How COVID-19 Affected Sleep Talking Episodes, Sleep and Dreams?

BACKGROUND

The COVID-19 pandemic increased symptoms of stress and anxiety and induced changes in sleep quality, dream activity, and parasomnia episodes. It has been shown that stressful factors and/or bad sleep habits can affect parasomnia behaviors. However, investigations on how COVID-19 has affected sleep, dreams, and episode frequency in parasomnias are rare. The current study focuses on the impact of the pandemic on a specific parasomnia characterized by speech production (sleep talking, ST).

METHODS

We selected 27 participants with frequent ST episodes (STs) during the pandemic and compared them with 27 participants with frequent STs from a previous study conducted during a pre-pandemic period. All participants performed home monitoring through sleep logs and recorded their nocturnal STs for one week.

RESULTS

We observed a higher frequency of STs in the pandemic group. Moreover, STs were related to the emotional intensity of dreams, independent of the pandemic condition. The pandemic was associated with lower bizarreness of dreams in the pandemic group. There were no differences in sleep variables between the two groups.

CONCLUSION

Overall, these results suggest a stressful effect of COVID-19 on the frequency of STs. Both the pandemic and the frequency of STs affect qualitative characteristics of dreams in this population.

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.

The Impact of Delayed School Start Times During COVID-19 on Academic Performance: A Longitudinal Naturalistic Study in Italian High Schools

Background

Delaying school start times has been proposed as a potential solution to address chronic sleep curtailment among adolescents and its negative consequences on their physical and mental well-being. This study investigates the impact of delayed school start times due to the COVID-19 pandemic on academic achievement.

Subjects and Methods

Two separate observational studies were conducted involving high school students from the first/second year (n=232) (Study 1) and from the final year (n=39) (Study 2). Multivariate Analyses of Covariance were performed to assess for statistical differences in academic performance (ie, global, humanistic, and scientific performance) and absenteeism (ie, number of school absences). Two main factors were considered: "school start time" (ie, standard-8:00 AM vs late-9:40 AM) and "time interval" (ie, first academic semester vs second academic semester), controlling for the school year (Study 1) and circadian preference (Study 2).

Results

Delaying school start times was positively associated with better academic performance in scientific subjects among first/second-year students (F1,229=6.083, p=0.026) and global academic performance among last-year students (F1,35=4.522, p=0.041). Furthermore, first/second-year students significantly increased their school achievement (F1,229>29.423, p<0.001) and school absences (F1,229=66.160, p<0.001) during the second semester of the academic year. No significant effect of "school start time" on school attendance was observed. Additionally, circadian preference was found to be a significant covariate among last-year students, with early chronotypes exhibiting better academic performance (r>0.369, p<0.025).

Conclusion

These findings confirm past evidence about the beneficial effects of delayed school start times on academic outcomes, with the additional advantage of observing them within a natural context that emerged during the pandemic. Further research is needed to explore the phenomenon more systematically and take into account the broader implications of implementing this change.

Purpose in life as an asset for well-being and a protective factor against depression in adolescents

Purpose in life, which is a central component of the eudaimonic paradigm of well-being, has been sparsely examined in adolescence. This is unfortunate as adolescence is characterised by identity development and is a key period for the onset of mental disorders. To inform future research on well-being and purpose in life in adolescents, we drew factors from several fields of research, including mental health and psychological factors, and explored which factors were most strongly associated with purpose in life. Data were collected in a sample of 444 Italian adolescents (Mage = 16.30 [SD = 1.50], range: 14 to 20 years; 58% girls) and associations with mental health (stress, anxiety, depression, anger), psychological traits (mindfulness, self-hate, self-inadequacy, self-reassurance, isolation), and sociodemographic variables (age, sex, place of birth) were examined. Regression, dominance, and network analyses indicated that a stronger sense of purpose in life was associated with lower depressive symptoms, higher levels of self-reassurance, and being born in Italy. Our findings suggest that purpose in life is an important asset for well-being in adolescents and may protect against depression. Future longitudinal and/or experimental research should examine the potential protective role of purpose in life in relation to adolescent depression and how self-reassurance and sociodemographic factors (e.g., immigrant background) are involved.

Imagine All the People: A Guided Internet-Based Imagery Training to Increase Assertiveness among University Students-Study Protocol for a Randomized Controlled Trial

The importance of communication skills for well-being and self-realization is widely accepted. Despite that, research on assertiveness and assertiveness training has declined significantly in recent decades. Consequently, traditional training does not consider the most recent novel technologies used to spread psychological interventions. This study proposes the development of ComunicaBene: a guided Internet-based imagery intervention to promote assertiveness. Moreover, it describes the study protocol for a randomized control trial to investigate the intervention's efficacy and acceptability. Participants will be randomly assigned to an experimental (ComunicaBene) or waitlist control condition. ComunicaBene consists of different online training modules corresponding to three phases: psychoeducation, imaginative exposure, and in vivo-exposure. Each module provides participants with theoretical and practical content about needs, emotions, communication style, and assertiveness. Moreover, during the program, every student is supervised by a Tutor. Participants in the control condition will be included in a waiting list. Primary and secondary outcomes will include changes in assertiveness, well-being, emotional awareness, worry, and rumination. Outcomes will be assessed at pre- and post-intervention, and via a 6-month follow-up. We expect that the results will support the efficacy of ComunicaBene as an innovative, scalable, affordable, and acceptable intervention to spread assertive training through the Internet and among a broad population.

Healthcare Workers after Two Years of COVID-19: The Consequences of the Pandemic on Psychological Health and Sleep among Nurses and Physicians

COVID-19 has challenged the health workforce worldwide. In this cross-sectional study with a retrospective assessment, we explored the impact of the pandemic on mental health and sleep among a sample of Italian nurses and medical doctors. A total of 287 healthcare workers (212 nurses and 75 physicians) completed a web survey on socio-demographic, psychological, and sleep-related aspects referring to the period before the pandemic and to the present period of February to June 2022. Comparisons between nurses and physicians revealed that the former had greater distress in response to the pandemic. Consistently, the multivariate analysis of covariance showed that even if both groups were negatively impacted by the pandemic, nurses presented a greater worsening over time regarding several psychological and sleep symptoms. Furthermore, we observed that working on the frontline represented an additional risk factor for nurses. In line with previous evidence, we also found that personal experiences with COVID-19 are significant predictors of the current health status. Our results underscore the urgent need for preventive programs among healthcare operators to increase their coping skills and prevent the long-term consequences of chronic stress, especially for high-risk professionals. Specific attention should also be devoted to programs to improve sleep quality and reduce sleep-related traumatic symptoms.

NoiBene, a Group Intervention for Promoting Mental Health Among University Students: A Study Protocol for a Randomized Controlled Trial

University students’ mental health has become a public health issue since increasingly students report high levels of psychological distress. Mental health difficulties influence students’ lives, such as academic performance, relationships satisfaction, and quality of life. Moreover, different kinds of obstacles often hinder help-seeking behavior. Such evidence strongly suggests the need to implement prevention and promotion strategies to increase health and well-being in educational contexts. This article presents a study protocol for implementing and evaluating NoiBene, an evidence-based group intervention that aims to promote mental health and well-being, improve a series of transversal competencies (e.g., emotional awareness, commitment to values, assertiveness, goal setting), and decrease dysfunctional transdiagnostic mechanisms (i.e., perfectionism, repetitive thinking, experiential avoidance). A randomized controlled trial will be conducted to evaluate the protocol’s efficacy. Participants will be assigned to one of the three conditions: the NoiBene Group condition (NB-G), the NoiBene guided web-based condition (NB-WB), or the waiting list condition (WLC). The NB-G intervention consists of six face-to-face group meetings, each dedicated to specific issues related to well-being or vulnerabilities. Every meeting includes an explanation of the theoretical contents, individual and group exercises, and role-plays. The NB-WB intervention covers the same topic addressed in the NB-G intervention. In this case, participants carry out a series of online modules, including theoretical explanations, practical exercises, useful activities, and self-monitoring tools. Students will individually meet the Tutor once every 2 weeks. The primary outcome will include an increase in mental health and well-being. Secondary outcomes will include changes in emotional awareness, assertiveness, perfectionism, rumination, worry, self-criticism, experiential avoidance, and academic performance and satisfaction. We expect that participants in both NoiBene conditions will show these outcomes. However, we hypothesized that the NB-G conditions will be more effective than the NB-WB in improving assertiveness. Besides treatment efficacy, we expect that students can benefit from the NB-G or NB-WB differently based on their specific behavioral and motivational patterns. Outcomes will be assessed at pre-, post-intervention and 6-months follow-up. In conclusion, we believe that NoiBene is a promising tool that can improve students’ well-being, and it could have positive implications for preventing mental health disorders among students.

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.

The Impact of COVID-19 Pandemic on Italian University Students' Mental Health: Changes across the Waves

To reduce the spread of COVID-19, the Italian government imposed a rigid lockdown and, for a whole year, continued to declare stringent rules to curb the community spread. This study provides an overview of university students' symptomatology and help-seeking behaviour before and during the pandemic. It aims to evaluate the impact of the different phases of the pandemic on students' mental health. We collected data in four-time points between March 2019 and March 2021. A total of 454 students (F = 85; M = 15) were included in the study. Students answered a socio-demographic and a standardized questionnaire (i.e., SCL-90-R) to evaluate a broad range of symptomatology. The results suggest that students experienced moderate to severe levels of depressive, obsessive-compulsive and anxiety symptomatology. About 14% of the sample met the criteria for at least one mental health disorder, but most were not receiving mental health care. During the lockdown, compared with other phases, female students reported worse symptoms in the obsessive-compulsive, interpersonal sensitivity, depression, paranoid ideation, and psychoticism dimensions. The increasing symptomatology disappeared after the lifting of the lockdown. The results showed no difference in the male groups. Preventive and support strategies should be improved in the university context.

Effectiveness of NoiBene: A Web-based programme to promote psychological well-being and prevent psychological distress in university students

Mental health problems are very common among university students. NoiBene is an evidence-based intervention for the promotion of well-being and the prevention of psychological distress among university students. NoiBene was tested in two studies. In study 1, a randomized controlled pilot trial was conducted to investigate the efficacy of NoiBene on students' well-being, emotional awareness, emotion regulation and assertiveness. The degree of satisfaction with the intervention was also investigated. Students (n = 24) were assigned to either the NoiBene programme or a control condition. In study 2, to confirm the usefulness of NoiBene, we analysed data from the current use of NoiBene (n = 178). The effectiveness of NoiBene on transdiagnostic mechanisms (perfectionism, repetitive thinking and experiential avoidance) was also investigated. In study 1, NoiBene improved self-acceptance and increased the ability to identify feelings. Students reported a good level of perceived usefulness. In study 2, the results confirmed findings from the first study and suggested that NoiBene can improve emotional awareness and decrease transdiagnostic mechanisms. NoiBene is a promising tool that can improve students' psychological well-being. More control studies are mandatory.

Executive functioning in relapsing-remitting multiple sclerosis patients without cognitive impairment: A task-switching protocol

Background:

Cognitive dysfunction affects 40%–65% of multiple sclerosis (MS) patients, most often affecting information processing speed and working memory, mediated by the pre-frontal cortex (PFC).

Objective:

Our study aimed to investigate PFC functioning through a task-switching protocol in relapsing-remitting multiple sclerosis (RRMS) patients without cognitive impairment.

Methods:

A total of 24 RRMS patients and 25 controls were enrolled. Two different tasks were performed in rapid and random succession, so that the task was either changed from one trial to the next one (switch trials) or repeated (repetition trials). Switch trials are usually slower than repetitions, causing a so-called switch cost (SC).

Results:

Patients had worse performance than controls only in the switch trials, as indicated by increased SC and reaction times. Moreover, patients showed a reduced ability to reconfigure the task-set for the execution of a new task and to disengage from the previous one.

Conclusion:

Our results showed a primary deficit in executive control processes involved in the task-switching performance in RRMS patients without cognitive impairment. This deficit may depend on the functional impairment of the PFC, which is essential to adjust behaviour rapidly and flexibly in response to environmental changes, representing one of the most sophisticated human abilities.

Reducing the Meta-Emotional Problem Decreases Physiological Fear Response during Exposure in Phobics

Anxiety disorders may not only be characterized by specific symptomatology (e.g., tachycardia) in response to the fearful stimulus (primary problem or first-level emotion) but also by the tendency to negatively evaluate oneself for having those symptoms (secondary problem or negative meta-emotion). An exploratory study was conducted driven by the hypothesis that reducing the secondary or meta-emotional problem would also diminish the fear response to the phobic stimulus. Thirty-three phobic participants were exposed to the phobic target before and after undergoing a psychotherapeutic intervention addressed to reduce the meta-emotional problem or a control condition. The electrocardiogram was continuously recorded to derive heart rate (HR) and heart rate variability (HRV) and affect ratings were obtained. Addressing the meta-emotional problem had the effect of reducing the physiological but not the subjective symptoms of anxiety after phobic exposure. Preliminary findings support the role of the meta-emotional problem in the maintenance of response to the fearful stimulus (primary problem).

Specific dysphoric symptoms are predicted by early maladaptive schemas

Early maladaptive schemas (EMSs) are cognitive patterns resulting from unmet core emotional needs in childhood that have been linked to the development of psychopathology. As depression is a multifaceted phenomenon, we hypothesized that specific dysphoric symptoms would be predicted by different EMSs. Four hundred and fifty-six participants completed a measure of EMSs (Young Schema Questionnaire) and reported on the severity of the symptoms of criterion A for major depression in DSM-IV during the occurrence of a dysphoric episode in the previous 12 months. A series of stepwise multiple regression analyses were performed to investigate the predictive power of the EMSs for the severity of each specific depressive symptom. When controlling for gender and current levels of depression, specific symptoms were predicted by different EMSs: sadness by Negativity/Pessimism; anhedonia by Failure; self-harm by Emotional Deprivation and Vulnerability to Harm or Illness; worthlessness by Failure and Negativity/Pessimism; psychomotor retardation/restlessness by Vulnerability to Harm or Illness and Entitlement/Grandiosity; and poor concentration by Insufficient Self-Control/Self-Discipline. The more physical symptoms of fatigue, insomnia/hypersomnia, and appetite loss/appetite gain were not predicted by any of the EMSs. Although the cross-sectional design of the study does not allow for conclusions about the direction of effects, results suggest that depression is not a unitary phenomenon and provide a possible explanation for previous inconsistent findings.

Pros and cons of a wandering mind: a prospective study

Mind wandering (MW) has recently been associated with both adaptive (e.g., creativity enhancement) and maladaptive (e.g., mood worsening) consequences. This study aimed at investigating whether proneness to MW was prospectively associated with negative health outcomes. At time 0, 21 women, 19 men; mean age = 24.5 (4.9) underwent a 5-min baseline electrocardiogram (ECG), a 20-min laboratory tracking task with thought probes, and personality questionnaires. At time 1 (1 year follow-up), the same participants underwent a 24-h Ecological Momentary Assessment characterized by ambulatory ECG recording and electronic diaries. First, we examined if the likelihood of being a “mind wanderer” was associated with specific personality dispositions. Then, we tested if the occurrence of episodes of MW in the lab would be correlated with frequency of MW in daily life. Finally, multiple regression models were used to test if MW longitudinally acted as a risk factor for health, accounting for the effects of biobehavioral variables. Among dispositional traits, the frequency of MW episodes in daily life was inversely associated with the capacity of being mindful (i.e., aware of the present moment and non-judging). There was a positive correlation between frequency of MW in the lab and in daily life, suggesting that it is a stable disposition of the individual. When differentiated from perseverative cognition (i.e., rumination and worry), MW did not predict the presence of health risk factors 1 year later, however, a higher occurrence of episodes of MW was associated with short-term adverse consequences, such as increased 24-h heart rate (HR) on the same day and difficulty falling asleep the subsequent night. Present findings suggest that MW may be associated with short term “side effects” but argue against a long term dysfunctional view of this cognitive process.

Intrapsychic and interpersonal guilt: a critical review of the recent literature

Various authors hold that some emotions (i.e., moral emotions) have the function of orienting people toward ethical actions. In addition to embarrassment, shame and pride, the moral emotion of guilt is believed to affect humans' behavior when they carry out transgressions that violate social and cultural standards. Over the past century, many studies (including controversial ones) have been conducted on guilt. In this study, we analyzed and summarized mainly the most recent literature on this emotion. On one side, the destructiveness of guilt is emphasized. It inflicts punishment and pain on individuals for their errors and can lead to psychopathology (e.g., depression). On the other side, it is described as a "friendly" emotion that motivates behavior adapted to social and cultural rules. How can this asymmetry be explained? Different existing views on guilt are presented and discussed, together with recent proposals, supported by research data. Finally, we discussed some systematic models that try to incorporate these different views in a single framework that could facilitate future researches.

The role of personal goals in depressive reaction to adverse life events: a cross-sectional study

Consistent with cognitive views of depression, we aimed to investigate the mediating role of personal goals in the relationship between stressful events and distinct patterns of depressive symptoms in a nonclinical sample. Participants identified a dysphoric episode that occurred in the previous year by reporting the severity of 12 depressive symptoms and their plausible cause. A goal taxonomy was used to determine how much the event interfered with the achievement of a series of personal goals. After controlling for age and current level of depression, the patterns of symptoms differed based on the triggering events. The relationship between sadness and affective losses was partially mediated by the personal goal of lovableness, and success was a partial mediator in the association between an event of failure and symptoms of worthlessness and anhedonia. Although the cross-sectional design of the study does not allow for conclusions on the direction of effects, findings suggest the importance of motivational factors in the development of specific patterns of depressive symptoms to adverse events. Assuming a continuum from low mood to clinical depression, treatment models could benefit from a precise identification of the specific stressors that initiate depressive behaviour and the personal meaning assigned to those events.

The impact of one night of sleep deprivation on moral judgments

Recent studies have shown the existence of a relationship between sleep and moral judgment. In this study, we investigated whether one night of sleep deprivation affects the ability to judge the appropriateness of moral dilemmas. Forty-eight students had to judge 30 moral dilemmas at test, after a night of home sleep, and another 30 dilemmas at retest, following one night of continuous wakefulness. The 60 dilemmas (20 moral impersonal, 20 moral personal, and 20 non-moral) were selected from Greene's dilemmas. Both groups judged the appropriateness of personal and impersonal dilemmas in the same way. A close to significant effect of sleep deprivation was observed on the reaction times for impersonal moral dilemmas, to which the deprived subjects responded faster (p = .05) than the control subjects. However, this was not the case for personal ones, for which no difference was significant. This result shows a greater ease/speed in responding to the (impersonal) dilemmas, which induce low emotional engagement after sleep deprivation, although the willingness to accept moral violations is not affected. This suggests that one night of sleep loss selectively influences the response speed only for moral impersonal dilemmas, probably due to disinhibition processes. The quality of moral judgment dilemmas does not seem to be easily influenced by a single night of sleep deprivation, but only by a longer lack of sleep.

Audio-visual dynamic remapping in an endogenous spatial attention task

Several studies on cross-modal attention showed that remapping processes between sensory modalities occur in the spatial orienting of attention. One hypothesis that accounts for such links is that spatial attention operates upon representations of common locations in the external space. However, convincing evidence only exists for cross-modal links in spatial orienting, leaving the dynamics of these effects unexplored. Four experiments were designed to cope with this issue by having participants being involved in an endogenous orienting task to visual and auditory target stimuli. Targets on invalid trials were embedded into two different kinds of sequences of stimuli: (1) long sequences, wherein three valid trials in one modality preceded the invalid trial in the other modality; (2) short sequences, wherein only one valid trial in one modality preceded the invalid trial in the other modality. Results revealed modality-specific meridian effects in the short sequences, and a significant decrement of the modality-specific meridian effect in the long sequences. The results of these experiments indicate that cross-modal links in visual and auditory spatial attention are based on representations of common locations in the external space across sensory modalities. Moreover, the results strongly support the hypothesis that representations of space are dynamically built and updated according to task demands.

Crossing the pillars of Hercules: the role of spatial frames of reference in error making

This paper introduces a perspective accounting for errors that may occur as a result of the human interaction with the three-dimensional (3D) space. Particularly, we are interested in errors that are caused by cognitively crossing the boundary between peripersonal and extrapersonal space. Several behavioural, neurophysiological, and neuropsychological perspectives are reviewed in order to develop the theoretical framework on which our ideas are founded. We argue that cognitively crossing the boundary implies switching from one frame of reference to another, which, as a consequence, implies specific costs. The results of five experiments (overall involving 76 participants) support our hypothesis, suggesting the existence of different action-oriented spatial frames of reference.

Can an inert sleeping pill affect sleep? Effects on polysomnographic, behavioral and subjective measures

RATIONALE

Since two recent meta-analyses on sleep changes associated with placebo in clinical trials suggested a beneficial effect of placebo treatments, pointing to a dissociation between subjective and objective measures of sleep, the current experiment was directly aimed to assess the effects of an inert compound, administered with the suggestion that it was a hypnotic substance in subjects with mild sleep complaints.

OBJECTIVES

The aim of this study was to compare subjective, behavioral, polysomnographic (PSG), and quantitative electroencephalographic (EEG) changes during a night preceded or not by the intake of two 50-mg lactose capsules.

METHODS

Ten female students, selected by the Pittsburgh Sleep Quality Index, slept for three consecutive nights in a sleep laboratory, with the experimental (EXP) night defined by the administration of two 50-mg lactose pills. Self-ratings of sleep quality and performance were assessed upon morning awakening of baseline (BSL) and EXP nights.

RESULTS

The EXP nights were self-rated as more restful and characterized by a decreased number of nocturnal awakenings than the BSL nights. PSG measures showed that wakefulness after sleep onset significantly decreased during the EXP night as compared to the BSL night. The EXP nights also showed an increase of 0.5-4.0 Hz power during nonrapid eye movement sleep and a decrease of EEG activity in the beta frequency range during rapid eye movement sleep only at central brain sites. A specific improvement of behavioral measures was also found upon morning awakening after the EXP night compared to the BSL night.

CONCLUSIONS

The administration of an inert pill improves both the subjective and objective quality of sleep. The reduced sleep fragmentation and the effects on some quantitative EEG markers of sleep homeostasis suggest that the experimental manipulation induced coherent changes in the subsequent sleep, resembling an enhancement of sleep pressure. The regional differences of EEG activity suggest the involvement of a specific physiological mechanism distinct from that of effective treatments.

Opposite visual field asymmetries for egocentric and allocentric spatial judgments

The purpose of the present study was to investigate the relation between visual hemifields and spatial frames of reference, according to the idea that multiple representations of 3D space exist. Results from two experiments clearly show that an upper visual hemifield advantage only arises when allocentric spatial judgments are required in order to perform a location task, whereas a lower visual hemifield advantage arises when egocentric spatial judgments are required. Such a double dissociation was interpreted as due to the activity of two separate neural pathways operating specific transformations of visual input for different functional outputs: scene recognition, mostly relying on allocentric frames of reference and subserved by the ventral, occipito-temporal pathway of the visual system, and goal directed actions, mostly relying on egocentric systems and subserved by the dorsal, occipito-parietal pathway of the visual system.

Functional representation of 3D space in endogenous attention shifts

The aim of this study was to explore whether the attentional system, as far as an endogenous orienting is concerned, allocates resources along the sagittal plane and whether such a process is affected by, and is likely to be based on, different functional representations of 3D space in the brain. Several models make a main action-based distinction between representations of peripersonal space and of those extrapersonal space. Accordingly, if attention has to move from one representation to another, it should be possible to observe a decrease in performance during such a transition. To test this hypothesis three experiments were run in which participants performed a cued detection task. Cue stimuli were informative and were centrally located around the fixation point. Target stimuli were displayed at four different depth planes. In the first experiment, assuming that the border between the peripersonal space and the extrapersonal space was at 1 m from the observer, half the target stimuli were located in the peripersonal space and half in the extrapersonal space. The fixation point was located at 1 m from the observer. In the second experiment, the fixation point was moved at 2 m from the observer in order to rule out the possible effects of ocular motor programming. In the third experiment, in order to rule out effects related to the spatial layout of target stimuli (i.e., centre of mass effect) two target stimuli were located in the peripersonal space and six in the extrapersonal space. In all the experiments, besides a validity effect, we observed greater reaction times when attention shift was across spatial representations than when it was within the same representation. The implications for action-oriented models of attention are discussed.