Selective attention to angry faces in clinical social phobia

This study investigated the time course of attentional responses to emotional facial expressions in a clinical sample with social phobia. With a visual probe task, photographs of angry, happy, and neutral faces were presented at 2 exposure durations: 500 and 1250 ms. At 500 ms, the social phobia group showed enhanced vigilance for angry faces, relative to happy and neutral faces, in comparison with normal controls. In the 1250-ms condition, there were no significant attentional biases in the social phobia group. Results are consistent with a bias in initial orienting to threat cues in social anxiety. Findings are discussed in relation to recent cognitive models of anxiety disorders.     

Time course of visual attention with emotional faces

When a briefly presented and then masked visual object is identified, it impairs the identification of the second target for several hundred milliseconds. This phenomenon is known as attentional blink or attentional dwell time. The present study is an attempt to investigate the role of salient emotional information in shifts of covert visual attention over time. Two experiments were conducted using the dwell time paradigm, in which two successive targets are presented at different locations with a variable stimulus onset asynchrony (SOA). In the first experiment, real emotional faces (happy/sad) were presented as the first target, and letters (L/T) were presented as the second target. The order of stimulus presentation was reversed in the second experiment. In the first experiment, identification of the letters preceded by happy faces showed better performance than did those preceded by sad faces at SOAs less than 200 msec. Similarly, happy faces were identified better than sad faces were at short SOAs in Experiment 2. The results show that the time course of visual attention is dependent on emotional content of the stimuli. The findings indicate that happy faces are associated with distributed attention or broad scope of attention and require fewer attentional resources than do sad faces.     

Covert and overt orienting of attention to emotional faces in anxiety

Attentional biases for emotional faces were investigated in high, medium, and low anxiety groups (N = 54) using a probe detection task. Four types of facial expression (threat, sad, happy, neutral) were used to examine the specificity of the bias. Attentional bias measures were derived from manual reaction times (RTs) to probes and the direction of initial eye movement (EM) to the faces. The RT data indicated enhanced vigilance for threat rather than neutral faces in high and medium, but not low, state anxiety. The bias for negative faces appeared to be a combined function of stimulus threat value and the individual's anxiety level. The RT bias did not seem to depend on overt orienting, as many participants made few EMs. However, those who made frequent EMs to the faces showed concordance between the RT and EM bias measures, and so the RT measure of attentional bias for negative versus positive faces at 500 ms appears to provide a valid index of the direction of initial orienting to emotional stimuli. There was no evidence of an anxiety - related bias for happy faces (predicted by the emotionality hypothesis), nor a dysphoria - related bias for sad faces. However, increased dysphoria scores were associated with reduced attentiveness to happy faces.     

Selective attention determines emotional responses to novel visual stimuli

Distinct complex brain systems support selective attention and emotion, but connections between them suggest that human behavior should reflect reciprocal interactions of these systems. Although there is ample evidence that emotional stimuli modulate attentional processes, it is not known whether attention influences emotional behavior. Here we show that evaluation of the emotional tone (cheery/dreary) of complex but meaningless visual patterns can be modulated by the prior attentional state (attending vs. ignoring) used to process each pattern in a visual selection task. Previously ignored patterns were evaluated more negatively than either previously attended or novel patterns. Furthermore, this emotional devaluation of distracting stimuli was robust across different emotional contexts and response scales. Finding that negative affective responses are specifically generated for ignored stimuli points to a new functional role for attention and elaborates the link between attention and emotion. This finding also casts doubt on the conventional marketing wisdom that any exposure is good exposure.     

Selective orienting of attention to masked threat faces in social anxiety

The aims of the study were two-fold: to examine whether previous evidence of a pre-attentive bias for masked threat faces in anxious individuals could be replicated, and to assess the relationship between the predicted bias and measures of trait and social anxiety. Pairs of face stimuli were briefly displayed and masked in a modified version of the visual probe task. Results indicated that high anxious individuals were faster to respond to probes occurring in the spatial location of masked threat rather than neutral faces; consistent with their attention being automatically captured by sub-threshold threat cues. Furthermore, this vigilance effect for masked threat faces appeared to be primarily a function of social anxiety and social avoidance, rather than trait anxiety. It was also more apparent when threat faces were presented in the left visual field, suggestive of right hemisphere involvement.     

Atypical depression: enhanced right hemispheric dominance for perceiving emotional chimeric faces

Two studies compared hemispatial bias for perceiving chimeric faces in patients having either atypical or typical depression and healthy controls. A total of 245 patients having major depressive disorder (MDD) or dysthymia (164 with atypical features) and 115 controls were tested on the Chimeric Faces Test. Atypical depression differed from typical depression and controls in showing abnormally large right hemisphere bias. This was present in patients having either MDD or dysthymia and was not related to anxiety, physical anhedonia, or vegetative symptoms. In contrast, patients having MDD with melancholia showed essentially no right hemisphere bias. This is further evidence that atypical depression is a biologically distinct subtype and underscores the importance of this diagnostic distinction for neurophysiologic studies.     

Neurocognitive mechanisms behind emotional attention: Inverse effects of anodal tDCS over the left and right DLPFC on gaze disengagement from emotional faces

Background

Attention to relevant emotional information in the environment is an important process related to vulnerability and resilience for mood and anxiety disorders. In the present study, the effects of left and right dorsolateral prefrontal cortex (i.e., DLPFC) stimulation on attentional mechanisms of emotional processing were tested and contrasted.

Methods

A sample of 54 healthy participants received 20 min of active and sham anodal transcranial direct current stimulation (i.e., tDCS) either of the left (n = 27) or of the right DLPFC (n = 27) on two separate days. The anode electrode was placed over the left or the right DLPFC, the cathode over the corresponding contra lateral supraorbital area. After each neurostimulation session, participants completed an eye-tracking task assessing direct processes of attentional engagement towards and attentional disengagement away from emotional faces (happy, disgusted, and sad expressions).

Results

Compared to sham, active tDCS over the left DLPFC led to faster gaze disengagement, whereas active tDCS over the right DLPFC led to slower gaze disengagement from emotional faces. Between-group comparisons showed that such inverse change patterns were significantly different and generalized for all types of emotion.

Conclusions

Our findings support a lateralized role of left and right DLPFC activity in enhancing/worsening the top-down regulation of emotional attention processing. These results support the rationale of new therapies for affective disorders aimed to increase the activation of the left over the right DLPFC in combination with attentional control training, and identify specific target attention mechanisms to be trained.

     

Affective learning increases sensitivity to graded emotional faces

How does the affective significance of emotional faces affect perceptual decisions? We manipulated affective significance by pairing 100% fearful faces with aversive electrical stimulation and hypothesized that increasing the significance of a stimulus via its prior history would lead to enhanced processing. After fear conditioning, participants viewed graded emotional faces that ranged from neutral to fearful. Faces were shown either in a color that was previously paired with shock or a color not paired with shock during conditioning. Increases in the frequency of "fearful" responses for faces shown in the shock-paired color were most robust for faces at intermediate intensity levels (40-60% fearful). Psychometric fits to the data revealed significant increased sensitivity for shock-paired relative to unpaired faces. Thus, despite identical physical features for shock-paired and unpaired stimuli (aside from the color, which was counterbalanced), more frequent (and faster) "fearful" responses were made when participants viewed affectively significant stimuli.     

Focusing on fear: Attentional disengagement from emotional faces

Evidence suggests that anxiety is associated with a shift of visual attention toward threatening stimuli in the environment, such as facial expressions (Mogg & Bradley, 1999). More recent evidence, however, indicates that anxiety may be better characterized by a failure to rapidly disengage the visual attention system away from threat-related facial expressions (Fox, Russo, Bowles, & Dutton, 2001). The present study further investigates this delayed disengagement hypothesis. Results show that high trait-anxious individuals, in contrast to low trait-anxious individuals, take longer to classify peripheral target letters when fearful facial expressions were presented at fixation relative to sad, happy, or neutral expressions. These findings demonstrate a specific tendency to dwell on fear-relevant stimuli, as opposed to negative information in general. These findings are considered from an evolutionary perspective and the possible role of delayed disengagement from threat in the maintenance of anxiety states is also discussed.     

Focusing on fear: attentional disengagement from emotional faces

Evidence suggests that anxiety is associated with a shift of visual attention toward threatening stimuli in the environment, such as facial expressions (Mogg & Bradley, 1999). More recent evidence, however, indicates that anxiety may be better characterized by a failure to rapidly disengage the visual attention system away from threat-related facial expressions (Fox, Russo, Bowles, & Dutton, 2001). The present study further investigates this delayed disengagement hypothesis. Results show that high trait-anxious individuals, in contrast to low trait-anxious individuals, take longer to classify peripheral target letters when fearful facial expressions were presented at fixation relative to sad, happy, or neutral expressions. These findings demonstrate a specific tendency to dwell on fear-relevant stimuli, as opposed to negative information in general. These findings are considered from an evolutionary perspective and the possible role of delayed disengagement from threat in the maintenance of anxiety states is also discussed.     

Temporal processing of emotional stimuli: the capture and release of attention by angry faces

Neuroimaging data suggest that emotional information, especially threatening faces, automatically captures attention and receives rapid processing. While this is consistent with the majority of behavioral data, behavioral studies of the attentional blink (AB) additionally reveal that aversive emotional first target (T1) stimuli are associated with prolonged attentional engagement or "dwell" time. One explanation for this difference is that few AB studies have utilized manipulations of facial emotion as the T1. To address this, schematic faces varying in expression (neutral, angry, happy) served as the T1 in the current research. Results revealed that the blink associated with an angry T1 face was, primarily, of greater magnitude than that associated with either a neutral or happy T1 face, and also that initial recovery from this processing bias was faster following angry, compared with happy, T1 faces. The current data therefore provide important information regarding the time-course of attentional capture by angry faces: Angry faces are associated with both the rapid capture and rapid release of attention.     

Paying attention to emotional images with impact

Emotional stimuli receive high processing priority in attention and memory. This processing "advantage" is generally thought to be predominantly mediated by arousal. However, recent data suggest that ratings of an image's affective "impact" may be a better predictor of recollection than arousal or valence. One interpretation of these findings is that high-impact images may draw an individual's attention, thus facilitating subsequent processing. We investigated the allocation of visual attention to negative emotional images that differed in impact but were matched for valence, arousal, and other characteristics. Participants viewed a central image flanked by 2 neutral indoor or outdoor scenes and made speeded judgments about whether the neutral scenes matched. In Experiment 1, responses were slower on high-impact relative to low-impact or neutral trials. In Experiment 2, responses on high-arousal relative to low-arousal trials did not differ significantly. These data provide evidence for differential allocation of attention to distinct sets of negative, equally arousing images, and argue against the prevailing view that heightened attention to and processing of emotional stimuli relate simply to arousal or valence.     

Event-related potentials related to normal and morphed emotional faces

S. Bentin and L. Y. Deouell (2000) have suggested that face recognition is achieved through a special-purpose neural mechanism, and its existence can be identified by a specific event-related potential (ERP) correlate, the N170 effect. In the present study, the authors explored the structural significance of N170 by comparing normal vs. morphed stimuli. They used a morphing procedure that allows a fine modification of some perceptual details (first-order relations). The authors also aimed to verify the independence of face identification from other cognitive mechanisms, such as comprehension of emotional facial expressions, by applying an emotion-by-emotion analysis to examine the emotional effect on N170 ERP variation. They analyzed the peak amplitude and latency variables in the temporal window of 120-180 ms. The ERP correlate showed a classic N170 ERP effect, more negative and more posteriorly distributed for morphed faces compared with normal faces. In addition, they found a lateralization effect, with a greater right-side distribution of the N170, but not directly correlated to the morphed or normal conditions. Two cognitive codes, structural and expression, are discussed, and the results are compared with the multilevel model proposed by V. Bruce and A. W. Young (1986, 1998).     

Anxiety and sensitivity to eye gaze in emotional faces

This paper reports three studies in which stronger orienting to perceived eye gaze direction was revealed when observers viewed faces showing fearful or angry, compared with happy or neutral, emotional expressions. Gaze-related spatial cueing effects to laterally presented fearful faces and centrally presented angry faces were also modulated by the anxiety level of participants, with high- but not low-state anxious individuals revealing enhanced shifts of attention. In contrast, both high- and low-state anxious individuals demonstrated enhanced orienting to averted gaze when viewing laterally presented angry faces. These results provide novel evidence for the rapid integration of facial expression and gaze direction information, and for the regulation of gaze-cued attention by both the emotion conveyed in the perceived face and the degree of anxiety experienced by the observer.     

Selective attention to the chemosensory modality

Previous studies have shown that behavioral responses to auditory, visual, and tactile stimuli are modulated by expectancies regarding the likely modality of an upcoming stimulus (see Spence & Driver, 1997). In the present study, we investigated whether people can also selectively attend to the chemosensory modality (involving responses to olfactory, chemical, and painful stimuli). Participants made speeded spatial discrimination responses (left vs. right) to an unpredictable sequence of odor and tactile targets. Odor stimuli were presented to either the left or the right nostril, embedded in a birhinally applied constant airstream. Tactile stimuli were presented to the left or the right hand. On each trial, a symbolic visual cue predicted the likely modality for the upcoming target (the cue was a valid predictor of the target modality on the majority of trials). Response latencies were faster when targets were presented in the expected modality than when they were presented in the unexpected modality, showing for the first time that behavioral responses to chemosensory stimuli can be modulated by selective attention.     

Self-esteem moderates affective reactions to briefly presented emotional faces

According to the sociometer hypothesis individuals with low self-esteem experience increased negative affect in response to negative social stimuli, even when these stimuli are not perceived consciously. Using an affective priming paradigm, the present study examined whether trait self-esteem would moderate mood following briefly presented facial expressions. Results from 43 undergraduates revealed that, after controlling for baseline mood, anxiety and depression, the degree of negative affect experienced by the participants following exposure to expressions of anger and disgust varied as a function of their self-esteem. Implications for individuals with low-self esteem and our understanding of the link between self-esteem and negative affect are discussed.     

Selective attention to words and colours

In the Stroop test it is found that the presence of words interferes with the task of naming colours. The usual account of this phenomenon is that the names of words are more readily obtained than are the names of colours and that the production of the latter is interfered with by the spontaneous occurrence of the former. Treisman and Fearnley (1969) have suggested a modification of the usual account such that stress is laid on the correspondence between the nature of the response (“verbal”) and that feature of a stimulus which will dominate. The present experiments seem to demonstrate that the data which Treisman and Fearnley use in support of their claim can be attributed to the strategy which their subjects adopted in their task. Some further observations are made concerning the different levels at which comparisons can be made between two stimuli.     

Selective attention to multidimensional auditory stimuli

Event-related brain potentials (ERPs) elicited by multidimensional auditory stimuli were recorded from the scalp in a selective-attention task. Subjects listened to tone pips varying orthogonally between two levels each of pitch, location, and duration and responded to longer duration target stimuli having specific values of pitch and location. The discriminability of the pitch and location attributes was varied between groups. By examining the ERPs to tones that shared pitch and/or locational cues with the designated target, we inferred interrelationships among the processing of these attributes. In all groups, stimuli that failed to match the target tone in an easily discriminable cue elicited only transitory ERP signs of selective processing. Tones sharing the "easy" but not the "hard" cue with the target elicited ERPs that indicated more extensive processing, but not as extensive as stimuli sharing both cues. In addition, reaction times and ERP latencies to the designated targets were not influenced by variations in the discriminability of pitch and location. This pattern of results is consistent with parallel, self-terminating models and holistic models of processing and contradicts models specifying either serial or exhaustive parallel processing of these dimensions. Both the parallel, self-terminating models and the holistic models provide a generalized mechanism for hierarchical stimulus selections that achieve an economy of processing, an underlying goal of classic, multiple-stage theories of selective attention.     

Selective attention in major depression: clinical retardation and cognitive inhibition]

Relationships between clinical retardation (measured by the Hamilton Depression Inventory) and selective attention (measured with a computerized version of the Stroop word colour test) were studied in a population of 21 depressed patients. Stroop interference was higher in depressed patients than in normals. Desynchronized presentations of the distractor and the target and intervals between responses and succeeding stimuli permitted depressed subjects to respectively apply and lift inhibition of the distractor so that their interference was reduced to control levels. Finally, successive inhibition scores were correlated with the retardation score in depressed subjects. The results are consistent with the hypothesis of a retardation in the application and the lifting of cognitive inhibition in depression.     

Selective attention to elements in working memory

Three experiments with an arithmetic working memory task examine the object switch effect first reported by Garavan (1998), which was interpreted as evidence for a focus of attention within working memory. Experiments 1a and 1b showed object switch costs with a task that requires selective access to items in working memory, but did not involve counting, and did not require updating of working memory contents, thus ruling out two alternative explanations of Garavan's results. Experiment 2 showed object switch costs with a task that required no selective access to working memory contents, but involved updating, thus providing evidence for a second component to the overall object switch costs. Further analyses revealed that the object switch cost increased with memory set size; that there were (smaller) switch costs when the switch was to an item of the same type; that repeating an arithmetic operation does not have the same effect as repeating the object it is applied to; and that object switching is not mediated by backward inhibition of the previously focused object.