Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder with pathological involvement of upper and lower motoneurons, subsequently leading to progressive loss of motor and speech abilities. In addition, cognitive functions are impaired in a subset of patients. To evaluate these potential deficits in severely physically impaired ALS patients, eye-tracking is a promising means to conduct cognitive tests. The present article focuses on how eye movements, an indirect means of communication for physically disabled patients, can be utilized to allow for detailed neuropsychological assessment. The requirements, in terms of oculomotor parameters that have to be met for sufficient eye-tracking in ALS patients are presented. The properties of stimuli, including type of neuropsychological tests and style of presentation, best suited to successfully assess cognitive functioning, are also described. Furthermore, recommendations regarding procedural requirements are provided. Overall, this methodology provides a reliable, easy to administer and fast approach for assessing cognitive deficits in patients who are unable to speak or write such as patients with severe ALS. The only confounding factor might be deficits in voluntary eye movement control in a subset of ALS patients.

OBJECTIVE:Reliable assessment of cognitive functions is a challenging task in amyotrophic lateral sclerosis (ALS) patients unable to speak and write. We therefore present an eye-tracking based neuropsychological screening tool based on the Edinburgh Cognitive and Behavioural ALS Screen (ECAS), a standard screening tool for cognitive deficits in ALS. METHODS:In total, 46 ALS patients and 50 healthy controls matched for age, gender and education were tested with an oculomotor based and a standard paper-and-pencil version of the ECAS. RESULTS:Significant correlation between both versions was observed for ALS patients and healthy controls in the ECAS total score and in all of its ALS-specific domains (all r > 0.3; all p < 0.05). The eye-tracking version of the ECAS reliably distinguished between ALS patients and healthy controls in the ECAS total score (p < 0.05). Also, cognitively impaired and non-impaired patients could be reliably distinguished with a specificity of 95%. CONCLUSION:This study provides first evidence that the eye-tracking based ECAS version is a promising approach for assessing cognitive deficits in ALS patients who are unable to speak or write.

BACKGROUND:Early development of neurocognitive functions in infants can be compromised by poverty, malnutrition and lack of adequate stimulation. Optimal management of neurodevelopmental problems in infants requires assessment tools that can be used early in life, and are objective and applicable across economic, cultural and educational settings. OBJECTIVE AND DESIGN:The present study examined the feasibility of infrared eye tracking as a novel and highly automated technique for assessing visual-orienting and sequence-learning abilities as well as attention to facial expressions in young (9-month-old) infants. Techniques piloted in a high-resource laboratory setting in Finland (N=39) were subsequently field-tested in a community health centre in rural Malawi (N=40). RESULTS:Parents' perception of the acceptability of the method (Finland 95%, Malawi 92%) and percentages of infants completing the whole eye-tracking test (Finland 95%, Malawi 90%) were high, and percentages of valid test trials (Finland 69-85%, Malawi 68-73%) satisfactory at both sites. Test completion rates were slightly higher for eye tracking (90%) than traditional observational tests (87%) in Malawi. The predicted response pattern indicative of specific cognitive function was replicated in Malawi, but Malawian infants exhibited lower response rates and slower processing speed across tasks. CONCLUSIONS:High test completion rates and the replication of the predicted test patterns in a novel environment in Malawi support the feasibility of eye tracking as a technique for assessing infant development in low-resource setting. Further research is needed to the test-retest stability and predictive validity of the eye-tracking scores in low-income settings.

Traditional cognitive assessment in neurological conditions involving physical disability is often prevented by the presence of verbal-motor impairment; to date, an extensive motor-verbal-free neuropsychological battery is not available for such purposes. We adapted a set of neuropsychological tests, assessing language, attentional abilities, executive functions and social cognition, for eye-tracking (ET) control, and explored its feasibility in a sample of healthy participants. Thirty healthy subjects performed a neuropsychological assessment, using an ET-based neuropsychological battery, together with standard "paper and pencil" cognitive measures for frontal (Frontal Assessment Battery-FAB) and working memory abilities (Digit Sequencing Task) and for global cognitive efficiency (Montreal Cognitive Assessment-MoCA). Psychological measures of anxiety (State-Trait Anxiety Inventory-Y-STAI-Y) and depression (Beck Depression Inventory-BDI) were also collected, and a usability questionnaire was administered. Significant correlations were observed between the "paper and pencil" screening of working memory abilities and the ET-based neuropsychological measures. The ET-based battery also correlated with the MoCA, while poor correlations were observed with the FAB. Usability aspects were found to be influenced by both working memory abilities and psychological components. The ET-based neuropsychological battery developed could provide an extensive assessment of cognitive functions, allowing participants to perform tasks independently from the integrity of motor or verbal channels. Further studies will be aimed at investigating validity and usability components in neurological populations with motor-verbal impairments.

Eye-tracking technology is an innovative tool that holds promise for enhancing dementia screening. In this work, we introduce a novel way of extracting salient features directly from the raw eye-tracking data of a mixed sample of dementia patients during a novel instruction-less cognitive test. Our approach is based on self-supervised representation learning where, by training initially a deep neural network to solve a pretext task using well-defined available labels (e.g. recognising distinct cognitive activities in healthy individuals), the network encodes high-level semantic information which is useful for solving other problems of interest (e.g. dementia classification). Inspired by previous work in explainable AI, we use the Layer-wise Relevance Propagation (LRP) technique to describe our network's decisions in differentiating between the distinct cognitive activities. The extent to which eye-tracking features of dementia patients deviate from healthy behaviour is then explored, followed by a comparison between self-supervised and handcrafted representations on discriminating between participants with and without dementia. Our findings not only reveal novel self-supervised learning features that are more sensitive than handcrafted features in detecting performance differences between participants with and without dementia across a variety of tasks, but also validate that instruction-less eye-tracking tests can detect oculomotor biomarkers of dementia-related cognitive dysfunction. This work highlights the contribution of self-supervised representation learning techniques in biomedical applications where the small number of patients, the non-homogenous presentations of the disease and the complexity of the setting can be a challenge using state-of-the-art feature extraction methods.

A rapid increase in the number of patients with dementia has emerged as a global health challenge. Accumulating evidence suggests that early diagnosis and timely intervention can delay cognitive decline. The diagnosis of dementia is commonly performed using neuropsychological tests, such as the Mini-Mental State Examination (MMSE), administered by trained examiners. While these traditional neuropsychological tests are valid and reliable, they are neither simple nor sufficiently short as routine screening tools for dementia. Here, we developed a brief cognitive assessment utilizing an eye-tracking technology. The subject views a series of short (178 s) task movies and pictures displayed on a monitor while their gaze points are recorded by the eye-tracking device, and the cognitive scores are determined from the gaze plots data. The cognitive scores were measured by both an eye tracking-based assessment and neuropsychological tests in 80 participants, including 27 cognitively healthy controls (HC), 26 patients with mild cognitive impairment (MCI), and 27 patients with dementia. The eye tracking-based cognitive scores correlated well with the scores from the neuropsychological tests, and they showed a good diagnostic performance in detecting patients with MCI and dementia. Rapid cognitive assessment using eye-tracking technology can enable quantitative scoring and the sensitive detection of cognitive impairment.

PURPOSE OF REVIEW:Eye tracking is a powerful method to investigate the relationship between behavior and neural mechanisms. In recent years, eye movement analysis has been used in patients with neurological disorders to assess cognitive function. In this review, we explore the latest eye tracking researches in neurological disorders that are commonly associated with cognitive deficits, specifically, amyotrophic lateral sclerosis (ALS), Alzheimer's disease (AD), Parkinson's disease (PD), multiple sclerosis (MS), and epilepsy. We focus on the application of ocular measures in these disorders, with the goal of understanding how eye tracking technology can be used in the clinical setting. FINDINGS:Eye tracking tasks (especially saccadic tasks) are often used as an adjunct to traditional scales for cognitive assessment. Eye tracking data confirmed that executive dysfunction is common in PD and ALS, whereas AD and MS are characterized by attention deficits. Research in evaluating cognitive function in epilepsy using eye tracking is still in its early stages, but this approach has shown advantages as a sensitive quantitative method with high temporal and spatial resolution. Eye tracking technology can facilitate the assessment of cognitive impairment with higher temporal resolution and finer granularity than traditional cognitive assessment. Oculomotor data collected during cognitive tasks can provide insight into biological processes. Eye tracking provides a nonverbal and less cognitively demanding method of measuring disease progression in cognitively impaired patients.

Neuropsychological disorders are common in stroke patients, ranging from an isolated impairment to impairment in multiple cognitive functions. The cognitive domains affected are in particular executive functions. These comprise planning, organising, conducting, assessing and controlling actions. Dual task abilities, that is the ability to perform successive or simultaneous tasks, are not easy to be evaluated and recovered by traditional paper and pencil methods, due to their ecological and contextual nature. NeuroVR 1.5 is a cost-free virtual reality platform based on open-source software, allowing professionals to easily modify a virtual world, to best suit the needs of the clinical setting.The present study was designed to develop and test a NeuroVR based tool for the rehabilitation of shifting of attention and action planning functions using tasks reminiscent of daily life tasks. We present the virtual environment and the cognitive procedure we developed, discussing two stroke patients case studies, which underwent an integrated neuropsychological and VR assessment.

Stroke and traumatic brain injury affect an increasing number of people, many of whom retain permanent damage in cognitive functions. Conventionally, cognitive function has been assessed by a paper-based neuropsychological evaluation. However these test environments differ substantially from everyday life. This problem can be overcome by using virtual reality (VR) to objectively evaluate behaviors and cognitive function in simulated daily activities. With our virtual shopping simulation, we compared people who had undergone a stroke with control participants in an immersive VR program that used a head-mounted display (HMD). We evaluated user satisfaction with the tests, complications, and the user interface. Significant differences were consistently found between the stroke group and the control group for the following tasks: stage 1 performance index, interaction error; stage 2 delayed recognition memory score, attention index; and stage 3 executive index (p < 0.001). Perceptive dysfunction, visuospatial dysfunction, level of computer experience, and level of education affected the performance of the stroke group. The frequency of complications in the stroke group, calculated using the cut-off score for the Simulator Sickness Questionnaire, was 9.6% for nausea, 41.9% for oculomotor complications, and 25.8% for disorientation. The frequency of complications between the stroke and control groups was not significantly different. Thirty-five percent of participants in the stroke group and 13% in the control group reported difficulties with using the joystick. This computer-generated VR-based cognitive test shows promise in assessing cognitive function in patients with stroke. More refinements are needed in the user interface and the projection methods.

Cognitive deficits in schizophrenia impair everyday functioning and instrumental daily living activities. These disabilities can be partly responsible for chronicity and institutionalization. We present here a virtual reality (VR) tool in which patients with schizophrenia performed a virtual game in an imaginary town during a 3-month program. In a pilot study, seven patients with schizophrenia (DSM-5), institutionalized for many years, attended weekly 1-h-and-a-half sessions organized by two clinicians. During the first sessions, they listed together the difficulties they experienced in everyday organization and planning. After being familiarized with the joystick and the VR environment, they navigated in the town, and planned actions that were difficult for them to carry out in their usual life (e.g., shopping, memorizing the way to the supermarket or being on time at a meeting point). They had to look for alternative routes and practice a switch from a 2D Map to the 3D Map. They also gathered their efforts to share strategies for each action, or discussed the action plan they could generate to solve concrete problems. The pre/post-neuropsychological evaluations showed attention, working memory, prospective, and retrospective memory benefits, but no improvement in planning as assessed by the Zoo map test and the action program subtest of Behavioral Assessment of the Dysexecutive Syndrome. Patients also clinically and functionally improved, gaining autonomy. Pragmatically, they reported a strong energy to elaborate concrete plans to search for jobs, or return to activities in the community. Qualitative assessments showed a benefit in sparing time, planning better, enriched relatedness, and better management of their housework. This VR game opens avenue to rehabilitation for patients with schizophrenia experiencing chronicity in their life, less attendance in daycare units, and a better community living. This program might reduce neurocognitive difficulties and might evolve into a true method for cognitive remediation (trial n° 2011-A00988-33).

Virtual reality (VR) allows for the creation of ecological environments that could be used for cognitive assessment and intervention. This study comprises two parts that describe and assess an immersive VR task, the , which can be used to measure episodic memory. Part 1 addresses its applicability in healthy older adults by measuring presence, motivation, and cybersickness symptoms. Part 2 addresses its construct validity by investigating correlations between performance in the VR task and on a traditional experimental memory task, and by measuring whether the VR task is sensitive to age-related memory differences. Fifty-seven older and 20 younger adults were assessed in the , in which they memorised and fetched 12 familiar items. Part 1 showed high levels of presence, higher levels of motivation for the VR than for the traditional task, and negligible cybersickness symptoms. Part 2 indicates that memory performance in the VR task is positively correlated with performance on a traditional memory task for both age groups, and age-related differences were found on the VR and traditional memory tasks. Thus, the use of VR is feasible in older adults and the is a valid task to assess and train episodic memory in this population.

Patients with schizophrenia have many trouble in their life due to their thinking disorders such as delusion or hallucination. It is because they have a deficit in the ability which to systematize and integrate information. Therefore, they cannot integrate or systematize properly the integrated stimuli occurring frequently in a real situation. In this study, we suggest a virtual reality system for the assessment of their ability to integrate, memorize and react to integrated stimuli. The virtual reality system we developed provided multimodal stimuli, such as visual and auditory stimuli or visuo-spatial integration, and the patients was assessed and compared their thought flexibility and working memory abilities based on multi-modal manner by making the patient experience and react to multimodal stimuli. From this study, we could conclude that the VR could provide a patient with various stimuli in an immersive environment and allow the assessment of cognitive ability, and the identification of the relationships between cognitive functions.

BACKGROUND:To delay the decline in cognition and reduce the incidence of dementia, the precise detection of Mild Cognitive Impairment (MCI) is necessary. The application of Virtual Reality (VR) technology in this detection can overcome the shortage of traditional paper-and-pencil tests. OBJECTIVE:This review aimed to summarize the research progress of the detection of MCI using VR. METHODS:Eight databases from their inception to November 19, 2019, were systematically searched for studies applying VR in the detection of MCI. A thematic analysis was conducted according to the specific detection purpose and the main corresponding cognitive domains assessed were summarized; characteristics of the VR applications were also summarized. RESULTS:Twenty-eight studies were finally included. The detection purposes included discrimination between healthy controls and those with MCI, discrimination between aMCI subtypes, detection of MCI patients at risk of Alzheimer's Disease (AD), and discrimination between MCI and AD. VR tasks assessing spatial memory were applicable for all detection purposes, and the assessment of combinations of memory and executive function seemed more sensitive. Executive function and intentional episodic memory could be assessed to discriminate among healthy controls, individuals with MCI and those with AD. Incidental episodic memory was effective in detecting MCI with hippocampal atrophy. The most common characteristics of the VR applications were the use of semi-immersion, joysticks or gamepad interactions and simple, one-time behavioral assessments. CONCLUSION:VR applications are promising in the detection of MCI, but further research is needed for clinical use.

Paper-pencil type tests are traditionally used in the assessment of executive functions (EF); however, concerns have been raised as to whether these represent actual functioning in everyday life. Virtual reality (VR) environments offer a novel alternative for the assessment of cognitive function and therefore have the potential to enhance the evaluation of EF by presenting individuals with stimuli that come closer to reproducing everyday situations. The aims of this study were to (1) establish which traditional paper-pencil EF tests from the Delis-Kaplan Executive Function System (D-KEFS) are associated with performance on a VR-Stroop task and (2) compare D-KEFS tests and the VR-Stroop task in their ability to predict everyday EF and behavior, as measured by the Behavioral Rating Inventory of Executive Function (BRIEF) and the Child Behavior Checklist (CBCL). Thirty-eight typically developing adolescents aged between 13 and 17 years completed the ClinicaVR: Classroom-Stroop, and five D-KEFS subtests (Trail Making, Tower, Twenty Questions, Verbal Fluency and Color-Word Interference). Their parents completed the BRIEF and CBCL questionnaires. The results indicate that performance on the VR-Stroop task correlates with both traditional forms of EF assessment (D-KEFS, BRIEF). In particular, performance on the VR-Stroop task was closely associated with performance on a paper-pencil inhibition task. Furthermore, VR-Stroop performance more accurately reflected everyday behavioral EF than paper-pencil tasks. VR appears to offer an ecological perspective on everyday functioning and could be seen as complementary to traditional tests in the assessment of complex cognitive abilities.