existing theories have difficulties in accounting for one or more of these phenomena A new theory is presented that avoids these difficulties. The basic assumption is that candidate answers to a particular problem are in cooperative/competitive interactions and these interactions favor small, five, and tie problems. The theory is implemented as a connectionist model, and simulation data are described that are in good accord with empirical data.     

A recurrent connectionist model of group biases

Major biases and stereotypes in group judgments are reviewed and modeled from a recurrent connectionist perspective. These biases are in the areas of group impression formation (illusory correlation), group differentiation (accentuation), stereotype change (dispersed vs. concentrated distribution of inconsistent information), and group homogeneity. All these phenomena are illustrated with well-known experiments, and simulated with an autoassociative network architecture with linear activation update and delta learning algorithm for adjusting the connection weights. All the biases were successfully reproduced in the simulations. The discussion centers on how the particular simulation specifications compare with other models of group biases and how they may be used to develop novel hypotheses for testing the connectionist modeling approach and, more generally, for improving theorizing in the field of social biases and stereotype change.     

SLAM: a connectionist model for attention in visual selection tasks

SLAM, the SeLective Attention Model, performs visual selective attention tasks, an analysis of which shows that two processes, object and attribute selection, are both necessary and sufficient. It is based upon the McClelland and Rumelhart (1981) model for visual word recognition, with the addition of a response selection and evaluation mechanism. The responses may be correct or incorrect and, in particular conditions, SLAM may not make a response at all. Moreover, it allows for the generation of specific responses in time. SLAM's main characteristics are parallelism restricted by competition within modules, heterarchical processing in a hierarchical structure, and generation of responses as a result of relaxation given the conjoint constraints of stimulation, object, and attribute selection. The model is considered to represent an individual subject performing filtering tasks and demonstrates appropriate selective behavior. It is also tested quantitatively using a single tentative set of model parameters. The study reports simulations of four different filtering experiments, modeling response latencies, and error proportions. Specifications are made to take account of instructions, previous trials, and the effect of a barmarker cue and of asynchronies in stimulus and cue onsets. The model is then extended in order to provide simulations of a number of Stroop experiments, which can be regarded as filtering tasks with nonequivalent stimuli. The extension required for Stroop simulations is the addition of direct connections between compatible stimulus and response aspects. The direct connections do not affect the simulation of simpler filtering tasks. A variety of different experiments carried out by different authors is simulated. The model is discussed in terms of how modular architecture and the interaction of excitation and inhibition generate facilitation or inhibition of response latencies.     

Perceptual skill in decoding facial affect

The perceptual skill in identifying the briefly exposed photographs of facial affect was examined with 75 men and 75 women who were asked to judge six cross-culturally recognizable slides, each expressing one of the six emotions exposed at three different time intervals. Each subject was required to give six judgments and the number of correct responses was considered his score. Analysis by a 3 X 2 factorial design indicated the longer the exposure of the photograph the better the recognition. Although there was no over-all sex difference, analysis by emotions confirmed significantly better accuracy by the women judging 'sadness' than by men, and men were more accurate for 'anger' than were women.     

Recognition of facial affect in psychopathic offenders

The authors examined the reliability of facial affect processing deficits found in psychopathic individuals (R. Blair et al., 2004) and whether they could be modified by attentional set. One hundred eleven offenders, classified using the Psychopathy Checklist--Revised (R. Hare, 2003) and Welsh Anxiety Scale (G. Welsh, 1956), performed a facial affect recognition task under 2 conditions. On the basis of research linking psychopathy, amygdala dysfunction, and deficits in facial affect recognition, the authors predicted that psychopathic offenders would display performance deficits when required to identify the emotional expression of particular faces. In addition, given evidence linking the affective processing deficits in psychopathy to focus of attention, the authors predicted that any deficits in facial affect processing would disappear when participants could anticipate which affective cues would be relevant on a given trial. Contrary to expectation, psychopathic offenders performed as well as controls in both conditions. The authors conclude that the conditions that reveal affective deficits in psychopathic individuals require further specification.     

Learning to attend: a connectionist model of situated language comprehension

Evidence from numerous studies using the visual world paradigm has revealed both that spoken language can rapidly guide attention in a related visual scene and that scene information can immediately influence comprehension processes. These findings motivated the coordinated interplay account ( Knoeferle & Crocker, 2006 ) of situated comprehension, which claims that utterance-mediated attention crucially underlies this closely coordinated interaction of language and scene processing. We present a recurrent sigma-pi neural network that models the rapid use of scene information, exploiting an utterance-mediated attentional mechanism that directly instantiates the CIA. The model is shown to achieve high levels of performance (both with and without scene contexts), while also exhibiting hallmark behaviors of situated comprehension, such as incremental processing, anticipation of appropriate role fillers, as well as the immediate use, and priority, of depicted event information through the coordinated use of utterance-mediated attention to the scene.     

Recognition of facial affect in Borderline Personality Disorder

Patients with Borderline Personality Disorder (BPD) have been described as emotionally hyperresponsive, especially to anger and fear in social contexts. The aim was to investigate whether BPD patients are more sensitive but less accurate in terms of basic emotion recognition, and show a bias towards perceiving anger and fear when evaluating ambiguous facial expressions. Twenty-five women with BPD were compared with healthy controls on two different facial emotion recognition tasks. The first task allowed the assessment of the subjective detection threshold as well as the number of evaluation errors on six basic emotions. The second task assessed a response bias to blends of basic emotions. BPD patients showed no general deficit on the affect recognition task, but did show enhanced learning over the course of the experiment. For ambiguous emotional stimuli, we found a bias towards the perception of anger in the BPD patients but not towards fear. BPD patients are accurate in perceiving facial emotions, and are probably more sensitive to familiar facial expressions. They show a bias towards perceiving anger, when socio-affective cues are ambiguous. Interpersonal training should focus on the differentiation of ambiguous emotion in order to reduce a biased appraisal of others.