Attentional Engagement During Mobile Application Skill Learning Among Patients With Memory Impairment: A Case Series Exploration.

IMPORTANCE: Attentional engagement is essential for successful cognitive rehabilitation, but little is known about longitudinal interactions with skill learning. OBJECTIVE: To examine how attentional engagement is associated with mobile application skill learning for memory compensation. We hypothesized that patients with greater functional capacity would demonstrate faster learning and attentional engagement drop with skill acquisition, whereas patients with lesser functional capacity would have to maintain attentional engagement to progress throughout training. DESIGN: A case series approach was used with longitudinal skill learning and electroencephalographic (EEG) data recorded across multiple trials and sessions of mobile calendar application training. SETTING: The study was run in a hospital-based neuropsychology clinic. PARTICIPANTS: Seven participants (5 with acquired brain injury, 1 with mild cognitive impairment, and 1 healthy older adult) were recruited. INTERVENTION: Mobile application operation was trained for the purpose of memory compensation. Skill learning was facilitated through a structured rehabilitation protocol, including large amounts of guided practice with the integration of errorless learning. OUTCOMES AND MEASURES: We quantified learning using the proportion of application steps completed independently at each session. We measured attentional engagement using an EEG marker: the Brain Engagement Index. RESULTS: For fast learners, attentional engagement generally decreased as mobile application learning progressed. In contrast, slow learners exhibited stable engagement over time with consistent, yet much slower, progress in skill learning. CONCLUSIONS AND RELEVANCE: The present data indicate that when cognitive impairment is more substantial, skill learning may involve greater attentional engagement. What This Article Adds: Patients undergoing memory rehabilitation may benefit from methods to enhance attentional engagement during skill learning when executive dysfunction is a considerable element of their cognitive profile. Monitoring attentional engagement during cognitive rehabilitation may be useful in identifying and addressing barriers to learning in real time.

Early mobile app training proficiency predicts how well memory-impaired individuals learn to use digital memory aids in the real world.

Functional memory impairment following acquired brain injury can lead to decreased independence. External memory aids such as smartphones can be highly effective compensation tools, but cognitive deficits may create barriers to implementation in daily life. The present study examined predictors of real-world use of mobile calendar applications for memory compensation in an acquired brain injury sample. A retrospective chart review was completed from an outpatient rehabilitation program, extending 15 years into the past, yielding data from 34 eligible participants. All participants demonstrated skill learning of the calendar function in their digital device and subsequently completed the generalization phase of training, which is focused on real-world implementation (measured through prospective memory tasks). The results showed that the length of time required for skill learning of mobile calendars (event entry or responding to alerts) was not predictive of the duration of generalization training. Initial training performance for responding to alerts, but not event entry, was a significant predictor of the duration of generalization training needed to complete the program. A secondary analysis with a subset of the data revealed that individuals with additional executive deficits took significantly longer to complete generalization training compared to those with a more focal memory impairment.

Mobile app learning in memory intervention for acquired brain injury: Neuropsychological associations of training duration.

Memory impairment is a common consequence of acquired brain injury, often leading to functional difficulties day-to-day and decreased independence. Memory Link is a theory-driven training programme for individuals with moderate-to-severe memory dysfunction, which enables the acquisition of digital device skills for functional compensation. The present study examined how neuropsychological functioning and initial training performance contribute to training duration in our outpatient memory rehabilitation programme. A retrospective chart review was conducted, extending 12 years into the past, yielding data from 37 eligible participants. All participants demonstrated skill learning of the calendar function in their digital device to the criterion point. The results showed that performance on neuropsychological tests of explicit memory (e.g., CVLT-II, BVMT-R), processing speed (e.g., Digit Symbol Coding, Trail Making sequencing), executive functioning (e.g., Trail Making switching), and perceptual ability (i.e., Block Design) were significantly associated with training duration to learn the core steps of calendar use. Furthermore, linear regression revealed that initial training performance was a significant predictor of training duration. Lastly, profile of cognitive impairment, with regard to severity of memory functioning and the presence of additional deficits, was found to be a significant factor contributing to how many training trials were required to learn application skills.

Reaction Time Intraindividual Variability Reveals Inhibitory Deficits in Single- and Multiple-Domain Amnestic Mild Cognitive Impairment.

OBJECTIVES: Amnestic mild cognitive impairment (aMCI), a prodromal stage of Alzheimer's disease and other dementias, is characterized by episodic memory impairment. Recent evidence has shown inhibitory control deficits in aMCI, but the extent of these deficits across inhibitory domains (i.e., response inhibition and interference control) and aMCI subtypes (i.e., single vs multiple domain) remains unclear. Few studies have included reaction time intraindividual variability (RT IIV) in these efforts. The aim of this study was to compare response inhibition and interference control between aMCI subtypes using measures of accuracy, mean RT, and RT IIV. METHODS: We report data from 34 individuals with single-domain aMCI (sdaMCI, 66-86 years), 20 individuals with multiple-domain aMCI (mdaMCI, 68-88 years), and 52 healthy controls (HC, 64-88 years) who completed tasks of response inhibition (Go-NoGo) and interference control (Flanker). Group differences in accuracy, mean RT, and RT IIV were examined for both tasks. RESULTS: Individuals with mdaMCI had higher RT IIV than the other groups on both tasks. In RT IIV, we observed an interference control deficit in mdaMCI and sdaMCI relative to healthy controls, a finding not observed through accuracy or mean RT. DISCUSSION: RT IIV may detect subtle differences in inhibition deficits between aMCI subtypes that may not be evident with conventional behavioral measures. Findings support the supplementary use of RT IIV when assessing early executive function deficits.

Inhibitory Control Deficits in Individuals with Amnestic Mild Cognitive Impairment: a Meta-Analysis.

Amnestic mild cognitive impairment (aMCI) is a prodromal stage of Alzheimer's disease that is characterized by impairments in episodic memory. Recent evidence has shown that inhibitory control is also impaired in aMCI. The aim of the present meta-analysis was to quantify inhibitory control ability in individuals with aMCI by examining performance across a range of well-defined inhibition paradigms that tapped into one of three inhibitory control subtypes (i) interference control (e.g., Stroop task), (ii) response inhibition (e.g., Go/Nogo task), or (iii) inhibition of cognitive sets (Wisconsin Card Sort Task). Reference databases (PsychINFO, PubMed, and Web of Science) were searched for studies comparing individuals with aMCI to healthy controls on behavioural measures of inhibition. Across 70 effect sizes involving 2184 adults with aMCI and 3049 controls, overall inhibition deficits of moderate magnitude (g = -0.73) were found among individuals with aMCI. Inhibition deficits were moderate in size regardless of inhibitory control subtype: interference control (g = -0.74), response inhibition (g = -0.71), inhibition of cognitive sets (g = -0.76). Subgroup analyses revealed that Stroop outcome measure (reaction time vs. accuracy) and recruitment source (clinical vs. community) moderated interference control deficits. Together these findings support a generalized inhibition deficit in aMCI, and suggest that inhibition tasks should be included routinely in neuropsychological test batteries to provide a more comprehensive overview of executive dysfunction in aMCI.

Comprehensive Neuropsychiatric and Cognitive Characterization of Former Professional Football Players: Implications for Neurorehabilitation.

Objectives: To identify novel targets for neurorehabilitation of people with a remote history of multiple concussions by: (1) comprehensively characterizing neuropsychiatric and cognitive functioning in former professional football players, with a focus on executive functions; (2) distinguishing concussion-related findings from pre-morbid/cohort characteristics of professional football players; and, (3) exploring the relationship between executive functions and neuropsychiatric symptoms. Participants: Sixty-one high-functioning former professional football players and 31 age- and sex-matched control participants without history of concussion or participation in contact sports. Design: Between-groups analyses. Main measures: Neuropsychiatric. Personality Assessment Inventory (PAI) clinical scales plus the Aggression treatment consideration scale; the Mini International Neuropsychiatric Interview (MINI). Cognitive. Comprehensive clinical neuropsychological battery assessing domains of verbal and visuospatial attention; speed of processing and memory; current and estimated pre-morbid IQ; and, executive functioning, including two experimental measures that were novel for this population (i.e., response inhibition and inconsistency of responding on a go/no-go task). Results: (1) Compared to control participants, former professional football players scored significantly higher on the PAI Depression, Mania, and Aggression scales, and significantly lower on response inhibition. (2) Relative to controls, former players with >3 concussions ( x ¯ = 6 . 1 ), but not former players with ≤ 3 concussions ( x ¯ = 2 . 0 ), showed (i) significantly higher scores on the PAI Depression scale, (ii) significantly more MINI clinical diagnoses overall, and manic/hypomanic episodes specifically, and (iii) significantly poorer executive function. (3) Mediation analysis revealed that concussion exposure had a significant indirect effect on PAI Depression, Mania, and Aggression via inconsistency of responding on the go/no-go task. Conclusions: Notable impairments to neuropsychiatric functioning and worse performance on a sensitive experimental measure of executive function were observed; these were related to both concussion history and pre-morbid (cohort) factors. Therefore, neuropsychiatric and executive functioning should be carefully assessed in those with a remote history of multiple concussions. Moreover, former players' neuropsychiatric symptoms were associated with inconsistency of responding; this suggests that treatments targeted at response inconsistency could help to mitigate neuropsychiatric dysfunction.

Slow and steady: Training induced improvements to response time consistency are due to overall slowing and minimized extremely slow responses.

Previous studies on response time intraindividual variability (RT IIV) have focused on differences between groups, ignoring the potential for modification. The current study provides a detailed analysis of RT IIV training effects across three age groups. Healthy adults (40 young [aged 18-30], 40 young-old [aged 65-74], and 41 old-old [aged 75-85]) were assigned to feedback or no feedback (standard) conditions during a touch-screen feature integration task. In the feedback condition, participants were shown their performance on the previous block of trials and encouraged to improve going forward. Transfer was assessed by comparing pre- and posttraining performance on a 4-choice RT task. Data were analyzed with respect to RT IIV, ex-Gaussian distribution fitting, and the diffusion model of RT decision making. Significant feedback-related reductions were observed in Target RT IIV and the ex-Gaussian parameter τ, accompanied by an increase in µ. There was no significant change in σ, and no evidence of transfer to the 4-choice RT task. The diffusion model analysis indicated that feedback training promoted a reduction in response threshold for the young and young-old groups, as well as a modulation of drift rate throughout training in the young group. The findings indicate that training to improve consistency induces overall slowing, but also reduces the frequency of extremely slow responses that have been linked to brief attention lapses. The results provide evidence that RT consistency is malleable, but improvements are not necessarily transferable. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Longitudinal Recovery of Executive Control Functions After Moderate-Severe Traumatic Brain Injury: Examining Trajectories of Variability and Ex-Gaussian Parameters.

BACKGROUND: Executive control deficits are deleterious and enduring consequences of moderate-severe traumatic brain injury (TBI) that disrupt everyday functioning. Clinically, such impairments can manifest as behavioural inconsistency, measurable experimentally by the degree of variability across trials of a reaction time (RT) task (also known as intraindividual variability [IIV]). Growing research on cognition after TBI points to cognitive deterioration in the chronic stages postinjury. OBJECTIVE: To examine the longitudinal recovery of RT characteristics (IIV and more detailed ex-Gaussian components, as well as the number of impulsively quick responses) following moderate-severe TBI. METHODS: Seventy moderate-severe TBI patients were assessed at 2, 5, 12, and 24+ months postinjury on a go/no-go RT task. RT indices (ex-Gaussian parameters mu and sigma [mean and variability of the normal distribution component], and tau [extremely slow responses]; mean, intraindividual coefficient of variation [ICV], and intraindividual standard deviation [ISD]) were analyzed with repeated-measures multivariate analysis of variance. RESULTS: ICV, ISD, and ex-Gaussian tau significantly decreased (ie, improved) over time in the first year of injury, but worsened from 1 to 2+ years, as did the frequency of extremely fast responses. These quadratic patterns were accentuated by age and shown primarily in tau (extremely slow) and extremely fast (impulsive) responses. CONCLUSIONS: The pattern of early recovery followed by decline in executive control function is consistent with growing evidence that moderate-severe TBI is a progressive and degenerative disorder. Given the responsiveness to treatment of executive control deficits, elucidating the trajectory and underpinnings of inconsistent behavioral responding may reveal novel prognostic and clinical management opportunities.

Response Time Consistency Is an Indicator of Executive Control Rather than Global Cognitive Ability.

OBJECTIVES: Intraindividual variability increases with age, but the relative strength of association with cognitive domains is still unclear. The objective of this study was to examine the relation between cognitive domains and the shape and spread of response time (RT) distributions as indexed by intraindividual standard deviation (ISD), and ex-Gaussian parameters (µ, σ, τ). METHODS: Healthy adults (40 young [aged 18-30 years], 40 young-old [aged 65-74 years], and 41 old-old [aged 75-85 years]) completed neuropsychological testing and a touch-screen attention task from which ISD and ex-Gaussian parameters were derived. The relation between RT performance and cognitive domains (memory, processing speed, executive functioning) was examined with structural equation modeling (SEM), and the predictive power of RT distribution indices over age was investigated with linear regression. RESULTS: ISD, µ, and τ, but not σ, showed a linear increase with age group. An SEM showed that independent of age, τ was most strongly associated with executive functioning, while µ exhibited less critical associations. Linear regression indicated that µ and τ explained a significant portion of variance in processing speed and executive ability in addition to age group. Memory was more parsimoniously predicted by age, without any significant contribution of ex-Gaussian parameters. CONCLUSIONS: The findings suggest that exceptionally slow responses convey attention lapses through wavering of cognitive control, which strongly correspond to executive functioning tests. General slowing and extremely slow responses predicted processing speed and executive performance beyond age group, indicating that RT metrics are sensitive to differences in cognitive ability. (JINS, 2018, 24, 456-465).

Staying on Task: Age-Related Changes in the Relationship Between Executive Functioning and Response Time Consistency.

OBJECTIVE: Little is known about the relationship of executive functioning with age-related increases in response time (RT) distribution indices (intraindividual standard deviation [ISD], and ex-Gaussian parameters mu, sigma, tau). The goals of this study were to (a) replicate findings of age-related changes in response time distribution indices during an engaging touch-screen RT task and (b) investigate age-related changes in the relationship between executive functioning and RT distribution indices. METHOD: Healthy adults (24 young [aged 18-30], 24 young-old [aged 65-74], and 24 old-old [aged 75-85]) completed a touch-screen attention task and a battery of neuropsychological tests. The relationships between RT performance and executive functions were examined with structural equation modeling (SEM). RESULTS: ISD, mu, and tau, but not sigma, increased with age. SEM revealed tau as the most salient RT index associated with neuropsychological measures of executive functioning. Further analysis demonstrated that correlations between tau and a weighted executive function composite were significant only in the old-old group. DISCUSSION: Our results replicate findings of greater RT inconsistency in older adults and reveal that executive functioning is related to tau in adults aged 75-85. These results support literature identifying tau as a marker of cognitive control, which deteriorates in old age.

The neuropsychological profile of vascular cognitive impairment not demented: a meta-analysis.

The most common cause of vascular cognitive impairment not demented (VCIND) is cerebral small vessel disease leading to diffuse subcortical white matter lesions. While many studies indicate that the core cognitive features of VCIND are executive dysfunction and impaired processing speed, this finding is not always consistent, and may be partially dependent on the comparison group applied. Hence, we undertook two systematic meta-analytic reviews on neuropsychological test performance across eight cognitive domains: between VCIND and healthy controls (data from 27 studies), and between VCIND and non-vascular mild cognitive impairment (nv-MCI; data from 20 studies). Our quantitative synthesis of the research literature demonstrates that individuals with VCIND show weaknesses across all cognitive domains relative to healthy controls, with the greatest impairment in the domain of processing speed (Md = -1.36), and the least affected being working memory (Md = -.48) and visuospatial construction (Md = -.63). When compared directly with nv-MCI, individuals with VCIND had significantly greater deficits in processing speed (Md = -.55) and executive functioning (Md = -.40), while those with nv-MCI exhibited a greater relative deficit in delayed memory (Md = .41). Our analyses indicate that disruption to subcortical white matter tracts impairs more cognitive processes than is typically thought to be directly related to the fronto-subcortical network. The data also suggest that differing brain aetiologies can be responsible for similar cognitive profiles. Although the findings do not evince diagnostic value, they allude to the interconnectivity of disparate cognitive processes and call for further research on the behavioural outcome of network disruption.

Dynamic working memory performance in individuals with single-domain amnestic mild cognitive impairment.

Previous studies have observed poorer working memory performance in individuals with amnestic mild cognitive impairment than in healthy older adults. It is unclear, however, whether these difficulties are true only of the multiple-domain clinical subtype in whom poorer executive functioning is common. The current study examined working memory, as measured by the self-ordered pointing task (SOPT) and an n-back task, in healthy older adults and adults with single-domain amnestic mild cognitive impairment (aMCI). Individuals with single-domain aMCI committed more errors and required longer to develop an organizational strategy on the SOPT. The single-domain aMCI group did not differ from healthy older adults on the 1-back or 2-back, but had poorer discrimination on the 3-back task. This is, to our knowledge, the first characterization of dynamic working memory performance in a single-domain aMCI group. These results lend support for the idea that clinical amnestic MCI subtypes may reflect different stages on a continuum of progression to dementia and question whether standardized measures of working memory (span tasks) are sensitive enough to capture subtle changes in performance.

A short bedside battery for visuoconstructive hemispatial neglect: Sunnybrook Neglect Assessment Procedure (SNAP).

Although it is currently not known whether early assessment and treatment of hemispatial neglect improves rehabilitation outcome, identification in the acute phase of post stroke is important for nursing, counseling families, and planning intervention strategies. Previous tests of neglect either fail to detect mild forms of neglect or are too lengthy for use at the bedside. We tested and selected an efficient, small battery of tests to address this gap. Two hundred and twenty-four stroke patients completed the Sunnybrook Neglect Assessment Procedure (SNAP). Normal performance was determined from a population of 100 normal elderly volunteers. The SNAP was shown to be a highly reliable and valid instrument. Factor analysis showed good internal consistency, suggesting that performance on each subtest is positively correlated with the others. The SNAP is a useful and reliable tool to assess neglect at the bedside in acute stroke patients.

Impairments in tactile search following superior parietal damage.

The superior parietal cortex is critical for the control of visually guided actions. Research suggests that visual stimuli relevant to actions are preferentially processed when they are in peripersonal space. One recent study demonstrated that visually guided movements towards the body were more impaired in a patient with damage to superior parietal cortex. Whereas past studies have explored disordered movement in optic ataxic patients, there has been less exploration of space perception in terms of search capacity in this population. In addition, there is some debate concerning the relationship between deficits of visuomotor control and impaired attention/perception in optic ataxia. Given that the dorsal stream has been implicated in the spatial processing of stimuli in peripersonal space, and damage to this region is known to cause optic ataxia, we felt that further investigation was warranted. We examined tactile search behavior in the fronto-parallel and radial planes in a patient with right superior parietal damage and optic ataxia. We used a pegboard with removable cylindrical pegs that allowed for the reorganization of targets between trials. To better characterize three-dimensional search behavior, we included both horizontal and vertical search conditions. Results showed that the patient spent more time searching, was more accurate and revisited more targets in right versus left space. Interestingly, the patient spent the majority of her time specifically searching the lower right quadrant of the stimulus array. Further analysis revealed lower target detection rates along the outer borders of the pegboard on all sides. The search pattern observed here is unusual considering that all targets were within arm's reach. The present experiment demonstrates that damage to superior parietal cortex impairs tactile search and biases exploration towards lower right peripersonal space.

Visual attention deficits in Alzheimer's disease: relationship to HMPAO SPECT cortical hypoperfusion.

Patients with Alzheimer's disease (AD) display a multiplicity of cognitive deficits in domains such as memory, language, and attention, all of which can be clearly linked to the underlying neuropathological alterations. The typical degenerative changes occur early on in the disease in the temporal-parietal lobes, with other brain regions, such as the frontal cortex, becoming more affected as the disease progresses. In light of the importance of the parietal cortex in mediating visuospatial attentional processing, in the present study, we investigated a deficit in covert orienting of visual attention and its relationship to cortical hypoperfusion in AD. We characterized the visual attentional profile of 21 AD patients, relative to that of 26 matched normal individuals, and then assessed the correspondence between behavior and hypoperfusion, as measured by regional cerebral blood flow using SPECT. Relative to controls, the AD group demonstrated a unilateral attentional deficit, with disproportionate slowing in reorienting attention to targets in the left compared to the right hemispace, especially following an invalid peripheral cue. Furthermore, even in the presence of bilateral pathology typical of AD, there was a positive correlation between this unilateral attentional disorder and the magnitude of the right superior parietal lobe hypoperfusion. The association of the altered attentional processing profile (i.e., greater difficulty disengaging attention from right-sided stimuli) with right-hemisphere-predominant hypoperfusion not only confirms the critical role of the right parietal lobe in covert attentional orienting but, more importantly, identifies a potential locus of the behavioral alterations in visuospatial processing in AD.