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ObjectivesInconsistencies in the literature make it difficult to outline the relationship between exercise and cognition in young adults. Our aim is to better understand the relationship between prolonged aerobic and resistance exercise and cognitive abilities in sedentary young adults, and how this relationship is mediated by changes in cardiovascular fitness.MethodsTwenty-three volunteers were recruited and assigned to two groups to complete one hour of continuous daily workout sessions of aerobic (SPIN) and anaerobic (SCSW) exercises over a 30 day period. Each subject was provided with a Polar-10 wearable to record the heart rate (HR) activity during the workout sessions. The workout sessions were completed during five consecutive days over four consecutive weeks. Each week, HR data were collected from the last workout session. Volunteers also completed a neurocognitive test battery (Cambridge Brain Sciences, CBS) each exercise session, including an additional baseline measure before exercise regime began.ResultsWe found that memory, reasoning and verbal abilities improved throughout the aerobic, but not the resistance exercise program. We found a positive correlation between heart rate index (HRI) and memory and reasoning test scores. We also found a negative correlation between reasoning ability and HRM (heart rate mean), and heart rate skewness (SKW). The results of a regression model to predict memory and reasoning abiltiies revealed that memory was best predicted by HRI and HRM, while the reasoning ability was best predicted by only HRI.ConclusionRegular aerobic exercises improved specific cognitive performance and it was possible to predict the performance by employing the HR parameters HRI and HRM.

Objective: We investigated the long-term cognitive effects of concussion in 19,261 members of the general population and a cohort of varsity American football players with a history of frequent head impacts, using tests that are known to be sensitive to small changes in performance. Methods: We asked 19,261 participants to complete a demographic questionnaire and 12 cognitive tests measuring aspects of executive function, including inhibitory control. We compared the performance of those reporting a history of concussion (post-concussion) to those reporting no history of concussion (non-concussed) on the cognitive battery and four non-cognitive variables. We used the results of this population-level study to predict the profile of cognitive performance in varsity American football players, who completed the same cognitive tasks. Results: Post-concussion and non-concussed participants did not differ on 11 of the 12 cognitive tasks employed. However, on a test of inhibitory control based on the classic Stroop paradigm, post-concussion participants showed accuracy-related impairments specific to the incongruent conditions of the task. Post-concussion participants reported higher levels of anxiety, depression, and trouble concentrating. An entirely independent sample of 74 varsity American football players demonstrated the same pattern of impairment: compared to healthy controls, they scored significantly lower on the test of inhibitory control but were indistinguishable from controls on the 11 other tasks. Interpretation: Self-reported concussion is not associated with long-term general effects on cognitive function. Nevertheless, those who report at least one concussion and those who expose themselves to long-term frequent sport-related head impacts do have a modest, but statistically robust, deficit of inhibitory control.

Sensory processing abilities are highly variable within and across people diagnosed with autism spectrum disorder (ASD) and attention-deficit/hyperactivity disorder (ADHD). This study examined the transdiagnostic nature of sensory processing abilities, and their association with features of ASD and ADHD, in a large sample of autistic people (n = 495) and people with ADHD (n = 461). Five similar data-driven sensory phenotypes characterized sensory processing abilities, and showed similar patterns of association with features of ASD and ADHD, across both diagnostic groups. These results demonstrate the transdiagnostic nature of sensory processing abilities, while contributing to a growing body of literature that suggests the ASD and ADHD diagnostic labels have poor explanatory power.

An outstanding issue in cognitive neuroscience concerns how the brain is organized across different conditions. For instance, during the resting-state condition, the brain can be clustered into reliable and reproducible networks (e.g., sensory, default, executive networks). Interestingly, the same networks emerge during active conditions in response to various tasks. If similar patterns of neural activity have been found across diverse conditions, and therefore, different underlying processes and experiences of the environment, is the brain organized by a fundamental organizational principle? To test this, we applied mathematical formalisms borrowed from quantum mechanisms to model electroencephalogram (EEG) data. We uncovered a tendency for EEG signals to be localized in anterior regions of the brain during “rest”, and more uniformly distributed while engaged in a task (i.e., watching a movie). Moreover, we found analogous values to the Heisenberg uncertainty principle, suggesting a common underlying architecture of human brain activity in resting and task conditions. This underlying architecture manifests itself in the novel constant KBrain, which is extracted from the brain state with the least uncertainty. We would like to state that we are using the mathematics of quantum mechanics, but not claiming that the brain behaves as a quantum object.

Improvements in behavior are known to be accompanied by both structural and functional changes in the brain. However, whether those changes lead to more general improvements, beyond the behavior being trained, remains a contentious issue. We investigated whether training on one of two cognitive tasks would lead to either near transfer (that is, improvements on a quantifiably similar task) or far transfer (that is, improvements on a quantifiably different task), and furthermore, if such changes did occur, what the underlying neural mechanisms might be. Healthy adults (n = 16, 15 females) trained on either a verbal inhibitory control task or a visuospatial working memory task for 4 weeks, over the course of which they received five diffusion tensor imaging scans. Two additional tasks served as measures of near and far transfer. Behaviorally, participants improved on the task that they trained on, but did not improve on cognitively similar tests (near transfer), nor cognitively dissimilar tests (far transfer). Extensive changes to white matter microstructure were observed, with verbal inhibitory control training leading to changes in a left‐lateralized network of frontotemporal and occipitofrontal tracts, and visuospatial working memory training leading to changes in right‐lateralized frontoparietal tracts. Very little overlap was observed in changes between the two training groups. On the basis of these results, we suggest that near and far transfer were not observed because the changes in white matter tracts associated with training on each task are almost entirely nonoverlapping with, and therefore afford no advantages for, the untrained tasks., We investigated whether training on one of two cognitive tasks would lead to either near or far transfer, and furthermore, if such changes did occur, what the underlying neural mechanisms might be. Healthy adults trained on either a verbal inhibitory control task or a visuospatial working memory task for four weeks, over the course of which they received five diffusion tensor imaging scans. Behavioral transfer was not observed and changes in white matter tracts associated with training on each task were almost entirely nonoverlapping, providing no advantages for the untrained tasks.

Humans have structures dedicated to the processing of faces, which include cortical components (e.g., areas in occipital and temporal lobes) and subcortical components (e.g., superior colliculus and amygdala). Although faces are processed more quickly than stimuli from other categories, there is a lack of consensus regarding whether subcortical structures are responsible for rapid face processing. In order to probe this, we exploited the asymmetry in the strength of projections to subcortical structures between the nasal and temporal hemiretina. Participants detected faces from unrecognizable control stimuli and performed the same task for houses. In Experiments 1 and 3, at the fastest reaction times, participants detected faces more accurately than houses. However, there was no benefit of presenting to the subcortical pathway. In Experiment 2, we probed the coarseness of the rapid pathway, making the foil stimuli more similar to faces and houses. This eliminated the rapid detection advantage, suggesting that rapid face processing is limited to coarse representations. In Experiment 4, we sought to determine whether the natural difference between spatial frequencies of faces and houses were driving the effects seen in Experiments 1 and 3. We spatially filtered the faces and houses so that they were matched. Better rapid detection was again found for faces relative to houses, but we found no benefit of preferentially presenting to the subcortical pathway. Taken together, the results of our experiments suggest a coarse rapid detection mechanism, which was not dependent on spatial frequency, with no advantage for presenting preferentially to subcortical structures. Electronic supplementary material The online version of this article (10.3758/s13414-019-01877-3) contains supplementary material, which is available to authorized users.

Background Atypical reactions to the sensory environment are often reported in autistic individuals, with a high degree of variability across the sensory modalities. These sensory differences have been shown to promote challenging behaviours and distress in autistic individuals and are predictive of other functions including motor, social, and cognitive abilities. Preliminary research suggests that specific sensory differences may cluster together within individuals creating discrete sensory phenotypes. However, the manner in which these sensory differences cluster, and whether the resulting phenotypes are associated with specific cognitive and social challenges is unclear. Methods Short sensory profile data from 599 autistic children and adults between the ages of 1 and 21 years were subjected to a K-means cluster analysis. Analysis of variances compared age, adaptive behaviour, and traits associated with autism, attention-deficit and hyperactivity disorder, and obsessive and compulsive disorder across the resultant clusters. Results A five-cluster model was found to minimize error variance and produce five sensory phenotypes: (1) sensory adaptive, (2) generalized sensory differences, (3) taste and smell sensitivity, (4) under-responsive and sensation seeking, and (5) movement difficulties with low energy. Age, adaptive behaviour, and traits associated with autism, attention-deficit and hyperactivity disorder, and obsessive and compulsive disorder were found to differ significantly across the five phenotypes. Limitations The results were based on parent-report measures of sensory processing, adaptive behaviour, traits associated with autism, attention-deficit and hyperactivity disorder, and obsessive and compulsive disorder, which may limit the generalizability of the findings. Further, not all measures are standardized, or psychometrically validated with an autism population. Autistic individuals with an intellectual disability were underrepresented in this sample. Further, as these data were obtained from established records from a large provincial database, not all measures were completed for all individuals. Conclusions These findings suggest that sensory difficulties in autistic individuals can be clustered into sensory phenotypes, and that these phenotypes are associated with behavioural differences. Given the large degree of heterogeneity in sensory difficulties seen in the autistic population, these sensory phenotypes represent an effective way to parse that heterogeneity and create phenotypes that may aid in the development of effective treatments and interventions for sensory difficulties.

An outstanding issue in cognitive neuroscience concerns how the brain is organized across different conditions. For instance, during the resting-state condition, the brain can be clustered into reliable and reproducible networks (e.g., sensory, default, executive networks). Interestingly, the same networks emerge during active conditions in response to various tasks. If similar patterns of neural activity have been found across diverse conditions, and therefore, different underlying processes and experiences of the environment, is the brain organized by a fundamental organizational principle? To test this, we applied principles of quantum mechanisms to model electroencephalogram (EEG) data. We uncovered a tendency for EEG signals to be localized in anterior regions of the brain during “rest”, and more uniformly distributed while engaged in a task (i.e., watching a movie). Moreover, we found analogous values to the Heisenberg uncertainty principle, suggesting a common underlying architecture of human brain activity in resting and task conditions. This underlying architecture manifests itself in the novel constant KBrain, which is extracted from the brain state with the least uncertainty. We would like to state that we are using the mathematics of quantum mechanics, but not claiming that the brain behaves as a quantum object.

The foundational tenet of brain training is that general cognitive functioning can be enhanced by completing computerized games, a notion that is both intuitive and appealing. Moreover, there is strong incentive to improve our cognitive abilities, so much so that it has driven a billion-dollar industry. However, whether brain training can really produce these desired outcomes continues to be debated. This is, in part, because the literature is replete with studies that use ill-defined criteria for establishing transferable improvements to cognition, often using single training and outcome measures with small samples. To overcome these limitations, we conducted a large-scale online study to examine whether practices and beliefs about brain training are associated with better cognition. We recruited a diverse sample of over 1000 participants, who had been using an assortment of brain training programs for up to 5 years. Cognition was assessed using multiple tests that measure attention, reasoning, working memory and planning. We found no association between any measure of cognitive functioning and whether participants were currently "brain training" or not, even for the most committed brain trainers. Duration of brain training also showed no relationship with any cognitive performance measure. This result was the same regardless of participant age, which brain training program they used, or whether they expected brain training to work. Our results pose a significant challenge for "brain training" programs that purport to improve general cognitive functioning among the general population. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Whether acquiring a second language affords any general advantages to executive function has been a matter of fierce scientific debate for decades. If being bilingual does have benefits over and above the broader social, employment, and lifestyle gains that are available to speakers of a second language, then it should manifest as a cognitive advantage in the general population of bilinguals. We assessed 11,041 participants on a broad battery of 12 executive tasks whose functional and neural properties have been well described. Bilinguals showed an advantage over monolinguals on only one test (whereas monolinguals performed better on four tests), and these effects all disappeared when the groups were matched to remove potentially confounding factors. In any case, the size of the positive bilingual effect in the unmatched groups was so small that it would likely have a negligible impact on the cognitive performance of any individual.

Children who have been diagnosed with autism spectrum disorder (ASD) often show a marked deficit in measures of social cognition. In autistic adults, measures of social cognition have been shown to relate to differences in brain synchronization (as measured by fMRI) when individuals are processing naturalistic stimuli, such as movies. However, whether children with social impairments, with or without a diagnosis of ASD, differ in their neural responses to movies has not yet been investigated. In the current study, neural synchrony, measured using fMRI, was examined in three groups of children aged 7 to 12, who differed with respect to scores on a measure of autistic traits associated with social impairment and whether or not they had been diagnosed with ASD. While watching the movie ‘Despicable Me’, those diagnosed with ASD had significantly less neural synchrony in areas that have been previously shown to be associated with social cognition (e.g. areas related to ‘theory of mind’), and plot following (e.g. the lateral prefrontal cortex), than those who did not have an ASD diagnosis. In contrast, two groups who differed in their degree of social impairment, but did not have a diagnosis of ASD, showed no significant differences in neural synchrony across the whole brain. These results shed some light on how autistic traits may contribute to an individual’s conscious experience of the world, and how, for children with ASD, that experience may differ markedly from that of those without ASD.

Identifying what an object is, and whether an object has been encountered before, is a crucial aspect of human behavior. Despite this importance, we do not yet have a complete understanding of the neural basis of these abilities. Investigations into the neural organization of human object representations have revealed category specific organization in the ventral visual stream in perceptual tasks. Interestingly, these categories fall within broader domains of organization, with reported distinctions between animate, inanimate large, and inanimate small objects. While there is some evidence for category specific effects in the medial temporal lobe (MTL), in particular in perirhinal and parahippocampal cortex, it is currently unclear whether domain level organization is also present across these structures. To this end, we used fMRI with a continuous recognition memory task. Stimuli were images of objects from several different categories, which were either animate or inanimate, or large or small within the inanimate domain. We employed representational similarity analysis (RSA) to test the hypothesis that object-evoked responses in MTL structures during recognition-memory judgments also show evidence for domain-level organization along both dimensions. Our data support this hypothesis. Specifically, object representations were shaped by either animacy, real-world size, or both, in perirhinal and parahippocampal cortex, and the hippocampus. While sensitivity to these dimensions differed across structures when probed individually, hinting at interesting links to functional differentiation, similarities in organization across MTL structures were more prominent overall. These results argue for continuity in the organization of object representations in the ventral visual stream and the MTL.

Highlights • Neural synchrony during movie watching was measured in children with and without ASD. • The ASD group had significantly less neural synchrony across the whole brain. • The ASD group also had significantly less synchrony in the theory of mind network. • Autistic traits did not predict neural synchrony in non-ASD children. • These results suggest children with ASD process movies in a unique way., Children who have been diagnosed with autism spectrum disorder (ASD) often show a marked deficit in measures of social cognition. In autistic adults, measures of social cognition have been shown to relate to differences in brain synchronization (as measured by fMRI) when individuals are processing naturalistic stimuli, such as movies. However, whether children who differ in their degree of autistic traits, with or without a diagnosis of ASD, differ in their neural responses to movies has not yet been investigated. In the current study, neural synchrony, measured using fMRI, was examined in three groups of children aged 7 to 12, who differed with respect to scores on a measure of autistic traits associated with social impairment and whether or not they had been diagnosed with ASD. While watching the movie ‘Despicable Me’, those diagnosed with ASD had significantly less neural synchrony in areas that have been previously shown to be associated with social cognition (e.g. areas related to ‘theory of mind’), and plot following (e.g. the lateral prefrontal cortex), than those who did not have an ASD diagnosis. In contrast, two groups who differed in their degree of autistic traits, but did not have a diagnosis of ASD, showed no significant differences in neural synchrony across the whole brain. These results shed some light on how autistic traits may contribute to an individual’s conscious experience of the world, and how, for children with ASD, that experience may differ markedly from that of those without ASD.

We rely upon visual short-term memory (VSTM) for continued access to perceptual information that is no longer available. Despite the complexity of our visual environments, the majority of research on VSTM has focused on memory for lower-level perceptual features. Using more naturalistic stimuli, it has been found that recognizable objects are remembered better than unrecognizable objects. What remains unclear, however, is how semantic information changes brain representations in order to facilitate this improvement in VSTM for real-world objects. To address this question, we used a continuous report paradigm to assess VSTM (precision and guessing rate) while participants underwent functional magnetic resonance imaging (fMRI) to measure the underlying neural representation of 96 objects from 4 animate and 4 inanimate categories. To isolate semantic content, we used a novel image generation method that parametrically warps images until they are no longer recognizable while preserving basic visual properties. We found that intact objects were remembered with greater precision and a lower guessing rate than unrecognizable objects (this also emerged when objects were grouped by category and animacy). Representational similarity analysis of the ventral visual stream found evidence of category and animacy information in anterior visual areas during encoding only, but not during maintenance. These results suggest that the effect of semantic information during encoding in ventral visual areas boosts visual short-term memory for real-world objects.

We investigated the long-term cognitive effects of concussion in 19,261 members of the general population and a cohort of varsity American football players with a history of frequent head impacts, using tests that are known to be sensitive to small changes in performance.We asked 19,261 participants to complete a demographic questionnaire and 12 cognitive tests measuring aspects of executive function, including inhibitory control. We compared the performance of those reporting a history of concussion (post-concussion) to those reporting no history of concussion (non-concussed) on the cognitive battery and four non-cognitive variables. We used the results of this population-level study to predict the profile of cognitive performance in varsity American football players, who completed the same cognitive tasks.Post-concussion and non-concussed participants did not differ on 11 of the 12 cognitive tasks employed. However, on a test of inhibitory control based on the classic Stroop paradigm, post-concussion participants showed accuracy-related impairments specific to the incongruent conditions of the task. Post-concussion participants reported higher levels of anxiety, depression, and trouble concentrating. An entirely independent sample of 74 varsity American football players demonstrated the same pattern of impairment: compared to healthy controls, they scored significantly lower on the test of inhibitory control but were indistinguishable from controls on the 11 other tasks.Self-reported concussion is not associated with long-term general effects on cognitive function. Nevertheless, those who report at least one concussion and those who expose themselves to long-term frequent sport-related head impacts do have a modest, but statistically robust, deficit of inhibitory control.

ObjectiveWe investigated the long-term cognitive effects of concussion in 19,261 members of the general population and a cohort of varsity American football players with a history of frequent head impacts, using tests that are known to be sensitive to small changes in performance. MethodsWe asked 19,261 participants to complete a demographic questionnaire and 12 cognitive tests measuring aspects of executive function, including inhibitory control. We compared the performance of those reporting a history of concussion (post-concussion) to those reporting no history of concussion (non-concussed) on the cognitive battery and four non-cognitive variables. We used the results of this population-level study to predict the profile of cognitive performance in varsity American football players, who completed the same cognitive tasks. ResultsPost-concussion and non-concussed participants did not differ on 11 of the 12 cognitive tasks employed. However, on a test of inhibitory control based on the classic Stroop paradigm, post-concussion participants showed accuracy-related impairments specific to the incongruent conditions of the task. Post-concussion participants reported higher levels of anxiety, depression, and trouble concentrating. An entirely independent sample of 74 varsity American football players demonstrated the same pattern of impairment: compared to healthy controls, they scored significantly lower on the test of inhibitory control but were indistinguishable from controls on the 11 other tasks.InterpretationSelf-reported concussion is not associated with long-term general effects on cognitive function. Nevertheless, those who report at least one concussion and those who expose themselves to long-term frequent sport-related head impacts, do have a modest, but statistically robust, deficit of inhibitory control.

The Late Positive Complex (LPC) is an Event-Related Potential (ERP) consistently observed in recognition-memory paradigms. In the present study, we investigated whether the LPC tracks the strength of multiple types of memory signals, and whether it does so in a decision dependent manner. For this purpose, we employed judgements of cumulative lifetime exposure to object concepts, and judgements of cumulative recent exposure (i.e., frequency judgements) in a study-test paradigm. A comparison of ERP signatures in relation to degree of prior exposure across the two memory tasks and the study phase revealed that the LPC tracks both types of memory signals, but only when they are relevant to the decision at hand. Another ERP component previously implicated in recognition memory, the FN400, showed a distinct pattern of activity across conditions that differed from the LPC; it tracked only recent exposure in a decision-dependent manner. Another similar ERP component typically linked to conceptual processing in past work, the N400, was sensitive to degree of recent and lifetime exposure, but it did not track them in a decision dependent manner. Finally, source localization analyses pointed to a potential source of the LPC in left ventral lateral parietal cortex, which also showed the decision-dependent effect. The current findings highlight the role of decision making in ERP markers of prior exposure in tasks other than those typically used in studies of recognition memory, and provides an initial link between the LPC and the previously suggested role of ventral lateral parietal cortex in memory judgements.

Neuroimaging is a valuable diagnostic tool for the early detection of neonatal brain injury, but equipment and radiologic staff are expensive and unavailable to most hospitals in developing countries. We evaluated an affordable, portable ultrasound machine as a quantitative and qualitative diagnostic tool and to establish whether a novice sonographer could effectively operate the equipment and obtain clinically important information. Cranial ultrasonography was performed on term healthy, pre-term and term asphyxiated neonates in Rwandan and Kenyan hospitals. To evaluate the detection of ventriculomegaly and compression injuries, we measured the size of the lateral ventricles and corpus callosum. The images were also assessed for the presence of other cerebral abnormalities. Measurements were reliable across images, and cases of clinically relevant ventriculomegaly were detected. A novice sonographer had good-to-excellent agreement with an expert. This study demonstrates that affordable equipment and cranial ultrasound protocols can be used in low-resource settings to assess the newborn brain.

© 2018 Sleep Research Society. Study Objectives The behavioral and cognitive consequences of severe sleep deprivation are well understood. Surprisingly, relatively little is known about the neural correlates of mild and acute sleep restriction on tasks that require sustained vigilance for prolonged periods of time during the day. Methods and Results Event-related potential (ERP) paradigms can reveal insight into the neural correlates underlying visual processing and behavioral responding that is impaired with reduced alertness, as a consequence of sleep loss. Here, we investigated the impact of reduced vigilance following at-home mild sleep restriction to better understand the associated behavioral consequences and changes in information processing revealed by ERPs. As expected, vigilance was reduced (e.g. increased lapses and response slowing) that increased over the course of the experiment in the "sleep restricted" (5 hr sleep) compared with the "sleep-extension" (9 hr sleep) condition. Corresponding to these lapses, we found decreased positivity of visually evoked potentials in the Sleep Restriction vs. Sleep Extension condition emerging from 316 to 449 ms, maximal over parietal/occipital cortex. We also investigated electrophysiological signs of motor-related processing by comparing lateralized readiness potentials (LRPs) and found reduced positivity of LRPs in the Sleep Restriction vs. Sleep Extension condition at 70-40 ms before, and 115-158 ms after a response was made. Conclusions These results suggest that even a single night of mild sleep restriction can negatively affect vigilance, reflected by reduced processing capacity for decision making, and dulls motor preparation and execution.

© 2018 Sleep Research Society. Most people will at some point experience not getting enough sleep over a period of days, weeks, or months. However, the effects of this kind of everyday sleep restriction on high-level cognitive abilities - such as the ability to store and recall information in memory, solve problems, and communicate - remain poorly understood. In a global sample of over 10000 people, we demonstrated that cognitive performance, measured using a set of 12 well-established tests, is impaired in people who reported typically sleeping less, or more, than 7-8 hours per night - which was roughly half the sample. Crucially, performance was not impaired evenly across all cognitive domains. Typical sleep duration had no bearing on short-term memory performance, unlike reasoning and verbal skills, which were impaired by too little, or too much, sleep. In terms of overall cognition, a self-reported typical sleep duration of 4 hours per night was equivalent to aging 8 years. Also, sleeping more than usual the night before testing (closer to the optimal amount) was associated with better performance, suggesting that a single night's sleep can benefit cognition. The relationship between sleep and cognition was invariant with respect to age, suggesting that the optimal amount of sleep is similar for all adult age groups, and that sleep-related impairments in cognition affect all ages equally. These findings have significant real-world implications, because many people, including those in positions of responsibility, operate on very little sleep and may suffer from impaired reasoning, problem-solving, and communications skills on a daily basis.

© 2018 Elsevier Ltd There is strong incentive to improve our cognitive abilities, and brain training has emerged as a promising approach for achieving this goal. While the idea that extensive ‘training’ on computerized tasks will improve general cognitive functioning is appealing, the evidence to support this remains contentious. This is, in part, because of poor criteria for selecting training tasks and outcome measures resulting in inconsistent definitions of what constitutes transferable improvement to cognition. The current study used a targeted training approach to investigate whether training on two different, but related, working memory tasks (across two experiments, with 72 participants) produced transferable benefits to similar (quantified based on cognitive and neural profiles) untrained test tasks. Despite significant improvement on both training tasks, participants did not improve on either test task. In fact, performance on the test tasks after training were nearly identical to a passive control group. These results indicate that, despite maximizing the likelihood of producing transferable benefits, brain training does not generalize, even to very similar tasks. Our study calls into question the benefit of cognitive training beyond practice effects, and provides a new framework for future investigations into the efficacy of brain training.

AimHead motion has a profound effect on MRI, and will contaminate comparisons of function or structure between groups that move differently. This work compares adults and infants. Infants might move differently for physical, physiological and cognitive reasons, but so far these differences have not been quantified.MethodsThe spatial modes and total magnitude of motion in the MRI scanner were measured (N=211). The effects of group (infant vs. adult) and stimulation paradigm (auditory vs. visual) were evaluated.ResultsSpatial modes of motion were found to be distinct between infant and adult groups. Infants had less anterior-posterior translational motion, but greater motion in other dimensions, often with complex multi-axis patterns. In magnitude distribution, sleeping infants often remained more still than adults, but when movement did occur it was more extreme and abrupt. Two groups of adults presented with different stimulation showed similar shapes of motion.ConclusionThe spatial modes and magnitude distribution of motion differed substantially between groups, and must be considered carefully as a confound in comparisons of structure or function. The abruptness and magnitude of movement suggests that for infants relative to adults post-processing strategies such as de-noising are likely to be more effective than prospective motion correction.Key notesQuantified the spatial and temporal distribution of motion during MRI in 211 adults and neonatesThe different spatial modes in adults and infants were visualized and statistically contrastedThe magnitude of motion had “heavier tails” in infants, with more still periods, and more large movements, than adults.

ObjectiveWe investigated the long-term cognitive effects of concussion in almost 20,000 members of the general population, using tests that are known to be sensitive to small changes in performance.BackgroundConcussions are the most common type of mild traumatic brain injury, with clinical symptoms such as headaches, dizziness, and nausea, persisting for months post-injury. Despite a growing understanding of the severity and duration of these symptoms, very little is known about the long-term effects of concussion on higher level cognitive functioning and emotional lability.Design/MethodsWe asked 19,261 participants to complete a demographic questionnaire as well as the Cambridge Brain Sciences (CBS) cognitive battery. We divided our sample into two groups: those reporting at least one concussion in their lifetime (post-concussion) and those reporting no concussions in their lifetime (non-concussed). We compared the performance of the two groups on the 12 CBS tasks, as well as on four non-cognitive variables measuring levels of social contact, anxiety, depression, and concentration difficulties.ResultsWe found that post-concussion individuals performed significantly worse on a modified Stroop task that measures aspects of response inhibition, but were no worse on any other cognitive measure, including short-term memory, reasoning, and verbal abilities. Crucially, performance profiles of the post-concussion individuals indicated that they made more errors on trials that involved an incongruent colour/word pair. Beyond measures of cognition, we found that post-concussion participants also reported higher levels of anxiety, depression, and trouble concentrating when compared to the non-concussed group. The number of reported concussions also predicted task scores on this task only.ConclusionsOur results suggest that sustaining a concussion is not associated with long-term global effects on cognition. Those who report at least one concussion appear to have a modest, but statistically significant deficit of response inhibition. This impairment seems to be related to the number of concussions reported.

Feature-based attention has been shown to aid object perception. Our previous ERP effects revealed temporally late feature-based modulation in response to objects relative to motion. The aim of the current study was to confirm the timing of feature-based influences on object perception while cueing within the feature dimension of shape. Participants were told to expect either "pillow" or "flower" objects embedded among random white and black lines. Participants more accurately reported the object's main color for valid compared to invalid shapes. ERPs revealed modulation from 252-502 ms, from occipital to frontal electrodes. Our results are consistent with previous findings examining the time course for processing similar stimuli (illusory contours). Our results provide novel insights into how attending to features of higher complexity aids object perception presumably via feed-forward and feedback mechanisms along the visual hierarchy.

To isolate the neural mechanisms associated with recognizing objects from those processing basic visual properties, control stimuli are required that contain the same perceptual properties as the objects but are unrecognizable. We demonstrate that conventional methods for generating control stimuli (phase scrambling, box scrambling, texture scrambling) yield poor controls because they dramatically distort the basic visual properties (e.g., spatial frequency, perceptual organization) to which even the earliest stages of visual processing are sensitive. We developed a new scrambling method, using a diffeomorphic transformation that preserves the basic perceptual properties of the image while removing meaning. We acquired perceptual ratings to determine the least amount of scrambling necessary to remove recognition. We hypothesized that our "diffeomorphic" images would produce neural activity at the earliest stages of the visual system that more closely matched activity in response to intact images relative to the other scrambling methods. To test this hypothesis, we used the HMAX computational model of object recognition and compared the simulated neural activity at the earliest stages of the visual system (layers S1, C1, and S2) between a set of 149 images scrambled using each distortion method to their intact version. We found that scrambled "diffeomorphed" images were indistinguishable to intact images in each layer of the model, but all of the other distortion methods yielded quite different patterns. Our results indicate that "diffeomorphed" images serve as more appropriate control stimuli in neuroimaging studies that aim to disentangle the representations of perceptual and semantic object properties.

Major clues to the human brain mechanisms of spatial attention and visual awareness have come from the syndrome of neglect, where patients ignore one half of space. A longstanding puzzle, though, is that neglect almost always comes from right-hemisphere damage, which suggests that the two sides of the brain play distinct roles. But tests of attention in healthy people have revealed only slight differences between the hemispheres. Here we show that major differences emerge if we look at the timing of brain activity in a task optimized to identify attentional functions. Using EEG to map cortical activity on a millisecond timescale, we found transient (20-30 ms) periods of interhemispheric competition, followed by short phases of marked right-sided activity in the ventral attentional network. Our data are the first to show interhemispheric interactions that, much like a toggle switch, quickly allocate neural resources to one or the other hemisphere.