Guided Search 6.0: An updated model of visual search

This paper describes Guided Search 6.0 (GS6), a revised model of visual search. When we encounter a scene, we can see something everywhere. However, we cannot recognize more than a few items at a time. Attention is used to select items so that their features can be "bound" into recognizable objects. Attention is "guided" so that items can be processed in an intelligent order. In GS6, this guidance comes from five sources of preattentive information: (1) top-down and (2) bottom-up feature guidance, (3) prior history (e.g., priming), (4) reward, and (5) scene syntax and semantics. These sources are combined into a spatial "priority map," a dynamic attentional landscape that evolves over the course of search. Selective attention is guided to the most active location in the priority map approximately 20 times per second. Guidance will not be uniform across the visual field. It will favor items near the point of fixation. Three types of functional visual field (FVFs) describe the nature of these foveal biases. There is a resolution FVF, an FVF governing exploratory eye movements, and an FVF governing covert deployments of attention. To be identified as targets or rejected as distractors, items must be compared to target templates held in memory. The binding and recognition of an attended object is modeled as a diffusion process taking > 150 ms/item. Since selection occurs more frequently than that, it follows that multiple items are undergoing recognition at the same time, though asynchronously, making GS6 a hybrid of serial and parallel processes. In GS6, if a target is not found, search terminates when an accumulating quitting signal reaches a threshold. Setting of that threshold is adaptive, allowing feedback about performance to shape subsequent searches. Simulation shows that the combination of asynchronous diffusion and a quitting signal can produce the basic patterns of response time and error data from a range of search experiments.

Value-driven attentional priority signals in human basal ganglia and visual cortex

Goal-directed and stimulus-driven factors determine attentional priority through a well defined dorsal frontal-parietal and ventral temporal-parietal network of brain regions, respectively. Recent evidence demonstrates that reward-related stimuli also have high attentional priority, independent of their physical salience and goal-relevance. The neural mechanisms underlying such value-driven attentional control are unknown. Using human functional magnetic resonance imaging, we demonstrate that the tail of the caudate nucleus and extrastriate visual cortex respond preferentially to task-irrelevant but previously reward-associated objects, providing an attentional priority signal that is sensitive to reward history. The caudate tail has not been implicated in the control of goal-directed or stimulus-driven attention, but is well suited to mediate the value-driven control of attention. Our findings reveal the neural basis of value-based attentional priority.

The negative priming paradigm: An update and implications for selective attention

Negative Priming (NP) is an influential paradigm in cognitive psychology that was originally developed to measure attentional selection. Yet, up to the mid-1990s, a large number of experimental reports questioned whether the NP effect is based on attentional inhibition and/or episodic retrieval processes. In this review, we summarize findings since the mid-1990s and discuss new and old theoretical approaches to Negative Priming. We conclude that more than one process contributes to NP and that future research should analyze the conditions under which a particular process contributes to NP. Moreover, we argue that the paradigm--although it does not measure a single cognitive process alone--is still a useful tool for understanding selection in cognition. In fact, it might be a virtue of the paradigm that several cognitive processes work here together as selection in nonexperimental contexts is surely a multidimensional process. From this perspective, research on NP is relevant for all research fields analyzing selection. We therefore close our review by discussing the implications of the new evidence on NP for theories of selective attention.

Generalization of value-based attentional priority

Attention is the mechanism by which important or salient stimuli are selected for perceptual and cognitive processing. Which stimuli are attended has important implications for effective goal-directed behaviour, survival, and well-being. A growing body of evidence suggests that reward-predicting stimuli capture attention involuntarily. In previous studies, value-based attentional priority has been observed only when the formerly reward-related stimuli themselves were presented as targets or distractors. Here we show that stimulus-reward associations learned in one task generalize to different stimuli that share a defining feature (colour) in another task. Our results reveal a broad and flexible role for reward learning in modulating attentional priority.

The effects of bilingual growth on toddlers' executive function

The mastery of two languages provides bilingual speakers with cognitive benefits over monolinguals, particularly on cognitive flexibility and selective attention. However, extant research is limited to comparisons between monolinguals and bilinguals at a single point in time. This study investigated whether growth in bilingual proficiency, as shown by an increased number of translation equivalents (TEs) over a 7-month period, improves executive function. We hypothesized that bilingual toddlers with a larger increase of TEs would have more practice in switching across lexical systems, boosting executive function abilities. Expressive vocabulary and TEs were assessed at 24 and 31 months of age. A battery of tasks, including conflict, delay, and working memory tasks, was administered at 31 months. As expected, we observed a task-specific advantage in inhibitory control in bilinguals. More important, within the bilingual group, larger increases in the number of TEs predicted better performance on conflict tasks but not on delay tasks. This unique longitudinal design confirms the relation between executive function and early bilingualism.

The past, present, and future of selection history

The last ten years of attention research have witnessed a revolution, replacing a theoretical dichotomy (top-down vs. bottom-up control) with a trichotomy (biased by current goals, physical salience, and selection history). This third new mechanism of attentional control, selection history, is multifaceted. Some aspects of selection history must be learned over time whereas others reflect much more transient influences. A variety of different learning experiences can shape the attention system, including reward, aversive outcomes, past experience searching for a target, target‒non-target relations, and more. In this review, we provide an overview of the historical forces that led to the proposal of selection history as a distinct mechanism of attentional control. We then propose a formal definition of selection history, with concrete criteria, and identify different components of experience-driven attention that fit within this definition. The bulk of the review is devoted to exploring how these different components relate to one another. We conclude by proposing an integrative account of selection history centered on underlying themes that emerge from our review.

Age differences in the Attention Network Test: Evidence from behavior and event-related potentials

The Attention Network Test (ANT) is widely used to capture group and individual differences in selective attention. Prior behavioral studies with younger and older adults have yielded mixed findings with respect to age differences in three putative attention networks (alerting, orienting, and executive control). To overcome the limitations of behavioral data, the current study combined behavioral and electrophysiological measures. Twenty-four healthy younger adults (aged 18-29years) and 24 healthy older adults (aged 60-76years) completed the ANT while EEG data were recorded. Behaviorally, older adults showed reduced alerting, but did not differ from younger adults in orienting or executive control. Electrophysiological components related to alerting and orienting (P1, N1, and CNV) were similar in both age groups, whereas components related to executive control (N2 and P3) showed age-related differences. Together these results suggest that comparisons of network effects between age groups using behavioral data alone may not offer a complete picture of age differences in selective attention, especially for alerting and executive control networks.

Selective attention deficits in obsessive-compulsive disorder: the role of metacognitive processes

While initial studies supported the hypothesis that cognitive characteristics that capture cognitive resources act as underlying mechanisms in memory deficits in obsessive-compulsive disorder (OCD), the influence of those characteristics on selective attention has not been studied, yet. In this study, we examined the influence of cognitive self-consciousness (CSC), rumination and worrying on performance in selective attention in OCD and compared the results to a depressive and a healthy control group. We found that 36 OCD and 36 depressive participants were impaired in selective attention in comparison to 36 healthy controls. In all groups, hierarchical regression analyses demonstrated that age, intelligence and years in school significantly predicted performance in selective attention. But only in OCD, the predictive power of the regression model was improved when CSC, rumination and worrying were implemented as predictor variables. In contrast, in none of the three groups the predictive power improved when indicators of severity of obsessive-compulsive (OC) and depressive symptoms and trait anxiety were introduced as predictor variables. Thus, our results support the assumption that mental characteristics that bind cognitive resources play an important role in the understanding of selective attention deficits in OCD and that this mechanism is especially relevant for OCD.

Neurobiological effects of the green tea constituent theanine and its potential role in the treatment of psychiatric and neurodegenerative disorders

Theanine (n-ethylglutamic acid), a non-proteinaceous amino acid component of green and black teas, has received growing attention in recent years due to its reported effects on the central nervous system. It readily crosses the blood-brain barrier where it exerts a variety of neurophysiological and pharmacological effects. Its most well-documented effect has been its apparent anxiolytic and calming effect due to its up-regulation of inhibitory neurotransmitters and possible modulation of serotonin and dopamine in selected areas. It has also recently been shown to increase levels of brain-derived neurotrophic factor. An increasing number of studies demonstrate a neuroprotective effects following cerebral infarct and injury, although the exact molecular mechanisms remain to be fully elucidated. Theanine also elicits improvements in cognitive function including learning and memory, in human and animal studies, possibly via a decrease in NMDA-dependent CA1 long-term potentiation (LTP) and increase in NMDA-independent CA1-LTP. Furthermore, theanine administration elicits selective changes in alpha brain wave activity with concomitant increases in selective attention during the execution of mental tasks. Emerging studies also demonstrate a promising role for theanine in augmentation therapy for schizophrenia, while animal models of depression report positive improvements following theanine administration. A handful of studies are beginning to examine a putative role in attention deficit hyperactivity disorder, and theoretical extrapolations to a therapeutic role for theanine in other psychiatric disorders such as anxiety disorders, panic disorder, obsessive compulsive disorder (OCD), and bipolar disorder are discussed.

Neurophysiological, psychological and behavioural correlates of rTMS treatment in alcohol dependence

BACKGROUND

Addiction is associated with dorso-lateral prefrontal cortex (DLPFC) dysfunction and altered brain-oscillations. High frequency repetitive transcranial magnetic stimulation (HFrTMS) over DLPFC reportedly reduces drug craving. Its effects on neuropsychological, behavioural and neurophysiological are unclear.

METHODS

We assessed psychological, behavioural and neurophysiological effects of 4 sessions of 10-min adjunctive HFrTMS over the left DLPFC during two weeks during a residential programme for alcohol detoxification. Participants were randomized to active HFrTMS (10 Hz, 100% motor threshold) or sham. Immediately before the first and after the last session, 32-channels EEG was recorded and alcohol craving Visual Analogue Scale, Symptom Check List-90-R, Numeric Stroop task and Go/No-go task administered. Tests were repeated at 1-month follow-up.

RESULTS

17 subjects (mean age 44.7 years, 4 F) were assessed. Active rTMS subjects performed better at Stroop test at end of treatment (p=0.036) and follow up (p=0.004) and at Go-NoGo at end of treatment (p=0.05) and follow up (p=0.015). Depressive symptoms decreased at end of active treatment (p=0.036). Active-TMS showed an overall decrease of fast EEG frequencies after treatment compared to sham (p=0.026). No significant modifications over time or group emerged for craving and number of drinks at follow up.

CONCLUSION

4 HFrTMS sessions over two weeks on the left DLPFC can improve inhibitory control task and selective attention and reduce depressive symptoms. An overall reduction of faster EEG frequencies was observed. Nonetheless, this schedule is ineffective in reducing craving and alcohol intake.

What is abnormal about addiction-related attentional biases?

BACKGROUND

The phenotype of addiction includes prominent attentional biases for drug cues, which play a role in motivating drug-seeking behavior and contribute to relapse. In a separate line of research, arbitrary stimuli have been shown to automatically capture attention when previously associated with reward in non-clinical samples.

METHODS AND RESULTS

Here, I argue that these two attentional biases reflect the same cognitive process. I outline five characteristics that exemplify attentional biases for drug cues: resistant to conflicting goals, robust to extinction, linked to dorsal striatal dopamine and to biases in approach behavior, and can distinguish between individuals with and without a history of drug dependence. I then go on to describe how attentional biases for arbitrary reward-associated stimuli share all of these features, and conclude by arguing that the attentional components of addiction reflect a normal cognitive process that promotes reward-seeking behavior.

Aging of the frontal lobe

Healthy aging is associated with numerous deficits in cognitive function, which have been attributed to changes within the prefrontal cortex (PFC). This chapter summarizes some of the most prominent cognitive changes associated with age-related alterations in the anatomy and physiology of the PFC. Specifically, aging of the PFC results in deficient aspects of cognitive control, including sustained attention, selective attention, inhibitory control, working memory, and multitasking abilities. Yet, not all cognitive functions associated with the PFC exhibit age-related declines, such as arithmetic, comprehension, emotion perception, and emotional control. Moreover, not all older adults exhibit declines in cognition. Multiple life-course and lifestyle factors, as well as genetics, play a role in the trajectory of cognitive performance across the life span. Thus many adults retain cognitive function well into advanced age. Moreover, the brain remains plastic throughout life and there is increasing evidence that most age-related declines in cognition can be remediated by various methods such as physical exercise, cognitive training, or noninvasive brain stimulation. Overall, because cognitive aging is associated with numerous life-course and lifestyle factors, successful aging likely begins in early life, while maintaining cognition or remediating declines is a life-long process.

On the value-dependence of value-driven attentional capture

Findings from an increasingly large number of studies have been used to argue that attentional capture can be dependent on the learned value of a stimulus, or value-driven. However, under certain circumstances attention can be biased to select stimuli that previously served as targets, independent of reward history. Value-driven attentional capture, as studied using the training phase-test phase design introduced by Anderson and colleagues, is widely presumed to reflect the combined influence of learned value and selection history. However, the degree to which attentional capture is at all dependent on value learning in this paradigm has recently been questioned. Support for value-dependence can be provided through one of two means: (1) greater attentional capture by prior targets following rewarded training than following unrewarded training, and (2) greater attentional capture by prior targets previously associated with high compared to low value. Using a variant of the original value-driven attentional capture paradigm, Sha and Jiang (Attention, Perception, and Psychophysics, 78, 403-414, 2016) failed to find evidence of either, and raised criticisms regarding the adequacy of evidence provided by prior studies using this particular paradigm. To address this disparity, here we provided a stringent test of the value-dependence hypothesis using the traditional value-driven attentional capture paradigm. With a sufficiently large sample size, value-dependence was observed based on both criteria, with no evidence of attentional capture without rewards during training. Our findings support the validity of the traditional value-driven attentional capture paradigm in measuring what its name purports to measure.

Brain mechanisms underlying the effects of aging on different aspects of selective attention

The ability to suppress irrelevant information declines with age, while the ability to enhance relevant information remains largely intact. We examined mechanisms behind this dissociation in an fMRI study, using a selective attention task in which relevant and irrelevant information appeared simultaneously. Slowing of response times due to distraction by irrelevant targets was larger in older than younger participants. Increased distraction was related to larger increases in activity and connectivity in areas of the dorsal attention network, indicating a more pronounced (re-)orientation of attention. The decreases in accuracy in target compared to nontarget trials were smaller in older compared to younger participants. In older adults we found increased recruitment of areas in the fronto-parietal control network (FPCN) during target detection. Moreover, older adults showed increased connectivity between the FPCN, supporting cognitive control, and somatomotor areas implicated in response selection and execution. This connectivity increase was related to improved target detection, suggesting that older adults engage additional cognitive control, which might enable the observed intact performance in detecting and responding to target stimuli.

Selective attention to the mouth is associated with expressive language skills in monolingual and bilingual infants

Infants increasingly attend to the mouths of others during the latter half of the first postnatal year, and individual differences in selective attention to talking mouths during infancy predict verbal skills during toddlerhood. There is some evidence suggesting that trajectories in mouth-looking vary by early language environment, in particular monolingual or bilingual language exposure, which may have differential consequences in developing sensitivity to the communicative and social affordances of the face. Here, we evaluated whether 6- to 12-month-olds' mouth-looking is related to skills associated with concurrent social communicative development-including early language functioning and emotion discriminability. We found that attention to the mouth of a talking face increased with age but that mouth-looking was more strongly associated with concurrent expressive language skills than chronological age for both monolingual and bilingual infants. Mouth-looking was not related to emotion discrimination. These data suggest that selective attention to a talking mouth may be one important mechanism by which infants learn language regardless of home language environment.

Selective attention neutralizes the adverse effects of low socioeconomic status on memory in 9-month-old infants

Socioeconomic status (SES) has a documented impact on brain and cognitive development. We demonstrate that engaging spatial selective attention mechanisms may counteract this negative influence of impoverished environments on early learning. We previously used a spatial cueing task to compare target object encoding in the context of basic orienting ("facilitation") versus a spatial selective attention orienting mechanism that engages distractor suppression ("IOR"). This work showed that object encoding in the context of IOR boosted 9-month-old infants' recognition memory relative to facilitation (Markant and Amso, 2013). Here we asked whether this attention-memory link further interacted with SES in infancy. Results indicated that SES was related to memory but not attention orienting efficacy. However, the correlation between SES and memory performance was moderated by the attention mechanism engaged during encoding. SES predicted memory performance when objects were encoded with basic orienting processes, with infants from low-SES environments showing poorer memory than those from high-SES environments. However, SES did not predict memory performance among infants who engaged selective attention during encoding. Spatial selective attention engagement mitigated the effects of SES on memory and may offer an effective mechanism for promoting learning among infants at risk for poor cognitive outcomes related to SES.

Cognitive control in media multitaskers: Two replication studies and a meta-Analysis

Ophir, Nass, and Wagner (2009, Proceedings of the National Academy of Sciences of the United States of America, 106(37), 15583-15587) found that people with high scores on the media-use questionnaire-a questionnaire that measures the proportion of media-usage time during which one uses more than one medium at the same time-show impaired performance on various tests of distractor filtering. Subsequent studies, however, did not all show this association between media multitasking and distractibility, thus casting doubt on the reliability of the initial findings. Here, we report the results of two replication studies and a meta-analysis that included the results from all published studies into the relationship between distractor filtering and media multitasking. Our replication studies included a total of 14 tests that had an average replication power of 0.81. Of these 14 tests, only five yielded a statistically significant effect in the direction of increased distractibility for people with higher scores on the media-use questionnaire, and only two of these effects held in a more conservative Bayesian analysis. Supplementing these outcomes, our meta-analysis on a total of 39 effect sizes yielded a weak but significant association between media multitasking and distractibility that turned nonsignificant after correction for small-study effects. Taken together, these findings lead us to question the existence of an association between media multitasking and distractibility in laboratory tasks of information processing.

Gaze-fixation and pupil dilation in the processing of emotional faces: the role of rumination

Sustained attentional processing of negative information plays a significant role in the development and maintenance of depression. The present study examines the relationships between rumination, a relevant factor in information processing in depression, and the attentional mechanisms activated in individuals with different levels of depression severity when attending to emotional information (i.e., sad, angry and happy faces). Behavioural and physiological indicators of sustained processing were assessed in 126 participants (39 dysphoric and 87 non-dysphoric) using eye-tracking technology. Pupil dilation and total time attending to negative faces were correlated with a global ruminative style in the total sample once depression severity was controlled. Furthermore, in dysphoric participants the brooding component of rumination was specifically associated with the total time attending to sad faces. Finally, bootstrapping analyses showed that the relationships between global rumination and pupil diameter to emotional faces were accounted by total time attending to emotional faces, specifically for participants reporting lower levels of depression severity. The results support the idea that sustained processing of negative information is associated with a higher ruminative style and indicate differential associations between these factors at different levels of depressive symptomatology.

An updated Italian normative dataset for the Stroop color word test (SCWT)

The Stroop color and word test (SCWT) is widely used to evaluate attention, information processing speed, selective attention, and cognitive flexibility. Normative values for the Italian population are available only for selected age groups, or for the short version of the test. The aim of this study was to provide updated normal values for the full version, balancing groups across gender, age decades, and education. Two kinds of indexes were derived from the performance of 192 normal subjects, divided by decade (from 20 to 90) and level of education (4 levels: 3-5; 6-8; 9-13; >13 years). They were (i) the correct answers achieved for each table in the first 30 s (word items, WI; color items, CI; color word items, CWI) and (ii) the total time required for reading the three tables (word time, WT; color time, CT; color word time, CWT). For each index, the regression model was evaluated using age, education, and gender as independent variables. The normative data were then computed following the equivalent scores method. In the regression model, age and education significantly influenced the performance in each of the 6 indexes, whereas gender had no significant effect. This study confirms the effect of age and education on the main indexes of the Stroop test and provides updated normative data for an Italian healthy population, well balanced across age, education, and gender. It will be useful to Italian researchers studying attentional functions in health and disease.

Topographic specificity of alpha power during auditory spatial attention

Visual and somatosensory spatial attention both induce parietal alpha (8-14 ​Hz) oscillations whose topographical distribution depends on the direction of spatial attentional focus. In the auditory domain, contrasts of parietal alpha power for leftward and rightward attention reveal qualitatively similar lateralization; however, it is not clear whether alpha lateralization changes monotonically with the direction of auditory attention as it does for visual spatial attention. In addition, most previous studies of alpha oscillation did not consider individual differences in alpha frequency, but simply analyzed power in a fixed spectral band. Here, we recorded electroencephalography in human subjects when they directed attention to one of five azimuthal locations. After a cue indicating the direction of an upcoming target sequence of spoken syllables (yet before the target began), alpha power changed in a task-specific manner. Individual peak alpha frequencies differed consistently between central electrodes and parieto-occipital electrodes, suggesting multiple neural generators of task-related alpha. Parieto-occipital alpha increased over the hemisphere ipsilateral to attentional focus compared to the contralateral hemisphere, and changed systematically as the direction of attention shifted from far left to far right. These results showing that parietal alpha lateralization changes smoothly with the direction of auditory attention as in visual spatial attention provide further support to the growing evidence that the frontoparietal attention network is supramodal.

Children's selective attention to pain and avoidance behaviour: the role of child and parental catastrophizing about pain

The present study investigated selective attention to pain in children, its implications for child avoidance behaviour, and the moderating role of dimensions comprising child and parental catastrophizing about pain (ie, rumination, magnification, and helplessness). Participants were 59 children (31 boys) aged 10-16 years and one of their parents (41 mothers). Children performed a dot-probe task in which child facial pain displays of varying pain expressiveness were presented. Child avoidance behaviour was indexed by child pain tolerance during a cold-pressor task. Children and parents completed measures of child and parent pain catastrophizing, respectively. Findings indicated that both the nature of child selective attention to pain and the impact of selective attention upon child avoidance behaviour were differentially sensitive to specific dimensions of child and parental catastrophizing. Specifically, findings showed greater tendency to shift attention away from pain faces (i.e.,, attentional avoidance) among children reporting greater pain magnification. A similar pattern was observed in terms of parental characteristics, such that children increasingly shifted attention away from pain with increasing levels of parental rumination and helplessness. Furthermore, child attentional avoidance was associated with greater avoidance behaviour (i.e., lower pain tolerance) among children reporting high levels of pain magnification and those whose parents reported greater rumination about pain. The current findings corroborate catastrophizing as a multidimensional construct that may differentially impact outcomes and attest to the importance of assessing both child and parental characteristics in relation to child pain-related attention and avoidance behaviour. Further research directions are discussed.

Attentional biases toward emotional images in the different episodes of bipolar disorder: an eye-tracking study

Attentional biases toward emotional information may represent vulnerability and maintenance factors in bipolar disorder (BD). The present experimental study examined the processing of emotional information in BD patients using the eye-tracking technology. Bipolar patients in their different states (euthymia, mania, depression) simultaneously viewed four pictures with different emotional valence (happy, neutral, sad, threatening) for 20s while their eye movements were monitored. A group of healthy individuals served as the control. The data revealed the following: (i) a decrease in attention to happy images in BD patients in their depressive episodes compared to healthy individuals, and (ii) an increase in attention to threatening images in BD patients (regardless of their episode) relative to the healthy controls. These biases appeared in the late stages of information processing and were sustained over the 20s interval. Thus, the present findings reveal that attentional biases toward emotional information can be a key feature of BD, in that: (i) an anhedonic lack of sensitivity to positive stimuli during the bipolar depressive episode may be considered a maintaining factor of this clinical state, and (ii) the trait-bias toward threat, even in asymptomatic patients, may reflect a marker of vulnerability in BD.

Components of reward-driven attentional capture

Recent research reported that task-irrelevant colors captured attention if these colors previously served as search targets and received high monetary reward. We showed that both monetary reward and value-independent mechanisms influenced selective attention. Participants searched for two potential target colors among distractor colors in the training phase. Subsequently, they searched for a shape singleton in a testing phase. Experiment 1 found that participants were slower in the testing phase if a distractor of a previous target color was present rather than absent. Such slowing was observed even when no monetary reward was used during training. Experiment 2 associated monetary rewards with the target colors during the training phase. Participants were faster finding the target associated with higher monetary reward. However, reward training did not yield value-dependent attentional capture in the testing phase. Attentional capture by the previous target colors was not significantly greater for the previously high-reward color than the previously low or no-reward color. These findings revealed both the power and limitations of monetary reward on attention. Although monetary reward can increase attentional priority for the high-reward target during training, subsequent attentional capture effects may not be reward-based, but reflect, in part, attentional capture by previous targets.

Happy heart, smiling eyes: A systematic review of positive mood effects on broadening of visuospatial attention

Positive mood contributes to mental and physical wellbeing. The broaden-and-build theory (Fredrickson, 2001) proposed that the beneficial effects of positive mood on life quality result from attentional broadening. In this article, we systematically review (following PRISMA guidelines; Moher et al., 2009), a host of studies investigating the nature and extent of attentional changes triggered by the experience of positive mood, with a focus on vision. While several studies reported a broadening of attention, others found that positive mood led to a more diffuse information processing style. Positive mood appears to lessen attention selectivity in a way that is context-specific and bound to limitations. We propose a new framework in which we postulate that positive mood impacts the balance between internally and externally directed attention, through modulations of cognitive control processes, instead of broadening attention per se. This novel model is able to accommodate discrepant findings, seeks to translate the phenomenon of the so-called broadening of attention with positive mood into functional terms, and provides plausible neurobiological mechanisms underlying this effect, suggesting a crucial role of the anterior and posterior cingulate cortex in this interaction.

Attentional bias toward suicide-relevant information in suicide attempters: A cross-sectional study and a meta-analysis

OBJECTIVE

Previous studies using a modified Stroop test suggested that suicide attempters, in contrast to depressed patients with no suicidal history, display a particular attentional bias toward suicide-related cues. However, negative results have also been reported. In the present study, we collected new data and pooled them as part of a meta-analysis intended to shed further light on this question.

METHOD

We conducted 1) a cross-sectional study comparing performance on the modified Stroop task for suicide-related, positively-valenced and negatively-valenced words in 33 suicide attempters and 46 patient controls with a history of mood disorders; 2) a systematic review and a meta-analysis of studies comparing performance on the modified Stroop task among patients with vs. without a history of suicidal acts in mood disorders.

RESULTS

The cross-sectional study showed no significant difference in interference scores for any type of words between suicide attempters and patient controls. A meta-analysis of four studies, including 233 suicide attempters and 768 patient controls, showed a significant but small attentional bias toward suicide-related words (Hedges'g=0.22, 95%CI [0.06-0.38], Z=2.73, p=0.006), but not negatively-valenced words (Hedges'g=0.06, 95%CI [-0.09-0.22], Z=0.77, p=0.4) in suicide attempters compared to patient controls.

LIMITATIONS

Positively-valenced words and healthy controls could not be assessed in the meta-analysis.

CONCLUSION

Our data support a selective information-processing bias among suicide attempters. Indirect evidence suggests that this effect would be state-related and may be a cognitive component of the suicidal crisis. However, we could not conclude about the clinical utility of this Stroop version at this stage.