Written threat: Electrophysiological evidence for an attention bias to affective words in social anxiety disorder

Social anxiety disorder (SAD) is associated with heightened sensitivity to threat cues, typically represented by emotional facial expressions. To examine if this bias can be transferred to a general hypersensitivity or whether it is specific to disorder relevant cues, we investigated electrophysiological correlates of emotional word processing (alpha activity and event-related potentials) in 20 healthy participants and 20 participants with SAD. The experimental task was a silent reading of neutral, positive, physically threatening and socially threatening words (the latter were abusive swear words) while responding to a randomly presented dot. Subsequently, all participants were asked to recall as many words as possible during an unexpected recall test. Participants with SAD showed blunted sensory processing followed by a rapid processing of emotional words during early stages (early posterior negativity – EPN). At later stages, all participants showed enhanced processing of negative (physically and socially threatening) compared to neutral and positive words (N400). Moreover, at later processing stages alpha activity was increased specifically for negative words in participants with SAD but not in healthy controls. Recall of emotional words for all subjects was best for socially threatening words, followed by negative and positive words irrespective of social anxiety. The present findings indicate that SAD is associated with abnormalities in emotional word processing characterised by early hypervigilance to emotional cues followed by cognitive avoidance at later processing stages. Most importantly, the specificity of these attentional biases seems to change as a function of time with a general emotional bias at early and a more specific bias at later processing stages.     

What artificial grammar learning reveals about the neurobiology of syntax

In this paper we examine the neurobiological correlates of syntax, the processing of structured sequences, by comparing FMRI results on artificial and natural language syntax. We discuss these and similar findings in the context of formal language and computability theory. We used a simple right-linear unification grammar in an implicit artificial grammar learning paradigm in 32 healthy Dutch university students (natural language FMRI data were already acquired for these participants). We predicted that artificial syntax processing would engage the left inferior frontal region (BA 44/45) and that this activation would overlap with syntax-related variability observed in the natural language experiment. The main findings of this study show that the left inferior frontal region centered on BA 44/45 is active during artificial syntax processing of well-formed (grammatical) sequence independent of local subsequence familiarity. The same region is engaged to a greater extent when a syntactic violation is present and structural unification becomes difficult or impossible. The effects related to artificial syntax in the left inferior frontal region (BA 44/45) were essentially identical when we masked these with activity related to natural syntax in the same subjects. Finally, the medial temporal lobe was deactivated during this operation, consistent with the view that implicit processing does not rely on declarative memory mechanisms that engage the medial temporal lobe. In the context of recent FMRI findings, we raise the question whether Broca’s region (or subregions) is specifically related to syntactic movement operations or the processing of hierarchically nested non-adjacent dependencies in the discussion section. We conclude that this is not the case. Instead, we argue that the left inferior frontal region is a generic on-line sequence processor that unifies information from various sources in an incremental and recursive manner, independent of whether there are any processing requirements related to syntactic movement or hierarchically nested structures. In addition, we argue that the Chomsky hierarchy is not directly relevant for neurobiological systems.     

Attachment anxiety and attentional control predict immediate and delayed emotional Stroop interference

Attachment anxiety has been associated with a hyperactivating response to threat. A modified emotional Stroop task was used to investigate temporal characteristics of the threat response by assessing response latencies to interpersonally threatening words (immediate interference) and two directly subsequent neutral filler words (delayed interference). Greater immediate and delayed interference to threatening words was observed (n = 125), with higher levels of attachment anxiety associated with immediate interference to threatening cues, and lower levels with delayed interference. Thus, attachment anxiety was related to the speed at which moderate perceived threat disrupted ongoing processes under top-down attentional control. Furthermore, top-down attentional control moderated the extent to which immediate or delayed interference was observed. Among participants who demonstrated relatively stronger top-down attentional control, immediate and delayed interference to threatening cues was minimal, suggesting that results involving emotional Stroop interference were primarily attributable to participants with relatively weaker top-down attentional control. The implications of these findings are considered within the broader context of performance-based and neuroimaging research, with suggestions for future applied research.     

Associations between four types of childhood neglect and personality disorder symptoms during adolescence and early adulthood: findings of a community-based longitudinal study

Data from a community-based longitudinal study were used to investigate the association between childhood neglect and personality disorder (PD) symptom levels during adolescence and early adulthood. Psychosocial and psychiatric interviews were administered to a representative sample of 738 youths and their mothers from upstate New York in 1975, 1983, 1985-1986, and 1991-1993. Evidence of childhood cognitive, emotional, physical, and supervision neglect was obtained from the maternal interviews that were conducted in 1975, 1983, and 1985-1986, and from New York State records. PDs were assessed among the youths in 1985-1986, when they were adolescents, and in 1991-1993, when they were young adults. Findings indicated that childhood emotional, physical, and supervision neglect were associated with increased risk for PDs and with elevated PD symptom levels during adolescence and early adulthood, after age, sex, childhood physical or sexual abuse, other types of childhood neglect, and cooccurring PD symptoms were controlled statistically. Childhood emotional neglect was associated with increased risk for avoidant PD and with paranoid and Cluster A PD symptom levels during adolescence and early adulthood. Childhood physical neglect was associated with increased risk for schizotypal PD and with Cluster A PD symptom levels during adolescence and early adulthood. Childhood supervision neglect was associated with increased risk for passive-aggressive and Cluster B PDs and with borderline, paranoid, and passive-aggressive PD symptom levels during adolescence and early adulthood. The present findings suggest that childhood emotional, physical, and supervision neglect may play a role in the etiology of some PDs.     

Learning related modulation of functional retrieval networks in man

The medial temporal lobe has been implicated in studies of episodic memory tasks involving spatio-temporal context and object-location conjunctions. We have previously demonstrated that an increased level of practice in a free-recall task parallels a decrease in the functional activity of several brain regions, including the medial temporal lobe, the prefrontal, the anterior cingulate, the anterior insular, and the posterior parietal cortices, that in concert demonstrate a move from elaborate controlled processing towards a higher degree of automaticity. Here we report data from two experiments that extend these initial observations. We used a similar experimental approach but probed for effects of retrieval paradigms and stimulus material. In the first experiment we investigated practice related changes during recognition of object-location conjunctions and in the second during free-recall of pseudo-words. Learning in a neural network is a dynamic consequence of information processing and network plasticity. The present and previous PET results indicate that practice can induce a learning related functional restructuring of information processing. Different adaptive processes likely subserve the functional re-organisation observed. These may in part be related to different demands for attentional and working memory processing. It appears that the role(s) of the prefrontal cortex and the medial temporal lobe in memory retrieval are complex, perhaps reflecting several different interacting processes or cognitive components. We suggest that an integrative interactive perspective on the role of the prefrontal and medial temporal lobe is necessary for an understanding of the processing significance of these regions in learning and memory. It appears necessary to develop elaborated and explicit computational models for prefrontal and medial temporal functions in order to derive detailed empirical predictions, and in combination with an efficient use and development of functional neuroimaging approaches, to further the understanding of the processing significance of these regions in memory.     

Depressive rumination and the emotional control circuit: An EEG localization and effective connectivity study

Ruminations are repetitive thoughts associated with symptoms, causes, and consequences of one’s negative feelings. The objective of this study was to explore the neuronal basis of depressive rumination in a non-clinical population within the context of emotional control. Participants scoring high or low on the tendency to ruminate scale took part in the EEG experiment. Their EEG data were collected during a state of induced depressive ruminations and compared with positive and neutral conditions. We hypothesized that both groups would differ according to the level of activation and effective connectivity among the structures involved in the emotional control circuit. Clustering of independent components, together with effective connectivity (Directed Transfer Function), was performed using the EEG signal. The main findings involved decreased activation of the left dorsolateral prefrontal cortex (DLPFC) and increased activation of the left temporal lobe structures in the highly ruminating group. The latter result was most pronounced during the ruminative condition. Decreased information from the left DLPFC to the left temporal lobe structures was also found, leading to the conclusion that hypoactivation of the left DLPFC and its inability to modulate the activation of the left temporal lobe structures is crucial for the ruminative tendencies.     

Electrophysiological spatiotemporal dynamics during implicit visual threat processing

Numerous studies have found evidence for corticolimbic theta band electroencephalographic (EEG) oscillations in the neural processing of visual stimuli perceived as threatening. However, varying temporal and topographical patterns have emerged, possibly due to varying arousal levels of the stimuli. In addition, recent studies suggest neural oscillations in delta, theta, alpha, and beta-band frequencies play a functional role in information processing in the brain. This study implemented a data-driven PCA based analysis investigating the spatiotemporal dynamics of electroencephalographic delta, theta, alpha, and beta-band frequencies during an implicit visual threat processing task. While controlling for the arousal dimension (the intensity of emotional activation), we found several spatial and temporal differences for threatening compared to nonthreatening visual images. We detected an early posterior increase in theta power followed by a later frontal increase in theta power, greatest for the threatening condition. There was also a consistent left lateralized beta desynchronization for the threatening condition. Our results provide support for a dynamic corticolimbic network, with theta and beta band activity indexing processes pivotal in visual threat processing.     

Lateralized spatial and object memory encoding in entorhinal and perirhinal cortices

The perirhinal and entorhinal cortices are critical components of the medial temporal lobe (MTL) declarative memory system. Study of their specific functions using blood oxygenation level-dependent (BOLD) functional magnetic resonance imaging (fMRI), however, has suffered from severe magnetic susceptibility signal dropout resulting in poor temporal signal-to-noise (tSNR) and thus weak BOLD signal detectability. We have demonstrated that higher spatial resolution in the z-plane leads to improved BOLD fMRI signal quality in the anterior medial temporal lobes when using a 16-element surface coil array at 3 T (Tesla). Using this technique, the present study investigated the roles of the anterior medial temporal lobe, particularly the entorhinal and perirhinal cortices, in both object and spatial memory. Participants viewed a series of fractal images and were instructed to encode either the object's identity or location. Object and spatial recognition memory were tested after 18-sec delays. Both the perirhinal and entorhinal cortices were active during the object and spatial encoding tasks. In both regions, object encoding was biased to the left hemisphere, whereas spatial encoding was biased to the right. A similar hemispheric bias was evident for recognition memory. Recent animal studies suggest functional dissociations among regions of the entorhinal cortex for spatial vs. object processing. Our findings suggest that this process-specific distinction may be expressed in the human brain as a hemispheric division of labor.     

Childhood maltreatment is associated with increased neural response to ambiguous threatening facial expressions in adulthood: Evidence from the late positive potential

Childhood maltreatment increases lifetime vulnerability for psychopathology. One proposed mechanism for this association is that early maltreatment increases vigilance for and attention to subtle threat cues, persisting outside of the environment in which maltreatment occurs. To test this possibility, the present study examined neural responses to ambiguous and nonambiguous threatening facial expressions in a sample of 25 adults reporting a history of low-to-moderate levels of abuse in childhood and 46 reporting no or low levels of childhood maltreatment. The measure of neural response used was the late positive potential (LPP), a neural marker of sustained attention to motivationally salient information that is sensitive to subtle variation in emotional content. Participants passively viewed angry–neutral and fearful–neutral face blends and rated emotional intensity for each face. In the maltreated group, as fearful faces increased in emotional intensity, the LPP similarly increased, suggesting increased sensitivity to subtle variation in threatening content. Moreover, the LPP at each level of emotional intensity was not related to current symptoms of anxiety and depression. However, contrary to our hypotheses, adults with a history of abuse did not rate angry or fearful faces as more threatening, nor did they exhibit a larger LPP to angry faces, compared to controls. These findings suggest that childhood maltreatment may be associated with increased sensitivity to ambiguous threatening information in adulthood.     

Pleasing frowns, disappointing smiles: an ERP investigation of counterempathy

The biological predisposition to resonate emotionally with another person is regarded as a critical aspect of social interaction. There are, however, situations in which the emotional response to others is discordant with their emotional experience. Using event-related potentials, the present study investigated the neural underpinnings of this phenomenon, termed "counterempathy." Participants played a card game under the belief that they were playing jointly with another player who sat in an adjoining room and whose smiles and frowns in response to winning or losing in the game they could observe on a computer screen. Depending upon the experimental setting, the other player's facial expressions conveyed either of two opposing values to the participant. In the empathic setting, his emotional expressions were congruent with the participant's outcome (win or loss), whereas in the counterempathic setting, they indicated incongruent outcomes. Results revealed a reversed pattern of brain responses to facial expressions between congruent and incongruent conditions at ~170 ms (N170) over the temporal cortex. That is, N170 was sensitive to frowns in the congruent condition and to smiles in the incongruent condition, both indicating losses for the participant. Furthermore, frowns in the incongruent condition yielded larger medial frontal negativity (MFN) over the medial prefrontal cortex, which correlated with the subjective pleasantness about one's own winning in the incongruent condition. These findings demonstrate that (1) counterempathic responses are associated with modulation of early sensory processing of emotional cues, (2) that MFN is sensitive to the detection of another person's loss during positive inequity, and (3) that MFN is associated with a pleasant feeling during positive inequity, which is possibly related to "Schadenfreude."     

The effect of bicephalic stimulation of the dorsolateral prefrontal cortex on the attentional bias for threat: A transcranial direct current stimulation study

Previous stimulation studies demonstrated that the dorsolateral prefrontal cortex (DLPFC) is involved in threat processing. According to a model of emotional processing, an unbalance between the two DLPFCs, with a hyperactivation of right frontal areas, is involved in the processing of negative emotions and genesis of anxiety. In the present study, we investigated the role of the right and left DLPFC in threat processing in healthy women who also completed the State-Trait Anxiety Inventory (STAI). We simultaneously modulated the activity of the right and left dorsolateral prefrontal cortex by applying bicephalic transcranial direct current stimulation (tDCS) before participants completed a modified version of the classic Posner task using threatening and nonthreatening stimuli as spatial cues. Anodal stimulation on the right DLPFC with a simultaneous cathodal stimulation over the left side induced a disengagement bias in individuals with low STAI scores and a facilitation bias in individuals with high STAI scores. Anodal stimulation on the left DLPFC with the simultaneous cathodal stimulation over the right side did not affect threat processing. The findings of the present study provided specific support to the hypothesis that unbalanced activation between left and right hemispheres with enhanced activation of the right DLPFC is critical in early top-down threat processing in healthy individuals.     

Behavioral and fMRI evidence that cognitive ability modulates the effect of semantic context on speech intelligibility

Text cues facilitate the perception of spoken sentences to which they are semantically related (Zekveld, Rudner, et al., 2011). In this study, semantically related and unrelated cues preceding sentences evoked more activation in middle temporal gyrus (MTG) and inferior frontal gyrus (IFG) than nonword cues, regardless of acoustic quality (speech in noise or speech in quiet). Larger verbal working memory (WM) capacity (reading span) was associated with greater intelligibility benefit obtained from related cues, with less speech-related activation in the left superior temporal gyrus and left anterior IFG, and with more activation in right medial frontal cortex for related versus unrelated cues. Better ability to comprehend masked text was associated with greater ability to disregard unrelated cues, and with more activation in left angular gyrus (AG). We conclude that individual differences in cognitive abilities are related to activation in a speech-sensitive network including left MTG, IFG and AG during cued speech perception.     

Verbal and Nonverbal Emotional Memory Following Unilateral Amygdala Damage

The amygdala is involved in the normal facilitation of memory by emotion, but the separate contributions of the left and right amygdala to memory for verbal or nonverbal emotional material have not been investigated. Fourteen patients with damage to the medial temporal lobe including the amygdala (seven left, seven right), 18 brain-damaged, and 36 normal controls were exposed to emotional and neutral pictures accompanied by verbal narratives. Memory for both narratives and pictures was assessed with a free recall test 24 h later. Subjects with left amygdala damage failed to show the normally robust enhancement of memory for verbal and nonverbal emotional stimuli. The group with right amygdala damage showed the normal pattern of facilitation of memory by emotion for both verbal and nonverbal stimuli despite an overall reduction in memory performance. Furthermore, subjects with left amygdala damage were disproportionately impaired on memory for emotional narratives as compared with memory for emotional pictures. The latter finding offers partial support for a lateralized and material-specific pattern of the amygdala's contribution to emotional memory.     

Neurodevelopmental differences in emotional prosody in normal children and children with left and right temporal lobe epilepsy

Emotional prosody, which has been defined as the emotional aspects of speech which communicate pleasure, fear, sorrow, anger, etc., has been demonstrated to be primarily a function of the nondominant hemisphere (typically, the right hemisphere) in adult populations. However, few researchers have addressed the developmental or lateralized nature of emotional prosody in children. In this study, an instrument was developed to measure the receptive aspects of emotional prosody in pediatric populations and administered to normal children ages 6 to 11 years old. An analysis of variance revealed significant age-related differences. Additionally, the instrument was administered to 12 children with right temporal lobe epilepsy and 11 children with left temporal lobe epilepsy. Analysis of variance indicated that there was no significant difference in scores between the left temporal and right temporal lobe groups. However, right temporal epileptic patients scored significantly lower than normal children on all sections of the instrument, suggesting that in children like adults, the right temporal lobe may be dominant with respect to the receptive aspects of emotional prosody.     

Nonverbal Amnesia and Asymmetric Cerebral Lesions Following Encephalitis

Global amnesia after herpes simplex encephalitis has been typically associated with lesions of anterior and medial temporal lobe, inferior and medial frontal lobe, and insula. The neuropathologic correlates of this disease are usually considered to be bilateral and similar across cases. We describe a 27-year-old woman whose chronic amnesia and cerebral lesions after viral encephalitis indicate a different pattern. Two features distinguish her presentation: (1) markedly asymmetric lesions extensively involving the right temporal lobe but sparing almost all of the same structures on the left and (2) severe compromise of nonverbal learning and a nonverbal retrograde amnesia in contrast to disproportionately small impairments of verbal learning and retention. The findings suggest that encephalitis patients cannot be treated as a homogeneous group and that detailed analysis of variability in their anatomic lesions may be an important explanatory factor in neural accounts of these severe human amnesias.     

The role of avoidance of emotional material in the anxiety disorders

Many psychotherapeutic traditions have conceptualized clinical levels of anxiety as resulting from the avoidance of threatening or emotional material. In this paper, we examine behavioral models of avoidance of emotions and emotional material, integrating findings that support established behavioral theories of emotional avoidance and anxiety, and that extend these theories to further explain the intense, intrusive, and interfering nature of clinical anxiety. Research on the suppression and avoidance of emotional material suggests that emotional avoidance and thought suppression may not only hinder the learning process and maintain anxious responding, but may also (a) paradoxically heighten anxious responding to threatening cues and (b) interfere with emotion functionality, thereby further impeding adaptive responding. Findings are discussed in terms of future research and implications for clinical treatment of anxiety disorders.     

Do temporal processes underlie left hemisphere dominance in speech perception?

It is not unusual to find it stated as a fact that the left hemisphere is specialized for the processing of rapid, or temporal aspects of sound, and that the dominance of the left hemisphere in the perception of speech can be a consequence of this specialization. In this review we explore the history of this claim and assess the weight of this assumption. We will demonstrate that instead of a supposed sensitivity of the left temporal lobe for the acoustic properties of speech, it is the right temporal lobe which shows a marked preference for certain properties of sounds, for example longer durations, or variations in pitch. We finish by outlining some alternative factors that contribute to the left lateralization of speech perception.     

Processing emotional tone from speech in Parkinson’s disease: A role for the basal ganglia

In this study, individuals with Parkinson's disease were tested as a model for basal ganglia dysfunction to infer how these structures contribute to the processing of emotional speech tone (emotional prosody). Nondemented individuals with and without Parkinson's disease (n = 21/group) completed neuropsychological tests and tasks that required them to process the meaning of emotional prosody in various ways (discrimination, identification, emotional feature rating). Individuals with basal ganglia disease exhibited abnormally reduced sensitivity to the emotional significance of prosody in a range of contexts, a deficit that could not be attributed to changes in mood, emotional-symbolic processing, or estimated frontal lobe cognitive resource limitations in most conditions. On the basis of these and broader findings in the literature, it is argued that the basal ganglia provide a critical mechanism for reinforcing the behavioral significance of prosodic patterns and other temporal representations derived from cue sequences (Lieberman, 2000), facilitating cortical elaboration of these events.     

Mood-induced shifts in attentional bias to emotional information predict ill- and well-being

Previous research has suggested that biased attention toward emotional (typically threatening) stimuli contributes to ill-being (e.g., high levels of anxiety), but its contribution to well-being is less clear. The researchers assessed naturalistic shifts in attentional bias toward threatening and pleasant schematic face cues in response to five induced mood states in college students. They also assessed state anxiety and satisfaction with life concurrently and 3 weeks later. Controlling for concurrent anxiety, a fear-induced shift in attention to threatening cues was associated with increased levels of later anxiety. Controlling for concurrent life satisfaction, a happiness-induced shift in attention to emotional cues (both threatening and pleasant) was associated with increased levels of later life satisfaction. These results suggest that mood-induced changes in deployment of attention to emotional information may accumulate in ways that impact psychological functioning, yet these effects depend on mood state and the emotional cues afforded by the context.