Just-in-Time Encoding Into Visual Working Memory Is Contingent Upon Constant Availability of External Information.

Humans maintain an intricate balance between storing information in visual working memory (VWM) and just-in-time sampling of the external world, rooted in a trade-off between the cost of maintaining items in VWM versus retrieving information as it is needed. Previous studies have consistently shown that one prerequisite of just-in-time sampling is a high degree of availability of external information, and that introducing a delay before being able to access information led participants to rely less on the external world and more on VWM. However, these studies manipulated availability in such a manner that the cost of sampling was stable and predictable. It is yet unclear whether participants become less reliant on external information when it is more difficult to factor in the cost of sampling that information. In two experiments, participants copied an example layout from the left to the right side of the screen. In Experiment 1, intermittent occlusion of the example layout led participants to attempt to encode more items per inspection than when the layout was constantly available, but this did not consistently result in more correct placements. However, these findings could potentially be explained by inherent differences in how long the example layout could be viewed. Therefore in Experiment 2, the example layout only became available after a gaze-contingent delay, which could be constant or variable. Here, the introduction of any delay led to increased VWM load compared to no delay, although the degree of variability in the delay did not alter behaviour. These results reaffirm that the nature of when we engage VWM is dynamical, and suggest that any disruption to the continuous availability of external information is the main driver of increased VWM usage relative to whether availability is predictable or not.

Does visuospatial neglect contribute to standing balance within the first 12 weeks post-stroke? A prospective longitudinal cohort study.

BACKGROUND: Visuospatial neglect (VSN) has been suggested to limit standing balance improvement post-stroke. However, studies investigating this association longitudinally by means of repeated within-subject measurements early post-stroke are lacking. This prospective longitudinal cohort study evaluates the longitudinal association of egocentric and allocentric VSN severity with 1) standing balance independence and 2) postural control and weight-bearing asymmetry (WBA) during quiet standing, in the first 12 weeks post-stroke. METHODS: Thirty-six hemiplegic individuals after a first-ever unilateral stroke were evaluated at weeks 3, 5, 8 and 12 post-stroke. Egocentric and allocentric VSN severity were evaluated using the Broken Hearts Test. The standing unperturbed item of the Berg Balance Scale (BBS-s) was used to clinically evaluate standing independence. Posturographic measures included measures of postural control (mediolateral (ML)/anteroposterior (AP) net center-of-pressure velocities (COPvel)) and WBA during quiet standing. A linear mixed model was used to examine longitudinal associations between egocentric and allocentric VSN, and BBS-s, COPvel-ML, COPvel-AP and WBA within the first 12 weeks post-stroke. RESULTS: Egocentric (ß = -0.08, 95%CI[-0.15;-0.01], P = .029) and allocentric VSN severity (ß = -0.09, 95%CI[-0.15; -0.04], P = .002) were significant independent factors for BBS-s scores in the first 12 weeks post-stroke. Egocentric and allocentric VSN were no significant independent factors for COPvel-ML, COPvel-AP and WBA in the first 12 weeks post-stroke. CONCLUSIONS: Allocentric and egocentric VSN severity were significantly associated with decreased standing independence, but not impaired postural control or greater asymmetric weight-bearing, in the early subacute post-stroke phase. This may involve traditional VSN measures being not sensitive enough to detect fine-grained VSN deficits due to a ceiling effect between 5 and 8 weeks post-stroke, once the individual regains standing ability. Future studies may require more sensitive VSN measurements to detect such deficits. Trial registration Clinicaltrials.gov. unique identifier NCT05060458.

The Association of Personal Neglect with Motor, Activities of Daily Living, and Participation Outcomes after Stroke: A Systematic Review.

Despite its potential clinical impact, the association of personal neglect (PN) with motor, activities of daily living (ADL), and participation outcomes after stroke is not well-understood. This first-ever systematic review on the topic therefore evaluates this association, taking into account suggested subtypes of PN, including body representation neglect, somatosensory neglect, motor neglect, and premotor neglect. A systematic literature search was conducted on February 17, 2023 in PubMed, Web of Science, Scopus, PubPsych, and PsycArticles databases. The study adheres to the guidelines of Preferred Reporting Items for Systematic Reviews and Meta-Analyses, and its protocol was registered on PROSPERO (CRD42020187460). Eleven observational studies were included, gathering 1,400 individuals after stroke (429 showed PN). Results show that individuals with body representation neglect after stroke have significantly decreased movement control and motor strength, lower functional mobility, and ADL independency compared with those without body representation neglect after stroke. Individuals with motor neglect after stroke showed worse motor function and spasticity than to those without motor neglect after stroke. Nonspecified PN (i.e., PN evaluated with an outcome measure that does not allow subcategorization) was related to worse lateropulsion with pushing, longer length of stay and greater odds of being discharged to somewhere other than home. No study evaluated somatosensory and premotor neglect. This review highlights the limited research in this area and emphasizes the need for a more comprehensive PN assessment. However, currently available assessment tools show limited ability to accurately diagnose PN subtypes and future research should prioritize the development of comprehensive diagnostic test batteries.

Zooming in on abnormal local and global processing biases after stroke: Frequency, lateralization, and associations with cognitive functions.

OBJECTIVES: The 'attentional spotlight' can be adjusted depending on the task requirements, resulting in processing information at either the local or global level. Stroke can lead to local or global processing biases, or the inability to simultaneously attend both levels. In this study, we assessed the (1) prevalence of abnormal local and global biases following stroke, (2) differences between left- and right-sided brain damaged patients, and (3) relations between local and global interference, the ability to attend local and global levels simultaneously, and lateralized attention, search organization, search speed, visuo-construction, executive functioning, and verbal (working) memory. METHODS: Stroke patients admitted for inpatient rehabilitation completed directed (N = 192 total; N = 46 left-sided/N = 48 right-sided lesion) and divided (N = 258 total; N = 67 left-sided/N = 66 right-sided lesion) local-global processing tasks, as well as a conventional neuropsychological assessment. Processing biases and interference effects were separately computed for directed and divided tasks. RESULTS: On the local-global tasks, 7.8-10.9% of patients showed an abnormal local bias and 6.3-8.3% an abnormal global bias for directed attention, and 5.4-10.1% an abnormal local bias and 6.6-15.9% an abnormal global bias for divided attention. There was no significant difference between patients with left- and right-sided brain damage. There was a moderate positive relation between local interference and search speed, and a small positive relation between global interference and neglect. CONCLUSIONS: Abnormal local and global biases can occur after stroke and might relate to a range of cognitive functions. A specific bias might require a different approach in assessment, psycho-education, and treatment.

Identification of candidate genes for developmental colour agnosia in a single unique family.

Colour agnosia is a disorder that impairs colour knowledge (naming, recognition) despite intact colour perception. Previously, we have identified the first and only-known family with hereditary developmental colour agnosia. The aim of the current study was to explore genomic regions and candidate genes that potentially cause this trait in this family. For three family members with developmental colour agnosia and three unaffected family members CGH-array analysis and exome sequencing was performed, and linkage analysis was carried out using DominantMapper, resulting in the identification of 19 cosegregating chromosomal regions. Whole exome sequencing resulted in 11 rare coding variants present in all affected family members with developmental colour agnosia and absent in unaffected members. These variants affected genes that have been implicated in neural processes and functions (CACNA2D4, DDX25, GRINA, MYO15A) or that have an indirect link to brain function, development or disease (MAML2, STAU1, TMED3, RABEPK), and a remaining group lacking brain expression or involved in non-neural traits (DEPDC7, OR1J1, OR8D4). Although this is an explorative study, the small set of candidate genes that could serve as a starting point for unravelling mechanisms of higher level cognitive functions and cortical specialization, and disorders therein such as developmental colour agnosia.

Prevalence, Severity and Impact of Visuospatial Neglect in Geriatric Stroke Rehabilitation, a Cross-Sectional Study.

OBJECTIVES: Visuospatial neglect (VSN) is a common cognitive deficit of lateralized attention after stroke and can have a negative influence on patients' daily activities, community participation, and caregiver burden. VSN prevalence has been investigated in several mixed-age populations, but rarely in only an older population. As the population in geriatric rehabilitation (GR) is understudied and VSN may influence rehabilitation goals in GR (return home), we examined the prevalence of VSN as well as associations between VSN (severity) and population characteristics and the impact of VSN on functioning, length of stay, and discharge destination after GR. DESIGN: Multicenter cross-sectional study. SETTING AND PARTICIPANTS: Stroke patients admitted to GR. METHODS: Three VSN tests (Star cancelation task, Line bisection task, and Catherine Bergego Scale) were administered in the first 2 weeks of GR admission. To examine VSN severity, a composite score was calculated based on scores of the 3 tests. RESULTS: A total of 114 stroke patients were included [55.3% female; mean age 80.2 (SD 8.0) years]. VSN prevalence was 47.4%, in which allocentric and egocentric neglect were more prevalent than VSN during activities of daily living. Participants with VSN spent more days in GR compared to participants without VSN (median 68.5 vs 35.5 days) and had fewer home returns. In addition, VSN participants showed less mobility, lower cognitive functioning, and less independence during self-care compared to participants without VSN. Mobility, self-care, cognition, duration of rehabilitation, and home return were negatively associated with VSN severity. CONCLUSIONS AND IMPLICATIONS: VSN is very prevalent in the GR stroke population. VSN severely hampers older people during daily activities and their rehabilitation process and, therefore, has a major personal and societal impact. Accordingly, systematic assessment of VSN in the early phase of geriatric rehabilitation with multiple VSN screening tests is recommended.

More (corrective) consecutive saccades after a lesion to the posterior parietal cortex.

To reach a target, primary saccades (S1s) are often followed by (corrective) consecutive saccades (S2, and potentially S3, S4, S5), which are based on retinal and extraretinal feedback. Processing these extraretinal signals was found to be significantly impaired by lesions to the posterior parietal cortex (PPC). Recent studies, however, added a more nuanced view to the role of the PPC, where patients with PPC lesions still used extraretinal signals for S2s and perceptual judgements (Fabius et al., 2020; Rath-Wilson & Guitton, 2015). Hence, it seems that a PPC lesion is not disrupting extraretinal processing per se. Yet, a lesion might still result in less reliable processing of extraretinal signals. Here, we investigated whether this lower reliability manifests as decreased or delayed S2 initiation. Patients with PPC lesions (n = 7) and controls (n = 26) performed a prosaccade task where the target either remained visible or was removed after S1 onset. When S1 is removed, accurate S2s (corrections of S1 error) rely solely on extraretinal signals. We analysed S2 quantity and timing using linear mixed-effects modelling and additive hazards analyses. Patients demonstrated slower S1 execution and lower S1 amplitudes than controls, but their S2s still compensated the S1 undershoot, also when they only relied on extraretinal information. Surprisingly, patients showed an increased amount of S2s. This deviation from control behaviour can be seen as suboptimal, but given the decreased accuracy of the primary saccade, it could be optimal for patients to employ more (corrective) consecutive saccades to overcome this inaccuracy.

Don't hide the instruction manual: A dynamic trade-off between using internal and external templates during visual search.

Visual search is typically studied by requiring participants to memorize a template initially, for which they subsequently search in a crowded display. Search in daily life, however, often involves templates that remain accessible externally, and may therefore be (re)attended for just-in-time encoding or to refresh internal template representations. Here, we show that participants indeed use external templates during search when given the chance. This behavior was observed during both simple and complex search, scaled with task difficulty, and was associated with improved performance. Furthermore, we show that participants used external sampling not only to offload memory, but also as a means of verifying whether the template was remembered correctly at the end of trials. We conclude that the external world may not only provide the challenge (e.g., distractors), but may dynamically ease search. These results argue for extensions of state-of-the-art models of search, because external sampling seems to be used frequently, in at least two ways and is actually beneficial for task performance. Our findings support a model of visual working memory that emphasizes a resource-efficient trade-off between storing and (re)attending external information.

Eye Movements as Proxy for Visual Working Memory Usage: Increased Reliance on the External World in Korsakoff Syndrome.

In the assessment of visual working memory, estimating the maximum capacity is currently the gold standard. However, traditional tasks disregard that information generally remains available in the external world. Only when to-be-used information is not readily accessible, memory is taxed. Otherwise, people sample information from the environment as a form of cognitive offloading. To investigate how memory deficits impact the trade-off between sampling externally or storing internally, we compared gaze behaviour of individuals with Korsakoff amnesia (n = 24, age range 47-74 years) and healthy controls (n = 27, age range 40-81 years) on a copy task that provoked different strategies by having information freely accessible (facilitating sampling) or introducing a gaze-contingent waiting time (provoking storing). Indeed, patients sampled more often and longer, compared to controls. When sampling became time-consuming, controls reduced sampling and memorised more. Patients also showed reduced and longer sampling in this condition, suggesting an attempt at memorisation. Importantly, however, patients sampled disproportionately more often than controls, whilst accuracy dropped. This finding suggests that amnesia patients sample frequently and do not fully compensate for increased sampling costs by memorising more at once. In other words, Korsakoff amnesia resulted in a heavy reliance on the world as 'external memory'.

Cognitive and Motor Therapy After Stroke Is Not Superior to Motor and Cognitive Therapy Alone to Improve Cognitive and Motor Outcomes: New Insights From a Meta-analysis.

OBJECTIVE: To evaluate whether cognitive and motor therapy (CMT) is more effective than no therapy, motor therapy, or cognitive therapy on motor and/or cognitive outcomes after stroke. Additionally, this study evaluates whether effects are lasting and which CMT approach is most effective. DATA SOURCES: AMED, EMBASE, MEDLINE/PubMed, and PsycINFO databases were searched in October 2022. STUDY SELECTION: Twenty-six studies fulfilled the inclusion criteria: randomized controlled trials published in peer-reviewed journals since 2010 that investigated adults with stroke, delivered CMT, and included at least 1 motor, cognitive, or cognitive-motor outcome. Two CMT approaches exist: CMT dual-task ("classical" dual-task where the secondary cognitive task has a distinct goal) and CMT integrated (where cognitive components of the task are integrated into the motor task). DATA EXTRACTION: Data on study design, participant characteristics, interventions, outcome measures (cognitive/motor/cognitive-motor), results and statistical analysis were extracted. Multilevel random effects meta-analysis was conducted. DATA SYNTHESIS: CMT demonstrated positive effects compared with no therapy on motor outcomes (g=0.49; 95% confidence interval [CI], 0.10, 0.88) and cognitive-motor outcomes (g=0.29; 95% CI, 0.03, 0.54). CMT showed no significant effects compared with motor therapy on motor, cognitive, and cognitive-motor outcomes. A small positive effect of CMT compared with cognitive therapy on cognitive outcomes (g=0.18; 95% CI, 0.01, 0.36) was found. CMT demonstrated no follow-up effect compared with motor therapy (g=0.07; 95% CI, -0.04, 0.18). Comparison of CMT dual-task and integrated revealed no significant difference for motor (F1,141=0.80; P=.371) or cognitive outcomes (F1,72=0.61, P=.439). CONCLUSIONS: CMT was not superior to monotherapies in improved outcomes after stroke. CMT approaches were equally effective, suggesting that training that enlists a cognitive load per se may benefit outcomes.

Longitudinal Effects of Asymptomatic C9orf72 Carriership on Brain Morphology.

OBJECTIVE: We investigated effects of C9orf72 repeat expansion and gene expression on longitudinal cerebral changes before symptom onset. METHODS: We enrolled 79 asymptomatic family members (AFMs) from 9 families with C9orf72 repeat expansion. Twenty-eight AFMs carried the mutation (C9+). Participants had up to 3 magnetic resonance imaging (MRI) scans, after which we compared motor cortex and motor tracts between C9+ and C9- AFMs using mixed effects models, incorporating kinship to correct for familial relations and lessen effects of other genetic factors. We also compared cortical, subcortical, cerebellar, and connectome structural measurements in a hypothesis-free analysis. We correlated regional C9orf72 expression in donor brains with the pattern of cortical thinning in C9+ AFMs using meta-regression. For comparison, we included 42 C9+ and 439 C9- patients with amyotrophic lateral sclerosis (ALS) in this analysis. RESULTS: C9+ AFM motor cortex had less gyrification and was thinner than in C9- AFMs, without differences in motor tracts. Whole brain analysis revealed thinner cortex and less gyrification in parietal, occipital, and temporal regions, smaller thalami and right hippocampus, and affected frontotemporal connections. Thinning of bilateral precentral, precuneus, and left superior parietal cortex was faster in C9+ than in C9- AFMs. Higher C9orf72 expression correlated with thinner cortex in both C9+ AFMs and C9+ ALS patients. INTERPRETATION: In asymptomatic C9orf72 repeat expansion carriers, brain MRI reveals widespread features suggestive of impaired neurodevelopment, along with faster decline of motor and parietal cortex than found in normal aging. C9orf72 expression might play a role in cortical development, and consequently explain the specific brain abnormalities of mutation carriers. ANN NEUROL 2023;93:668-680.

Association between spatial neglect and impaired verticality perception after stroke: A systematic review.

BACKGROUND: Although most research on spatial neglect (SN) has focused on spatial perception deficits with regard to the lateral (left-right) axis, deficits of spatial perception with regard to the vertical (up-down) axis, such as disturbances in the perception of verticality (e.g., judgement of vertical orientations), have also been suggested. OBJECTIVE: We aimed to systematically analyse reported associations between SN and characteristics of verticality perception while considering the time post-stroke. METHODS: PubMed, Web of Science, Scopus, PubPsych and PsycArticles databases were searched on May 24, 2022 for articles written in English that evaluated the association between SN and verticality perception (i.e., the subjective visual vertical [SVV], subjective postural vertical [SPV] and subjective haptic vertical [SHV]) in adults after stroke. Left and right SN were considered and had to be assessed using standardized methods. Data were manually extracted, and risk of bias was assessed with the Newcastle-Ottawa Scale. The tilt of the line/chair relative to the gravitational vector and its direction, together with uncertainty (i.e., variability across measurements), were evaluated. RESULTS: Thirteen studies were included (431 participants after stroke); at least 191 participants exhibited SN. Mainly the first 3 to 6 months post-stroke were evaluated. SN was associated with SVV misperception, which resulted in larger SVV tilts (mostly in the contralesional direction) and uncertainty in participants with than without SN. SVV tilt magnitudes ranged from a mean/median of -8.9° to -2.3° in SN participants and from -1.6° to 0.6° in non-SN participants, the latter falling within normative ranges. For SPV and SHV measurements, the magnitude of tilt and the uncertainty were insufficiently assessed or results were inconclusive. CONCLUSIONS: SN was associated with larger SVV tilts and uncertainty, which suggests that SVV misperception is a key feature of SN. This observation highlights the importance of regular SVV assessment in people with SN in clinical practice. PROSPERO: CRD42019127616.

Study protocol of transcranial electrical stimulation at alpha frequency applied during rehabilitation: A randomized controlled trial in chronic stroke patients with visuospatial neglect.

BACKGROUND: A frequent post stroke disorder in lateralized attention is visuospatial neglect (VSN). As VSN has a strong negative impact on recovery in general and independence during daily life, optimal treatment is deemed urgent. Next to traditional stroke treatment, non-invasive brain stimulation offers the potential to facilitate stroke recovery as a complementary approach. In the present study, visual scanning training (VST; the current conventional treatment) will be combined with transcranial alternating current stimulation (tACS) to evaluate the additive effects of repeated sessions of tACS in combination with six-weeks VST rehabilitation. METHODS: In this double-blind randomized placebo-controlled intervention study (RCT), we will compare the effects of active tACS plus VST to sham (placebo) tACS plus VST, both encompassing 18 VST training sessions, 40 minutes each, during 6 weeks. Chronic stroke patients with VSN (> 6 months post-stroke onset) are considered eligible for study participation. In total 22 patients are needed for the study. The primary outcome is change in performance on a cancellation task. Secondary outcomes are changes in performance on a visual detection task, two line bisection tasks, and three measures to assess changes in activities of daily living. Assessment is at baseline, directly after the first and ninth training session, after the last training session (post training), and 1 week and 3 months after termination of the training (follow-up). DISCUSSION: If effective, a tACS-VST rehabilitation program could be implemented as a treatment option for VSN. TRIAL REGISTRATION: ClinicalTrials.gov ; registration number: NCT05466487; registration date: July 18, 2022 retrospectively registered; https://clinicaltrials.gov/ct2/show/NCT05466487.

Seeing the Forrest through the trees: Oculomotor metrics are linked to heart rate.

Fluctuations in a person's arousal accompany mental states such as drowsiness, mental effort, or motivation, and have a profound effect on task performance. Here, we investigated the link between two central instances affected by arousal levels, heart rate and eye movements. In contrast to heart rate, eye movements can be inferred remotely and unobtrusively, and there is evidence that oculomotor metrics (i.e., fixations and saccades) are indicators for aspects of arousal going hand in hand with changes in mental effort, motivation, or task type. Gaze data and heart rate of 14 participants during film viewing were used in Random Forest models, the results of which show that blink rate and duration, and the movement aspect of oculomotor metrics (i.e., velocities and amplitudes) link to heart rate-more so than the amount or duration of fixations and saccades. We discuss that eye movements are not only linked to heart rate, but they may both be similarly influenced by the common underlying arousal system. These findings provide new pathways for the remote measurement of arousal, and its link to psychophysiological features.

Can serious play and clinical cognitive assessment go together? On the feasibility and user-experience of virtual reality simulations in paediatric neurorehabilitation.

PURPOSE: Cognitive impairments frequently occur in children and adolescents with acquired brain injury (ABI), causing significant disabilities in daily life. Current paper-and-pencil neuropsychological tests do not capture the complexity of daily life activities, often failing to objectify subtle cognitive impairments. Virtual Reality (VR) simulations might overcome this discrepancy, as it resembles daily life situations. The aim of this study was to evaluate the feasibility, user-experience and preference of a VR simulation with a non-immersive (computer monitor; CM)) and immersive (head mounted display; HMD)) VR setup. METHODS: Children and adolescents with ABI (n = 15) and typically developing children and adolescents (n = 21) completed a VR-task with a CM and HMD. RESULTS: Both VR setups were feasible for children and adolescents with ABI. User-experience was enhanced with the HMD compared to CM in both groups. Side effects were low and comparable for both groups, and there were no differences between setups (HMD and CM). The majority of the children and adolescents with ABI preferred the HMD. CONCLUSION: VR simulations appear feasible to use in paediatric rehabilitation. The preference for a VR setup should be discussed with the child. Further research is needed to develop more sensitive measures to further explore the potential of VR for cognitive assessment.

The mobility assessment course: A ready-to-use dynamic measure of visuospatial neglect.

The Mobility Assessment Course (MAC) is a tool to measure visuospatial neglect in a dynamic fashion. Although the MAC has been shown to dissociate between patients with and without neglect, it remains unclear whether it is applicable in clinical settings. We evaluated the MAC regarding its (1) feasibility as a diagnostic tool as part of standard care, (2) construct validity, and (3) underlying constructs and potential confounders. A consecutive sample of stroke patients admitted to inpatient rehabilitation completed the MAC, shape cancellation, line bisection, and/or Catherine Bergego Scale (CBS) as part of the standard assessment. To assess feasibility, we computed the percentage of patients who completed the MAC. Construct validity was tested by evaluating MAC performance between patients with and without neglect and controls. Finally, a regression analysis was conducted to assess underlying constructs and potential confounders of MAC performance (i.e., level of mobility and lesion side). The MAC was completed by 82% of patients (N = 182/223; of whom 145 completed all tasks). Patients with neglect performed worse on the MAC (indicating more severe neglect) compared to patients without neglect and controls. The MAC had a lower sensitivity and higher specificity than paper-and-pencil tasks and the CBS. Performance on shape cancellation, line bisection, and CBS were predictors of MAC performance. Level of mobility and lesion side did not predict MAC scores, indicating that these factors do not confound its reliability. To conclude, the MAC is an easy-to-implement tool to evaluate neglect in a dynamic manner, which can be administered in addition to conventional paper-and-pencil tasks.

Applying machine learning to dissociate between stroke patients and healthy controls using eye movement features obtained from a virtual reality task.

Conventional neuropsychological tests do not represent the complex and dynamic situations encountered in daily life. Immersive virtual reality simulations can be used to simulate dynamic and interactive situations in a controlled setting. Adding eye tracking to such simulations may provide highly detailed outcome measures, and has great potential for neuropsychological assessment. Here, participants (83 stroke patients and 103 healthy controls) we instructed to find either 3 or 7 items from a shopping list in a virtual super market environment while eye movements were being recorded. Using Logistic Regression and Support Vector Machine models, we aimed to predict the task of the participant and whether they belonged to the stroke or the control group. With a limited number of eye movement features, our models achieved an average Area Under the Curve (AUC) of .76 in predicting whether each participant was assigned a short or long shopping list (3 or 7 items). Identifying participant as either stroke patients and controls led to an AUC of .64. In both classification tasks, the frequency with which aisles were revisited was the most dissociating feature. As such, eye movement data obtained from a virtual reality simulation contain a rich set of signatures for detecting cognitive deficits, opening the door to potential clinical applications.

Feasibility and user-experience of virtual reality in neuropsychological assessment following stroke.

Virtual Reality (VR) offers the possibility to assess cognitive functioning in a dynamic environment resembling daily life. In this cross-sectional study, we used two user interfaces, namely non-immersive VR by using a computer monitor (CM) and immersive VR by using a head-mounted display (HMD). We investigated (1) potential differences in feasibility, user-experience, and a potential preference for one user interface over another between stroke patients and healthy controls; (2) potential differences in feasibility, user-experience, and preference between patients referred for inpatient rehabilitation care and patients referred for outpatient rehabilitation care; and (3) potential demographic and clinical characteristics that were related to patients' preference for one user interface over another. Stroke patients (n = 88) and healthy controls (n = 66) performed a VR-task with a CM and HMD. Both user interfaces were feasible to use, irrespective of clinical referral (in- or outpatient rehabilitation care). Patients reported an enhanced feeling of engagement, transportation, flow, and presence, but more negative side effects when tested with a HMD, compared to a CM. The majority of stroke patients had no preference for one user interface over the other, yet younger patients tended to prefer a HMD. VR seems highly feasible in stroke patients.

Epidemiology of paediatric moderate and severe traumatic brain injury in the Netherlands.

INTRODUCTION: Traumatic brain injury (TBI) is the main cause of death in children around the world. The last Dutch epidemiological study described the incidence over 10 years ago. Mechanism of injury seems to change with the age of the child, therefore it is important to appreciate different age groups. To be able to lower the impact of childhood TBI, an understanding of current incidence, mechanism of injury and outcome is necessary. METHODS: A nationwide retrospective cohort study was conducted. The Dutch National Trauma Database was used to identify all patients 18 years and younger who were admitted to a Dutch hospital with moderate-severe TBI (Abbreviated Injury Score≥3) in the Netherlands, from January 2015 until December 2017. Subanalyses were done for different age groups. RESULTS: In total, 1413 patients were included, of whom 5% died. The incidence rate of moderate-severe TBI was 14/100,000 person years. Median age was 10.4 years. Largest age group was patients <5 years, incidence rate was highest in patients ≥16 years. Falls were more common than road traffic accidents (RTA), but RTAs occurred far more frequently amongst children over 10. RTAs predominantly consisted of bicycle accidents. Mortality rates increased from youngest to oldest age groups, as did the chances of a Glasgow Outcome Scale score of 3. CONCLUSION: Paediatric moderate-severe TBI represents a significant problem in the Netherlands. Falls are the most common mechanism of injury amongst younger children and RTAs amongst older children. Unique for the Netherlands is the vast amount of bicycle accident related injuries.