Validity of Visuoconstructional Assessment Methods within Healthy Elderly Greek Australians: Quantitative and Error Analysis.

AIMS: Visuospatial skills are frequently assessed with drawing tests. Research has suggested that the use of drawing tasks in low educated groups may lack the ability to discriminate healthy individuals from clinical populations. The aims of this study were to investigate the validity of visuoconstructional tests in a sample of older Greek Australian immigrants and compare their performances to a matched sample of patients with Alzheimer's disease (ad). METHOD: We assessed visuoconstructional performances in a sample of 90 healthy older Greek Australians, with a primary school level of education, and compared performances to a demographically matched sample of 20 Greek Australians with a diagnosis of ad on four visuoconstructional drawing tests: Greek cross, four-pointed star, intersecting pentagons, and the Necker Cube. RESULTS: While healthy participants tended to outperform the ad group on most copy tasks, high fail rates within the healthy sample were observed for the intersecting pentagons and Necker cube (78% and 73% fail rates, respectively) when using established clinical cut-off scores. High rates of curved angle, omission, distorted relation between elements, spatial disorganization and three-dimensional design errors were found across the four-pointed star, intersecting pentagons, and the Necker cube in both healthy participants and those with ad. Exploratory receiver operating characteristic curve analysis revealed that, with perhaps the exception of the Greek cross, meaningful sensitivity and specificity could not be reached for the four-pointed star, intersecting pentagons, and Necker cube. CONCLUSION: Cognitively healthy immigrants with low education appear to be at a disadvantage when completing visuoconstructional drawing tests, as their performance may be misinterpreted as indicating cognitive impairment. Future research is needed to identify alternative approaches to assess visuoconstructional ability in culturally and linguistically diverse older cohorts with limited education.

Atypically larger variability of resource allocation accounts for visual working memory deficits in schizophrenia.

Working memory (WM) deficits have been widely documented in schizophrenia (SZ), and almost all existing studies attributed the deficits to decreased capacity as compared to healthy control (HC) subjects. Recent developments in WM research suggest that other components, such as precision, also mediate behavioral performance. It remains unclear how different WM components jointly contribute to deficits in schizophrenia. We measured the performance of 60 SZ (31 females) and 61 HC (29 females) in a classical delay-estimation visual working memory (VWM) task and evaluated several influential computational models proposed in basic science of VWM to disentangle the effect of various memory components. We show that the model assuming variable precision (VP) across items and trials is the best model to explain the performance of both groups. According to the VP model, SZ exhibited abnormally larger variability of allocating memory resources rather than resources or capacity per se. Finally, individual differences in the resource allocation variability predicted variation of symptom severity in SZ, highlighting its functional relevance to schizophrenic pathology. This finding was further verified using distinct visual features and subject cohorts. These results provide an alternative view instead of the widely accepted decreased-capacity theory and highlight the key role of elevated resource allocation variability in generating atypical VWM behavior in schizophrenia. Our findings also shed new light on the utility of Bayesian observer models to characterize mechanisms of mental deficits in clinical neuroscience.

A Brief Digital Cognitive Assessment for Detection of Cognitive Impairment in Cuban Older Adults.

BACKGROUND: Rapid technological advances offer a possibility to develop cost-effective digital cognitive assessment tools. However, it is unclear whether these measures are suitable for application in populations from Low and middle-income countries (LMIC). OBJECTIVE: To examine the accuracy and validity of the Brain Health Assessment (BHA) in detecting cognitive impairment in a Cuban population. METHODS: In this cross-sectional study, 146 participants (cognitively healthy = 53, mild cognitive impairment (MCI) = 46, dementia = 47) were recruited at primary care and tertiary clinics. The main outcomes included: accuracy of the BHA and the Montreal Cognitive Assessment (MoCA) in discriminating between controls and cognitively impaired groups (MCI and dementia) and correlations between the BHA subtests of memory, executive functions, and visuospatial skills and criterion-standard paper-and-pencil tests in the same domains. RESULTS: The BHA had an AUC of 0.95 (95% CI: 0.91-0.98) in discriminating between controls and cognitively impaired groups (MCI and dementia, combined) with 0.91 sensitivity at 0.85 specificity. In discriminating between control and MCI groups only, the BHA tests had an AUC of 0.94 (95% CI: 0.90-0.99) with 0.71 sensitivity at 0.85 specificity. Performance was superior to the MoCA across all diagnostic groups. Concurrent and discriminant validity analyses showed moderate to strong correlations between the BHA tests and standard paper-and-pencil measures in the same domain and weak correlations with standard measures in unrelated domains. CONCLUSION: The BHA has excellent performance characteristics in detecting cognitive impairment including dementia and MCI in a Hispanic population in Cuba and outperformed the MoCA. These results support potential application of digital cognitive assessment for older adults in LMIC.

Hemifield-specific control of spatial attention and working memory: Evidence from hemifield crossover costs.

Attentional tracking and working memory tasks are often performed better when targets are divided evenly between the left and right visual hemifields, rather than contained within a single hemifield (Alvarez & Cavanagh, 2005; Delvenne, 2005). However, this bilateral field advantage does not provide conclusive evidence of hemifield-specific control of attention and working memory, because it can be explained solely from hemifield-limited spatial interference at early stages of visual processing. If control of attention and working memory is specific to each hemifield, maintaining target information should become more difficult as targets move between the two hemifields. Observers in the present study maintained targets that moved either within or between the left and right hemifields, using either attention (Experiment 1) or working memory (Experiment 2). Maintaining spatial information was more difficult when target items moved between the hemifields compared with when target items moved within their original hemifields, consistent with hemifield-specific control of spatial attention and working memory. However, this pattern was not found for maintaining identity information (e.g., color) in working memory (Experiment 3). Together, these results provide evidence that control of spatial attention and working memory is specific to each hemifield, and that hemifield-specific control is a unique signature of spatial processing.

Emotional Intelligence Predicts Accurate Self-Assessment of Surgical Quality: A Pilot Study.

BACKGROUND: Self-assessment is fundamental in surgical training. Accuracy of self-assessment is superior with greater age, experience, and the use of video playback. Presently, there is scarce evidence in the literature regarding predictors for a surgical trainee's aptitude for self-assessment. The objective of this study was to investigate whether emotional intelligence or visual-spatial aptitude can predict effective self-assessment among novice surgeons performing laparoscopic appendectomy (LA). MATERIALS AND METHODS: Eighteen novice trainees performed a simulated LA, and two aptitude measures were evaluated: (1) emotional intelligence questionnaire and (2) visual spatial ability test. Self-assessment of their performance was conducted using the Objective Assessment of Surgical and Technical Skills global rating scale and ranking five subtasks of the procedure in order of quality of performance after watching a playback of their LA. Two blinded experts (senior consultant surgeons, performed >100 LAs) assessed surgical quality using the same scoring system. Candidates were ranked into higher and lower aptitude groups for the two aptitude measures. Spearman's rank correlation coefficient was calculated to identify if either of the two groups demonstrated greater agreement between self and expert assessment in relation to the two aptitude measures. RESULTS: Participants with a higher degree of emotional intelligence demonstrated significant agreement with expert assessment (r = 0.73, P = 0.031). CONCLUSIONS: Emotional intelligence can predict better self-assessment of surgical quality after performing a simulated LA. This may facilitate early identification of individuals who might require mentoring or guidance with self-assessment as well as contribute to selection criteria.

No effect of cold pressor test-induced arousal on attentional benefits and costs in an endogenous spatial orienting paradigm.

Previous studies have shown that arousal can influence hemispatial bias, suggesting that changes in arousal affect the neural networks involved in spatial attention control. The goal of the present study was to measure the effects of increased arousal on endogenous attentional orienting. We used a Spatial Orienting Paradigm to quantify attentional benefits and costs as measures of attentional orienting and re-orienting responses and exposed participants (N = 25; Experiment 1) to a bilateral feet Cold Pressor Test (CPT) to manipulate arousal. Increases in subjective distress ratings and blood pressure confirmed the effect of CPT on arousal. Although no overall effects of CPT on reaction times in the Spatial Orienting Paradigm were detected, an exploratory analysis of sex-specific effects revealed a left-lateralised decrease in benefits and increase in costs after CPT exposure in the male subsample (N = 11). To confirm these preliminary results, we repeated the experiment in a larger sample (N = 29, all male), but found no effect of CPT on orienting, with moderate to strong evidence in favour of a model excluding all (interaction) effects of CPT exposure (all BFIncl < 0.3). Instead, our replicated results indicate that voluntary orienting is unaffected by CPT-induced increases of arousal. In the light of previous studies, and keeping in mind the interpretative challenges of null results, we discuss how and why our findings may be specific to endogenous as opposed to exogenous orienting and how arousal could possibly lead to the previously established effects on visuospatial bias without simultaneously affecting orienting and the underlying attention control networks.

VisMET: a passive, efficient, and sensitive assessment of visuospatial memory in healthy aging, mild cognitive impairment, and Alzheimer's disease.

The entorhinal-hippocampal circuit is one of the earliest sites of cortical pathology in Alzheimer's disease (AD). Visuospatial memory paradigms that are mediated by the entorhinal-hippocampal circuit may offer a means to detect memory impairment during the early stages of AD. In this study, we developed a 4-min visuospatial memory paradigm called VisMET (Visuospatial Memory Eye-Tracking Task) that passively assesses memory using eye movements rather than explicit memory judgements. We had 296 control or memory-impaired participants view a set of images followed by a modified version of the images with either an object removed, or a new object added. Healthy controls spent significantly more time viewing these manipulations compared to subjects with mild cognitive impairment and AD. Using a logistic regression model, the amount of time that individuals viewed these manipulations could predict cognitive impairment and disease status with an out of sample area under the receiver-operator characteristic curve of 0.85. Based on these results, VisMET offers a passive, sensitive, and efficient memory paradigm capable of detecting objective memory impairment and predicting cognitive and disease status.

No direction specific costs in trans-saccadic memory.

Even though we frequently execute saccades, we perceive the external world as coherent and stable. An important mechanism of trans-saccadic perception is spatial remapping: the process of updating information across eye movements. Previous studies have indicated a right hemispheric dominance for spatial remapping, which has been proposed to translate into enhanced trans-saccadic memory for locations that are remapped into the right compared to the left hemisphere in healthy participants. Previous study designs suffered from several limitations, however (i.e. multiple eye movements had to be made instead of one, fixations were not controlled for, and ceiling effects were likely present). We therefore compared accuracy of trans-saccadic memory for central items after left- versus rightward eye movements, and secondary, for items that were remapped within the left versus right visual field. Participants memorized the location of a briefly presented item, made one saccade, and subsequently decided in what direction the item had shifted. We used a staircase to adjust task difficulty. Bayesian repeated measures ANOVAs were used to compare between left versus right eye movements and items in the left versus right visual field. We found most evidence against directional differences in trans-saccadic memory (BF10 = 0.23). We found some evidence suggestive of enhanced trans-saccadic memory for items that were remapped within the left compared to the right visual field (BF10 = 4.00). The latter result could be explained by a leftward spatial attention bias. As such, the hypothesized right hemispheric dominance for spatial remapping does not result in asymmetric trans-saccadic memory capacities in healthy participants.

Dynamic assessment of visual neglect: The Mobility Assessment Course as a diagnostic tool.

INTRODUCTION: Visual neglect is a frequent disorder following stroke and is often diagnosed by neuropsychological assessment. However, paper-and-pencil tasks have low predictive value as they lack sensitivity to capture neglect in complex, dynamic situations, such as activities of daily living. Aims of the current study were to assess the feasibility of the Mobility Assessment Course (MAC), a visual search multitask, to assess neglect, and its relation with existing neglect tasks. METHOD: Stroke patients admitted for inpatient rehabilitation and healthy controls were tested with the MAC in different corridors. Participants had to move through a corridor, finding and reporting 24 targets attached to the walls. In addition, the shape cancellation, line bisection, and Catherine Bergego Scale (CBS) were used in order to compare the MAC with existing diagnostic tools for neglect. RESULTS: Administering the MAC was feasible, as 112 of 113 patients completed the MAC with a median duration of 4.09 min. Depending on the corridor where the assessment took place, in 88.5-93.3% of assessments all targets were visible. The number of omissions (total and contralesional) and the asymmetry score (contralesional-ipsilesional omissions) on the MAC as well as collisions and corrections, were higher for patients with neglect than for those without neglect. Depending on the neglect task used, 4.0-18.6% of patients without neglect on neuropsychological tasks or the CBS showed neglect on the MAC. Vice versa, 17.2-29.3% of patients who showed neglect at neuropsychological assessment or the CBS did not do so on the MAC. Finally, a moderate to strong positive relation was seen between neglect at neuropsychological assessment, the CBS, and the MAC. CONCLUSIONS: The MAC is an ecological task in which both quantitative and qualitative data on neglect can be collected. In order to assess the presence of neglect and neglect severity in a dynamic way, the MAC could be administered in conjunction with neuropsychological assessment.

Validation of the Cognition Test Battery for Spaceflight in a Sample of Highly Educated Adults.

BACKGROUND: Neuropsychological changes that may occur due to the environmental and psychological stressors of prolonged spaceflight motivated the development of the Cognition Test Battery. The battery was designed to assess multiple domains of neurocognitive functions linked to specific brain systems. Tests included in Cognition have been validated, but not in high-performing samples comparable to astronauts, which is an essential step toward ensuring their usefulness in long-duration space missions. METHODS: We administered Cognition (on laptop and iPad) and the WinSCAT, counterbalanced for order and version, in a sample of 96 subjects (50% women; ages 25-56 yr) with at least a Master's degree in science, technology, engineering, or mathematics (STEM). We assessed the associations of age, sex, and administration device with neurocognitive performance, and compared the scores on the Cognition battery with those of WinSCAT. Confirmatory factor analysis compared the structure of the iPad and laptop administration methods using Wald tests. RESULTS: Age was associated with longer response times (mean ß = 0.12) and less accurate (mean ß = -0.12) performance, women had longer response times on psychomotor (ß = 0.62), emotion recognition (ß = 0.30), and visuo-spatial (ß = 0.48) tasks, men outperformed women on matrix reasoning (ß = -0.34), and performance on an iPad was generally faster (mean ß = -0.55). The WinSCAT appeared heavily loaded with tasks requiring executive control, whereas Cognition assessed a larger variety of neurocognitive domains. DISCUSSION: Overall results supported the interpretation of Cognition scores as measuring their intended constructs in high performing astronaut analog samples.Moore TM, Basner M, Nasrini J, Hermosillo E, Kabadi S, Roalf DR, McGuire S, Ecker AJ, Ruparel K, Port AM, Jackson CT, Dinges DF, Gur RC. Validation of the Cognition Test Battery for spaceflight in a sample of highly educated adults. Aerosp Med Hum Perform. 2017; 88(10):937-946.

The Role of Parieto-Occipital Junction in the Interaction between Dorsal and Ventral Streams in Disparity-Defined Near and Far Space Processing.

Neuropsychological and functional MRI data suggest that two functionally and anatomically dissociable streams of visual processing exist: a ventral perception-related stream and a dorsal action-related stream. However, relatively little is known about how the two streams interact in the intact brain during the production of adaptive behavior. Using functional MRI and a virtual three-dimensional paradigm, we aimed at examining whether the parieto-occipital junction (POJ) acts as an interface for the integration and processing of information between the dorsal and ventral streams in the near and far space processing. Virtual reality three-dimensional near and far space was defined by manipulating binocular disparity, with -68.76 arcmin crossed disparity for near space and +68.76 arcmin uncrossed disparity for near space. Our results showed that the POJ and bilateral superior occipital gyrus (SOG) showed relative increased activity when responded to targets presented in the near space than in the far space, which was independent of the retinotopic and perceived sizes of target. Furthermore, the POJ showed the enhanced functional connectivity with both the dorsal and ventral streams during the far space processing irrespective of target sizes, supporting that the POJ acts as an interface between the dorsal and ventral streams in disparity-defined near and far space processing. In contrast, the bilateral SOG showed the enhanced functional connectivity only with the ventral stream if retinotopic sizes of targets in the near and far spaces were matched, which suggested there was a functional dissociation between the POJ and bilateral SOG.

Visual-spatial perception: a comparison between instruments frequently used in the primary care setting and a computerized cognitive assessment battery.

BACKGROUND: The development of screening instruments will help the primary care team to determine when further comprehensive cognitive assessment is necessary. DESIGN: A retrospective analysis based on medical records. PATIENTS AND SETTING: Patients referred to a comprehensive geriatric assessment unit. ANALYSIS: Cognitive screening and assessment included visual-spatial components: the Mini Mental State Examination, the Clock Drawing Test, the Montreal Cognitive Assessment Test, and the Neurotrax (Mindstreams) computerized cognitive assessment battery. RESULTS: The average age of the 190 eligible patients was 81.09±5.42 years. Comparing the individual tests with that of the visual-spatial index of Neurotrax, we found the Trail Making B test to be most sensitive (72.4%) and the Cube Test to have the highest specificity (72.8%). A combination of tests resulted in higher sensitivity and lower specificity. CONCLUSION: The use of a combination of visual-spatial tests for screening in neurocognitive disorders should be evaluated in further prospective studies.

The flip side of the auditory spatial selection benefit: larger attentional mixing costs for target selection by ear than by gender in auditory task switching.

In cued auditory task switching, one of two dichotically presented number words, spoken by a female and a male, had to be judged according to its numerical magnitude. One experimental group selected targets by speaker gender and another group by ear of presentation. In mixed-task blocks, the target-defining feature (male/female vs. left/right) was cued prior to each trial, but in pure blocks it remained constant. Compared to selection by gender, selection by ear led to better performance in pure blocks than in mixed blocks, resulting in larger "global" mixing costs for ear-based selection. Selection by ear also led to larger "local" switch costs in mixed blocks, but this finding was partially mediated by differential cue-repetition benefits. Together, the data suggest that requirements of attention shifting diminish the auditory spatial selection benefit.

Adapting to the 30-degree visual perspective by emulating the angled laparoscope: a simple and low-cost solution for basic surgical training.

INTRODUCTION: The ability to handle and adapt to the visual perspectives generated by angled laparoscopes is crucial for skilled laparoscopic surgery. However, the control of the visual work space depends on the ability of the operator of the camera, who is often not the most experienced member of the surgical team. Here, we present a simple, low-cost option for surgical training that challenges the learner with static and dynamic visual perspectives at 30 degrees using a system that emulates the angled laparoscope. METHODS: A system was developed using a low-cost camera and readily available materials to emulate the angled laparoscope. Nine participants undertook 3 tasks to test spatial adaptation to the static and dynamic visual perspectives at 30 degrees. Completing each task to a predefined satisfactory level ensured precision of execution of the tasks. Associated metrics (time and error rate) were recorded, and the performance of participants were determined. RESULTS: A total of 450 repetitions were performed by 9 residents at various stages of training. All the tasks were performed with a visual perspective of 30 degrees using the system. Junior residents were more proficient than senior residents. CONCLUSIONS: This system is a viable and low-cost alternative for developing the basic psychomotor skills necessary for the handling and adaptation to visual perspectives of 30 degrees, without depending on a laparoscopic tower, in junior residents. More advanced skills may then be acquired by other means, such as in the operating theater or through clinical experience.

Feasibility of cognitive functional assessment in cardiac arrest survivors using an abbreviated laptop-based neurocognitive battery.

Cardiac arrest survivors exhibit varying degrees of neurological recovery even in the setting of targeted temperature management (TTM) use, ranging from severe impairments to making a seemingly full return to neurologic baseline function. We sought to explore the feasibility of utilizing a laptop-based neurocognitive battery to identify more subtle cognitive deficits in this population. In a convenience sample of cardiac arrest survivors discharged with a cerebral performance category (CPC) of 1, we evaluated the use of a computerized neurocognitive battery (CNB) in this group compared to a healthy control normative population. The CNB was designed to test 11 specific neurocognitive domains, including such areas as working memory and spatial processing. Testing was scored for both accuracy and speed. In a feasibility convenience sample of 29 cardiac arrest survivors, the mean age was 52.9±16.7 years; 12 patients received postarrest TTM and 17 did not receive TTM. Patients tolerated the battery well and performed at normative levels for both accuracy and speed on most of the 11 domains, but showed reduced accuracy of working memory and speed of spatial memory with large magnitudes (>1 SD), even among those receiving TTM. Across all domains, including those using speed and accuracy, 7 of the 29 subjects (24%) achieved statistically significant scores lower from the normative population in two or more domains. In this population of CPC 1 cardiac arrest survivors, a sensitive neurocognitive battery was feasible and suggests that specific cognitive deficits can be detected compared to a normative population, despite CPC 1 designation. Such testing might allow improved measurement of outcomes following TTM interventions in future trials.