Federica Solca

The use of P300-based BCIs in amyotrophic lateral sclerosis: from augmentative and alternative communication to cognitive assessment

The use of augmentative and alternative communication (AAC) tools in patients with amyotrophic lateral sclerosis (ALS), as effective means to compensate for the progressive loss of verbal and gestural communication, has been deeply investigated in the recent literature. The development of advanced AAC systems, such as eye‐tracking (ET) and brain‐computer interface (BCI) devices, allowed to bypass the important motor difficulties present in ALS patients. In particular, BCIs could be used in moderate to severe stages of the disease, since they do not require preserved ocular‐motor ability, which is necessary for ET applications. Furthermore, some studies have proved the reliability of BCIs, regardless of the severity of the disease and the level of physical decline. However, the use of BCI in ALS patients still shows some limitations, related to both technical and neuropsychological issues. In particular, a range of cognitive deficits in most ALS patients have been observed. At the moment, no effective verbal‐motor free measures are available for the evaluation of ALS patients’ cognitive integrity; BCIs could offer a new possibility to administer cognitive tasks without the need of verbal or motor responses, as highlighted by preliminary studies in this field. In this review, we outline the essential features of BCIs systems, considering advantages and challenges of these tools with regard to ALS patients and the main applications developed in this field. We then outline the main findings with regard to cognitive deficits observed in ALS and some preliminary attempts to evaluate them by means of BCIs. The definition of specific cognitive profiles could help to draw flexible approaches tailored on patients’ needs. It could improve BCIs efficacy and reduce patients’ efforts. Finally, we handle the open question, represented by the use of BCIs with totally locked in patients, who seem unable to reliably learn to use such tool.

The validation of the Italian Edinburgh Cognitive and Behavioural ALS Screen (ECAS)

Abstract This study presents the Italian validation of the recently developed Edinburgh Cognitive and Behavioural ALS Screen (ECAS), a short screen for cognitive/behavioural alterations in patients with amyotrophic lateral sclerosis (ALS). We evaluated the psychometric properties of the ECAS Italian version in terms of reliability and convergent validity for both cognitive and behavioural features. Furthermore, we investigated the relationship with affective and clinical variables, in addition to ECAS usability and patients’ insight into cognitive/behaviour changes. Finally, correlations between genetic and cognitive/behavioural data were analysed. We recruited 107 patients with ALS. Normative data were collected on 248 healthy subjects. Participants were administered the ECAS and two standard cognitive screening tools (FAB, MoCA), two psychological questionnaires (BDI, STAI/Y) and an ad hoc usability questionnaire. The FBI was also carried out with caregivers. Results showed that the ECAS Italian version discriminated well between patients and controls. The most prevalent deficit occurred in executive functions and fluency. Correlations were observed between the ECAS and standard cognitive screening tools and between the ECAS carer interview and the FBI, supporting its full convergent validity. In conclusion, the ECAS Italian version provides clinicians with a rapid, feasible and sensitive tool, useful to identify different profiles of cognitive-behavioural impairment in ALS.

Cognitive assessment in Amyotrophic Lateral Sclerosis by means of P300-Brain Computer Interface: a preliminary study.

Abstract Objective: To investigate the use of P300-based Brain Computer Interface (BCI) technology for the administration of motor-verbal free cognitive tests in Amyotrophic Lateral Sclerosis (ALS). Methods: We recruited 15 ALS patients and 15 age- and education-matched healthy subjects. All participants underwent a BCI-based neuropsychological assessment, together with two standard cognitive screening tools (FAB, MoCA), two psychological questionnaires (BDI, STAI-Y) and a usability questionnaire. For patients, clinical and respiratory examinations were also performed, together with a behavioural assessment (FBI). Results: Correlations were observed between standard cognitive and BCI-based neuropsychological assessment, mainly concerning execution times in the ALS group. Moreover, patients provided positive rates concerning the BCI perceived usability and subjective experience. Finally, execution times at the BCI-based neuropsychological assessment were useful to discriminate patients from controls, with patients achieving lower processing speed than controls regarding executive functions. Conclusions: The developed motor-verbal free neuropsychological battery represents an innovative approach, that could provide relevant information for clinical practice and ethical issues. Its use for cognitive evaluation throughout the course of ALS, currently not available by means of standard assessment, must be addressed in further longitudinal validation studies. Further work will be aimed at refining the developed system and enlarging the cognitive spectrum investigated.

An eye-tracking controlled neuropsychological battery for cognitive assessment in neurological diseases

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.

Cognitive assessment of executive functions using brain computer interface and eye-tracking

New technologies to enable augmentative and alternative communication in Amyotrophic Lateral Sclerosis (ALS) have been recently used in several studies. However, a comprehensive battery for cognitive assessment has not been implemented yet. Brain computer interfaces are innovative systems able to generate a control signal from brain responses conveying messages directly to a computer. Another available technology for communication purposes is the Eye-tracker system, that conveys messages from eye-movement to a computer. In this study we explored the use of these two technologies for the cognitive assessment of executive functions in a healthy population and in a ALS patient, also verifying usability, pleasantness, fatigue, and emotional aspects related to the setting. Our preliminary results may have interesting implications for both clinical practice (the availability of an effective tool for neuropsychological evaluation of ALS patients) and ethical issues.

Counterfactual Thinking Deficit in Huntington's Disease.

Background and Objective Counterfactual thinking (CFT) refers to the generation of mental simulations of alternatives to past events, actions and outcomes. CFT is a pervasive cognitive feature in every-day life and is closely related to decision-making, planning and problem-solving – all of which are cognitive processes linked to unimpaired frontal lobe functioning. Huntington’s Disease (HD) is a neurodegenerative disorder characterised by motor, behavioral and cognitive dysfunctions. Because an impairment in frontal and executive functions has been described in HD, we hypothesised that HD patients may have a CFT impairment. Methods Tests of spontaneous counterfactual thoughts and counterfactual-derived inferences were administered to 24 symptomatic HD patients and 24 age- and sex-matched healthy subjects. Results Our results show a significant impairment in the spontaneous generation of CFT and low performance on the Counterfactual Inference Test (CIT) in HD patients. Low performance on the spontaneous CFT test significantly correlates with impaired attention abilities, verbal fluency and frontal lobe efficiency, as measured by Trail Making Test – Part A, Phonemic Verbal Fluency Test and FAB. Conclusions Spontaneous CFT and the use of this type of reasoning are impaired in HD patients. This deficit may be related to frontal lobe dysfunction, which is a hallmark of HD. Because CFT has a pervasive role in patients’ daily lives regarding their planning, decision making and problem solving skills, cognitive rehabilitation may improve HD patients’ ability to analyse current behaviors and future actions.

Brain Computer Interface and Eye-tracking for Neuropsychological Assessment of Executive Functions: A Pilot Study

In this study we explored the use of Brain Computer Interface (BCI) and Eye-Tracking (ET) technology both as augmentative and alternative communication (AAC) tool and to assess cognitive deficits. Specifically, we focused on the possible development of a neuropsychological battery for cognitive assessment based on the integration of BCI and ET tools. To preliminary test this approach we assessed eight healthy subjects with a widespread used cognitive task. AAC and usability of both instruments have also been evaluated with the aim to fine-tune the overall system architecture for clinical use.

An eye-tracker controlled cognitive battery: overcoming verbal-motor limitations in ALS

We assessed language, attention, executive, and social cognition abilities in a sample of patients with Amyotrophic Lateral Sclerosis (ALS) by means of a recently developed cognitive battery based on oculomotor control with eye-tracking (ET) technology. Twenty-one ALS patients and 21 age- and education-matched healthy subjects underwent the ET-based cognitive assessment, together with the standard cognitive screening tools [Frontal Assessment Battery (FAB); Montreal Cognitive Assessment (MoCA); and Digit Sequencing Task]. Psychological measures of anxiety (State-Trait Anxiety Inventory-Y) and depression (Beck Depression Inventory) were also collected, and an ET usability questionnaire was administered. For patients, clinical and respiratory examinations were also performed, together with behavioural assessment (Frontal Behavioural Inventory). The developed battery discriminated among patients and controls with regard to measures of verbal fluency, frontal abilities, and social cognition. Measures of diagnostic utility confirmed a higher diagnostic accuracy of such ET-based tests with respect to FAB; similar diagnostic accuracy emerged when comparing them to the other standard cognitive tools (MoCA, WM). Usability ratings about the ET tests were comparable among the two groups. The ET-based neuropsychological battery demonstrated good levels of diagnostic accuracy and usability in a clinical population of non-demented ALS patients, compared to matched healthy controls. Future studies will be aimed at further investigate validity and usability components by recruiting larger sample of patients, both in moderate-to-severe stages of the disease and affected by more severe cognitive impairment.

Counterfactual thinking in Tourette's syndrome: a study using three measures.

Pathophysiological evidence suggests an involvement of frontostriatal circuits in Tourette syndrome (TS) and cognitive abnormalities have been detected in tasks sensitive to cognitive deficits associated with prefrontal damage (verbal fluency, planning, attention shifting, working memory, cognitive flexibility, and social reasoning). A disorder in counterfactual thinking (CFT), a behavioural executive process linked to the prefrontal cortex functioning, has not been investigated in TS. CFT refers to the generation of a mental simulation of alternatives to past factual events, actions, and outcomes. It is a pervasive cognitive feature in everyday life and it is closely related to decision-making, planning, problem-solving, and experience-driven learning—cognitive processes that involve wide neuronal networks in which prefrontal lobes play a fundamental role. Clinical observations in patients with focal prefrontal lobe damage or with neurological and psychiatric diseases related to frontal lobe dysfunction (e.g., Parkinsons disease, Huntingtons disease, and schizophrenia) show counterfactual thinking impairments. In this work, we evaluate the performance of CFT in a group of patients with Tourettes syndrome compared with a group of healthy participants. Overall results showed no statistical differences in counterfactual thinking between TS patients and controls in the three counterfactual measures proposed. The possible explanations of this unexpected result are discussed below.

The Arrows and Colors Cognitive Test (ACCT): A new verbal-motor free cognitive measure for executive functions in ALS

Background and objective The presence of executive deficits in patients with Amyotrophic Lateral Sclerosis is well established, even if standardized measures are difficult to obtain due to progressive physical disability of the patients. We present clinical data concerning a newly developed measure of cognitive flexibility, administered by means of Eye-Tracking (ET) technology in order to bypass verbal-motor limitations. Methods 21 ALS patients and 21 age-and education-matched healthy subjects participated in an ET-based cognitive assessment, including a newly developed test of cognitive flexibility (Arrows and Colors Cognitive Test–ACCT) and other oculomotor-driven measures of cognitive functions. A standard screening of frontal and working memory abilities and global cognitive efficiency was administered to all subjects, in addition to a psychological self-rated assessment. For ALS patients, a clinical examination was also performed. Results ACCT successfully discriminated between patients and healthy controls, mainly concerning execution times obtained at different subtests. A qualitative analysis performed on error distributions in patients highlighted a lower prevalence of perseverative errors, with respect to other type of errors. Correlations between ACCT and other ET-based frontal-executive measures were significant and involved different frontal sub-domains. Limited correlations were observed between ACCT and standard ‘paper and pencil’ cognitive tests. Conclusions The newly developed ET-based measure of cognitive flexibility could be a useful tool to detect slight frontal impairments in non-demented ALS patients by bypassing verbal-motor limitations through the oculomotor-driven administration. The findings reported in the present study represent the first contribution towards the development of a full verbal-motor free executive test for ALS patients.