Understanding the structure of autobiographical memories: A study of trauma memories from the 1994 Rwandan genocide

How do we remember traumatic events, and are these memories different in individuals who experience post-traumatic stress? Some evidence suggests that traumatic events are mnemonically enhanced, or include more episodic detail, relative to other types of memories. Simultaneously, individuals with post-traumatic stress disorder (PTSD) have more non-episodic details in all of their memories, a pattern hypothesized to result from impairment in executive function. Here, we explore these questions in a unique population that experienced severely traumatic events more than 20 years ago - individuals who lived through the 1994 genocide in Rwanda. Participants recalled events from the genocide, negative events unrelated to the genocide, neutral events, and positive events. We used the Autobiographical Interview method to label memory details as episodic or non-episodic. We found that memories from the genocide showed robust mnemonic enhancement, with more episodic than non-episodic details, and contained more details overall than any other memory type. This pattern was not impacted by post-traumatic stress. Overall, this study provides evidence that traumatic events create vivid long-lasting episodic memories, in this case even more than 20 years later.

The relationships between urbanicity, general cognitive ability, and susceptibility to the Ebbinghaus illusion

Previous studies have shown that, in samples of non-Western observers, susceptibility to the Ebbinghaus illusion is stronger in urban than rural dwellers. While such relationship between illusion strength and urbanicity has often been ascribed to external factors (such as the visual impact of the environment), the present study explored the possibility that it is instead mediated by general cognitive ability, an internal factor. We recruited a sample of remote Namibians who varied in their level of urbanicity, and measured their susceptibility to the Ebbinghaus illusion, their levels of education and literacy, and their general cognitive ability. The results showed that urbanicity was related to Ebbinghaus susceptibility, and that general cognitive ability, literacy and education did not mediate this effect, which is reassuring with regard to the findings of previous studies that did not control for these variables. However, we found robust relationships between urbanicity, on the one hand, and cognitive ability, education and literacy, on the other, which advocates for careful consideration of the impact of the latter variables in studies about the cognitive effects of urban environments.

Debiasing thinking among non-WEIRD reasoners

Human reasoning has been shown to be biased in a variety of situations. While most studies have focused on samples of WEIRD participants (from Western Educated Industrialized Rich and Democratic societies), the sparse non-WEIRD data on the topic suggest an even stronger propensity for biased reasoning. This could be explained by a competence issue (people lack the ability to integrate logical knowledge into their reasoning) or a performance issue (people possess the logical knowledge but do not know it is relevant). We addressed this question using a debiasing paradigm with the base-rate task on a sample of non-industrialized people, the Himba of Namibia. After a short training, most participants were debiased, lending credence to the performance account. Debiasing was however to some extent boosted by schooling and living environment suggesting that competence also plays a role (in that more acquired knowledge allows for a higher training benefit). Results imply that debias interventions can be successfully employed to boost sound reasoning around the world.

Association between relative age at school and persistence of ADHD in prospective studies: an individual participant data meta-analysis

BACKGROUND

The youngest children in a school class are more likely than the oldest to be diagnosed with ADHD, but this relative age effect is less frequent in older than in younger school-grade children. However, no study has explored the association between relative age and the persistence of ADHD diagnosis at older ages. We aimed to quantify the association between relative age and persistence of ADHD at older ages.

METHODS

For this meta-analysis, we searched MEDLINE, Embase, CINAHL, PsycINFO, and PubPsych up to April 1, 2022, with terms related to "cohort" and "ADHD" with no date, publication type, or language restrictions. We gathered individual participant data from prospective cohorts that included at least ten children identified with ADHD before age 10 years. ADHD was defined by either a clinical diagnosis or symptoms exceeding clinical cutoffs. Relative age was recorded as the month of birth in relation to the school-entry cutoff date. Study authors were invited to share raw data or to apply a script to analyse data locally and generate anonymised results. Our outcome was ADHD status at a diagnostic reassessment, conducted at least 4 years after the initial assessment and after age 10 years. No information on sex, gender, or ethnicity was collected. We did a two-stage random-effects individual participant data meta-analysis to assess the association of relative age with persistence of ADHD at follow-up. This study was registered with PROSPERO, CRD42020212650.

FINDINGS

Of 33 119 studies generated by our search, we identified 130 eligible unique studies and were able to gather individual participant data from 57 prospective studies following up 6504 children with ADHD. After exclusion of 16 studies in regions with a flexible school entry system that did not allow confident linkage of birthdate to relative age, the primary analysis included 41 studies in 15 countries following up 4708 children for a period of 4 to 33 years. We found that younger relative age was not statistically significantly associated with ADHD persistence at follow-up (odds ratio 1·02, 95% CI 0·99-1·06; p=0·19). We observed statistically significant heterogeneity in our model (Q=75·82, p=0·0011, I2=45%). Participant-level sensitivity analyses showed similar results in cohorts with a robust relative age effect at baseline and when restricting to cohorts involving children with a clinical diagnosis of ADHD or with a follow-up duration of more than 10 years.

INTERPRETATION

The diagnosis of ADHD in younger children in a class is no more likely to be disconfirmed over time than that of older children in the class. One interpretation is that the relative age effect decreases the likelihood of children of older relative age receiving a diagnosis of ADHD, and another is that assigning a diagnostic label of ADHD leads to unexplored carryover effects of the initial diagnosis that persist over time. Future studies should be conducted to explore these interpretations further.

FUNDING

None.

Trend judgment as a perceptual building block of graphicacy and mathematics, across age, education, and culture

Data plots are widely used in science, journalism and politics, since they efficiently allow to depict a large amount of information. Graphicacy, the ability to understand graphs, has thus become a fundamental cultural skill comparable to literacy or numeracy. Here, we introduce a measure of intuitive graphicacy that assesses the perceptual ability to detect a trend in noisy scatterplots ("does this graph go up or down?"). In 3943 educated participants, responses vary as a sigmoid function of the t-value that a statistician would compute to detect a significant trend. We find a minimum level of core intuitive graphicacy even in unschooled participants living in remote Namibian villages (N = 87) and 6-year-old 1st-graders who never read a graph (N = 27). The sigmoid slope that we propose as a proxy of intuitive graphicacy increases with education and tightly correlates with statistical and mathematical knowledge, showing that experience contributes to refining graphical intuitions. Our tool, publicly available online, allows to quickly evaluate and formally quantify a perceptual building block of graphicacy.

Intergenerational transmission of trauma and its association with attitudes toward reconciliation

OBJECTIVE

We aimed to investigate the link between mothers' posttraumatic stress disorder (PTSD) symptoms and their adult offspring's attitudes toward reconciliation and psychopathology among survivors of the 1994 genocide perpetrated against the Tutsi in Rwanda. We also sought to examine whether parenting styles mediate the relationship between mothers' PTSD symptoms and their adult offspring's psychopathology, if any.

METHOD

Mother-child dyads (N = 181) were recruited in Rwanda and completed measures of trauma exposure, PTSD, depression, attitudes toward reconciliation, and parenting styles.

RESULTS

Adult offspring of mothers who suffered from more severe PTSD symptoms had less favorable attitudes toward reconciliation, even after controlling for their own PTSD symptoms. Mothers' PTSD symptoms were not associated with their adult offspring's PTSD or depression symptoms. In addition, mothers' PTSD symptoms did not predict their parenting styles.

CONCLUSIONS

These results suggest that the mental health of survivors of mass violence has repercussions on the intergroup attitudes of the following generation. This study has practical implications for sustainable peacebuilding in postconflict societies. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Effects of a Cognitive Schema Account on the Stigma of Schizophrenia: A Study in a French University Student Sample

Among people with psychiatric disorders, those with schizophrenia are subject to high levels of stigmatization. Research is necessary to identify new strategies that may help reduce the stigma of schizophrenia. Educational strategies using cognitive accounts, particularly early maladaptive schemas (EMSs), have shown promising results in the context of depression, but they have not been evaluated in the context of schizophrenia. The present study compared the effect on the stigma of three different educational strategies, based on cognitive distortions, biogenetics, and EMSs. A total of 378 students were randomly assigned to 1 of 4 groups. Three experimental groups were presented with a vignette that introduced 1 of 3 different etiological accounts of schizophrenia (cognitive distortions, EMSs, or biogenetics). The fourth group was presented with a text unrelated to schizophrenia. The participants completed questionnaires that measured their attitudes, empathic concern, and social distance toward people with schizophrenia, before and after reading the text. The intervention using the EMS etiology account for schizophrenia was the only one that led to a significant decrease in stigma. The latter effect was driven mainly by an increase in the level of empathic concern toward people with schizophrenia. Given that similar results have been observed for depression and that the role of EMSs in many psychiatric disorders has been demonstrated, studying the effects of EMS explanations for other stigmatized disorders may be promising for reducing the stigma of psychiatric disorders.

A 21st century cognitive portrait of the Himba, a remote people of Namibia

This research sketches the cognitive portrait of the Himba, a remote population from Northern Namibia living in a non-industrial society almost completely devoid of modern artefacts. We compared the Himba sample to a French sample, exploring cognitive reflection, moral judgement, cooperative behaviour, paranormal beliefs, and happiness. We looked for both differences and similarities across cultures, and for the way cognitive functioning is associated with a range of demographic variables. Results showed some important group differences, with the Himba being more intuitive, more religious, happier, and less utilitarian than the French participants. Further, the predictors of these beliefs and behaviours differed between the two groups. The present results provide additional support to the recent line of research targeting cultural variations and similarities, and call for the need to expand psychology research beyond the Western world.

Cultural Differences in Face Recognition and Potential Underlying Mechanisms

The ability to recognize a face is crucial for the success of social interactions. Understanding the visual processes underlying this ability has been the focus of a long tradition of research. Recent advances in the field have revealed that individuals having different cultural backgrounds differ in the type of visual information they use for face processing. However, the mechanisms that underpin these differences remain unknown. Here, we revisit recent findings highlighting group differences in face processing. Then, we integrate these results in a model of visual categorization developed in the field of psychophysics: the RAP framework. On the basis of this framework, we discuss potential mechanisms, whether face-specific or not, that may underlie cross-cultural differences in face perception.

From bias to sound intuiting: Boosting correct intuitive reasoning

Although human thinking is often biased by erroneous intuitions, recent de-bias studies suggest that people's performance can be boosted by short training interventions, where the correct answers to reasoning problems are explained. However, the nature of this training effect remains unclear. Does training help participants correct erroneous intuitions through deliberation? Or does it help them develop correct intuitions? We addressed this issue in three studies, by focusing on the well-known Bat-and-Ball problem. We used a two-response paradigm in which participants first gave an initial intuitive response, under time pressure and cognitive load, and then gave a final response after deliberation. Studies 1 and 2 showed that not only did training boost performance, it did so as early as the intuitive stage. After training, most participants solved the problems correctly from the outset and no longer needed to correct an initial incorrect answer through deliberation. Study 3 indicated that this sound intuiting sustained over at least two months. The findings confirm that a short training can boost sound reasoning at an intuitive stage. We discuss key theoretical and applied implications.

Influence of the month of birth on persistence of ADHD in prospective studies: protocol for an individual patient data meta-analysis

INTRODUCTION

Attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder with symptoms, especially the hyperactive ones, that tend to decrease in severity with age. Interestingly, children born just before the school-entry cut-off date (ie, the youngest pupils of a classroom) are at higher risk of being diagnosed with ADHD compared with children born just after the cut-off date. Noteworthy, this month-of-birth effect tends to disappear with increasing absolute age. Therefore, it is possible that young children erroneously diagnosed with ADHD due to their month of birth present a lower chance to have their diagnosis confirmed at a later age, artificially reinforcing the low persistence of ADHD across the lifespan. This protocol outlines an individual patient data (IPD) meta-analysis of prospective observational studies to explore the role of the month of birth in the low persistence of ADHD across the lifespan.

METHODS AND ANALYSIS

Five databases will be systematically searched in order to find prospective observational studies where the presence of ADHD is assessed both at baseline and at a follow-up of at least 4 years. We will use a two-stage IPD meta-analytic approach to estimate the role of the month of birth in the persistence of ADHD. Various sensitivity analyses will be performed to assess the robustness of the results.

ETHICS AND DISSEMINATION

No additional data will be collected and no de-identified raw data will be used. Ethics approval is thus not required for the present study. Results of this IPD meta-analysis will be submitted for publication in a peer-reviewed journal.

PROSPERO REGISTRATION NUMBER

CRD42020212650.

Impact of Music on Working Memory in Rwanda

Previous research shows that listening to pleasant, stimulating and familiar music is likely to improve working memory performance. The benefits of music on cognition have been widely studied in Western populations, but not in other cultures. The purpose of this study was to explore the impact of music on working memory in a non-Western sociocultural context: Rwanda. One hundred and nineteen participants were randomly assigned to a control group (short story) or one of four different musical conditions varying on two dimensions: arousal (relaxing, stimulating) and cultural origin (Western, Rwandan). Working memory was measured using a behavioral task, the n-back paradigm, before and after listening to music (or the short story in the control condition). Unlike in previous studies with Western samples, our results with this Rwandan sample did not show any positive effect of familiar, pleasant and stimulating music on working memory. Performance on the n-back task generally improved from pre to post, in all conditions, but this improvement was less important in participants who listened to familiar Rwandan music compared to those who listened to unfamiliar Western music or to a short story. The study highlights the importance of considering the sociocultural context in research examining the impact of music on cognition. Although different aspects of music are considered universal, there may be cultural differences that limit the generalization of certain effects of music on cognition or that modulate the characteristics that favor its beneficial impact.

The psychological correlates of transitional justice in Rwanda: A long-term assessment

OBJECTIVE

We tested the psychological correlates of the Gacaca tribunals, a massive program of transitional justice put in place by the Rwandan government following the 1994 genocide perpetrated against the Tutsi.

METHOD

The sample consisted of 679 Rwandese participants, among which 373 (55%) were survivors of the genocide. We contrasted three groups of participants: (1) those who had never attended the Gacaca (N = 229), the control group, (2) those who had attended without testifying (N = 275), the attendance group, and (3) those who had attended and testified (N = 120), the testimony group. In the analyses, we controlled for the level of genocide-related negative consequences that participants reported.

RESULTS

The attendance group presented lower levels of PTSD and depression symptoms than both the control and testimony groups. Both attendance and testimony groups had more positive opinions of the Gacaca and higher openness to reconciliation than the control group.

CONCLUSIONS

contrary to what has been reported in two previous studies, participation in the Gacaca was not, in our data, negatively related to mental health or to social cohesion. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

The interplay between the importance of a decision and emotion in decision-making

Decision-making literature has demonstrated that individuals' preferences are strongly affected by the way in which choices are presented. This cognitive bias, termed the framing effect, is influenced by the importance of the possible outcomes that a decision can have. However, the direction of this influence remains poorly understood. The aim of this paper was to examine the role of the importance of a decision in framing susceptibility and to explore a potential mechanism underlying this influence. Our first study revealed that participants display a framing effect when their decision implies a high importance outcome, but resist framing manipulation when their decision implies a low importance outcome. Our second study confirmed that an increase in the importance of a decision is associated with increasing framing susceptibility. Moreover, a moderated mediation analysis revealed that the more a decision was important, the more the gain and loss frames aroused opposite emotions, and this accounted for the increase in framing susceptibility. The results of these two studies confirmed that an increase in the importance of a decision is associated with increasing framing susceptibility and suggest that this influence on framing susceptibility is underpinned by emotion. Implications and direction for future studies are discussed.

Urbanisation, the arousal system, and covert and overt attentional selection

Urbanisation is growing rapidly. We review evidence that this growth is altering the default information processing style of human beings by impacting both overt and covert processes of attentional selection (i.e. attentional selection with and without eye movements respectively), in ways consistent with reduced attentional engagement and increased exploration. While the factors and systems mediating these effects are likely to be many and various, we focus on one system which may be responsible for mediating effects on both covert and overt attentional selection. Specifically, the neuromodulatory locus coeruleus-norepinephrine (LC-NE) system is key to regulating cognitive function in a behaviourally relevant and arousal-dependent manner and therefore well suited to supporting adaptation to the profound socio-ecological changes inherent in urbanisation.

Long-term cognitive correlates of exposure to trauma: Evidence from Rwanda

Research increasingly shows links between trauma exposure, posttraumatic stress symptoms, and cognitive functioning. We know relatively little about the long-term cognitive correlates of exposure to trauma, especially in civilian populations exposed to war and political violence.

OBJECTIVE

Our goal was to examined short-term memory (STM) and executive function 20 years after the 1994 genocide of the Tutsis in Rwanda. We hypothesized that performance on these tasks would be negatively related to trauma exposure and to posttraumatic stress disorder (PTSD) symptoms.

METHOD

In two studies, 470 Rwandan participants answered questionnaires measuring the severity of experiences that occurred during the 1994 genocide and current levels of PTSD symptoms. In both studies, we tested STM using a forward digit span task. In the second study, we also measured executive function using a semantic fluency task.

RESULTS

There were modest but significant negative links between the severity of experiences during the genocide and STM function more than 20 years after. Current levels of PTSD symptoms were also related to STM and executive function.

CONCLUSIONS

This study reveals the important link between exposure to highly emotional events and cognitive function and highlights the need to attend not only to the mental health but also to the cognitive health of populations exposed to political violence. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Sexual Abuse Exposure Alters Early Processing of Emotional Words: Evidence from Event-Related Potentials

This study aimed to compare the time course of emotional information processing between trauma-exposed and control participants, using electrophysiological measures. We conceived an emotional Stroop task with two types of words: trauma-related emotional words and neutral words. We assessed the evoked cerebral responses of sexual abuse victims without post-traumatic stress disorder (PTSD) and no abuse participants. We focused particularly on an early wave (C1/P1), the N2pc, and the P3b. Our main result indicated an early effect (55–165 ms) of emotionality, which varied between non-exposed participants and sexual abuse victims. This suggests that potentially traumatic experiences modulate early processing of emotional information. Our findings showing neurobiological alterations in sexual abuse victims (without PTSD) suggest that exposure to highly emotional events has an important impact on neurocognitive function even in the absence of psychopathology.

Urban experience alters lightness perception

We present the first empirical evidence that experience alters lightness perception. The role of experience in lightness perception was investigated through a cross-cultural comparison of 2 visual contrast phenomena: simultaneous lightness contrast and White's illusion. The Himba, a traditional seminomadic group known to have a local bias in perception, showed enhanced simultaneous lightness contrast but reduced White's illusion compared with groups that have a more global perceptual style: Urban-dwelling Himba and Westerners. Thus, experience of the urban environment alters lightness perception and we argue it does this by fostering the tendency to integrate information from across the visual scene. (PsycINFO Database Record

Twenty years later, the cognitive portrait of openness to reconciliation in Rwanda

With this work, we intended to draw a cognitive portrait of openness to reconciliation. No study had yet examined the potential contribution of high-level cognitive functioning, in addition to psychological health, to explaining attitudes towards reconciliation in societies exposed to major trauma such as post-genocide Rwanda. We measured the contribution of general cognitive capacity, analytical thinking, and subjective judgements. Our results show that higher cognitive capacity is not associated with greater openness to reconciliation. On the other hand, proneness to think analytically about the genocide predicts more favorable attitudes towards reconciliation. The latter effect is associated with more tempered judgements about retrospective facts (e.g., number of genocide perpetrators) and prospective events (e.g., risk of genocide reoccurrence). This work establishes the importance of cognitive functioning in the aftermath of political violence: A better understanding of the influence of information processing on openness to reconciliation may help improve reconciliation policies and contribute to reducing risks of conflict reoccurrence.

Working memory function is linked to trauma exposure, independently of post-traumatic stress disorder symptoms

INTRODUCTION

The purpose of the study was to examine how working memory (WM) may be related to exposure to potentially traumatic events and symptoms of post-traumatic stress disorder (PTSD).

METHOD

In four studies, we measured WM function using adaptations of the running span and the reading span tasks. We compared the performance of women reporting experiences of sexual abuse to control participants (total n = 144 controls and 84 victims). We measured severity of the sexual abuse experiences as well as exposure to general life stress.

RESULTS

In all studies, trauma-exposed participants showed significantly lower WM function compared to control participants. In addition to traditional null hypothesis testing, we used a mini-meta analysis to estimate the combined estimated effect size of this difference, which was in the moderate range (d = 0.43 with 0.15-0.70 95% confidence interval). Regression equations showed that PTSD symptoms did not mediate the relationship between trauma exposure and WM function.

CONCLUSIONS

Our results show that trauma exposure per se can be associated with important cognitive correlates even in individuals who do not develop psychopathological reactions.

Independent effects of relevance and arousal on deductive reasoning

Emotional content can have either a deleterious or a beneficial impact on logicality. Using standard deductive-reasoning tasks, we tested the hypothesis that the interplay of two factors - personal relevance and arousal - determines the nature of the effect of emotional content on logicality. Arousal was assessed using measures of skin conductance. Personal relevance was manipulated by asking participants to reason about semantic contents linked to an emotional event that they had experienced or not. Findings showed that (1) personal relevance exerts a positive effect on logicality while arousal exerts a negative effect, and that (2) these effects are independent of each other.

The tree to the left, the forest to the right: political attitude and perceptual bias

A prominent model suggests that individuals to the right of the political spectrum are more cognitively rigid and less tolerant of ambiguity than individuals to the left. On the basis of this model, we predicted that a psychological mechanism linked to the resolution of visual ambiguity--perceptual bias--would be linked to political attitude. Perceptual bias causes western individuals to favour a global interpretation when scrutinizing ambiguous hierarchical displays (e.g., alignment of trees) that can be perceived either in terms of their local elements (e.g., several trees) or in terms of their global structure (e.g., a forest). Using three tasks (based on Navon-like hierarchical figures or on the Ebbinghaus illusion), we demonstrate (1) that right-oriented Westerners present a stronger bias towards global perception than left-oriented Westerners and (2) that this stronger bias is linked to higher cognitive rigidity. This study establishes for the first time that political ideology, a high-level construct, is directly reflected in low-level perception. Right- and left-oriented individuals actually see the world differently.

Urbanization increases left-bias in line-bisection: an expression of elevated levels of intrinsic alertness?

Urbanization impairs attentional selection and increases distraction from task-irrelevant contextual information, consistent with a reduction in attentional engagement with the task in hand. Previously, we proposed an attentional-state account of these findings, suggesting that urbanization increases intrinsic alertness and with it exploration of the wider environment at the cost of engagement with the task in hand. Here, we compare urbanized people with a remote people on a line-bisection paradigm. We show that urbanized people have a left spatial bias where remote people have no significant bias. These findings are consistent with the alertness account and provide the first test of why remote peoples have such an extraordinary capacity to concentrate.

Do Local and Global Perceptual Biases Tell Us Anything About Local and Global Selective Attention?

Local, as opposed to global, perceptual bias has been linked to a lesser ability to attend globally. We examined this proposed link in Himba observers, members of a remote Namibian population who have demonstrated a strong local bias compared with British observers. If local perceptual bias is related to a lesser ability to attend globally, Himba observers, relative to British observers, should be less distracted by global information when performing a local-selection task but more distracted by local information when performing a global-selection task. However, Himba observers performed better than British observers did on both a local-selection task and a global-selection task (both of which used local/global hierarchical figures as stimuli), which suggests that they possessed greater control over attentional selection in response to task demands. We conclude that local and global perceptual biases must be distinguished from local and global selective attention.

"Bouba" and "Kiki" in Namibia? A remote culture make similar shape-sound matches, but different shape-taste matches to Westerners

Western participants consistently match certain shapes with particular speech sounds, tastes, and flavours. Here we demonstrate that the "Bouba-Kiki effect", a well-known shape-sound symbolism effect commonly observed in Western participants, is also observable in the Himba of Northern Namibia, a remote population with little exposure to Western cultural and environmental influences, and who do not use a written language. However, in contrast to Westerners, the Himba did not map carbonation (in a sample of sparkling water) onto an angular (as opposed to a rounded) shape. Furthermore, they also tended to match less bitter (i.e., milk) chocolate samples to angular rather than rounded shapes; the opposite mapping to that shown by Westerners. Together, these results show that cultural-environmental as well as phylogenetic factors play a central role in shaping our repertoire of crossmodal correspondences.

Trait anxiety focuses spatial attention

Some findings suggest that trait anxiety impairs selective attention (e.g., Fox, 1993) while others suggest the opposite (e.g., Murray & Janelle, 2003). Both views may hold some truth if trait anxiety affects different levels of selective attention in opposite directions: trait anxiety might improve spatial attention, or perceptual selection, but weaken postperceptual selection. We used an adaptation of the flanker task (Eriksen & Hoffman, 1973) which distinguishes between spatial attention and postperceptual selection (Caparos & Linnell, 2010) to test this hypothesis. Trait anxiety was found to improve spatial attention but not to affect post-perceptual selection. The latter null effect may have resulted from the relatively high perceptual load used in this study. The focusing effect of trait anxiety suggests that anxiety reduces perceptual resources or increases cognitive engagement.

Reduced distractibility in a remote culture

Background

In visual processing, there are marked cultural differences in the tendency to adopt either a global or local processing style. A remote culture (the Himba) has recently been reported to have a greater local bias in visual processing than Westerners. Here we give the first evidence that a greater, and remarkable, attentional selectivity provides the basis for this local bias.

Methodology/Principal Findings

In Experiment 1, Eriksen-type flanker interference was measured in the Himba and in Western controls. In both groups, responses to the direction of a task-relevant target arrow were affected by the compatibility of task-irrelevant distractor arrows. However, the Himba showed a marked reduction in overall flanker interference compared to Westerners. The smaller interference effect in the Himba occurred despite their overall slower performance than Westerners, and was evident even at a low level of perceptual load of the displays. In Experiment 2, the attentional selectivity of the Himba was further demonstrated by showing that their attention was not even captured by a moving singleton distractor.

Conclusions/Significance

We argue that the reduced distractibility in the Himba is clearly consistent with their tendency to prioritize the analysis of local details in visual processing.

Focused attention is not enough to activate discontinuities in lines, but scrutiny is

We distinguish between the roles played by spatial attention and conscious intention in terms of their impact on the processing of segmentation signals, like discontinuities in lines, associated with the act of scrutinizing. We showed previously that the processing of discontinuities in lines can be activated. This is evidenced by an impairment in the detection of a gap between parallel elements when it follows a gap between collinear elements in the same location and orientation. This effect is no longer observed if attention is divided between two gaps in the first stimulus. The results from this study show that focusing attention on a gap between collinear elements is not enough to observe a modulation, consistently with the need to integrate, rather than to separate, collinear elements in usual conditions. The modulation is sensitive to the conscious expectations of subjects, suggesting that an intention can trigger modulations that spatial attention cannot.