Theories of object-based attention suggest that attending to an object binds its features together. Yet, there is a growing body of work to suggest that the intention to grasp an object can alter the representation of features such that they are separately represented during different stages of motor planning and execution, whereas some object features such as shape and size might form integrated representations when afforded by motor control. However, it remains untested whether these features were integrated as an outcome of the requirements of grasping motor control, or due to attention towards the object in general. Therefore, here we investigated how task-relevancy modulates the integration of grasp-relevant object features. To this end, we recorded electroencephalography while human participants grasped or reached for objects that varied in their orientation and size. Using multivariate analyses, we found a superadditive integration of object orientation and size during action planning for grasping but not reaching. These integrated representations likely facilitated the calculation of stable grasp points as further evidenced by the representations of grasp-specific visual size and grip size emerging at similar times. Our results provide novel insights into the vital role of action intention on cognitive representations in the human brain.

Observable working-memory (WM) performance reflects multiple sources of error, including systematic distortions, unsystematic variability, and failures of item selection. Previous work using transsaccadic paradigms has identified separable dimensions of spatial WM error, but most paradigms provide limited access to retrieval and item-selection processes during recall. To address this limitation, the present study used a retrieval procedure requiring iterative selection among candidate memory items prior to spatial report, permitting direct measurement of item-selection error alongside traditional spatial error metrics. This design additionally allowed assessment of whether previously identified dimensions of WM error generalize across spatial and nonspatial representational domains. Neurotypical adults and individuals with ADHD completed colour and verbal WM tasks under fixational and transsaccadic conditions. We quantified systematic distortion, unsystematic variability, and item-selection error, and examined their covariance structure using principal component analysis (PCA). Unlike previous paradigms emphasizing direct spatial report, the present task yielded a single dominant component integrating spatial error and item-selection measures across verbal and colour conditions, whereas secondary components showed little cognitive relevance. Component scores were reliably disrupted by saccades but did not differ as a function of saccade direction or ADHD diagnosis. These findings suggest that the observable organization of WM performance depends partly on the retrieval and selection processes engaged during recall. Taken together, the results indicate that the latent structure of WM performance may be more context-sensitive and less domain-specific than previously assumed.

Seminal frameworks of predictive coding propose a hierarchy of generative modules, each attempting to infer the neural representation of the module one level below; the predictions are carried by top-down feedback projections, while the predictive error is propagated by reciprocal forward pathways. Such symmetric feedback connections support visual processing of noisy stimuli in computational models. However, neurophysiological studies have yielded evidence of asymmetric cortical feedback connections. We investigated the contribution of neural feedback in visual processing for computing grasp parameters, by utilizing convolutional neural network models that had been augmented with predictive feedback and were trained to compute grasp positions for real-world objects. After establishing an ameliorative effect of symmetric feedback on grasp detection performance when evaluated on noisy stimuli, we characterized the performance effects of asymmetric feedback, similar to that observed in the cortex. Specifically, we tested model variants extended with short-, medium-, long- and longer-range feedback connections (i) originating at the same source layer or (ii) terminating at the same target layer. We found that the performance-enhancing effect of predictive coding under adverse conditions was optimal for medium-range asymmetric feedback. Moreover, this effect was most prominent when medium-range feedback originated at a level of representational abstraction that was proximal to the input layer, in contrast to more distal layers. To conclude, our simulations show that introducing biologically realistic asymmetric predictive feedback improves model robustness to noisy visual stimuli in a neural network model optimized for grasp detection.

Recent research emphasizes how working memory (WM) supports action in dynamic environments. But action almost always involves fast, “saccadic” eye movements that challenge WM representations, requiring spatial remapping and distorting spatial perception, especially along the saccade direction. To capture the impact of these distortions, we used a spatial WM task where participants, after a saccade or fixation, indicated remembered locations of memory items with a mouse. From the responses we extracted multiple measures of spatial error: response variability, shifts relative to the fixation point, rotations, compression and nonlinear distortions of space. These measures submitted to a principal component analysis (PCA) yielded two components: systematic and unsystematic spatial error both of which were correlated with established WM tasks, showing their relevance for WM fidelity. Systematic error revealed a centripetal bias, pulling towards spatial anchors like the fixation point and the memory array’s centre of mass. This suggests that systematic error reflects a spatial scaffold that encodes relational information but is inherently imprecise. Saccades increased both error components and amplified WM load effects. Notably, we found that distortions of systematic error were especially pronounced along saccade direction for items that were remapped across visual fields, implying that WM fidelity is more vulnerable when information needs to pass through the corpus callosum. Together, our findings are consistent with the idea of WM actively reconstructing spatial information. They offer new insights into how saccades and spatial remapping shape WM in a dynamic world.

Recent research shows that the intention to act on an object alters its neural representation in ways as afforded by underlying sensorimotor processes. For example, the intention to grasp and pick up an object results in representations of the object's weight. But these representations become grasp-specific only immediately before object lift if weight information is relayed through object material. This feature triggers earlier representations regardless of intention probably because material-weight contingencies are overlearned. In contrast, recently learned weight cues should be recalled deliberately during grasp planning resulting in early grasp-specific representations. Here, we examined how action intentions affect the representation of newly acquired color-weight contingencies. We recorded electroencephalography while human participants grasped or reached for objects that varied in shape and density as indicated by their color. Multivariate analyses revealed a grasp-specific reactivation of color during planning that was mirrored in beta band. This suggests that task relevancy influences the representation of color such that previously encoded color-weight contingencies may be reactivated as required for grasping, mediated top-down via working memory. Grasp-specific representations of shape and color were also present in theta band, perhaps reflecting attentional activity. These results provide novel insights into the interplay between cognition and motor planning processes.

OBJECTIVES:In ADHD a common obstacle of academic success is impaired reading comprehension. Impaired comprehension in ADHD is accompanied by altered eye movements during reading as well as more general eye movement deficits associated with non-verbal stimuli. This suggests that the reading deficits do not cause the eye movement impairment. Instead, eye movements might contribute to reading comprehension difficulties. METHODS:We tested whether minimizing the need for eye movements during reading aids comprehension. We measured reading comprehension in a sample of undergraduate students with and without ADHD. Students read short paragraphs using normal text reading with all words fully visible (FULL), PACED reading that preserved text layout with one word at a time appearing at its usual location in the text, and reading with minimal eye movements in which one word at a time appeared in the center of the screen in a rapid serial visual presentation (RSVP). RESULTS:ADHD participants performed better in the RSVP condition relative to the other two reading conditions that required eye movements, and they benefited from the RSVP condition requiring minimal eye movements by almost 13% relative to neurotypical controls, who showed comprehension difficulties using the RSVP mode. CONCLUSIONS:Minimizing eye movement boosted reading comprehension in the ADHD suggesting that eye movements are implicated in reading processes in ADHD, an interference that can be avoided in the RSVP reading condition. Future work should explore the possibility of RSVP as a reading aid in ADHD adults and potentially school-aged children.

Theories of object-based attention suggest that attending to an object binds its features together. Yet, there is a growing body of work to suggest that the intention to grasp an object can alter the representation of features such that they are separately represented during different stages of motor planning and execution, whereas some object features such as shape and size might form integrated representations when afforded by motor control. However, it remains untested whether these features were integrated as an outcome of the requirements of grasping motor control, or due to attention towards the object in general. Therefore, here we investigated how task-relevancy modulates the integration of grasp-relevant object features. To this end, we recorded electroencephalography while human participants grasped or reached for objects that varied in their orientation and size. Using multivariate analyses, we found a superadditive integration of object orientation and size during action planning for grasping but not reaching. These integrated representations likely facilitated the calculation of stable grasp points as further evidenced by the representations of grasp-specific visual size and grip size emerging at similar times. Our results provide novel insights into the vital role of action intention on cognitive representations in the human brain. ### Competing Interest Statement The authors have declared no competing interest. Natural Sciences and Engineering Research Council of Canada, , RGPIN-2020-06018

Major evidence for a right-hemisphere dominance of the brain in spatial and/or attentional tasks comes from lesion studies in patients with spatial neglect. However, the neuroanatomy of the different forms of neglect remains a matter of debate, and it remains unclear how dysfunctions in neglect relate to intact processes. In the healthy brain, perceptual pseudoneglect is the equivalent of neglect as observed in paradigms such as the line bisection task. Therefore, the current study investigated the intact functional anatomy of perceptual pseudoneglect using a meta-analysis to compensate for some of the limitations of individual imaging studies. We collated the data from 24 articles that tested 952 participants with a range of paradigms (landmark task, line bisection, grating-scales task, and number line task) obtaining 337 foci. Using Activation Likelihood Estimation (ALE) we identified a right-hemisphere biased network of cortical areas, including superior and intraparietal regions, the intraoccipital sulcus together with other occipital regions, as well as inferior frontal areas that were associated with perceptual pseudoneglect in partial agreement with lesion studies in patients with neglect. The present results are consistent with a framework of neural computations that explains the neural and behavioural asymmetries of perceptual pseudoneglect as due the need for to an integrated representation of spatial information during perceptual judgments. ### Competing Interest Statement The authors have declared no competing interest.

The primate visual system is organized into dorsal and ventral pathways, classically linked to visuomotor control and perception. A long-standing question is whether this division reflects intrinsic architectural priors or emerges from task demands. We trained a single convolutional network to perform classification and grasp prediction of 3D objects, without imposing modular structure. Dual-stream topology - functionally distinct visuomotor and perceptual pathways - emerged spontaneously with rich cross-communication. Shapley value analyses revealed that action- and perception-selective features developed progressively across depth, reflecting task-driven hierarchical specialization. Time-resolved EEG showed that model activity mapped onto dissociable temporal components in human cortex: ventral-aligned signals emerged early and late, where dorsal- and ventral-aligned responses coincided in the intervening interval. These results demonstrate that task optimization alone can explain core features of dorsal-ventral organization, and that distinct temporal roles for perception and action arise naturally atop a shared feedforward scaffold, without requiring architectural hard-coding or recurrence. ### Competing Interest Statement The authors have declared no competing interest. Natural Sciences and Engineering Research Council, https://ror.org/01h531d29, RGPIN-2020-06018

Major evidence for a right-hemisphere dominance of the brain in spatial and/or attentional tasks comes from lesion studies in patients with spatial neglect. However, the neuroanatomy of the different forms of neglect remains a matter of debate, and it remains unclear how dysfunctions in neglect relate to intact processes. In the healthy brain, perceptual pseudoneglect has been considered to be a phenomenon complementary to specific subtypes of neglect as observed in paradigms such as the line bisection task. Therefore, the current study investigated the intact functional anatomy of perceptual pseudoneglect using a meta-analysis to compensate for some of the limitations of individual imaging studies. We collated the data from 24 articles that tested 952 participants with a range of paradigms (landmark task, line bisection, grating-scales task, and number line task) obtaining 337 foci. Using Activation Likelihood Estimation (ALE) we identified a right-hemisphere biased network of cortical areas, including superior and intraparietal regions, the intraoccipital sulcus together with other occipital regions, as well as inferior frontal areas that were associated with perceptual pseudoneglect in partial agreement with lesion studies in patients with neglect. Our study is the first meta-analysis on the mechanisms underlying perceptual judgments which have been shown to give rise to perceptual pseudoneglect.

Attention-deficit/hyperactivity disorder (ADHD) is typically characterized by executive dysfunction, yet emerging evidence points to spatially asymmetrical features of cognition. We examined whether transsaccadic working memory (tWM), the mechanism that integrates visual and motor signals across eye movements, shows directional vulnerability in ADHD. Participants with ADHD completed a spatial tWM task in which memory arrays (one or three items) were presented before leftward, rightward, or fixation trials, and repositioned a probe to the remembered target location. For comparison, data from a previously tested neurotypical sample were included in group-level analyses. Errors were decomposed into systematic and unsystematic components. Compared to controls, ADHD participants showed a modest but reliable rightward-saccade disadvantage, with greater systematic distortions after rightward than leftward eye movements. Saccades disrupted working memory in both groups, but the typical load-dependent increase in unsystematic error observed in neurotypical participants was absent in ADHD. Two complementary interpretations may account for this asymmetry. The integration-imbalance hypothesis attributes it to weakened right-hemisphere contributions to spatial working memory, which impair integration of left-hemisphere oculomotor and right-hemisphere spatial signals during rightward saccades. Alternatively, the anchoring-disruption hypothesis suggests that rightward eye movements destabilize the spatial scaffold anchoring remembered locations, producing geometric distortions without increased error. Together, these findings identify a direction-specific fragility of visuomotor-cognitive coupling in ADHD not explained by general capacity limits. More broadly, they reveal a partial neglect-like pattern of transsaccadic vulnerability: selective impairment for rightward saccades without a left-field deficit—highlighting the utility of oculomotor paradigms for revealing hidden spatial asymmetries in neurocognitive function.

The intention to act influences the computations of various task-relevant features. However, little is known about the time course of these computations. Furthermore, it is commonly held that these computations are governed by conjunctive neural representations of the features. But, support for this view comes from paradigms arbitrarily combining task features and affordances, thus requiring representations in working memory. Therefore, the present study used electroencephalography and a well-rehearsed task with features that afford minimal working memory representations to investigate the temporal evolution of feature representations and their potential integration in the brain. Female and male human participants grasped objects or touched them with a knuckle. Objects had different shapes and were made of heavy or light materials with shape and weight being relevant for grasping, not for “knuckling.” Using multivariate analysis showed that representations of object shape were similar for grasping and knuckling. However, only for grasping did early shape representations reactivate at later phases of grasp planning, suggesting that sensorimotor control signals feed back to the early visual cortex. Grasp-specific representations of material/weight only arose during grasp execution after object contact during the load phase. A trend for integrated representations of shape and material also became grasp-specific but only briefly during the movement onset. These results suggest that the brain generates action-specific representations of relevant features as required for the different subcomponents of its action computations. Our results argue against the view that goal-directed actions inevitably join all features of a task into a sustained and unified neural representation.

The simple act of viewing and grasping an object involves complex sensorimotor control mechanisms that have been shown to vary as a function of multiple object and other task features such as object size, shape, weight, and wrist orientation. However, these features have been mostly studied in isolation. In contrast, given the nonlinearity of motor control, its computations require multiple features to be incorporated concurrently. Therefore, the present study tested the hypothesis that grasp computations integrate multiple task features superadditively in particular when these features are relevant for the same action phase. We asked male and female human participants to reach-to-grasp objects of different shapes and sizes with different wrist orientations. Also, we delayed the movement onset using auditory signals to specify which effector to use. Using electroencephalography and representative dissimilarity analysis to map the time course of cortical activity, we found that grasp computations formed superadditive integrated representations of grasp features during different planning phases of grasping. Shape-by-size representations and size-by-orientation representations occurred before and after effector specification, respectively, and could not be explained by single-feature models. These observations are consistent with the brain performing different preparatory, phase-specific computations; visual object analysis to identify grasp points at abstract visual levels; and downstream sensorimotor preparatory computations for reach-to-grasp trajectories. Our results suggest the brain adheres to the needs of nonlinear motor control for integration. Furthermore, they show that examining the superadditive influence of integrated representations can serve as a novel lens to map the computations underlying sensorimotor control.

Recent research shows that the intention to act on an object alters its neural representation in ways as afforded by underlying sensorimotor processes. For example, the intention to grasp and pick up an object results in representations of the object`s weight. But these representations become grasp-specific only immediately before object lift if weight information is relayed through object material. This feature triggers earlier representations regardless of intention probably because material-weight contingencies are overlearned. By contrast, recently learned weight cues should be recalled deliberately during grasp planning resulting in early grasp-specific representations. Here, we examined how action intentions affect the representation of newly acquired colour-weight contingencies. We recorded electroencephalography while human participants grasped or reached for objects that varied in shape and density as indicated by their colour. Multivariate analyses revealed a grasp-specific reactivation of colour during planning that was mirrored in beta band. This suggests that task-relevancy influences the representation of colour such that previously encoded colour-weight contingencies may be reactivated as required for grasping, mediated top-down via working memory. Grasp-specific representations of shape and colour were also present in theta band, perhaps reflecting attentional activity. These results provide novel insights into the interplay between cognition and motor planning processes. ### Competing Interest Statement The authors have declared no competing interest.

Impaired reading comprehension is a common complaint in ADHD that is accompanied by altered eye movement patterns. Here we tested whether minimizing the need for eye movements during reading aids comprehension. We measured reading comprehension in a sample of undergraduate students with and without ADHD using normal text reading with all words fully visible (FULL), PACED reading that preserved text layout with one word at a time appearing at its usual location in the text, and reading with minimal eye movements in which one word at a time appeared in the center of the screen in a rapid serial visual presentation (RSVP). ADHD participants benefited from RSVP by almost 13% relative to neurotypical controls, who showed comprehension difficulties using the RSVP mode. Minimizing eye movement boosted reading comprehension in the ADHD adults. Our results suggest that eye movements can be disruptive to cognitive processes in ADHD. Future work should explore the possibility of RSVP as a reading aid in ADHD.

We recently showed that the functional brain network (FBN) for saccades shows increased integration, segregation, and synchronization (Ghaderi et al. Cerebral Cortex 2022). However, the influence of saccades on FBN modularity, remains unclear. We hypothesized that when saccades reverse the visual field of an attended object, processes related to spatial updating would increase communication between FBN modules in two hemispheres. 64-channel EEG was recorded in two conditions (N=18). In the fixation condition, participants fixated to the left/right of centre while a reference stimulus (three horizontal/vertical lines, 10°×10° located 5° below the fixation-point, repeated 1-3 times) appeared, followed by a target stimulus (same type/location, opposite orientation). Participants judged the duration of the reference and target stimuli, requiring them to retain information from the stimulus train (Ghaderi et al. Heliyon 2021). The saccade condition was the same, except that 100ms before target presentation, participants were cued to re-fixate the opposite horizontal side, reversing the visual field of the presaccadic stimulus train. We extracted 250ms EEGs in the perisaccadic and corresponding fixation intervals. After preprocessing, we calculated lagged coherence between EEG source localized current densities in 84 Brodmann areas. Unsupervised extraction, followed by a supervised modularity analysis revealed four FBN modules in fixation: a bilateral fronto-parietal network (likely corresponding to the dorsal attention network) and three more lateralized networks (likely corresponding to visual, default mode, and cognitive control networks). In the saccade condition, the dorsal network extended bilaterally from occipital to frontal cortex, subsuming more ventral cortical nodes, but otherwise retained the same degree of modularity. Conversely, FDR showed a significant decrease in visual and control networks modularity (alpha band) and increase in the default network modularity (beta band). These results suggest saccades have a widespread impact on FBN modularity and increase bilateral communication of correlated signals, likely supporting trans-saccadic perception and integration.

Every waking second, we make three saccadic eye movements that move our retinal images. Thus, to attain a coherent image of the world we need to remember visuo-spatial information across saccades. But transsaccadic working memory (tWM) remains poorly understood. Crucially, there has been a debate whether there are any differences in tWM for the left vs. right visual field and depending on saccade direction. However, previous studies have probed tWM with minimal loads whereas spatial differences might arise with higher loads. Here we employed a task that probed higher memory load for spatial information in the left and right visual field and with horizontal as well as vertical saccades. We captured several measures of precision and accuracy of performance that, when submitted to principal component analysis, produced two components. Component 1, mainly associated with precision, yielded greater error for the left than the right visual field. Component 2 was associated with performance accuracy and unexpectedly produced a disadvantage after rightward saccades. Both components showed that performance was worse when rightward or leftward saccades afforded a shift of memory representations between visual fields compared to remapping within the same field. Our study offers several novel findings. It is the first to show that tWM involves at least two components likely reflecting working memory capacity and strategic aspects of working memory, respectively. Reduced capacity for the left, rather than the right visual field is consistent with how the left and right visual fields are known to be represented in the two hemispheres. Remapping difficulties between visual fields is consistent with the limited information transfer across the corpus callosum. Finally, the impact of rightward saccades on working memory might be due to greater interference of the accompanying shifts of attention. Our results highlight the dynamic nature of transsaccadic working memory.

Parietal and frontal cortex are involved in saccade generation, but their output signals also modify visual signals throughout cortex. These signals produce well-documented behavioral phenomena (saccades, saccadic suppression, various perisaccadic perceptual distortions) but their underlying influence on cortical network dynamics is not known. Here, we combined electroencephalography (EEG) with frequency-dependent source localization and graph theory analysis (GTA) to understand how saccades and pre-saccadic visual stimuli interactively alter cortical network dynamics in humans. 21 participants viewed series of 1-3 vertical or horizontal grids, followed by grid with the opposite orientation just before a horizontal saccade or continued fixation. EEG signals from the presaccadic interval (cue + 200ms, or equivalent fixation period) were used for source localization. Source localization (saccade – fixation) identified bilateral dorsomedial frontoparietal activity across frequency bands, whereas stimulus repetition produced band-specific modulations in left prefrontal, posterior parietal, and central-superior frontal and/or parietal cortex, with significant saccade-repetition interactions in frontal and parietal regions. GTA analysis revealed a saccade-specific functional network with major hubs in inferior parietal cortex (alpha) and the frontal eye fields (beta), and major saccade-repetition interactions in left prefrontal (theta) and supramarginal gyrus (gamma). Overall, quantitative measures of whole-brain network topology and dynamics (segregation, integration, synchronization, complexity) were enhanced during the presaccadic interval, but repetition interactions reduced synchronization and complexity. These results show that presaccadic signals have widespread, coherent influence on cortical network dynamics, likely responsible for both saccade production and the perceptual phenomena associated with saccades. Highlights Source localization & graph theory were used to analyze presaccadic EEG signals Presaccadic signals produced band-specific modulations/hubs in parietofrontal cortex Frontal/parietal eye fields showed extensive functional connectivity across all lobes Presaccadic stimulus repetition further modulated functional network connectivity Saccades and repetition both influenced network clustering, integration, & complexity