Depressive Symptoms Account for Loss of Positive Attention Bias in ADHD Patients: An Eye-Tracking Study

Objectives: Depression and ADHD often co-occur and are both characterized by altered attentional processing. Differences and overlap in the profile of attention to emotional information may help explain the co-occurence. We examined negative attention bias in ADHD as neurocognitive marker for comorbid depression. Methods: Patients with depression ( n = 63), ADHD ( n = 43), ADHD and depression ( n = 25), and non-psychiatric controls ( n = 68) were compared on attention allocation toward emotional faces. The following eye-tracking indices were used: gaze duration, number of revisits, and location and duration of first fixation. Results: Controls revisited the happy faces more than the other facial expressions. Both the depression and the comorbid group showed significantly less revisits of the happy faces compared to the ADHD and the control group. Interestingly, after controlling for depressive symptoms, the groups no longer differed on the number of revisits. Conclusion: ADHD patients show a relative positive attention bias, while negative attention bias in ADHD likely indicates (sub)clinical comorbid depression.

Unraveling the Mystery About the Negative Valence Bias: Does Arousal Account for Processing Differences in Unpleasant Words?

Many studies have found that the emotional content of words affects visual word recognition. However, most of them have only considered affective valence, finding inconsistencies regarding the direction of the effects, especially in unpleasant words. Recent studies suggest that arousal might explain why not all unpleasant words elicit the same behavior. The aim of the present research was to study the role of arousal in unpleasant word recognition. To do that, we carried out an ERP experiment in which participants performed a lexical decision task that included unpleasant words which could vary across three levels of arousal (intermediate, high, and very high) and words which were neutral in valence and had an intermediate level of arousal. Results showed that, within unpleasant words, those intermediate in arousal evoked smaller LPC amplitudes than words that were high or very high in arousal, indicating that arousal affects unpleasant word recognition. Critically, arousal determined whether the effect of negative valence was found or not. When arousal was not matched between unpleasant and neutral valenced words, the effect of emotionality was weak in the behavioral data and absent in the ERP data. However, when arousal was intermediate in both unpleasant and neutral valenced words, larger EPN amplitudes were reported for the former, pointing to an early allocation of attention. Interestingly, these unpleasant words which had an intermediate level of arousal showed a subsequent inhibitory effect in that they evoked smaller LPC amplitudes and led to slower reaction times and more errors than neutral words. Our results highlight the relevance that the arousal level has for the study of negative valence effects in word recognition.

Taking the perspective of narrative characters

An ongoing debate in the interpretation of referring expressions concerns the degree to which listeners make use of perspective information during referential processing. We aim to contribute to this debate by considering perspective shifting in narrative discourse. In a web-based mouse-tracking experiment in Dutch, we investigated whether listeners automatically shift to a narrative character’s perspective when resolving ambiguous referring expressions, and whether different linguistic perspective-shifting devices affect how and when listeners switch to another perspective. We compared perspective-neutral, direct, and free indirect discourse, manipulating which objects are visible to the character. Our results do not show a clear effect of the perspective shifting devices on participants’ eventual choice of referent, but our online mouse-tracking data reveal processing differences that suggest that listeners are indeed sensitive to the conventional markers of perspective shift associated with direct and (to a lesser degree) free indirect discourse.

Early visual processing as a marker of disease, not vulnerability: Event-related potential (ERP) evidence from 22q11.2 deletion syndrome, a population at high risk for schizophrenia

We investigated visual processing in 22q11.2 deletion syndrome (22q11.2DS), a condition characterized by an increased risk for schizophrenia. Visual processing differences have been described in schizophrenia but remain understudied early in the disease course. Electrophysiology was recorded during a visual adaptation task with different interstimulus intervals to investigate visual processing and adaptation in 22q11.2DS (with (22q+) and without (22q-) psychotic symptoms), compared to control and idiopathic schizophrenia groups. Analyses focused on early windows of visual processing. While increased amplitudes were observed in 22q11.2DS in an earlier time window (90-140 ms), decreased responses were seen later (165-205 ms) in schizophrenia and 22q+. 22q11.2DS, and particularly 22q-, presented increased adaptation effects. We argue that while amplitude and adaptation in the earlier time window may reflect specific neurogenetic aspects associated with a deletion in chromosome 22, amplitude in the later window may be a marker of the presence of psychosis and/or of its chronicity/severity.

The Mediating Effects of Alexithymia, Intolerance of Uncertainty, and Anxiety on the Relationship Between Sensory Processing Differences and Restricted and Repetitive Behaviours in Autistic Adults

Distress caused by sensory processing differences for autistic individuals may be reduced by repetitive behaviours (RRB), including repetitive motor (RMB) and insistence on sameness (ISB) behaviours. Intolerance of uncertainty (IU) and anxiety mediate the relationship between sensory processing and RRB in autistic children. We replicated this model in autistic adults, extending it to include alexithymia. Serial mediation, using data from 426 autistic adults, identified significant direct effects from sensory processing to RMB and ISB, and indirect effects through alexithymia-IU-anxiety for RMB, and IU alone, and alexithymia-IU for ISB. Different mechanisms may underpin RMB and ISB. Alexithymia alongside, IU and anxiety, should be considered when understanding the relationship between sensory processing and RRB, and when offering interventions to support autistic people.

Dynamic representation of space in the hippocampus: spatial novelty detection and consolidation in CA1 and CA2

Hippocampal place cells are the functional units of spatial navigation and are present in all subregions- CA1, CA2, CA3 and CA4. Recent studies on CA2 have indicated its role in social and contextual memory, but its contribution towards spatial novelty detection and consolidation remains largely unknown. The current study aims to uncover how CA1 and CA2 detect, process, assimilate and consolidate spatial novelty. Accordingly, a novel 3-day paradigm was designed where the animal was introduced to a completely new environment on the first day and to varying degrees of familiarity and novelty on subsequent days, as the track was extended in length and modified in shape, keeping other environmental constraints fixed. Detection of spatial novelty was found to be a dynamic and complex phenomenon, characterized by different responses from hippocampal place cells, depending on when novelty was introduced. Therefore, the study concludes that early novelty detection (the first time a novel space is introduced in a relatively familiar environment) and subsequent novelty detection are not processed in the same way. Additionally, while neuronal responses to spatial novelty detection (early and subsequent) were found to be the same in CA1 and CA2 ensembles, their responses differed in spatial consolidation mechanisms during subsequent sleep replays. For CA1, spatial coverage of prior behaviour was found to be closely reflected in subsequent sleep for that particular day, but CA2 showed no such coherent response, highlighting mnemonic processing differences between CA2 and CA1 with respect to spatial novelty.