Enhanced insular/prefrontal connectivity when resisting from emotional distraction during visual search

Effective connectivity during face processing in major depression - distinguishing markers of pathology, risk, and resilience

BACKGROUND

Aberrant brain connectivity during emotional processing, especially within the fronto-limbic pathway, is one of the hallmarks of major depressive disorder (MDD). However, the methodological heterogeneity of previous studies made it difficult to determine the functional and etiological implications of specific alterations in brain connectivity. We previously reported alterations in psychophysiological interaction measures during emotional face processing, distinguishing depressive pathology from at-risk/resilient and healthy states. Here, we extended these findings by effective connectivity analyses in the same sample to establish a refined neural model of emotion processing in depression.

METHODS

Thirty-seven patients with MDD, 45 first-degree relatives of patients with MDD and 97 healthy controls performed a face-matching task during functional magnetic resonance imaging. We used dynamic causal modeling to estimate task-dependent effective connectivity at the subject level. Parametric empirical Bayes was performed to quantify group differences in effective connectivity.

RESULTS

MDD patients showed decreased effective connectivity from the left amygdala and left lateral prefrontal cortex to the fusiform gyrus compared to relatives and controls, whereas patients and relatives showed decreased connectivity from the right orbitofrontal cortex to the left insula and from the left orbitofrontal cortex to the right fusiform gyrus compared to controls. Relatives showed increased connectivity from the anterior cingulate cortex to the left dorsolateral prefrontal cortex compared to patients and controls.

CONCLUSIONS

Our results suggest that the depressive state alters top-down control of higher visual regions during face processing. Alterations in connectivity within the cognitive control network present potential risk or resilience mechanisms.

Spatial distribution of emotional attentional blink under top-down attentional control

Emotion-induced blindness (EIB) refers to the impaired perception of a neutral target that follows an emotional distractor within the time gap of 100-500 ms. Recent studies on EIB show that EIB is spatially localized. Blink occurs when both target and emotional distractor appear in the same stream but not the opposite. However, the influence of top-down attentional control over the dual-stream EIB remains poorly understood. Examining the role of top-down control in EIB will help understand the impact of attentional control over the spatial distribution of EIB and in understanding the Attentional Blink (AB) and EIB distinction. Hence, in the present study, we used dual-stream and manipulated the attentional control by changing the relevance of the emotional image and asking participants to report both emotional and neutral targets. Our results show a similar level of blink irrespective of the spatial location of the emotional T1, suggesting the role of attentional control on the spatial distribution of EIB and in the AB-EIB distinction. Results have implications for the theoretical understanding of EIB.

Trait Anxiety Influences Negative Affect-modulated Distribution of Visuospatial Attention

Visuospatial attention allows humans to selectively gate and prioritize visual (including salient, emotional) information for efficiently navigating natural visual environments. As emotions have been known to influence attentional performance, we asked if emotions also modulate the spatial distribution of visual attention and whether any such effect was further associated with individual differences in anxiety. Participants (n = 28) discriminated the orientation of target Gabor patches co-presented with distractors, speedily and accurately. The key manipulation was randomly presenting a task-irrelevant face emotion prime briefly (50 ms), conveying Neutral/Disgust/Scrambled (Null) emotion signal 150 ms preceding the target patches. We calculated attention gradient (change in negative inverse attentional efficiency with unit change in distance from the source of emotion signal) as a metric to answer our questions. Specifically, the Disgust signal modulated the direction of attention gradients differentially in individuals with varying degrees of trait - anxiety, such that the gradients correlated negatively with individual trait-anxiety scores. This implies spatial shifts in Disgust-signalled visual attention with varying trait - anxiety levels. Neutral yielded attention gradients comparable to Scrambled, implying no specific effect of this signal and there was no association with anxiety levels in both. No correlation was observed between state - anxiety and the emotion-cued attention gradients. In sum, the results suggest that individual trait - anxiety levels influence the effect of negative and physiologically arousing emotion signals (e.g., Disgust) on the spatial distribution of visual attention. The findings could be of relevance for understanding biases in visual behaviour underlying affective states and disorders.

Developmental differences in the impact of perceptual salience on short-term memory performance and meta-memory skills

In everyday life, individuals are surrounded by many stimuli that compete to access attention and memory. Evidence shows that perceptually salient stimuli have more chances to capture attention resources, thus to be encoded into short-term memory (STM). However, the impact of perceptual salience on STM at different developmental stages is entirely unexplored. Here we assessed STM performance and meta-memory skills of 6, 10, and 18 years-old participants (total N = 169) using a delayed match-to-sample task. On each trial, participants freely explored a complex (cartoon-like) scene for 4 s. After a retention interval of 4 s, they discriminated the same/different position of a target-object extracted from the area of maximal or minimal salience of the initially-explored scene. Then, they provided a confidence judgment of their STM performance, as an index of meta-memory skills. When taking into account 'confident' responses, we found increased STM performance following targets at maximal versus minimal salience only in adult participants. Similarly, only adults showed enhanced meta-memory capabilities following maximal versus minimal salience targets. These findings documented a late development in the impact of perceptual salience on STM performance and in the improvement of metacognitive capabilities to properly judge the content of one's own memory representation.

Neural correlates of visuospatial processing in migraine: does the pain network help?

Migraine patients frequently report cognitive symptoms during the different phases of migraine. The most affected cognitive domains are visuospatial abilities, processing speed, attention and executive functions. We explored migraine patients' performance during a visuospatial task and investigated the activity of brain areas involved in visuospatial processing. A functional magnetic resonance imaging (MRI) visuospatial task, including an angle and a colour discrimination paradigm, was administrated to 17 headache-free migraine patients and 16 controls. Correlations between functional MRI abnormalities and subjects' performance, clinical and neuropsychological variables were also investigated. Deficits at visuospatial cognitive tests were present in around 20% of patients. Migraine patients maintained a preserved behavioural performance (reaction time and number of correct responses) during the angle discrimination task, while they performed less correctly in the colour task compared to controls (p = 0.05).The comparison of angle vs. colour task revealed an increased activity of the right insula, bilateral orbitofrontal cortex and medial frontal gyrus, and decreased activity of the bilateral posterior cingulate cortex in migraine patients compared to controls. In migraine patients, a better performance in the angle task was associated with higher activation of the right insula and orbitofrontal cortex, as well as with decreased activation of the right posterior cingulate cortex. Our results suggest an adaptive functional plasticity that might help migraine patients to overcome impaired visuospatial skills and preserve an adequate performance during a visuospatial task. These compensatory mechanisms seem to take advantage of recruiting brain areas that are commonly involved also in nociception.

Impact of Distracting Emotional Stimuli on the Characteristics of Movement Performance: A Kinematic Study

It is well-documented that emotional stimuli impact both the cognitive and motor aspects of “goal-directed” behavior. However, how emotional distractors impact motor performance remains unclear. This study aimed to characterize how movement quality was impacted during emotional distractors. We used a modified oddball paradigm and documented the performance of pure movement. Participants were designated to draw a triangle or a polygon, while an emotional stimulus was presented. Speed was assessed using reaction time and movement time. The quality and precision of movement were assessed by calculating the accuracy and root-mean-square error (RMSE). Compared to drawings of triangles, polygons had higher accuracy under negative stimuli, but lower RMSE under positive stimuli. The results indicate that distracting emotional stimuli impact different aspects of movement quality, with movement complexity influencing accuracy under negative distractors and precision under positive distractors. This study provides further evidence that movement precision is an important feature of emotional embodiment that should be incorporated in future studies.

Neural substrates of the interplay between cognitive load and emotional involvement in bilingual decision making

Prior work has reported that foreign language influences decision making by either reducing access to emotion or imposing additional cognitive demands. In this fMRI study, we employed a cross-task design to assess at the neural level whether and how the interaction between cognitive load and emotional involvement is affected by language (native L1 vs. foreign L2). Participants completed a Lexico-semantic task where in each trial they were presented with a neutrally or a negatively valenced word either in L1 or L2, either under cognitive load or not. We manipulated cognitive load by varying the difficulty of the task: to increase cognitive demands, we used traditional characters instead of simplified ones in L1 (Chinese), and words with capital letters instead of lowercase letters in L2 (English). After each trial, participants decided whether to take a risky decision in a gambling game. During the Gamling task, left amygdala and right insula were more activated after having processed a negative word under cognitive load in the Lexico-semantic task. However, this was true for L1 but not for L2. In particular, in L1, cognitive load facilitated rather than hindered access to emotion. Further suggesting that cognitive load can enhance emotional sensitivity in L1 but not in L2, we found that functional connectivity between reward-related striatum and right insula increased under cognitive load only in L1. Overall, results suggest that cognitive load in L1 can favor access to emotion and lead to impulsive decision making, whereas cognitive load in L2 can attenuate access to emotion and lead to more rational decisions.

The Missing Pieces of the Puzzle: A Review on the Interactive Nature of A-Priori Expectancies and Attention Bias toward Threat

The role of attention bias in the etiology and maintenance of anxiety disorders has been studied extensively over decades. Attention bias reflects maladaptation in cognitive processing, as perceived threatening stimuli receive prioritized processing even when they are task-irrelevant or factually unthreatening. Recently, there has been some interest in the role of a-priori expectancies in attention bias toward threat. The current review article will present recent studies as examples that emphasize the need for more comprehensive research about the interactive effects of various factors that affect the relationship between expectancies and attention bias toward threatening stimuli in anxiety. The current review article suggests a holistic view, which advocates for more integrative research, as a dynamic network could underlie changes in attention bias. The study of the interaction between such factors, with a focus on expectancy, can lead to more ecological and clinically important results, and thus to more informed and fine-tuned treatments that are based on manipulation of expectancies. Such methods, in turn, can also help in shedding light on the research of attention bias, in a mutual relationship between research and therapy.

Hungry for colours? Attentional bias for food crucially depends on perceptual information

Attentional bias has been consistently investigated with both threatening and rewarding stimuli, such as food. Several studies demonstrated the presence of an attentional bias for high-calorie food cues compared to neutral (non-food) cues. Authors have interpreted this effect in the context of top-down processes (e.g. the food draws attention thanks to the experience we have with it). The aim of the present study is to test whether perceptual features (bottom-up processes) can modulate the attentional bias effect of food stimuli. Using a dot-probe task, we investigated the relevance of colours in the occurrence of the attentional bias. We compared two different categories of naturalistic food images (high-calorie versus low-calorie) both coloured (Exp. 1) and greyscale (Exp. 2). While we found the occurrence of the attentional bias with high-calorie food coloured images, we did not obtain any significant differences with greyscale images. In Experiments 3 and 4, we compared greyscale office items images, respectively, with greyscale high-calorie food images (Exp. 3) and greyscale low-calorie food images (Exp. 4). In both these last experiments, we did not find any attentional bias. Thus, taken together, our results show that colours convey crucial identity information that could orient our attention. We interpret these results as linked to the relevance of visual appearance in our experience of food.