Combined spatial and temporal imaging of brain activity during visual selective attention in humans

Conflicting Sensory Information Sharpens the Neural Representations of Early Selective Visuospatial Attention

Adaptive behaviors require the ability to resolve conflicting information caused by the processing of incompatible sensory inputs. Prominent theories of attention have posited that early selective attention helps mitigate cognitive interference caused by conflicting sensory information by facilitating the processing of task-relevant sensory inputs and filtering out behaviorally irrelevant information. Surprisingly, many recent studies that investigated the role of early selective attention on conflict mitigation have failed to provide positive evidence. Here, we examined changes in the selectivity of early visuospatial attention in male and female human subjects performing an attention-cueing Eriksen flanker task, where they discriminated the shape of a visual target surrounded by congruent or incongruent distractors. We used the inverted encoding model to reconstruct spatial representations of visual selective attention from the topographical patterns of amplitude modulations in alpha band oscillations in scalp EEG (∼8-12 Hz). We found that the fidelity of the alpha-based spatial reconstruction was significantly higher in the incongruent compared with the congruent condition. Importantly, these conflict-related modulations in the reconstruction fidelity occurred at a much earlier time window than those of the lateralized posterior event-related potentials associated with target selection and distractor suppression processes, as well as conflict-related modulations in the frontocentral negative-going wave and midline-frontal theta oscillations (∼3-7 Hz), thought to track executive control functions. Taken together, our data suggest that conflict resolution is supported by the cascade of neural processes underlying early selective visuospatial attention and frontal executive functions that unfold over time.

Early Electrophysiological Correlates of Perceptual Consciousness Are Affected by Both Exogenous and Endogenous Attention

It has been proposed that visual awareness negativity (VAN), which is an early ERP component, constitutes a neural correlate of visual consciousness that is independent of perceptual and cognitive mechanisms. In the present study, we investigated whether VAN is indeed a specific marker of phenomenal awareness or rather reflects the involvement of attention. To this end, we reanalyzed data collected in a previously published EEG experiment in which awareness of visual stimuli and two aspects that define attentional involvement, namely, the inherent saliency and task relevance of a stimulus, were manipulated orthogonally. During the experimental procedure, participants (n = 41) were presented with images of faces that were backward-masked or unmasked, fearful or neutral, and defined as task-relevant targets or task-irrelevant distractors. Single-trial ERP analysis revealed that VAN was highly dependent on attentional manipulations in the early time window (140-200 msec), up to the point that the effect of awareness was not observed for attentionally irrelevant stimuli (i.e., neutral faces presented as distractors). In the late time window (200-350 msec), VAN was present in all attentional conditions, but its amplitude was significantly higher in response to fearful faces and task-relevant face images than in response to neutral ones and task-irrelevant ones, respectively. In conclusion, we demonstrate that the amplitude of VAN is highly dependent on both exogenous (stimulus saliency) and endogenous attention (task requirements). Our results challenge the view that VAN constitutes an attention-independent correlate of phenomenal awareness.

Exploring Binocular Visual Attention by Presenting Rapid Dichoptic and Dioptic Series

This study addresses an issue in attentional distribution in a binocular visual system using RSVP tasks under Attentional Blink (AB) experimental protocols. In Experiment 1, we employed dichoptic RSVP to verify whether, under interocular competition, attention may be captured by a monocular channel. Experiment 2 was a control experiment, where a monoptic RSVP assessed by both or only one eye determines whether Experiment 1 monocular condition results were due to an allocation of attention to one eye. Experiment 3 was also a control experiment designed to determine whether Experiment 1 results were due to the effect of interocular competition or to a diminished visual contrast. Results from Experiment 1 revealed that dichoptic presentations caused a delay in the type stage of the Wyble's eSTST model, postponing the subsequent tokenization process. The delay in monocular conditions may be further explained by a visual attenuation, due to fusion of target and an empty frame. Experiment 2 evidenced the attentional allocation to monocular channels when forced by eye occlusion. Experiment 3 disclosed that monocular performance in Experiment 1 differs significantly from conditions with interocular competition. While both experiments revealed similar performance in monocular conditions, rivalry conditions exhibit lower detection rates, suggesting that competing stimuli was not responsible for Experiment 1 results. These findings highlight the differences between dichoptic and monoptic presentations of stimuli, particularly on the AB effect, which appears attenuated or absent in dichoptic settings. Furthermore, results suggest that monoptic presentation and binocular fusion stages were a necessary condition for the attentional allocation.

Contralateral delay activity and alpha lateralization reflect retinotopic and screen-centered reference frames in visual memory

The visual system represents objects in a lateralized manner, with contralateral cortical hemispheres responsible for left and right visual hemifields. This organization extends to visual short-term memory (VSTM), as evidenced by electrophysiological indices of VSTM maintenance: contralateral delay activity (CDA) and alpha-band lateralization. However, it remains unclear if VSTM represents object locations in gaze-centered (retinotopic) or screen-centered (spatiotopic) coordinates, especially after eye movements. In two experiments, participants encoded the colors of target objects and made a lateral saccade during the maintenance interval, thereby shifting the object's location on the retina. A non-lateralized probe stimulus was then presented at the new fixation for a change detection task. The CDA maintained lateralization towards the target's original retinotopic location, unaffected by subsequent saccades, and did not invert polarity even when a saccade brought that location into the opposite hemifield. We also found conventional alpha lateralization towards the target's location before a saccade. After a saccade, however, alpha was lateralized towards the screen center regardless of the target's original location, even in a control condition without any memory requirements. This suggests that post-saccadic alpha-band lateralization reflects attentional processes unrelated to memory, while pre- and post-saccade CDA reflect VSTM maintenance in a retinotopic reference frame.

Cognitive-Motor Training Improves Reading-Related Executive Functions: A Randomized Clinical Trial Study in Dyslexia

Children with developmental dyslexia (DD) often struggle with executive function difficulties which can continue into adulthood if not addressed. This double-blinded randomized clinical trial study evaluated the short-term effects of the Verbal Working Memory-Balance (VWM-B) program on reading-related executive functions, reading skills, and reading comprehension in Persian children with DD. The active control group [12 children with DD with a mean age of 9 years (SD = 0.90)] received training using the single-task VWM program, while the experiment group [15 children with DD with a mean age of 8 years (SD = 0.74)] received training with the dual-task VWM-B program. Both groups received fifteen training sessions, and assessments were conducted before and after the intervention. The groups were homogenized for possible confounders of age, gender, IQ level, and attention level. The study employed separate mixed ANOVA analyses to estimate the impact of training programs on various measured functions. Significant improvements were observed in the outcome measures of backward digit span, text comprehension, verbal fluency, Stroop color-word test and interference, and the reading subtests. Additionally, significant correlations were found between reading skills and backward digit span, text comprehension, verbal fluency, and Stroop variables. In conclusion, the dual-task VWM-B program was found to be more effective than the single-task VWM program in improving selective attention, cognitive inhibition, verbal working memory capacity, information processing speed, naming ability, and lexical access speed. These enhanced executive functions were associated with improved reading skills in children with DD.

Attentional biases toward auditory weight-related information among females with weight dissatisfaction

Although there is substantial evidence of visual attentional biases in processing weight-related information among individuals with weight dissatisfaction, few studies have examined auditory attentional biases in these individuals. The identification of attentional biases may provide an impetus for interventions to reduce distress, negative body image, and pathological eating patterns among weight-dissatisfied individuals. Therefore, the present study aimed to investigate the attentional biases, as well as the neural consequences, toward auditory weight-related information among weight-dissatisfied young females. In this experiment, young female participants were assigned to an experimental group with high weight dissatisfaction (HWD) and a control group with low weight dissatisfaction (LWD) according to the levels of weight dissatisfaction. Using a spatial cueing paradigm, auditory fatness-related, thinness-related, and neutral household words were presented laterally as cue stimuli, followed by visual stimuli presented at either the cued or uncued location. The results revealed that auditory fatness-related words elicited significantly larger N2ac amplitudes than auditory thinness-related and neutral words in the HWD group. However, for the LWD group, thinness-related words elicited a significantly larger N2ac than fatness-related and neutral words. These results suggest an orienting attentional bias toward auditory fatness-related body words among females with HWD and an orienting attentional bias toward auditory thinness-related words among females with LWD.

Top-Down Biasing of Visual Cortical Activity Encodes Attended Information and Facilitates Behavioral Performance in Visual Spatial Attention

Top-down attention plays a vital role in selecting relevant stimuli and suppressing distracting information. During top-down visual-spatial attention, control signals from the dorsal attention network modulate the baseline neuronal activity in the visual cortex in favor of task-relevant stimuli. While several studies have demonstrated that baseline shift during anticipatory attention occurs in multiple visual areas, such effects have not been systematically investigated across the visual hierarchy, especially when different attention conditions are matched for stimulus and task factors. In this fMRI study, we investigated anticipatory attention signals using univariate and multivariate (MVPA) analysis in multiple visual cortical areas. First, the univariate analysis yielded significant activation differences in higher-order visual areas, with the effect weaker in early visual areas. Second, however, in contrast, MVPA decoding was significant in predicting attention conditions in all visual areas and IPS, with lower-order visual areas (e.g., V1) having greater decoding accuracy than higher-order visual areas (e.g., LO1). Third, the strength of decoding accuracy predicted the behavioral performance in the discrimination task. All the results were highly replicable and consistent across two datasets with same experimental paradigms but recorded at two research sites, and two experimental conditions where the direction of spatial attention was driven either by external instructions (cue-instructed attention) or from internal decisions (free-choice attention). Our results provide clear evidence, not available in past univariate investigations, that top-down attentional control signals selectively bias neuronal processing throughout the visual hierarchy, and that this biasing is correlated with the task performance.

Integrated effects of top-down attention and statistical learning during visual search: An EEG study

The present study aims to investigate how the competition between visual elements is solved by top-down and/or statistical learning (SL) attentional control (AC) mechanisms when active together. We hypothesized that the "winner" element that will undergo further processing is selected either by one AC mechanism that prevails over the other, or by the joint activity of both mechanisms. To test these hypotheses, we conducted a visual search experiment that combined an endogenous cueing protocol (valid vs. neutral cue) and an imbalance of target frequency distribution across locations (high- vs. low-frequency location). The unique and combined effects of top-down control and SL mechanisms were measured on behaviour and amplitudes of three evoked-response potential (ERP) components (i.e., N2pc, P1, CNV) related to attentional processing. Our behavioural results showed better performance for validly cued targets and for targets in the high-frequency location. The two factors were found to interact, so that SL effects emerged only in the absence of top-down guidance. Whereas the CNV and P1 only displayed a main effect of cueing, for the N2pc we observed an interaction between cueing and SL, revealing a cueing effect for targets in the low-frequency condition, but not in the high-frequency condition. Thus, our data support the view that top-down control and SL work in a conjoint, integrated manner during target selection. In particular, SL mechanisms are reduced or even absent when a fully reliable top-down guidance of attention is at play.

Characterization of attentional event-related potential from REM sleep behavior disorder patients based on explainable machine learning

BACKGROUND AND OBJECTIVE

Idiopathic rapid eye movement sleep behavior disorder (iRBD) is a prodromal stage of neurodegeneration and is associated with cortical dysfunction. The purpose of this study was to investigate the spatiotemporal characteristics of cortical activities underlying impaired visuospatial attention in iRBD patients using an explainable machine-learning approach.

METHODS

An algorithm based on a convolutional neural network (CNN) was devised to discriminate cortical current source activities of iRBD patients due to single-trial event-related potentials (ERPs), from those of normal controls. The ERPs from 16 iRBD patients and 19 age- and sex-matched normal controls were recorded while the subjects were performing visuospatial attentional task, and converted to two-dimensional images representing current source densities on flattened cortical surface. The CNN classifier was trained based on overall data, and then, a transfer learning approach was applied for the fine-tuning to each patient.

RESULTS

The trained classifier yielded high classification accuracy. The critical features for the classification were determined by layer-wise relevance propagation, so that the spatiotemporal characteristics of cortical activities that were most relevant to cognitive impairment in iRBD were revealed.

CONCLUSIONS

These results suggest that the recognized dysfunction in visuospatial attention of iRBD patients originates from neural activity impairment in relevant cortical regions and may contribute to the development of useful iRBD biomarkers based on neural activity.

Acute aerobic exercise benefits allocation of neural resources related to selective attention

A single session of aerobic exercise has been shown to potentially benefit subsequent performance in a wide range of cognitive tasks, but the underlying mechanisms are still not fully understood. In this study, we investigated the effects of exercise on selective attention, a cognitive process that involves prioritized processing of a subset of available inputs over others. Twenty-four healthy participants (12 women) underwent two experimental interventions in a random, crossover, and counterbalanced design: a vigorous-intensity exercise (60-65% HRR) and a seated rest (control) condition. Before and after each protocol, participants performed a modified selective attention task that demanded attending stimuli of different spatial frequencies. Event-related magnetic fields were concurrently recorded using magnetoencephalography. The results showed that exercise, relative to the seated rest condition, reduced neural processing of unattended stimuli and increased processing of attended stimuli. The findings suggest that changes in neural processing related to selective attention may be one of the mechanisms underlying exercise-induced improvements in cognition.

Time Courses of Attended and Ignored Object Representations

Selective attention prioritizes information that is relevant to behavioral goals. Previous studies have shown that attended visual information is processed and represented more efficiently, but distracting visual information is not fully suppressed, and may also continue to be represented in the brain. In natural vision, to-be-attended and to-be-ignored objects may be present simultaneously in the scene. Understanding precisely how each is represented in the visual system, and how these neural representations evolve over time, remains a key goal in cognitive neuroscience. In this study, we recorded EEG while participants performed a cued object-based attention task that involved attending to target objects and ignoring simultaneously presented and spatially overlapping distractor objects. We performed support vector machine classification on the stimulus-evoked EEG data to separately track the temporal dynamics of target and distractor representations. We found that (1) both target and distractor objects were decodable during the early phase of object processing (∼100 msec to ∼200 msec after target onset), and (2) the representations of both objects were sustained over time, remaining decodable above chance until ∼1000-msec latency. However, (3) the distractor object information faded significantly beginning after about 300-msec latency. These findings provide information about the fate of attended and ignored visual information in complex scene perception.

Evidence of target enhancement and distractor suppression in early visual areas

Although the mechanisms of target enhancement and distractor suppression have been investigated along the visual processing hierarchy, there remains some unknown as to the role of perceptual load on the competition between different task-related information as attention deployment is manipulated. We present an fMRI spatial cueing paradigm, in which 32 participants had to attend to either a left or a right hemifield location and to indicate the orientation of the target Gabor that was presented simultaneously to a noise patch distractor. Critically, the target could appear at either the cued, valid location or at the uncued, invalid location; in the latter, the noise patch distractor appeared at the cued location. Perceptual load was manipulated by the presence or absence of high-contrast Gabor patches close to the fixation cross, which acted as lateral masks. Behavioural results indicated that participants performed more efficiently in validly cued trials compared to invalidly cued trials and under low compared to high load. Enhancement effects for targets and suppression effects for noise patches were greater in early visual areas at high load, that is in the presence of lateral masks. These results are in line with the hypothesis that attention results in both target enhancement and distractor suppression, and that these effects are most marked under high perceptual load. Theoretical implications of these results for different models of attention are discussed.

A cortical zoom-in operation underlies covert shifts of visual spatial attention

Shifting the focus of attention without moving the eyes poses challenges for signal coding in visual cortex in terms of spatial resolution, signal routing, and cross-talk. Little is known how these problems are solved during focus shifts. Here, we analyze the spatiotemporal dynamic of neuromagnetic activity in human visual cortex as a function of the size and number of focus shifts in visual search. We find that large shifts elicit activity modulations progressing from highest (IT) through mid-level (V4) to lowest hierarchical levels (V1). Smaller shifts cause those modulations to start at lower levels in the hierarchy. Successive shifts involve repeated backward progressions through the hierarchy. We conclude that covert focus shifts arise from a cortical coarse-to-fine process progressing from retinotopic areas with larger toward areas with smaller receptive fields. This process localizes the target and increases the spatial resolution of selection, which resolves the above issues of cortical coding.

The neurovascular couplings between electrophysiological and hemodynamic activities in anticipatory selective attention

Selective attention is thought to involve target enhancement and distractor inhibition processes. Here, we recorded simultaneous electroencephalographic (EEG) and functional near-infrared spectroscopy (fNIRS) data from human adults when they were pre-cued by the visual field of coming target, distractor, or both of them. From the EEG data, we found alpha power relatively decreased contralaterally to the to-be-attended target, as reflected by the positive-going alpha modulation index. Late alpha power relatively increased contralaterally to the to-be-suppressed distractor, as reflected by the negative-going alpha modulation index. From the fNIRS data, we found enhancements of hemodynamic activity over the contralateral hemisphere in response to both the target and the distractor anticipation but within nonoverlapping posterior brain regions. More importantly, we described the specific neurovascular modulation between alpha power and oxygenated hemoglobin signal, which showed a positive coupling effect during target anticipation and a negative coupling effect during distractor anticipation. Such flexible neurovascular couplings between EEG oscillation and hemodynamic activity seem to play an essential role in the final behavioral outcomes. These results provide unique neurovascular evidence for the dissociation of the mechanisms of target enhancement and distractor inhibition. Individual behavioral differences can be related to individual differences in neurovascular coupling.

The role of task demands in racial face encoding

People more accurately remember faces of their own racial group compared to faces of other racial groups; this phenomenon is called the other-race effect. To date, numerous researchers have devoted themselves to exploring the reasons for this other-race effect, and they have posited several theoretical explanations. One integrated explanation is the categorization-individuation model, which addresses two primary ways (categorization and individuation) of racial face processing and emphasizes the emergence of these two ways during the encoding stage. Learning-recognition and racial categorization tasks are two classical tasks used to explore racial face processing. Event-related potentials can facilitate investigation of the encoding differences of own- and other-race faces under these two typical task demands. Unfortunately, to date, results have been mixed. In the current study, we investigated whether categorization and individuation differ for own- and other-race faces during the encoding stage by using racial categorization and learning-recognition tasks. We found that task demands not only influence the encoding of racial faces, but also have a more profound effect in the encoding stage of recognition tasks for other-race faces. More specifically, own-race faces demonstrate deeper structural encoding than other-race faces, with less attentional involvement. Moreover, recognitions tasks might ask for more individual-level encoding, requiring more attentional resources in the early stage that may be maintained until relatively late stages. Our results provide some evidence concerning task selection for future racial face studies and establish a groundwork for a unified interpretation of racial face encoding.

Dynamics of retinotopic spatial attention revealed by multifocal MEG

Visual focal attention is both fast and spatially localized, making it challenging to investigate using human neuroimaging paradigms. Here, we used a new multivariate multifocal mapping method with magnetoencephalography (MEG) to study how focal attention in visual space changes stimulus-evoked responses across the visual field. The observer's task was to detect a color change in the target location, or at the central fixation. Simultaneously, 24 regions in visual space were stimulated in parallel using an orthogonal, multifocal mapping stimulus sequence. First, we used univariate analysis to estimate stimulus-evoked responses in each channel. Then we applied multivariate pattern analysis to look for attentional effects on the responses. We found that attention to a target location causes two spatially and temporally separate effects. Initially, attentional modulation is brief, observed at around 60-130 ms post stimulus, and modulates responses not only at the target location but also in adjacent regions. A later modulation was observed from around 200 ms, which was specific to the location of the attentional target. The results support the idea that focal attention employs several processing stages and suggest that early attentional modulation is less spatially specific than late.

Simultaneous electroencephalography-functional magnetic resonance imaging for assessment of human brain function

Electroencephalography (EEG) and functional Magnetic Resonance Imaging (MRI) have long been used as tools to examine brain activity. Since both methods are very sensitive to changes of synaptic activity, simultaneous recording of EEG and fMRI can provide both high temporal and spatial resolution. Therefore, the two modalities are now integrated into a hybrid tool, EEG-fMRI, which encapsulates the useful properties of the two. Among other benefits, EEG-fMRI can contribute to a better understanding of brain connectivity and networks. This review lays its focus on the methodologies applied in performing EEG-fMRI studies, namely techniques used for the recording of EEG inside the scanner, artifact removal, and statistical analysis of the fMRI signal. We will investigate simultaneous resting-state and task-based EEG-fMRI studies and discuss their clinical and technological perspectives. Moreover, it is established that the brain regions affected by a task-based neural activity might not be limited to the regions in which they have been initiated. Advanced methods can help reveal the regions responsible for or affected by a developed neural network. Therefore, we have also looked into studies related to characterization of structure and dynamics of brain networks. The reviewed literature suggests that EEG-fMRI can provide valuable complementary information about brain neural networks and functions.

Assessing the attentional bias of smokers in a virtual reality anti-saccade task using eye tracking

INTRODUCTION

Cognitive biases (among them attentional bias, AB) are considered an important factor in the development, maintenance, and recurrence of addiction. However, traditional paradigms to measure AB have been criticized regarding external validity and methodical issues. Therefore, and because the neurophysiological correlates of anti-saccade tasks are known, we implemented a novel smoking anti-saccade task in virtual reality (VR) to measure AB and inhibitory control in different contexts and with higher ecological validity.

METHODS

Smokers (n = 20) and non-smokers (n = 20) were tested on a classic pro- and anti-saccade task, a VR anti-saccade task and a VR attention fixation task (all containing smoking-related and neutral stimuli) while eye-tracking data was collected. Two VR contexts (park and office room) were applied.

RESULTS

Saccade latencies were significantly higher for the smoking group in the VR anti-saccade task. However, this effect did not differ between smoking-related and neutral stimuli, thus overall no AB was observed. Instead, AB was only present in the park context. Additionally, saccade latencies and error rates were significantly higher in the park context.

CONCLUSIONS

Results indicate impaired inhibitory control in smokers relative to non-smokers. The lack of evidence for a general AB might be due to the lower severity of smoking dependence in the smoking sample. Instead, results suggest context specificity of AB. Implications for smoking cessation interventions in the field of inhibitory control training and attention bias modification are discussed.

A brain-based general measure of attention

Attention is central to many aspects of cognition, but there is no singular neural measure of a person's overall attentional functioning across tasks. Here, using original data from 92 participants performing three different attention-demanding tasks during functional magnetic resonance imaging, we constructed a suite of whole-brain models that can predict a profile of multiple attentional components (sustained attention, divided attention and tracking, and working memory capacity) for novel individuals. Multiple brain regions across the salience, subcortical and frontoparietal networks drove accurate predictions, supporting a common (general) attention factor across tasks, distinguished from task-specific ones. Furthermore, connectome-to-connectome transformation modelling generated an individual's task-related connectomes from rest functional magnetic resonance imaging, substantially improving predictive power. Finally, combining the connectome transformation and general attention factor, we built a standardized measure that shows superior generalization across four independent datasets (total N = 495) of various attentional measures, suggesting broad utility for research and clinical applications.

Treatment effects on event-related EEG potentials and oscillations in Alzheimer's disease

Alzheimer's disease dementia (ADD) is the most diffuse neurodegenerative disorder belonging to mild cognitive impairment (MCI) and dementia in old persons. This disease is provoked by an abnormal accumulation of amyloid-beta and tauopathy proteins in the brain. Very recently, the first disease-modifying drug has been licensed with reserve (i.e., Aducanumab). Therefore, there is a need to identify and use biomarkers probing the neurophysiological underpinnings of human cognitive functions to test the clinical efficacy of that drug. In this regard, event-related electroencephalographic potentials (ERPs) and oscillations (EROs) are promising candidates. Here, an Expert Panel from the Electrophysiology Professional Interest Area of the Alzheimer's Association and Global Brain Consortium reviewed the field literature on the effects of the most used symptomatic drug against ADD (i.e., Acetylcholinesterase inhibitors) on ERPs and EROs in ADD patients with MCI and dementia at the group level. The most convincing results were found in ADD patients. In those patients, Acetylcholinesterase inhibitors partially normalized ERP P300 peak latency and amplitude in oddball paradigms using visual stimuli. In these same paradigms, those drugs partially normalize ERO phase-locking at the theta band (4-7 Hz) and spectral coherence between electrode pairs at the gamma (around 40 Hz) band. These results are of great interest and may motivate multicentric, double-blind, randomized, and placebo-controlled clinical trials in MCI and ADD patients for final cross-validation.

Dynamic causal interactions between occipital and parietal cortex explain how endogenous spatial attention and stimulus-driven salience jointly shape the distribution of processing priorities in 2D visual space

Visuo-spatial attention prioritizes the processing of relevant inputs via different types of signals, including current goals and stimulus salience. Complex mixtures of these signals engage in everyday life situations, but little is known about how these signals jointly modulate distributed patterns of activity across the occipital regions that represent visual space. Here, we measured spatio-topic, quadrant-specific occipital activity during the processing of visual displays containing both task-relevant targets and salient color-singletons. We computed spatial bias vectors indexing the effect of attention in 2D space, as coded by distributed activity in the occipital cortex. We found that goal-directed spatial attention biased activity towards the target and that salience further modulated this endogenous effect: salient distractors decreased the spatial bias, while salient targets increased it. Analyses of effective connectivity revealed that the processing of salient distractors relied on the modulation of the bidirectional connectivity between the occipital and the posterior parietal cortex, as well as the modulation of the lateral interactions within the occipital cortex. These findings demonstrate that goal-directed attention and salience jointly contribute to shaping processing priorities in the occipital cortex and highlight that multiple functional paths determine how spatial information about these signals is distributed across occipital regions.

Therapeutic Garden With Contemplative Features Induces Desirable Changes in Mood and Brain Activity in Depressed Adults

The therapeutic values of contact with nature have been increasingly recognized. A growing body of evidence suggests that a unique subcategory of "contemplative landscapes" is particularly therapeutic. Previous studies predominantly focused on observational designs in non-clinical populations. It is not known if these effects can be extrapolated to populations suffering from depression, and experimental designs need to be utilized to establish causality. We examined the effects of in-situ passive exposure to three urban spaces on brain activity, namely a Therapeutic Garden with high Contemplative Landscape scores (TG), Residential Green (RG) and Busy Downtown (BD), and self-reported momentary mood in adults aged 21-74 (n = 92), including 24 clinically depressed and 68 healthy participants. Portable, multimodal electroencephalography (EEG) and functional near-infrared spectroscopy (fNIRS) systems were used to record brain activity, and a Profile of Mood States (POMS) questionnaire was used to record mood before and after exposure. We tested the interactions between the site, time and group for the mood, and between site and group for the neuroelectric oscillations and brain hemodynamics. Self-reported pre- post-mood was significant only at the TG (p = 0.032) in both groups. The lowest Total Mood Disturbance (TMD) was reported at TG and the highest in BD (p = 0.026). Results from fNIRS indicated marginally significant lower oxy-Hb in the frontal region at TG as compared to BD (p = 0.054) across both groups. The marginally significant effect of site and group was also observed (p = 0.062), with the Clinical group showing much lower oxy-Hb at TG than Healthy. The opposite pattern was observed at BD. EEG results showed differences between Healthy and Clinical groups in the Frontal Alpha Asymmetry (FAA) pattern across the sites (p = 0.04), with more frontal alpha right in the Clinical sample and more left lateralization in the Healthy sample at TG. Temporal Beta Asymmetry (TBA) analyses suggested that patients displayed lower bottom-up attention than Healthy participants across all sites (p = 0.039). The results suggest that both healthy and depressed adults benefitted from exposure to TG, with possibly different pathways of mood improvement. Visiting therapeutic nature with contemplative features may provide valuable support for the treatment of depression in clinical populations and a self-care intervention in non-clinical populations.

No smoking signs with strong smoking symbols induce weak cravings: an fMRI and EEG study

No smoking signs (NSSs) that combine smoking symbols (SSs) and prohibition symbols (PSs) represent common examples of reward and prohibition competition. To evaluate how SSs within NSSs influence their effectiveness in guiding reward vs. prohibition, we studied 93 male smokers. We collected self-reported craving ratings (N=30), cue reactivity under fMRI/EEG (N=33), and smoking-behavior anticipation for paired NSSs and SSs (N=30). We found that NSS-induced cravings were negatively correlated with SS-induced cravings and PS-induced inhibition. fMRI indicated that both correlations were mediated by activation of the inferior frontal gyrus and precuneus, suggesting that the effects of SSs and PSs interact with each other. EEG revealed that the prohibition response occurs after the cigarette response, indicating that the cigarette response might be precluded by the prohibition, supporting the effect of SSs in discouraging smoking. Moreover, stronger SSs induced stronger slow positive waves and late positive potentials, and the stronger the late positive potentials, the stronger the late positive potentials. Both the amplitudes of late positive potentials and slow positive waves were positively correlated with the amplitude of N2, which was positively correlated with the attention grabbed score by the NSS. In addition, the weaker the NSS-induced craving, the greater the smoking behavior anticipation reduction, indicating the capability of NSSs to decrease smoking behavior. Our study provides empirical evidence for selecting the most effective NSSs: those combining strong SS and PS, offering insights about competition between cigarette reward and prohibition and providing neural evidence on how cigarette reward and prohibition interact.

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.

Is an anthropomorphic app icon more attractive? Evidence from neuroergonomomics

Exploring what types of app icons are attractive has been a topic of great interest in recent years. The main purpose of this study was to explore the neural mechanism of attention capturing of the anthropomorphic app icons based on neuroergonomics. Participants' perception of different app icons was investigated by using event-related potentials (ERPs) and attractiveness evaluation. The results showed that anthropomorphic app icons were evaluated more attractive and elicted larger P2, P3 and LPP amplitude than non-anthropomorphic app icons, which indicated an attention bias to attractive anthropomprphic app icons. The time course of the attention towards anthropomorphic app icons includes three main processes: an early stimulus-driven perceptual detection of app icon features (P2 during 160-200 ms), an involuntary allocation of attention to evaluate and categorize app icons (P3 during 300-500 ms), and experiencing different emotions to anthropomorphic versus non-anthropomorphic app icons (LPP during 500-800 ms). That is, the process of users' perception and attention toward app icons combines "bottom-up" and "top-down" processes. Our findings suggest a new perspective to use ERP components (P2, P3, and LPP) to deep understanding of app icon design. A practical implication is that app icons could be designed using anthropomorphic elements to attract users.

Does feature intertrial priming guide attention? The jury is still out

Our search performance is strongly influenced by our past experience. In the lab, this influence has been demonstrated by investigating a variety of phenomena, including intertrial priming, statistical learning, and reward history, and collectively referred to as selection history. The resulting findings have led researchers to claim that selection history guides attention, thereby challenging the prevailing dichotomy, according to which top-down and bottom-up factors alone determine attentional priority. Here, we re-examine this claim with regard to one selection-history phenomenon, feature intertrial priming (aka priming of pop-out). We evaluate the evidence that specifically pertains to the role of feature intertrial priming in attentional guidance, rather than in later selective processes occurring after the target is found. We distinguish between the main experimental rationales, while considering the extent to which feature intertrial priming, as studied through different protocols, shares characteristics of top-down attention. We show that there is strong evidence that feature intertrial priming guides attention when the experimental protocol departs from the canonical paradigm and encourages observers to maintain the critical feature in visual working memory or to form expectations about the upcoming target. By contrast, the current evidence regarding the standard feature intertrial priming phenomenon is inconclusive. We propose directions for future research and suggest that applying the methodology used here in order to re-evaluate of the role of other selection history phenomena in attentional guidance should clarify the mechanisms underlying the strong impact of past experience on visual search performance.

Top-Down Modulation of Early Visual Processing in V1: Dissociable Neurophysiological Effects of Spatial Attention, Attentional Load and Task-Relevance

Until today, there is an ongoing discussion if attention processes interact with the information processing stream already at the level of the C1, the earliest visual electrophysiological response of the cortex. We used two highly powered experiments (each N = 52) and examined the effects of task relevance, spatial attention, and attentional load on individual C1 amplitudes for the upper or lower visual hemifield. Bayesian models revealed evidence for the absence of load effects but substantial modulations by task-relevance and spatial attention. When the C1-eliciting stimulus was a task-irrelevant, interfering distracter, we observed increased C1 amplitudes for spatially unattended stimuli. For spatially attended stimuli, different effects of task-relevance for the two experiments were found. Follow-up exploratory single-trial analyses revealed that subtle but systematic deviations from the eye-gaze position at stimulus onset between conditions substantially influenced the effects of attention and task relevance on C1 amplitudes, especially for the upper visual field. For the subsequent P1 component, attentional modulations were clearly expressed and remained unaffected by these deviations. Collectively, these results suggest that spatial attention, unlike load or task relevance, can exert dissociable top-down modulatory effects at the C1 and P1 levels.

Electrophysiological mechanisms underlying hypoxia-induced deficits in visual spatial and non-spatial discrimination

Impaired visual cognition in residents of hypoxic environment has been widely reported; however, the underlying electrophysiological mechanisms remain unclear. In this study, 23 college students underwent three sessions of a Clock task test before a 30-day high-altitude exposure (Test 1) and 1 week (Test 2) and 3 months (Test 3) after they returned to lowlands. The Clock task consists of a visual spatial angle and a visual non-spatial color discrimination subtask. Simultaneously, electroencephalography (EEG) was recorded during the Clock task. The behavioral results showed that, compared with Test 1, accuracy in Test 2 was significantly decreased in both the Angle and Color tasks, and reaction time (RT) was significantly increased in the Angle task. The event-related potentials results showed that, during both tasks amplitudes of the occipital N1 and P3 components during both tasks were significantly decreased in Test 2, compared with Test 1. Moreover, N1 amplitude was negatively correlated with RT and positively correlated with accuracy. Further time-frequency EEG analysis showed that theta power at occipital sites was significantly decreased in both tasks in Test 2, compared with Test 1, and was negatively correlated with RT in the Angle task. In Test 3, both the behavioral performance and EEG activity recovered to the baseline level in Test 1. These findings suggested that hypoxia impairs both visual spatial and visual non-spatial discriminations, and these impairments can recover after subjects return to lowlands. Inhibition of brain electrophysiological activity in the visual cortex may explain the deficits in visual cognition.

Modulation of the Earliest Component of the Human VEP by Spatial Attention: An Investigation of Task Demands

Spatial attention modulations of initial afferent activity in area V1, indexed by the first component “C1” of the human visual evoked potential, are rarely found. It has thus been suggested that early modulation is induced only by special task conditions, but what these conditions are remains unknown. Recent failed replications—findings of no C1 modulation using a certain task that had previously produced robust modulations—present a strong basis for examining this question. We ran 3 experiments, the first to more exactly replicate the stimulus and behavioral conditions of the original task, and the second and third to manipulate 2 key factors that differed in the failed replication studies: the provision of informative performance feedback, and the degree to which the probed stimulus features matched those facilitating target perception. Although there was an overall significant C1 modulation of 11%, individually, only experiments 1 and 2 showed reliable effects, underlining that the modulations do occur but not consistently. Better feedback induced greater P1, but not C1, modulations. Target-probe feature matching had an inconsistent influence on modulation patterns, with behavioral performance differences and signal-overlap analyses suggesting interference from extrastriate modulations as a potential cause.

Attentional eye selection modulates sensory eye dominance

Brief periods of monocular deprivation significantly modify binocular visual processing. For example, patching one eye for a few hours alters the inter-ocular balance, with the previously patched eye becoming dominant once the patch is removed. However, the contribution of higher-level visual processing to this phenomenon is still unclear. Here, we compared changes in sensory eye dominance produced by three types of monocular manipulations in adult participants with normal binocular vision. One eye was covered for 150 min using either an opaque patch, a diffusing lens, or a prism that inverted the image. All three manipulations altered dominance duration and predominance during binocular rivalry (BR) in favour of the treated eye and the time courses of the changes were similar. These results indicate that modifications of luminance or contrast are not strictly necessary to drive shifts in eye dominance, as both were unaltered in the prism condition. Next, we found that shifts in eye dominance were dependent on attentional demands during the monocular treatment period, providing support for the role of attentional eye selection in modulating eye dominance. Finally, we found relatively rapid build-up of the ocular dominance shift after the onset of monocular treatment. Taken together, our results suggest that modifications to monocular input alter inter-ocular balance via selective attentional mechanisms that bias output towards the deprived eye. Eye-based attention may play an important role in conditions where normal input to one eye is disrupted, such as childhood amblyopia.

Epigenetic Markers of Aging Predict the Neural Oscillations Serving Selective Attention

Chronological age remains an imperfect measure of accumulated physiological stress. Biological measures of aging may provide key advantages, allowing scientists focusing on age-related functional changes to use metrics derived from epigenetic factors like DNA methylation (DNAm), which could provide greater precision. Here we investigated the relationship between methylation-based age and an essential cognitive function that is known to exhibit age-related decline: selective attention. We found that DNAm-age predicted selective attention abilities and fully mediated the relationship between selective attention and chronological age. Using neuroimaging with magnetoencephalography, we found that gamma activity in the anterior cingulate was robustly predicted by DNAm-derived biological age, revealing the neural dynamics underlying this DNAm age-related cognitive decline. Anterior cingulate gamma activity also significantly predicted behavior on the selective attention task, indicating its functional relevance. These findings suggest that DNAm age may be a better predictor of cognitive and brain aging than more traditional chronological metrics.

Hemodynamic Response to Three Types of Urban Spaces before and after Lockdown during the COVID-19 Pandemic

(1) Background: Prolonged lockdowns with stay-at-home orders have been introduced in many countries since the outbreak of the COVID-19 pandemic. They have caused a drastic change in the everyday lives of people living in urbanized areas, and are considered to contribute to a modified perception of the public space. As research related to the impact of COVID-19 restrictions on mental health and well-being emerges, the associated longitudinal changes of brain hemodynamics in healthy adults remain largely unknown. (2) Methods: this study examined the hemodynamic activation patterns of the prefrontal and occipital cortices of 12 participants (5 male, Mage = 47.80, SDage = 17.79, range 25 to 74, and 7 female, Mage = 39.00, SDage = 18.18, range 21 to 65) passively viewing videos from three urban sites in Singapore (Urban Park, Neighborhood Landscape and City Center) at two different time points-T1, before the COVID-19 pandemic and T2, soon after the lockdown was over. (3) Results: We observed a significant and marginally significant decrease in average oxyhemoglobin (Oxy-Hb) over time for each of the visual conditions. For both green spaces (Urban Park and Neighborhood Landscape), the decrease was in the visual cortex, while for the City Center with no green elements, the marginal decrease was observed in the visual cortex and the frontal eye fields. (4) Conclusions: The results suggest that the COVID-19-related lockdown experienced by urban inhabitants may have contributed to decreased brain hemodynamics, which are further related to a heightened risk of mental health disorders, such as depression or a decline in cognitive functions. Moreover, the busy City Center scenes induced a hemodynamic pattern associated with stress and anxiety, while urban green spaces did not cause such an effect. Urban green scenes can be an important factor to offset the negative neuropsychological impact of busy urban environments post-pandemic.

Effects of irrelevant object structure on early attention deployment

Event-related potential (ERP) studies have suggested that Gestalt principles or grouping factors in a visual scene modulate attention deployment in early visual processing. The present study examined the effects of an extrinsic grouping factor, region commonality, on early ERP spatial attention. Effects of sex were also explored, since the processing of task-irrelvant objects may differ between the sexes. Twenty-four participants were required to discriminate one side of rapidly-presented bilateral letters, and attention effects were indexed by hemispheric lateralization accroding to attended visual fields. In results, an early P1 attention effect (70-110 ms) increased when the letters were surrounded by an object, compared to the control stimulus without a complete object, and this result was more prominent in women than in men. The present study demonstrates that visual object and sex differences play a novel role at very early cortical stages of processing in attention deployment to a task-irrelevant visual structure.

The Microstructure of Attentional Control in the Dorsal Attention Network

The top-down control of attention involves command signals arising chiefly in the dorsal attention network (DAN) in frontal and parietal cortex and propagating to sensory cortex to enable the selective processing of incoming stimuli based on their behavioral relevance. Consistent with this view, the DAN is active during preparatory (anticipatory) attention for relevant events and objects, which, in vision, may be defined by different stimulus attributes including their spatial location, color, motion, or form. How this network is organized to support different forms of preparatory attention to different stimulus attributes remains unclear. We propose that, within the DAN, there exist functional microstructures (patterns of activity) specific for controlling attention based on the specific information to be attended. To test this, we contrasted preparatory attention to stimulus location (spatial attention) and to stimulus color (feature attention), and used multivoxel pattern analysis to characterize the corresponding patterns of activity within the DAN. We observed different multivoxel patterns of BOLD activation within the DAN for the control of spatial attention (attending left vs. right) and feature attention (attending red vs. green). These patterns of activity for spatial and feature attentional control showed limited overlap with each other within the DAN. Our findings thus support a model in which the DAN has different functional microstructures for distinctive forms of top-down control of visual attention.

Examination of Driver Visual and Cognitive Responses to Billboard Elicited Passive Distraction Using Eye-Fixation Related Potential

Distractions external to a vehicle contribute to visual attention diversion that may cause traffic accidents. As a low-cost and efficient advertising solution, billboards are widely installed on side of the road, especially the motorway. However, the effect of billboards on driver distraction, eye gaze, and cognition has not been fully investigated. This study utilises a customised driving simulator and synchronised electroencephalography (EEG) and eye tracking system to investigate the cognitive processes relating to the processing of driver visual information. A distinction is made between eye gaze fixations relating to stimuli that assist driving and others that may be a source of distraction. The study compares the driver’s cognitive responses to fixations on billboards with fixations on the vehicle dashboard. The measured eye-fixation related potential (EFRP) shows that the P1 components are similar; however, the subsequent N1 and P2 components differ. In addition, an EEG motor response is observed when the driver makes an adjustment of driving speed when prompted by speed limit signs. The experimental results demonstrate that the proposed measurement system is a valid tool in assessing driver cognition and suggests the cognitive level of engagement to the billboard is likely to be a precursor to driver distraction. The experimental results are compared with the human information processing model found in the literature.

The Struggle for Human Attention: Between the Abuse of Social Media and Digital Wellbeing

Human attention has become an object of study that defines both the design of interfaces and the production of emotions in a digital economy ecosystem. Guided by the control of users' attention, the consumption figures for digital environments, mainly social media, show that addictive use is associated with multiple psychological, social, and physical development problems. The study presented develops a theoretical proposal regarding attention. In the first part, the research analyzes how attention has been studied and how it behaves using three disciplines: neurophysiology, neuropsychology, and economics. In the second part, considering this general framework, the study uses categories of the three disciplines to explain the functioning of social media, with special emphasis on their interactive, attractive, and addictive design. Finally, the article presents, as a practical example of the exposed theory, the main results of two case studies that describe social media consumption among young people. The research shows the relevance of the theoretical study of attention as a key element by which to understand the logics that dominate the interactive design of social media. It also uses a multidisciplinary perspective. The addictive behaviors identified in the two examples support the theoretical proposals and open research lines oriented to the measurement and understanding of the attention given to social media.

Neural Correlate Differences in Number Sense Between Children With Low and Middle/High Socioeconomic Status

Although some cognitive studies provided reasons that children with low socioeconomic status (SES) showed poor mathematical achievements, there was no explicit evidence to directly explain the root of lagged performance in children with low SES. Therefore, the present study explored the differences in neural correlates in the process of symbolic magnitude comparison between children with different SESs by the event-related potentials (ERPs). A total of 16 second-graders from low-SES families and 16 from middle/high-SES families participated in this study. According to the results of anterior N1 (early attention) and P2 (extraction of numerical meaning) over the frontal region, the differences among children with different SESs were manifested as differences in general neural activities in terms of attention and top-down cognitive control. In the late stage of cognitive processing, there was no significant difference in the average amplitude of the late positive component (LPC) between children with different SES, indicating that low SES did not influence the information encoding and memory updating of numerical representation, which was responsible by the parietal lobe. The educational implications of this study are mentioned in the discussion.

Spatial attention modulates earliest visual processing: An electrical neuroimaging study

Several studies showed that shifting of visuospatial attention modulates sensory processing at multiple levels of the visual pathways and beyond, including the occipital striate cortices level. However, inconsistent findings have been reported thus leaving these issues still disputed. 21 participants took part to the present study (the EEG signals of 4 of them were discarded due to artifacts). We used ERPs and their neural sources to investigate whether shifting spatial attention in space across the horizontal meridian of the visual field affected striate cortices activation at the earliest latency. Time-series of scalp topographical maps indicated that, unlike ERPs to attentional-neutral central cues, ERPs to attention-directing local cues showed earliest polarity inversions as a function of stimulated field and processing latency range considered, at occipital-parietal electrodes. In between 60-75 ms, attentional shifting cues elicited a positivity for both visual fields, whereas at a later latency (75–90 ms) they elicited a positivity and a negativity for the upper and lower visual hemifields, respectively. Computed neural sources included striate, besides extrastriate, cortices for both visual hemifields and latency ranges. Conjointly, behavioral responses to targets were faster when they were preceded by local than by neutral cues, and when presented in the upper than the lower hemifield. Our findings support the hypothesis that attention shifts may affect early sensory processing in visual cortices.

Peripheral visual perception during natural overground dual-task walking in older and younger adults

Little is known about the neurophysiological processes underlying visual processing during active behavior and how these change over the life span. This study investigated early (P1) and later (P3) event-related potentials of the electroencephalogram associated with visual perception in older and younger adults while sitting, standing, and walking. While sitting and standing, accurate performance in both groups was not associated with event-related potential characteristics. During walking, in contrast, prolonged latencies and reduced amplitudes of the P1 were related to slower responses and increased misses, respectively. No covariations of behavior and P3 characteristics were observed. However, prolonged P3 latencies with increasing motor task complexity were present for both age groups, and reduced amplitudes while walking were replicated in younger participants. Older participants were more affected by walking in general as reflected in slower walking speeds as well as reduced accuracy and relative P1 amplitudes. These results provide further insights into cognitive-motor interference during natural walking in younger and older adults on early attentional-perceptual processing stages, even for simple additional visual tasks.

Gender Role, But Not Sex, Shapes Humans' Susceptibility to Emotion

It is unknown whether the famous sex-related difference in emotion processing is accounted for by biological sex, gender role, or their interaction. To clarify the issue, in Study 1 we recorded event-related potentials in response to negative and positive images of diverse intensities when 47 masculine (26 males) and 47 feminine (22 males) subjects performed a non-emotional task. The occipital P1 and N1 amplitudes were larger in women than in men, while feminine subjects showed larger N1 amplitudes than masculine subjects, regardless of sex. Moreover, feminine subjects showed enhanced frontocentral N2 (210-270 ms) amplitudes for highly and mildly negative than for neutral stimuli, while masculine subjects showed an emotion effect only for highly negative stimuli. The feminine-specific effect for mildly negative stimuli was positively correlated to the feminine score, and this correlation was located to the anterior cingulate and the superior and medial frontal gyri. Furthermore, feminine but not masculine subjects showed enhanced parietal P3 (330-560 ms) amplitudes for highly and mildly positive than for neutral stimuli, an effect positively related to the feminine score and localized to the precuneus, posterior cingulate, and superior temporal gyrus. Machine learning analyses verified that single-trial N2 and P3 amplitudes of feminine subjects reliably discriminated the intensity of negative and positive stimuli, respectively. For ecological considerations, in Study 2 we used an observational approach (n = 300) and confirmed that feminine gender role, rather than biological sex, predicted individual differences in daily experience of emotion-related psychopathological symptoms. These findings provide solid evidence for the critical impact of gender role rather than sex on emotional susceptibility.

Theta Oscillations Index Frontal Decision-Making and Mediate Reciprocal Frontal-Parietal Interactions in Willed Attention

Attention can be attracted reflexively by sensory signals, biased by learning or reward, or focused voluntarily based on momentary goals. When voluntary attention is focused by purely internal decision processes (will), rather than instructions via external cues, we call this "willed attention." In prior work, we reported ERP and fMRI correlates of willed spatial attention in trial-by-trial cuing tasks. Here we further investigated the oscillatory mechanisms of willed attention by contrasting the event-related EEG spectrogram between instructional and choice cues. Two experiments were conducted at 2 different sites using the same visuospatial attention paradigm. Consistent between the 2 experiments, we found increases in frontal theta power (starting at ~500 ms post cue) for willed attention relative to instructed attention. This frontal theta increase was accompanied by increased frontal-parietal theta-band coherence and bidirectional Granger causality. Additionally, the onset of attention-related posterior alpha power lateralization was delayed in willed attention relative to instructed attention, and the amount of delay was related to the timing of frontal theta increase. These results, replicated across 2 experiments, suggest that theta oscillations are the neuronal signals indexing decision-making in the frontal cortex, and mediating reciprocal communications between the frontal executive and parietal attentional control regions during willed attention.

Auditory attentional biases in young males with physical stature dissatisfaction

The attentional biases toward body-related information for individuals with weight concerns and eating disorders have been well documented. However, our knowledge of the attentional biases toward body-related information for subjects with physical stature concerns is only at the beginning. And the research on the auditory attentional biases for individuals with physical stature concerns is rare. The identification of attentional biases may provide an impetus for interventions to reduce distress among height dissatisfied individuals. Therefore, the present study investigated the neural mechanisms of attentional bias toward auditory physical stature-related words among height dissatisfied young males by using event-related potential recordings. Forty-four young male participants screened by Negative Physical Self Scale-Stature Concerns subscale (NPS-S) were assigned into an experimental group with high levels of height dissatisfaction (HHD) and a control group with low levels of height dissatisfaction (LHD). Task irrelevant auditory tall-related words, short-related words and neutral words were presented unilaterally to the participants as the cue in a cue-target paradigm. Participants were required to respond to the visual target preceded by the task-irrelevant auditory cue. The results found that significantly larger N2ac was elicited by tall-related words than short-related words and neutral words only for the HHD group, but not for the LHD group. LPCpc amplitudes did not differ significantly by the functions of word types and experimental groups. These results suggest an attentional orienting bias toward auditory tall-related words for young males with high levels of height dissatisfaction.

Age-related changes in the neural dynamics of bottom-up and top-down processing during visual object recognition: an electrophysiological investigation

When recognizing objects in our environments, we rely on both what we see and what we know. While older adults often display increased sensitivity to top-down influences of contextual information during object recognition, the locus of this increased sensitivity remains unresolved. To examine the effects of aging on the neural dynamics of bottom-up and top-down visual processing during rapid object recognition, we probed the differential effects of object perceptual ambiguity and scene context congruity on specific EEG event-related potential components indexing dissociable processes along the visual processing stream. Older adults displayed larger behavioral scene congruity effects than young adults. Older adults' larger visual P2 amplitudes to object perceptual ambiguity (as opposed to the scene congruity P2 effects in young adults) suggest continued resolution of perceptual ambiguity that interfered with scene congruity processing, while post-perceptual semantic integration (as indexed by N400) remained largely intact. These findings suggest that compromised bottom-up perceptual processing in healthy aging leads to an increased involvement of top-down processes to resolve greater perceptual ambiguity during object recognition.

Developmental maturation of inhibitory control circuitry in a high-risk sample: A longitudinal fMRI study

Background

The goal of this work was to characterize the maturation of inhibitory control brain function from childhood to early adulthood using longitudinal data collected in two cohorts.

Methods

Functional MRI during a go/no-go task was conducted in 290 participants, with 88 % undergoing repeated scanning at 1- to 2-year intervals. One group entered the study at age 7–13 years (n = 117); the other entered at age 18–23 years (n = 173). 33.1 % of the sample had two parents with a substance use disorder (SUD), 43.8 % had one parent with an SUD, and 23.1 % had no parents with an SUD. 1162 scans were completed, covering ages 7–28, with longitudinal data from the cohorts overlapping across ages 16–21. A marginal model with sandwich estimator standard errors was used to characterize voxel-wise age-related changes in hemodynamic response associated with successful inhibitory control.

Results

There was significant positive linear activation associated with age in the frontal, temporal, parietal, and occipital cortices. No clusters survived thresholding with negative linear, positive or negative quadratic, or positive or negative cubic contrasts.

Conclusions

These findings extend previous cross-sectional and small-scale longitudinal studies that have observed positive linear developmental trajectories of brain function during inhibitory control.

Neural Mechanisms of Attentional Control for Objects: Decoding EEG Alpha When Anticipating Faces, Scenes,and Tools

Attentional selection mechanisms in visual cortex involve changes in oscillatory activity in the EEG alpha band (8-12 Hz), with decreased alpha indicating focal cortical enhancement and increased alpha indicating suppression. This has been observed for spatial selective attention and attention to stimulus features such as color versus motion. We investigated whether attention to objects involves similar alpha-mediated changes in focal cortical excitability. In experiment 1, 20 volunteers (8 males; 12 females) were cued (80% predictive) on a trial-by-trial basis to different objects (faces, scenes, or tools). Support vector machine decoding of alpha power patterns revealed that late (>500 ms latency) in the cue-to-target foreperiod, only EEG alpha differed with the to-be-attended object category. In experiment 2, to eliminate the possibility that decoding of the physical features of cues led to our results, 25 participants (9 males; 16 females) performed a similar task where cues were nonpredictive of the object category. Alpha decoding was now only significant in the early (<200 ms) foreperiod. In experiment 3, to eliminate the possibility that task set differences between the different object categories led to our experiment 1 results, 12 participants (5 males; 7 females) performed a predictive cuing task where the discrimination task for different objects was identical across object categories. The results replicated experiment 1. Together, these findings support the hypothesis that the neural mechanisms of visual selective attention involve focal cortical changes in alpha power not only for simple spatial and feature attention, but also for high-level object attention in humans.SIGNIFICANCE STATEMENT Attention is the cognitive function that enables relevant information to be selected from sensory inputs so it can be processed in the support of goal-directed behavior. Visual attention is widely studied, yet the neural mechanisms underlying the selection of visual information remain unclear. Oscillatory EEG activity in the alpha range (8-12 Hz) of neural populations receptive to target visual stimuli may be part of the mechanism, because alpha is thought to reflect focal neural excitability. Here, we show that alpha-band activity, as measured by scalp EEG from human participants, varies with the specific category of object selected by attention. This finding supports the hypothesis that alpha-band activity is a fundamental component of the neural mechanisms of attention.