Explicit memory in anxiety disorders

Response Inhibition, Cognitive Flexibility and Working Memory in Obsessive-Compulsive Disorder, Generalized Anxiety Disorder and Social Anxiety Disorder

This study analyzed response inhibition, cognitive flexibility and working memory in three groups of patients diagnosed with obsessive-compulsive disorder, social anxiety disorder and generalized anxiety disorder, considering some variables that may influence results (nonverbal reasoning, comorbidity, use of pharmacotherapy). Neuropsychological measures were completed using a computerized Wisconsin card sorting test, Stroop color word test, go/no-go task, digits and Corsi. Significant differences were obtained among groups in cognitive flexibility and working memory variables. The obsessive-compulsive disorder (OCD) group showed the worst results. The social anxiety disorder group obtained greater effect sizes in visuospatial memory. However, significant differences between groups in visuospatial memory were no longer present when nonverbal reasoning was controlled. Comorbidity influenced interference in the OCD and generalized anxiety disorder (GAD) groups. In addition, the executive functions were differently influenced by the level of obsessions and anxiety, and the use of pharmacotherapy. Study limitations include a non-random selection of participants, modest sample size and design type (cross-sectional). The OCD group showed the worst results in flexibility cognitive and verbal working memory. Comorbidity, use of pharmacotherapy and level anxiety and obsessions were variables influencing the performance of executive functions.

The Complex Role of Mental Time Travel in Depressive and Anxiety Disorders: An Ensemble Perspective

The ensemble hypothesis proposes that uniquely human cognitive abilities depend on more than just language. Besides overt language, inner speech, and causal interpretations, executive attention, mental time travel, and theory of mind abilities are essential parts that combine additively and even multiplicatively. In this review, we consider the implications of the ensemble hypothesis for the psychopathologies of anxiety and depression. Generalized anxiety disorder (GAD) and major depressive disorder (MDD) are two of the most common mental disorders worldwide. The mechanisms that differentiate them are difficult to identify, however. Mental time travel has been implicated in models of depressive and anxiety disorders, but here we argue that at least two other ensemble components, namely, interpreter biases and executive attention, must also be considered. Depressive and anxiety disorders have both been found to show impairments in all three of these components, but the precise relationships seem to distinguish the two kinds of disorders. In reviewing the literature, we develop models for depression and anxiety that take into account an ensemble of mental components that are unique for each disorder. We specify how the relations among mental time travel, interpreter biases, and executive attentional control differ in depression and anxiety. We conclude by considering the implications of these models for treating and conceptualizing anxiety and depression.

Targeted Reactivation during Sleep Differentially Affects Negative Memories in Socially Anxious and Healthy Children and Adolescents

Cognitive models propose a negative memory bias as one key factor contributing to the emergence and maintenance of social anxiety disorder (SAD). The long-term consolidation of memories relies on memory reactivations during sleep. We investigated in SAD patients and healthy controls the role of memory reactivations during sleep in the long-term consolidation of positive and negative information. Socially anxious and healthy children and adolescents learnt associations between pictures showing ambiguous situations and positive or negative words defining the situations' outcome. Half of the words were re-presented during postlearning sleep (i.e., they were cued). Recall of picture-word associations and subjective ratings of pleasantness and arousal in response to the pictures was tested for cued and uncued stimuli. In the morning after cueing, cueing facilitated retention of positive and negative memories equally well in SAD patients and healthy controls. One week later, cueing led to reduced ratings of pleasantness of negative information in SAD but not in healthy controls. Coincidental to these findings was more pronounced EEG theta activity over frontal, temporal and parietal regions in response to negative stimuli in SAD patients. Our findings suggest that the preferential abstraction of negative emotional information during sleep might represent one factor underlying the negative memory bias in SAD.SIGNIFICANCE STATEMENT We aim to uncover mechanisms underlying the characteristic negative memory bias in social anxiety disorder (SAD). The formation of long-lasting memories-a process referred to as memory consolidation-depends on the reactivation of newly acquired memories during sleep. We demonstrated that experimentally induced memory reactivation during sleep renders long-term memories of negative experiences more negative in SAD patients but not in healthy controls. We also found in SAD patients that the reactivation of negative experiences coincided with more pronounced oscillatory theta activity. These results provide first evidence that memory reactivation during sleep might contribute to the negative memory bias in SAD.

The influence of self-awareness on emotional memory formation: an fMRI study

Evidence from functional neuroimaging studies of emotional perception shows that when attention is focused on external features of emotional stimuli (external perceptual orienting--EPO), the amygdala is primarily engaged, but when attention is turned inwards towards one's own emotional state (interoceptive self-orienting--ISO), regions of the salience network, such as the anterior insula (AI) and the dorsal anterior cingulate cortex (dACC), also play a major role. Yet, it is unknown if ISO boosts the contributions of AI and dACC not only to emotional 'perception' but also to emotional 'memory'. To investigate this issue, participants were scanned with functional magnetic resonance imaging (fMRI) while viewing emotional and neutral pictures under ISO or EPO, and memory was tested several days later. The study yielded three main findings: (i) emotion boosted perception-related activity in the amygdala during both ISO and EPO and in the right AI exclusively during ISO; (ii) emotion augmented activity predicting subsequent memory in AI and dACC during ISO but not during EPO and (iii) high confidence memory was associated with increased amygdala-dACC connectivity, selectively for ISO encoding. These findings show, for the first time, that ISO promotes emotional memory formation via regions associated with interoceptive awareness of emotional experience, such as AI and dACC.

Are Anxiety Disorders Associated with Accelerated Aging? A Focus on Neuroprogression

Anxiety disorders (AnxDs) are highly prevalent throughout the lifespan, with detrimental effects on daily-life functioning, somatic health, and quality of life. An emerging perspective suggested that AnxDs may be associated with accelerated aging. In this paper, we explored the association between AnxDs and hallmarks of accelerated aging, with a specific focus on neuroprogression. We reviewed animal and human findings that suggest an overlap between processes of impaired neurogenesis, neurodegeneration, structural, functional, molecular, and cellular modifications in AnxDs, and aging. Although this research is at an early stage, our review suggests a link between anxiety and accelerated aging across multiple processes involved in neuroprogression. Brain structural and functional changes that accompany normal aging were more pronounced in subjects with AnxDs than in coevals without AnxDs, including reduced grey matter density, white matter alterations, impaired functional connectivity of large-scale brain networks, and poorer cognitive performance. Similarly, molecular correlates of brain aging, including telomere shortening, Aβ accumulation, and immune-inflammatory and oxidative/nitrosative stress, were overrepresented in anxious subjects. No conclusions about causality or directionality between anxiety and accelerated aging can be drawn. Potential mechanisms of this association, limitations of the current research, and implications for treatments and future studies are discussed.

Episodic memories in anxiety disorders: clinical implications

The aim of this review is to summarize research on the emerging role of episodic memories in the context of anxiety disorders (AD). The available literature on explicit, autobiographical, and episodic memory function in AD including neuroimaging studies is critically discussed. We describe the methodological diversity of episodic memory research in AD and discuss the need for novel tests to measure episodic memory in a clinical setting. We argue that alterations in episodic memory functions might contribute to the etiology of AD. We further explain why future research on the interplay between episodic memory function and emotional disorders as well as its neuroanatomical foundations offers the promise to increase the effectiveness of modern psychological treatments. We conclude that one major task is to develop methods and training programs that might help patients suffering from AD to better understand, interpret, and possibly actively use their episodic memories in a way that would support therapeutic interventions and counteract the occurrence of symptoms.

Attention and Memory Biases in Social Anxiety Disorder: The Role of Comorbid Depression

Cognitive biases play an important role in the onset and maintenance of Social Anxiety Disorder (SAD). Few studies, however, have examined the role of comorbid Major Depressive Disorder (MDD) in the processing of emotional material. In addition, little is known about the relation among different cognitive biases. In the current study, 73 participants (54.79% female) completed an emotion face dot-probe task followed by a recognition memory test. Compared to participants with SAD, participants with comorbid SAD and MDD oriented away from supraliminally presented angry faces. Subsequently, SAD participants with and without comorbidity recognized fewer angry faces than non-disordered controls. Furthermore, attention biases for subliminally presented stimuli predicted recognition accuracy only for comorbid participants. These results suggest that the presence of comorbid MDD affects attentional orienting in SAD participants. In addition, it highlights the interconnectedness of attention and memory biases for comorbid participants.

Relationship between Disgust and Memory Biases in Spider Fear

The literatures examining disgust's role in information processing biases and evidence for memory biases in anxiety disorders are both mixed, suggesting small or fragile effects. Thus, to maximize power and reliability, a mega-analytic approach was used to examine data across two studies to determine whether a memory bias for spider-relevant information exists under conditions when disgust is elevated and if the bias is specific to highly fearful individuals. Disgust was manipulated by having a large tarantula present or absent (at encoding and/or at recall) when individuals high (N=158) or low (N=108) in spider fear completed a free recall task. Results indicated that, as expected, the spider's presence was related to enhanced recall of spider information. However, this bias was driven by the presence of the spider during encoding only (as opposed to during recall), and high trait spider fear was not necessary for the memory bias to be expressed. Finally, there was a small effect for individual differences in trait and state disgust to predict spider recall, but this effect disappeared when anxiety was also included as a predictor, suggesting only a limited role for disgust in memory biases related to specific fears.

Emotional memory function, personality structure and psychopathology: a neural system approach to the identification of vulnerability markers

It is well established that emotional events are ingrained stronger into memory relative to neutral events. Facilitated emotional memory is highly variable between individuals within the normal population and is particularly exacerbated in those diagnosed with mood and anxiety disorders. In order to elucidate how variation of enhanced emotional memory within the normal population may manifest into psychopathological states, we explored the convergence between studies investigating the neural systems engaged in emotional memory facilitation and studies investigating how these systems differ from person to person. Converging evidence highlights the roles of three neural systems (1. Amygdala function and attention, 2. Neuroendocrine function, 3. Interactive effects with mood) that all govern emotional memory facilitation and are highly variable between individuals as a function of personality. We applied this neural system approach to models of vulnerability of three forms of psychopathology that are particularly characterized by atypical emotional memory function (depression, generalized anxiety disorder and post-traumatic stress disorder). This application suggests that the incorporation of known vulnerability markers across psychological, neuroimaging and neuroendocrinological domains is cardinal to how susceptibility is conceptualized and assessed in these disorders.

Mood-congruent free recall bias in anxious individuals is not a consequence of response bias

The status of mood-congruent free recall bias in anxious individuals was evaluated following incidental encoding of target words. Individuals with high and low levels of trait anxiety completed a modified Stroop task, which revealed an attentional bias for threat-related stimuli in anxious individuals. This group was significantly slower in naming the colour in which threat-related words were displayed compared to neutral words. In a subsequent free recall test for the words used in the modified Stroop task, anxious individuals recalled more threat-related words compared to low-anxious people. This difference was significant even when controlling for the false recall of items that had not been presented during study. These results support the view put forward by Russo, Fox, Bellinger, and Nguyen-Van-Tam (2001) that mood-congruent free recall bias in anxious individuals can be observed if the target material is encoded at a relatively shallow level. Moreover, contrary to Dowens and Calvo (2003), the current results show that the memory advantage for threat-related information in anxious individuals is not a consequence of response bias.

Mood-congruent free recall bias in anxiety

The present study evaluated the status of mood-congruent free recall bias in anxious individuals following incidental encoding of target words. In the first experiment, high trait anxiety individuals showed increased recall of threat-related information after an orienting task promoting lexical processing of target words. In a second experiment, both lexical and semantic orienting tasks were performed at study. In this experiment, anxious individuals displayed a mood-congruent recall bias only for target information processed at a lexical level. Theoretical and practical implications of these findings are discussed.