Perception of the temporal order of digits during rapid serial visual presentation is influenced by their ordinality.

Psychological research has extensively shown that individuals are limited in their ability to process environmental information temporally. In a rapid serial visual presentation, the ability to identify the second of two targets presented in close succession among distractors is usually impaired, a phenomenon known as attentional blink (AB). Paradoxically, when the second target immediately succeeds the first one (lag 1), such an ability is relatively spared, but individuals are more prone to misreport their correct temporal succession. Competitive mechanisms based on prior entry and perceptual integration processes have been suggested to account for the apparent loss of temporal information. We report findings from four experiments, showing that, once identified, categorical dimensions of the stimuli used as targets (here, the ordinality of numbers) may guide the perception and the resulting report of their temporal order. Specifically, at lag 1 individuals more frequently encode the two digits in ascending order. Such a biased regularization may represent another possible outcome of the failure in temporal segregation observed at lag 1, indicating that a mechanism based on prior entry is not generalizable in explaining order reversals. The kind of stimuli chosen as targets in AB paradigms can activate high-level categorical dimensions capable of influencing the performance on this task.

Changes in sleep pattern and dream activity across and after the COVID-19 lockdown in Italy: A longitudinal observational study.

A large body of evidence has documented the impact of the global COVID-19 outbreak - and especially the lockdown period - on sleep quality and quantity. Here, we present the first Italian longitudinal study on sleep and COVID-19 considering four different time points collected during lockdown (from 29 March 2020 to 3 May 2020) and a subsequent follow-up period (October 2020). We used an online survey to collect socio-demographic and COVID-19 related information. Subjects were also asked to complete a sleep diary at each time point of the study. Our longitudinal sample included 147 participants. Statistical comparison across time intervals showed remarkable changes in sleep patterns during and after the lockdown. In particular, during lockdown we observed longer sleep latency, less ease of falling asleep, a higher total bedtime, and a lower dream frequency. The week-by-week evaluation described relatively stable patterns in the observed measures during the lockdown period, except for dream frequency, affected by a rapid increase in the early phase of lockdown. Our findings are in line with the current literature. Furthermore, the prospective longitudinal investigation comprising several time points offered the possibility of (a) observing the temporal dynamics and the different entities of such changes over time, and (b) reducing the typical memory bias for these studies.

The impact of stimulus format on task inhibition during task switching.

Switching between competing tasks is supported by active inhibition of the preceding task. The level of task stimulus processing at which interference between competing tasks must occur for inhibition to be recruited is still unclear. Here, we investigated whether inhibition is recruited by task conflict occurring at an early or late (semantic) stage of task stimulus processing by dissociating the task stimulus format from its meaning. In two experiments, participants performed three different numerical judgment tasks on numerical stimuli that could be presented as digits or number words (e.g., "6" or "six") in a cued task-switching procedure. The effects of the change of stimulus format for the inhibition of the previous task were investigated and assessed by the N-2 task repetition cost, an index of the extent to which task representations are inhibited. The N-2 task repetition cost observed in the same stimulus format condition disappeared when target stimuli on task N-1 were presented in a different format from stimuli of task N-2 and N. This occurred both when the format changed from digits to number words stimuli (Experiment 1) as well as when it changed from number words to digits stimuli (Experiment 2). Results indicated that task set inhibition is recruited very early during the stimulus processing stage. They also provided evidence that task inhibition is not tied to task preparation processes but operates as a reactive, rather than proactive mechanism of conflict resolution.

COVID-19 lockdown and poor sleep quality: Not the whole story.

A growing body of evidence consistently describes the side-effects of coronavirus disease 2019 lockdown on mental health and sleep quality. We conducted a longitudinal web-based survey of 217 Italian participants at two time points: lockdown and subsequent follow-up. To thoroughly investigate lockdown-related changes in sleep quality, we first evaluated variations in overall sleep quality assessed by the Pittsburgh Sleep Quality Index. We then examined sleep changes in specific components of sleep quality. Results revealed a clear dissociation of sleep effects, as a function of the specific domain considered, with longer sleep latency, worse sleep efficiency, and massive sleep medication use during forced confinement. On the other hand, we simultaneously observed an increased sleep duration and better daytime functioning. Our present findings highlight the importance of an accurate examination of sleep quality during lockdown, as the effects were not uniform across populations and different sleep domains.

Anaclitic-sociotropic and introjective-autonomic personality dimensions and depressive symptoms: a systematic review.

Sociotropy (anaclitic) and autonomy (introjective) are conceptualised as two personality dimensions that confer vulnerability to depression. According to Blatt and Beck's theories, sociotropic individuals exhibit distinctive patterns of symptoms such as prominent anxiety, depressed mood, helplessness, crying and somatic concerns, while self-critical ones seem to exhibit a pattern of symptoms including prominent guilt, hopelessness, feelings of failure and worthlessness and other cognitive symptoms.This systematic review was performed with the aim of investigating whether and to what extent psychological dimensions of anaclitic-sociotropic and introjective-autonomy are related to a specific core of depressive symptoms. The search was conducted in three databases (PubMed, PsycINFO and Scopus) and 27 articles were selected.Results showed a weak association between somatic symptoms and dependent personality traits, while the relationship between self-criticism and cognitive symptomatology was significantly higher. These findings are discussed in the context of future research, necessary to corroborate the existence of a form of depression characterised by somatic features usually ignored by diagnostic criteria, essential to direct psychological treatments to these depressive personality differences.

Out with the Old and in with the New: the Contribution of Prefrontal and Cerebellar Areas to Backward Inhibition.

The inhibitory mechanism named backward inhibition (BI) counteracts interference of previous tasks supporting task switching. For instance, if task set A is inhibited when switching to task B, then it should take longer to immediately return to task set A (as occurring in an ABA sequence), as compared to a task set that has not been just inhibited (as occurring in a CBA sequence), because extra time will be needed to overcome the inhibition of task set A.The evidenced prefrontal and cerebellar role in inhibitory control suggests their involvement even in BI. Here, for the first time, we modulated the excitability of multiple brain sites (right presupplementary motor area (pre-SMA), left and right cerebellar hemispheres) through continuous theta burst stimulation (cTBS) in a valuable sham-controlled order-balanced within-subject experimental design in healthy individuals performing two domain-selective (verbal and spatial) task-switching paradigms. Verbal BI was abolished by prefrontal or cerebellar stimulations through opposite alterations of the basal pattern: cTBS on pre-SMA increased CBA reaction times, disclosing the current prefrontal inhibition of any interfering old task. Conversely, cerebellar cTBS decreased ABA reaction times, disclosing the current cerebellar recognition of sequences in which it is necessary to overcome previously inhibited events.

Memory for positional movements as a component of the visuospatial working memory.

Though the Corsi block-tapping task (CBT) is widely used for assessing visuospatial memory, information about what exactly it measures is still debated. We investigated such issue by observing how motor, visual, and spatial secondary tasks affect the performance on three versions of the CBT. Results showed a double dissociation pattern, wherein two motor secondary tasks had larger effects when the CBT was administered by the examiner tapping on the blocks. A spatial secondary task had larger effects when the CBT was administered by automatically illuminating the blocks. Finally, a visual secondary task had larger effects on a two-dimensional, computerized version of the CBT. These findings suggest that memory for movements plays a relevant role in the CBT, and are especially relevant due to their implications for assessment of brain-damaged patients, besides providing further evidence of a fractionation of visuospatial memory into multiple subcomponents.

Persisting inhibition biases efficient rule inference under uncertainty.

Introduction: Task set inhibition supports optimal switching among tasks by actively suppressing the interference from recently executed competing task sets. It is typically studied in cued task-switching paradigms where there is no uncertainty about the task set or rule to prepare for on each trial. While inhibition has been shown to influence the speed and the accuracy of task execution, affecting task set retrieval, preparation, or implementation in conditions of task set switching, it remains uninvestigated whether it also affects rule selection under uncertainty. Methods: We implemented an ad-hoc four-rule card sorting task and categorized the rules selected by participants after a rule shift according to the recency of their last usage. We included a measure of working memory capacity (WMC) to control for its involvement in the rule selection process. Results: Participants exhibited a reduced preference for recently abandoned rules than less recently abandoned ones. Furthermore, we found that such a preference was not associated with WMC. Discussion: The results suggest that decision-making processes underlying rule inference and selection may be influenced by task-set inhibition, configuring as a conflict adjustment mechanism to the sequential history of rules application.

Decision-Making and Risk-Propensity Changes during and after the COVID-19 Pandemic Lockdown.

The imposition of lockdowns during the COVID-19 pandemic placed individuals under conditions of environmental stress, threatening individual and collective wellbeing. This study aimed to investigate the temporal effects of isolation and confinement during and after the Italian lockdown on decision-making, risk propensity, and cognitive control processes. The present study covered almost the entire Italian lockdown period (each week from the end of March to mid-May 2020), plus a follow-up measure (September 2020). At each time-point, respondents completed online behavioral tasks, which involved measuring risk-propensity (Balloon Analogue Risk Task), decision-making (Iowa Gambling Task), and cognitive flexibility (Category Switch Task). They also filled in questionnaires regarding subjective stress and anxiety. The main findings showed that the decision-making abilities of the respondents were affected as the confinement progressed. Furthermore, individuals who were more subjectively impacted by the lockdown/isolation experience exhibited impaired decision-making, especially during the lockdown. The results of the study highlight that prolonged confinement may affect human decision making, and help understand individuals' misbehaviors during emergencies and develop effective countermeasures aimed at reducing the burden of the healthcare system.

Spatiotemporal brain mapping of spatial attention effects on pattern-reversal ERPs.

Recordings of event-related potentials (ERPs) were combined with structural and functional magnetic resonance imaging (fMRI) to investigate the timing and localization of stimulus selection processes during visual-spatial attention to pattern-reversing gratings. Pattern reversals were presented in random order to the left and right visual fields at a rapid rate, while subjects attended to the reversals in one field at a time. On separate runs, stimuli were presented in the upper and lower visual quadrants. The earliest ERP component (C1, peaking at around 80 ms), which inverted in polarity for upper versus lower field stimuli and was localized in or near visual area V1, was not modulated by attention. In the latency range 80-250 ms, multiple components were elicited that were increased in amplitude by attention and were colocalized with fMRI activations in specific visual cortical areas. The principal anatomical sources of these attention-sensitive components were localized by fMRI-seeded dipole modeling as follows: P1 (ca. 100 ms-source in motion-sensitive area MT+), C2 (ca. 130 ms-same source as C1), N1a (ca. 145 ms-source in horizontal intraparietal sulcus), N1b (ca. 165 ms-source in fusiform gyrus, area V4/V8), N1c (ca. 180 ms-source in posterior intraparietal sulcus, area V3A), and P2 (ca. 220 ms-multiple sources, including parieto-occipital sulcus, area V6). These results support the hypothesis that spatial attention acts to amplify both feed-forward and feedback signals in multiple visual areas of both the dorsal and ventral streams of processing.

EEG-based Brain-Computer Interfaces for people with Disorders of Consciousness: Features and applications. A systematic review.

Background: Disorders of Consciousness (DoC) are clinical conditions following a severe acquired brain injury (ABI) characterized by absent or reduced awareness, known as coma, Vegetative State (VS)/Unresponsive Wakefulness Syndrome (VS/UWS), and Minimally Conscious State (MCS). Misdiagnosis rate between VS/UWS and MCS is attested around 40% due to the clinical and behavioral fluctuations of the patients during bedside consciousness assessments. Given the large body of evidence that some patients with DoC possess "covert" awareness, revealed by neuroimaging and neurophysiological techniques, they are candidates for intervention with brain-computer interfaces (BCIs). Objectives: The aims of the present work are (i) to describe the characteristics of BCI systems based on electroencephalography (EEG) performed on DoC patients, in terms of control signals adopted to control the system, characteristics of the paradigm implemented, classification algorithms and applications (ii) to evaluate the performance of DoC patients with BCI. Methods: The search was conducted on Pubmed, Web of Science, Scopus and Google Scholar. The PRISMA guidelines were followed in order to collect papers published in english, testing a BCI and including at least one DoC patient. Results: Among the 527 papers identified with the first run of the search, 27 papers were included in the systematic review. Characteristics of the sample of participants, behavioral assessment, control signals employed to control the BCI, the classification algorithms, the characteristics of the paradigm, the applications and performance of BCI were the data extracted from the study. Control signals employed to operate the BCI were: P300 (N = 19), P300 and Steady-State Visual Evoked Potentials (SSVEP; hybrid system, N = 4), sensorimotor rhythms (SMRs; N = 5) and brain rhythms elicited by an emotional task (N = 1), while assessment, communication, prognosis, and rehabilitation were the possible applications of BCI in DoC patients. Conclusion: Despite the BCI is a promising tool in the management of DoC patients, supporting diagnosis and prognosis evaluation, results are still preliminary, and no definitive conclusions may be drawn; even though neurophysiological methods, such as BCI, are more sensitive to covert cognition, it is suggested to adopt a multimodal approach and a repeated assessment strategy.

"Stay at Home" in Italy during the COVID-19 Outbreak: A Longitudinal Study on Individual Well-Being among Different Age Groups.

The restrictions imposed by the Italian government because of the coronavirus outbreak have been shown to be demanding on the Italian population. Data were collected at four different time points from 29 March 2020 to 3 May 2020 and during the final follow-up survey on 12 October 2020. In the present study, we provided longitudinal evidence on the relationship between the lockdown and mental health dimensions, such as emotional state, perceived stress, and time perspective, for three age groups. The results allowed us to observe their psychological status from different perspectives at five different time points. Notably, a negative effect of the lockdown individual well-beings emerged as a trend, and differences in individual adaptation strategies to a prolonged stressful situation were observed at the follow-up. Indeed, pairwise comparisons between age groups showed that the young adult group (18-23 years old) seemed to be the most psychologically affected by the lockdown. The findings are discussed according to the most recent literature on the topic. To the best of our knowledge, this is one of the first longitudinal studies carried out in Italy concerning the general psychological effects of the coronavirus lockdown.

The effects of sleep and sleep deprivation on task-switching performance.

Neural systems of the prefrontal cortex (PFC) involved in executive functions are particularly vulnerable to sleep deprivation (SD). In this study, we investigated whether SD selectively affects specific components of the executive control processes involved in task-switching performance. Two different tasks are performed in rapid and random succession in this procedure, so that the to-be-executed task may change from one trial to the next (switch trial), or may be repeated (repetition trial). Task-switches are usually slower than task repetitions, giving way to the 'switch cost'. One hundred and eight university students were assigned randomly to the sleep (S) or the SD group. Each of them was tested on a task-switching paradigm before and after an experimental night (S or SD), and after one recovery night. SD impaired both task-switching accuracy and speed. A higher proportion of errors and increased switch costs after SD have been observed, compared to normal sleep. Control analyses on switch and repetition trials showed that the SD group was significantly worse only on the switch trials. The effects of SD are reverted by one night of recovery sleep. It is concluded that the ability to adjust behaviour rapidly and flexibly to changing environmental demands, which relies on the functional integrity of the PFC, is impacted negatively by sleep loss.

Anodal tDCS over the right parietal but not frontal cortex enhances the ability to overcome task set inhibition during task switching.

Switching between tasks requires individuals to inhibit mental representations of the previous task demands and to activate representations of the new task demands. The inhibition of the executed task remains active for a while so that when the inhibited task set must be re-activated shortly after, the need to overcome residual task set inhibition leads to behavioral costs. In a sham-controlled balanced-order within-subjects experimental design we investigated whether applying right anodal/left cathodal transcranial direct current stimulation (tDCS) over the dorsolateral prefrontal or parietal cortex modulated the ability to overcome persistent task inhibition during task switching. Results showed that right anodal/left cathodal tDCS over the parietal cortex improves performance selectively when switching back to a recently inhibited task that requires previous inhibition to be overcome. Right Anodal/left cathodal tDCS over the prefrontal cortex improves performance during task switching in general, either when re-engaging in a inhibited task or when engaging in a non-inhibited task. Results suggest a different contribution of prefrontal and parietal regions to task switching, with parietal cortex being selectively involved in overcoming persistent task inhibition and prefrontal cortex being more generally involved in the control of task set during task switching.

Access to consciousness of briefly presented visual events is modulated by transcranial direct current stimulation of left dorsolateral prefrontal cortex.

Adaptive behaviour requires the ability to process goal-relevant events at the expense of irrelevant ones. However, perception of a relevant visual event can transiently preclude access to consciousness of subsequent events - a phenomenon called attentional blink (AB). Here we investigated involvement of the left dorsolateral prefrontal cortex (DLPFC) in conscious access, by using transcranial direct current stimulation (tDCS) to potentiate or reduce neural excitability in the context of an AB task. In a sham-controlled experimental design, we applied between groups anodal or cathodal tDCS over the left DLPFC, and examined whether this stimulation modulated the proportion of stimuli that were consciously reported during the AB period. We found that tDCS over the left DLPFC affected the proportion of consciously perceived target stimuli. Moreover, anodal and cathodal tDCS had opposing effects, and exhibited different temporal patterns. Anodal stimulation attenuated the AB, enhancing conscious report earlier in the AB period. Cathodal stimulation accentuated the AB, reducing conscious report later in the AB period. These findings support the notion that the DLPFC plays a role in facilitating information transition from the unconscious to the conscious stage of processing.

Switching between goals mediates the attentional blink effect.

Humans are fundamentally limited in processing information from the outside world. This is particularly evident in the attentional blink (AB), the impaired ability to identify the second of two targets presented in close succession. We report findings from three experiments showing that the AB is significantly reduced when observers are set to achieve one single goal (reporting combinations of the two targets) instead of separate goals (reporting the two targets). This finding raises questions about the nature of AB, and suggests that processes involved in goal-switching must be taken into account by theories of the AB phenomenon.

Change is good: Inter-trial switching of target category improves attentional selection in time.

Limitations in the rate at which our attention can sample rapidly presented visual events are reflected in the attentional blink (AB), the inability to successfully report the second of two target stimuli embedded among distractors when separated by a temporal interval of approximately 300 ms. In two experiments we tested for predictions of two accounts of AB that ascribe the phenomenon to a temporary loss of attentional control or to an overzealous application of attentional control over the input filter. Manipulating the control load during the rapid serial presentation of visual events by means of a cued attentional switching procedure, we found an AB improvement when the target category was switched from the previous trial compared to when it was repeated from the previous trial. Findings appear inconsistent with the temporary loss of control account of the AB and support the hypothesis that AB results from an over-investment of attentional control.

Evidence for reading improvement following tDCS treatment in children and adolescents with Dyslexia.

PURPOSE: There is evidence that non-invasive brain stimulation transitorily modulates reading by facilitating the neural pathways underactive in individuals with dyslexia. The study aimed at investigating whether multiple sessions of transcranial direct current stimulation (tDCS) would enhance reading abilities of children and adolescents with dyslexia and whether the effect is long-lasting. METHODS: Eighteen children and adolescents with dyslexia received three 20-minute sessions a week for 6 weeks (18 sessions) of left anodal/right cathodal tDCS set at 1 mA over parieto-temporal regions combined with a cognitive training. The participants were randomly assigned to the active or the sham treatment; reading tasks (text, high and low frequency words, non-words) were used as outcome measures and collected before treatment, after treatment and one month after the end of treatment. The tolerability of tDCS was evaluated. RESULTS: The active group showed reduced low frequency word reading errors and non-word reading times. These positive effects were stable even one month after the end of treatment. None reported adverse effects. CONCLUSIONS: The study shows preliminary evidence of tDCS feasibility and efficacy in improving non-words and low frequency words reading of children and adolescents with dyslexia and it opens new rehabilitative perspectives for the remediation of dyslexia.

Reading changes in children and adolescents with dyslexia after transcranial direct current stimulation.

Noninvasive brain stimulation offers the possibility to induce changes in cortical excitability and it is an interesting option as a remediation tool for the treatment of developmental disorders. This study aimed to investigate the effect of transcranial direct current stimulation (tDCS) on reading and reading-related skills of children and adolescents with dyslexia. Nineteen children and adolescents with dyslexia performed different reading and reading-related tasks (word, nonword, and text reading; lexical decision; phonemic blending; verbal working memory; rapid automatized naming) in a baseline condition without tDCS and after 20 min of exposure to three different tDCS conditions: left anodal/right cathodal tDCS to enhance left lateralization of the parietotemporal region, right anodal/left cathodal tDCS to enhance right lateralization of the parietotemporal region, and sham tDCS. In text reading, results showed a significant reduction in errors after left anodal/right cathodal tDCS and an increase in errors after left cathodal/right anodal tDCS. No effect was found in the other reading and reading-related tasks. Our findings indicate for the first time that one session of tDCS modulates some aspects of reading performance of children and adolescents with dyslexia and that the effect is polarity dependent. These single-session results support a potential role of tDCS for developing treatment protocols and suggest possible parameters for tDCS treatment customization in children and adolescents with dyslexia.

Out with the Old and in with the New--Is Backward Inhibition a Domain-Specific Process?

Effective task switching is supported by the inhibition of the just executed task, so that potential interference from previously executed tasks is adaptively counteracted. This inhibitory mechanism, named Backward Inhibition (BI), has been inferred from the finding that switching back to a recently executed task (A-B-A task sequence) is harder than switching back to a less recently executed task (C-B-A task sequence). Despite the fact that BI effects do impact performance on everyday life activities, up to now it is still not clear whether the BI represents an amodal and material-independent process or whether it interacts with the task material. To address this issue, a group of individuals with Williams syndrome (WS) characterized by specific difficulties in maintaining and processing visuo-spatial, but not verbal, information, and a mental age- and gender-matched group of typically developing (TD) children were subjected to three task-switching experiments requiring verbal or visuo-spatial material to be processed. Results showed that individuals with WS exhibited a normal BI effect during verbal task-switching, but a clear deficit during visuo-spatial task-switching. Overall, our findings demonstrating that the BI is a material-specific process have important implications for theoretical models of cognitive control and its architecture.