Tonic and phasic alertness training: a novel treatment for executive control dysfunction following mild traumatic brain injury

Many individuals with traumatic brain injury (TBI) suffer difficulty regulating fundamental aspects of attention (focus, sustained attention) and may also exhibit hypo- or hyper-states of alertness. Deficits in the state of attention may underlie or exacerbate higher order executive dysfunction. Recent studies indicate that computerized cognitive training targeting attentional control and alertness can ameliorate attention deficits evident in patients with TBI or acquired brain injury. The current study examined whether improvements in attentional state following training can also influence performance on higher-order executive function and mood in individuals with mild TBI (mTBI). The current study examined five patients with executive control deficits as a result of mTBI, with or without persistent anxiety. Three patients engaged in ~5 hours of an executive control training task targeting inhibitory control and sustained attention; two additional patients were re-tested following the same period of time. Performance on standard neuropsychological measures of attention, executive function, and mood were evaluated pre- and post-training. The results indicate that tonic and phasic alertness training may improve higher-order executive function and mood regulation in individuals with TBI.     

Effect of mood states on the breadth of spatial attentional focus: an event-related potential study

In order to determine the processing stage that is responsible for the effect of mood states on the breadth of attentional focus, we recorded event-related potentials from 18 students who performed a flanker task involving adjacent letters. To induce a specific mood state, positive, neutral, or negative affective pictures were presented repeatedly during the task. The participants’ task was to respond to the central target letter by pressing a corresponding button. Spacing between each letter was manipulated so that it appeared either near or far. In 80% of the task trials, a probe stimulus was presented at one of four locations superimposed on the letter array: 0.5° left or right from the central letter or 1.5° left or right from the central letter. Reaction time data showed that the effect of spacing on the flanker compatibility effect was absent under positive mood state. The probe-evoked P1 amplitude was larger in the positive mood state than in the neutral and negative mood states. These results indicate that positive mood states may broaden the focus of attention during visual input stage.     

Positive and detached reappraisal in older adulthood: A temporal examination of gaze patterns

Abstract

Objectives: Cognitive reappraisal is an emotion regulation strategy that involves the adaptive restructuring of one’s thoughts surrounding an emotionally evocative stimulus. Previous studies have produced mixed results on how distinct reappraisal and attentional processes are, but few studies have teased apart specific reappraisal methods. This is of particular interest in aging as older adults’ regulation success may vary by reappraisal type. The current study examined whether detached and positive reappraisal are associated with distinct temporal patterns of attention in a sample of older adults.

Method: 29 older adult participants viewed negative IAPS images and were instructed to implement both positive and detached reappraisal while eye movements were monitored. Participants also reported on their mood before and after viewing the images.

Results: Participants fixated on negative areas early on and looked at them less over time, however their attention was oriented specifically towards the most negative region during reappraisal. They also re-fixated on the negative areas of the images during the last second of viewing during detached reappraisal, and reported feeling best while using this strategy.

Conclusion: These findings provide information about the temporal nature of visual attention while utilizing distinct cognitive reappraisal strategies. Results highlight the importance of further teasing apart differences between detached and positive reappraisal as regulatory success and attentional shifts differ between these reappraisal types in older adulthood.     

Positive symptoms and duration of illness predict functional laterality and attention modulation in schizophrenia

OBJECTIVE: Dichotic listening (DL) performance in schizophrenia, reflecting hemispheric asymmetry and the functional integrity of the left temporal lobe, can vary with clinical characteristics. Previous studies have not taken the co-linearity of clinical variables into account. The aim of the present study was to evaluate the roles of positive symptoms and duration of illness in DL through Structural Equation Modeling (SEM), thus allowing for complex relationships between the variables. METHOD: We pooled patients from four previous DL studies to create a heterogeneous group of 129 schizophrenic patients, all tested with a consonant-vowel syllables DL procedure that included attentional instructions. RESULTS: A model where positive symptoms predicted a laterality component and duration of illness predicted an attention component in DL was confirmed. CONCLUSION: Positive symptoms predicted reduced functional laterality, suggesting involvement of left temporal lobe language processing. Duration of illness predicted impaired attention modulation, possibly reflecting the involvement of frontotemporal networks.     

Efficacy of visuo-spatial training in right-brain damaged patients with spatial hemineglect and attention disorders

Several rehabilitative approaches have been used to reduce neglect disorders. Some studies tried to demonstrate that hemineglect can be ameliorated by using tasks promoting attentional activation towards the neglected hemispace (Robertson et al., 1995, 2001). As a consequence, a functional link between level of attention and disorders of space exploration has been proposed. For this reason we tried to explore the possible role of attentional deficits on the efficacy of a standard neglect treatment based on visuo spatial rehabilitation. In this study we then examined the performances of a selected group of seven right brain damaged patients, suffering from both severe hemineglect and attentional deficits (of both phasic and tonic components of attention), to several tasks before and after a visuo-spatial training (VST) whose efficacy has been already demonstrated (Pizzamiglio et al., 1992). Results showed that VST induces a significant remission of hemineglect symptoms independently from disorders of attention. Moreover, after visuo-spatial rehabilitation, no improvement of attentional deficits is detectable.     

The influence of rightward and leftward spatial deviations of spatial attention on emotional picture recognition

Objectives: Several studies have reported that positive emotions are primarily mediated by the left hemisphere and negative emotions by the right hemisphere. Since each hemisphere primarily allocates attention toward the contralateral hemispace, we wanted to learn how inducing a spatial attentional orienting bias to right and left egocentric hemispace might influence the recognition and perception of visually presented emotional scenes.

Method: Participants were 42 healthy, right-handed young adults. To induce a directional change in spatial attention, we used a horizontal prism adaptation (PA) method that trains participants to allocate attention in the opposite direction to the prism-induced deviation. After each PA, participants evaluated a set of affective (positive/neutral/negative) pictures from the Nencki Affective Picture System. Responses in each emotional category and reaction times were recorded and analyzed.

Results: There was no PA effects on reaction times between the experimental conditions. However, when compared to the control condition, both rightward and leftward PA resulted in a reduction of correctly recognized positive emotions as well as altering the perception of neutral and positive pictures as more emotionally negative.

Conclusions: The results do not support the proposed left–right spatial attentional valence hypothesis. The reason why PA in both directions negatively altered emotion perception is not known. However, a portion of the dorsal visual stream, the parietal lobes, and especially the right parietal lobe, are critical for mediating horizontal egocentric spatial attention. The right hemisphere also mediates negative emotions, and the activation of this right hemispheric attention network may have induced the changes in perception found in this study. However, future studies are needed to further test this hypothesis.     

Oscillatory dynamics in the dorsal and ventral attention networks during the reorienting of attention

The ability to reorient attention within the visual field is central to daily functioning, and numerous fMRI studies have shown that the dorsal and ventral attention networks (DAN, VAN) are critical to such processes. However, despite the instantaneous nature of attentional shifts, the dynamics of oscillatory activity serving attentional reorientation remain poorly characterized. In this study, we utilized magnetoencephalography (MEG) and a Posner task to probe the dynamics of attentional reorienting in 29 healthy adults. MEG data were transformed into the time‐frequency domain and significant oscillatory responses were imaged using a beamformer. Voxel time series were then extracted from peak voxels in the functional beamformer images. These time series were used to quantify the dynamics of attentional reorienting, and to compute dynamic functional connectivity. Our results indicated strong increases in theta and decreases in alpha and beta activity across many nodes in the DAN and VAN. Interestingly, theta responses were generally stronger during trials that required attentional reorienting relative to those that did not, while alpha and beta oscillations were more dynamic, with many regions exhibiting significantly stronger responses during non‐reorienting trials initially, and the opposite pattern during later processing. Finally, stronger functional connectivity was found following target presentation (575‐700 ms) between bilateral superior parietal lobules during attentional reorienting. In sum, these data show that visual attention is served by multiple cortical regions within the DAN and VAN, and that attentional reorienting processes are often associated with spectrally‐specific oscillations that have largely distinct spatiotemporal dynamics.     

Comparing the performance of people who stutter and people who do not stutter on the Test of Everyday Attention

Introduction: Compelling findings into the relationship between stuttering and attentional ability have started to emerge, with some child and adult studies indicating poorer attentional ability among people who stutter (PWS). The purpose of the present research was to provide a more complete picture of the attentional abilities of PWS, as well as to gather insights into their individual attentional performance.

Method: We compared the attentional ability of PWS to that of people who do not stutter (PWNS) by using the Test of Everyday Attention (TEA). TEA is a clinical assessment battery with a very good validity and reliability comprising 8 subtests that pose differential demands on sustained attention, selective attention, attentional switching, and divided attention. Fifty age- and gender-matched PWS and PWNS (aged 19–77 years) took part in the study. Importantly, we also examined stuttering severity in the PWS group.

Results: PWS performed significantly worse on tasks tapping into visual selective and divided attentional resources. Furthermore despite failing to reach statistical significance, the results also revealed an interesting trend for stuttering to be associated with poorer performance on two subtests measuring attentional switching and one tapping into auditory selective attention. Moreover, as hypothesized, there was also a negative association between stuttering severity and performance on two TEA subtests measuring visual selective attention. Finally, the type of TEA test variant produced no significant effect on performance.

Conclusions: We interpret these results as indicative of stuttering being associated with poorer performance on tasks measuring certain attentional abilities. These tie in well with theoretical models identifying speech production as particularly attention-demanding in stuttering or approaches placing attentional dysfunction at the heart of the condition. The present research also has practical implications for the use of attentional training to improve fluency.     

Persistent attentional dysfunction in remitted bipolar disorder

Objectives: Although previous research has shown that attentional dysfunction is common during acute mood episodes in individuals with bipolar disorder (BPD), few studies have examined whether attentional deficits are evident during periods of symptom stability. The goal of this study was to determine whether clinically stable individuals with BPD would have attentional disturbances relative to healthy subjects. Methods: Fourteen patients with BPD and 12 healthy comparison subjects participated in the study, and were administered the Degraded Stimulus Continuous Performance Test (DSCPT), Digit Span Distractibility Test (DSDT) and Grooved Pegboard Test (GPT). Psychiatric symptoms were assessed with the Young Mania Rating Scale and the Scale for the Assessment of Positive Symptoms. Medication side effects were measured with the Simpson Rating Scale. Results: The patient group responded significantly more slowly than the control group on the DSCPT (z=−2.52, p=0.01) and the GPT (z=−3.37, p=0.001). There was a trend towards the BPD patients demonstrating impaired perceptual sensitivity on the DSCPT (z=1.68, p=0.09). The two groups did not differ on the DSDT (z=−1.06, p=0.3). Poor performance on the GPT and DSCPT target reaction time were not associated with symptom ratings or medications. Conclusion: The findings suggest that impairments in fine motor skills and reaction time may be present in clinically stable patients with BPD, even after accounting for psychiatric symptoms and medication effects. Performance decrements on attentional tasks may be in part reflective of motor impairments in patients with BPD.     

The right temporoparietal junction in attention and social interaction: A transcranial magnetic stimulation study

The right temporoparietal junction (rTPJ) has been associated with the ability to reorient attention to unexpected stimuli and the capacity to understand others' mental states (theory of mind [ToM]/false belief). Using activation likelihood estimation meta‐analysis we previously unraveled that the anterior rTPJ is involved in both, reorienting of attention and ToM, possibly indicating a more general role in attention shifting. Here, we used neuronavigated transcranial magnetic stimulation to directly probe the role of the rTPJ across attentional reorienting and false belief. Task performance in a visual cueing paradigm and false belief cartoon task was investigated after application of continuous theta burst stimulation (cTBS) over anterior rTPJ (versus vertex, for control). We found that attentional reorienting was significantly impaired after rTPJ cTBS compared with control. For the false belief task, error rates in trials demanding a shift in mental state significantly increased. Of note, a significant positive correlation indicated a close relation between the stimulation effect on attentional reorienting and false belief trials. Our findings extend previous neuroimaging evidence by indicating an essential overarching role of the anterior rTPJ for both cognitive functions, reorienting of attention and ToM. Hum Brain Mapp 37:796–807, 2016. © 2015 Wiley Periodicals, Inc .     

Étude préliminaire de l’effet de l’activation comportementale sur les biais attentionnels envers l’information émotionnelle à valence positive et négative

ObjectivesBehavioural activation improves mental health and psychological functioning, especially among patients with depression. Behavioural activation is associated with the improvement of several mechanisms, such as activation, avoidance, and environmental reward. Behavioural activation may also improve cognitive control abilities. Finally, studies on neurological changes suggested an improvement of the functioning of reward structures in response to positive stimuli after a BA treatment. Yet, uncertainty abounds regarding the putative mechanisms of behavioural activation. Prominent cognitive models of depression posit that attentional bias for negative and positive information may play an important role in the maintenance of a depressive mood. Inspired by these models and the results by the mentioned above, we investigated the impact of behavioural activation treatment for depression on attentional selectivity for sad and positive materials. We predicted that (1) attention to sad faces would be reduced after the intervention, (2) attention to happy faces would be enhanced after the intervention, and finally (3) the intervention would improve depressive symptomatology, activation, avoidance and environmental reward.Materials and methodEight undergraduate students with medium to moderate depressive symptoms participated in a six-week behavioural activation intervention. A dot-probe task with happy and sad faces and self-report questionnaires focused on depression, activation, avoidance, and environmental reward were administered before and after the intervention.ResultsDepression, avoidance, and environmental reward scores improved after treatment with large effect sizes. Behavioural activation likewise improves attentional bias for positive faces. However, there was no attentional bias for sad faces at either evaluation time.ConclusionThe preliminary nature of our findings notwithstanding, this study is the first to provide evidence of behavioural activation impact on attentional selectivity vis-à-vis positive material.     

The effects of a visual search attentional bias modification paradigm on attentional bias in dysphoric individuals

Background and ObjectivesAttentional Bias Modification (ABM) may constitute a new type of treatment for affective disorders. ABM refers to computerized training programs that have been developed based on laboratory findings in experimental psychology. Meta-analyses have reported moderate effect sizes in anxiety disorders. Two small studies have also claimed an effect in dysphoria. Furthermore, a series of studies in individuals with low self-esteem has shown that they benefit from a single session of an ABM variant based on a visual search task. The current study tested the working mechanism of visual search ABM in dysphoria.MethodsForty dysphoric individuals engaged in a single session of ABM training or control training. Attentional bias for positive and negative facial expressions was assessed pre- and post training. Positive and negative mood states were assessed throughout the procedure.ResultsAttentional training had no effect on attentional bias. Positive and negative mood states were not differentially affected by training condition.LimitationsSmall treatment effects may have gone undetected and there are some methodological differences with prior research.ConclusionWe found no evidence that engaging in a single session of a visual search ABM modifies attentional biases for happy, sad or disgusted facial expressions.     

Effect of Vagus Nerve Stimulation on Attention and Working Memory in Neuropsychiatric Disorders: A Systematic Review

BackgroundIt has been suggested that vagus nerve stimulation (VNS) may enhance attention and working memory. The neuromodulator effects of VNS are thought to activate the release of neurotransmitters involving cognition and to promote neuronal plasticity. Therefore, VNS has been studied for its effects on attention and working memory impairment in neuropsychiatric disorders.ObjectivesThis study aimed to assess the effects of VNS on attention and working memory among patients with neuropsychiatric disorders, examine stimulation parameters, provide mechanistic hypotheses, and propose future studies using VNS.Materials and MethodsWe conducted a systematic review using electronic databases MEDLINE (Ovid), Embase (Ovid), Cochrane library, and PsycINFO (Ovid). Narrative analysis was used to describe the therapeutic effects of VNS on attention and working memory, describe stimulation parameters, and propose explanatory mechanisms.ResultsWe identified 20 studies reporting VNS effects on attention and working memory in patients with epilepsy or mood disorders. For epilepsy, there was one randomized controlled trial from all 18 studies. It demonstrated no statistically significant differences in the cognitive tasks between active and control VNS. From a within-subject experimental design, significant improvement of working memory after VNS was demonstrated. One of three nonrandomized controlled trials found significantly improved attentional performance after VNS. The cohort studies compared VNS and surgery and found attentional improvement in both groups. Nine of 12 pretest-posttest studies showed improvement of attention or working memory after VNS. For mood disorders, although one study showed significant improvement of attention following VNS, the other did not.ConclusionsThis review suggests that, although we identified some positive results from eligible studies, there is insufficient good-quality evidence to establish VNS as an effective intervention to enhance attention and working memory in persons with neuropsychiatric disorders. Further studies assessing the efficacy of such intervention are needed.     

The interactions of multisensory integration with endogenous and exogenous attention

Stimuli from multiple sensory organs can be integrated into a coherent representation through multiple phases of multisensory processing; this phenomenon is called multisensory integration. Multisensory integration can interact with attention. Here, we propose a framework in which attention modulates multisensory processing in both endogenous (goal-driven) and exogenous (stimulus-driven) ways. Moreover, multisensory integration exerts not only bottom-up but also top-down control over attention. Specifically, we propose the following: (1) endogenous attentional selectivity acts on multiple levels of multisensory processing to determine the extent to which simultaneous stimuli from different modalities can be integrated; (2) integrated multisensory events exert top-down control on attentional capture via multisensory search templates that are stored in the brain; (3) integrated multisensory events can capture attention efficiently, even in quite complex circumstances, due to their increased salience compared to unimodal events and can thus improve search accuracy; and (4) within a multisensory object, endogenous attention can spread from one modality to another in an exogenous manner.     

Attentional load modifies early activity in human primary visual cortex

Recent theories of selective attention assume that the more attention is required by a task, the earlier are irrelevant stimuli filtered during perceptual processing. Previous functional MRI studies have demonstrated that primary visual cortex (V1) activation by peripheral distractors is reduced by higher task difficulty at fixation, but it remains unknown whether such changes affect initial processing in V1 or subsequent feedback. Here we manipulated attentional load at fixation while recording peripheral visual responses with high-density EEG in 28 healthy volunteers, which allowed us to track the exact time course of attention-related effects on V1. Our results show a modulation of the earliest component of the visual evoked potential (C1) as a function of attentional load. Additional topographic and source localization analyses corroborated this finding, with significant load-related differences observed throughout the first 100 ms post-stimulus. However, this effect was observed only when stimuli were presented in the upper visual field (VF), but not for symmetrical positions in the lower VF. Our findings demonstrate early filtering of irrelevant information under increased attentional demands, thus supporting models that assume a flexible mechanism of attentional selection, but reveal important functional asymmetries across the VF.     

Increased acetylcholine release in the rat medial prefrontal cortex during performance of a visual attentional task

Recent studies have suggested a functional link between cortical cholinergic output and attentional task demands, whereby acetylcholine (ACh) release is regulated according to the outcome of ongoing behaviour. To explore this hypothesis we measured ACh efflux in the rat medial prefrontal cortex (mPFC) during between-session manipulations of the cognitive demands of an attentional task. Rats were trained to detect visual stimuli in a five-choice serial reaction time task (5-CSRTT) which involves sustained and divided attention. Following habituation to tethering and implantation with a microdialysis probe in the mPFC, rats were tested in the 5-CSRTT for three consecutive days, with different lengths of stimulus duration. During performance of the 5-CSRTT we measured robust, reproducible, task-related increases in ACh release in the mPFC across all sessions. Variations of the stimulus duration from the standard 0.5 s resulted in the predicted behavioural effects (reductions and increases in choice accuracy with 0.25 s and 5 s, respectively), but there was no evidence of either greater changes in ACh release in the more demanding condition or smaller changes in the less demanding condition. By contrast, in the session with 5-s stimulus duration there was a positive correlation between prefrontal cortical ACh efflux and the total number of trials completed. In summary, the present study shows that ACh efflux in the rat mPFC is increased during performance of a 5-CSRTT, but has found no evidence to support a specific relationship between cholinergic cortical output and attentional performance.     

Anterior insula hyperactivation in ADHD when faced with distracting negative stimuli

Patients with attention deficit hyperactivity disorder (ADHD) suffer from poor emotion regulation that might arise from problems in the distribution of attentional resources when confronted with emotional distractors. Previous studies investigating the neurocognitive basis of these problems remain inconclusive. Moreover, most of these studies did not exclude participants with comorbidity, particularly of conduct or oppositional defiant disorder. The aim of this study was to assess alterations in fronto‐limbic activation in ADHD adolescents specifically during negative distractors in an emotional attention task. For this purpose, we used functional magnetic resonance imaging to assess 25 boys with noncomorbid ADHD and 25 typically developing (TD) boys while they performed an emotional attention task with positive, negative, and neutral emotional distractors. Boys with ADHD had increased activation relative to TD boys specifically during the negative valenced stimuli in an emotional processing network comprising left anterior insula reaching into the inferior frontal gyrus. The findings suggest altered salience processing in ADHD of negative valenced emotional stimuli that may lead to higher distractibility in ADHD specifically when faced with negative emotional distractors.     

Role of Inferior Frontal Junction (IFJ) in the Control of Feature versus Spatial Attention

Feature-based visual attention refers to preferential selection and processing of visual stimuli based on their nonspatial attributes, such as color or shape. Recent studies have highlighted the inferior frontal junction (IFJ) as a control region for feature but not spatial attention. However, the extent to which IFJ contributes to spatial versus feature attention control remains a topic of debate. We investigated in humans of both sexes the role of IFJ in the control of feature versus spatial attention in a cued visual spatial (attend-left or attend-right) and feature (attend-red or attend-green) attention task using fMRI. Analyzing cue-related fMRI using both univariate activation and multivoxel pattern analysis, we found the following results in IFJ. First, in line with some prior studies, the univariate activations were not different between feature and spatial attentional control. Second, in contrast, the multivoxel pattern analysis decoding accuracy was above chance level for feature attention (attend-red vs attend-green) but not for spatial attention (attend-left vs attend-right). Third, while the decoding accuracy for feature attention was above chance level during attentional control in the cue-to-target interval, it was not during target processing. Fourth, the right IFJ and visual cortex (V4) were observed to be functionally connected during feature but not during spatial attention control, and this functional connectivity was positively associated with subsequent attentional selection of targets in V4, as well as with behavioral performance. These results support a model in which IFJ plays a crucial role in top-down control of visual feature but not visual spatial attention.SIGNIFICANCE STATEMENT Past work has shown that the inferior frontal junction (IFJ), a prefrontal structure, is activated by both attention-to-feature (e.g., color) and attention-to-location, but the precise role of IFJ in the control of feature- versus spatial-attention is debated. We investigated this issue in a cued visual spatial (attend-left or attend-right) and feature (attend-red or attend-green) attention task using fMRI, multivoxel pattern analysis, and functional connectivity methods. The results show that (1) attend-red versus attend-green can be decoded in single-trial cue-evoked BOLD activity in IFJ but not attend-left versus attend-right and (2) only right IFJ modulates V4 to enhance task performance. This study sheds light on the function and hemispheric specialization of IFJ in the control of visual attention.     

Attention networks and the intrinsic network structure of the human brain

Attention network theory distinguishes three independent systems, each supported by its own distributed network: an alerting network to deploy attentional resources in anticipation, an orienting network to direct attention to a cued location, and a control network to select relevant information at the expense of concurrently available information. Ample behavioral and neuroimaging evidence supports the dissociation of the three attention domains. The strong assumption that each attentional system is realized through a separable network, however, raises the question how these networks relate to the intrinsic network structure of the brain. Our understanding of brain networks has advanced majorly in the past years due to the increasing focus on brain connectivity. The brain is intrinsically organized into several large‐scale networks whose modular structure persists across task states. Existing proposals on how the presumed attention networks relate to intrinsic networks rely mostly on anecdotal and partly contradictory arguments. We addressed this issue by mapping different attention networks at the level of cifti‐grayordinates. Resulting group maps were compared to the group‐level topology of 23 intrinsic networks, which we reconstructed from the same participants'' resting state fMRI data. We found that all attention domains recruited multiple and partly overlapping intrinsic networks and converged in the dorsal fronto‐parietal and midcingulo‐insular network. While we observed a preference of each attentional domain for its own set of intrinsic networks, implicated networks did not match well to those proposed in the literature. Our results indicate a necessary refinement of the attention network theory.     

Hemifield effects of spatial attention in early human visual cortex

Early visual areas (V1, V2, V3/VP, V4v) contain representations of the contralateral hemifield within each hemisphere. Little is known about the role of the visual hemifields along the visuo-spatial attention processing hierarchy. It is hypothesized that attentional information processing is more efficient across the hemifields (known as bilateral field advantage) and that the integration of information is greater within one hemifield as compared with across the hemifields. Using functional magnetic resonance imaging we examined the effect of distance and hemifield on parallel attentional processing in the early visual areas (V1-V4v) at individually mapped retinotopic locations aligned adjacently or separately within or across the hemifields. We found that the bilateral field advantage in parallel attentional processing over separated attended locations can be assigned, at least partly, to differences in distractor position integration in early visual areas. These results provide evidence for a greater integration of locations between two attended locations within one hemifield than across both hemifields. This nicely correlates with behavioral findings of a bilateral field advantage in parallel attentional processing (when distractors in between cannot be excluded) and a unilateral field advantage if attention has to be shifted across separated locations (when locations in between were integrated).