Psychometric Evaluation of an ICF-Based Instrumental Activities of Daily Living Assessment With Older Adults With Cognitive Decline.

IMPORTANCE: Identifying cognitive or physical limitations that contribute to difficulties in instrumental activities of daily living (IADLs) is critical for adequate intervention with community-dwelling older adults with cognitive decline. OBJECTIVE: To establish the validity and responsiveness of an IADL scale based on the International Classification of Functioning, Disability and Health (the ICF-IADL) with respect to both cognitive and physical limitations. DESIGN: Cross-sectional study. SETTING: Multiple community care and senior centers. PARTICIPANTS: Eighty-two older adults. INTERVENTION: Combination of physical exercise and cognitive training. MEASURES: Five criterion measures-Lawton IADL Scale, Montreal Cognitive Assessment (MoCA), Digit Symbol Substitution Test (DSS), Word Lists Test (WLT), and Timed Up and Go Test (TUG). RESULTS: The ICF-IADL's three summary scales-Disability Index (DI), Cognitive Disability Index (CDI), and Physical Disability Index (PDI)-had good concurrent validity with the Lawton IADL Scale. The DI and CDI had moderate to good associations with the MoCA. The DI's and CDI's predictive validity for scores on the Lawton IADL Scale, MoCA, and TUG was moderate to good and that of the PDI was fair. Responsiveness was large for the DI, moderate for the CDI, and small for the PDI. CONCLUSIONS AND RELEVANCE: The ICF-IADL can be used to measure disability in IADLs related to cognitive and physical limitations. The DI and CDI were better than the PDI in predicting outcomes in general cognitive function and dynamic balance and were more responsive to change after intervention than the PDI. WHAT THIS ARTICLE ADDS: The ICF-IADL addresses both cognitive and physical limitations and can be a valid assessment of IADLs. Occupational therapists can use it to determine difficulties in IADLs and causes of those difficulties, guide treatment planning, and monitor intervention effectiveness with community-dwelling older adults with cognitive decline.

Exploring the contributions of the supplementary eye field to subliminal inhibition using double-pulse transcranial magnetic stimulation.

It is widely accepted that the supplementary eye fields (SEF) are involved in the control of voluntary eye movements. However, recent evidence suggests that SEF may also be important for unconscious and involuntary motor processes. Indeed, Sumner et al. ([2007]: Neuron 54:697-711) showed that patients with micro-lesions of the SEF demonstrated an absence of subliminal inhibition as evoked by masked-prime stimuli. Here, we used double-pulse transcranial magnetic stimulation (TMS) in healthy volunteers to investigate the role of SEF in subliminal priming. We applied double-pulse TMS at two time windows in a masked-prime task: the first during an early phase, 20-70 ms after the onset of the mask but before target presentation, during which subliminal inhibition is present; and the second during a late phase, 20-70 ms after target onset, during which the saccade is being prepared. We found no effect of TMS with the early time window of stimulation, whereas a reduction in the benefit of an incompatible subliminal prime stimulus was found when SEF TMS was applied at the late time window. These findings suggest that there is a role for SEF related to the effects of subliminal primes on eye movements, but the results do not support a role in inhibiting the primed tendency. Hum Brain Mapp 38:339-351, 2017. © 2016 Wiley Periodicals, Inc.

Effects of computer-based cognitive training combined with physical training for older adults with cognitive impairment: A four-arm randomized controlled trial.

Objective: Combined physical (PHY) and cognitive (COG) training in sequential (SEQ) and simultaneous (SIMUL) sessions may delay the progression of cognitive impairment. To date, no study has directly compared in older adults with cognitive impairment the effects of COG training, PHY training, SEQ motor-cognitive training and SIMUL motor-cognitve training on specific indices of cognitive performance and activities of daily living (ADL). The purpose of this study was to determine whether SEQ and SIMUL motor-cognitive training can improve treatment outcomes compared with PHY or COG training alone. We also aimed to compare the effects of SEQ versus SIMUL motor-cognitive training on cognitive functions and instrumental ADL (IADL) in older adults with cognitive impairment. Methods: A cluster randomized controlled trial was conducted. Eighty older adults with cognitive impairment were randomly assigned to COG, PHY, SEQ or SIMUL training groups. The intervention consisted of 90-min training sessions, totaling 36 sessions. Outcome measures were the Montreal Cognitive Assessment, three subtests of the Wechsler Memory Scale (WMS) and the Lawton IADL scale. Results: Significant interaction effects between group and time were found in WMS-spatial span (p = 0.04) and WMS-word lists (p = 0.041). For WMS-spatial span, the SIMUL group showed outperformed the COG (p = 0.039), PHY (p = 0.010) and SEQ groups (p = 0.017). For WMS-word lists, the SEQ group improve more than COG (p = 0.013), PHY (p = 0.030) and SIMUL (p = 0.019) groups. No significant differences were found in IADL performance among four groups (p = 0.645). Conclusions: Our study showed SEQ and SIMUL motor-cognitive training led to more pronounced improvements in visuospatial working memory or verbal memory compared with isolated COG or PHY training for community-based older adults with cognitive impairment. For enhancing effects on IADL, we suggest the use of sensitive measurement tools and context-enriched cognitive training involving real-life task demands.

Trial type probability modulates the cost of antisaccades.

The antisaccade task, where eye movements are made away from a target, has been used to investigate the flexibility of cognitive control of behavior. Antisaccades usually have longer saccade latencies than prosaccades, the so-called antisaccade cost. Recent studies have shown that this antisaccade cost can be modulated by event probability. This may mean that the antisaccade cost can be reduced, or even reversed, if the probability of surrounding events favors the execution of antisaccades. The probabilities of prosaccades and antisaccades were systematically manipulated by changing the proportion of a certain type of trial in an interleaved pro/antisaccades task. We aimed to disentangle the intertwined relationship between trial type probabilities and the antisaccade cost with the ultimate goal of elucidating how probabilities of trial types modulate human flexible behaviors, as well as the characteristics of such modulation effects. To this end, we examined whether implicit trial type probability can influence saccade latencies and also manipulated the difficulty of cue discriminability to see how effects of trial type probability would change when the demand on visual perceptual analysis was high or low. A mixed-effects model was applied to the analysis to dissect the factors contributing to the modulation effects of trial type probabilities. Our results suggest that the trial type probability is one robust determinant of antisaccade cost. These findings highlight the importance of implicit probability in the flexibility of cognitive control of behavior.

Antisaccade cost is modulated by contextual experience of location probability.

It is well known that pro- and antisaccades may deploy different cognitive processes. However, the specific reason why antisaccades have longer latencies than prosaccades is still under debate. In three experiments, we studied the factors contributing to the antisaccade cost by taking attentional orienting and target location probabilities into account. In experiment 1, using a new antisaccade paradigm, we directly tested Olk and Kingstone's hypothesis, which attributes longer antisaccade latency to the time it takes to reorient from the visual target to the opposite saccadic target. By eliminating the reorienting component in our paradigm, we found no significant difference between the latencies of the two saccade types. In experiment 2, we varied the proportion of prosaccades made to certain locations and found that latencies in the high location-probability (75%) condition were faster than those in the low location-probability condition. Moreover, antisaccade latencies were significantly longer when location probability was high. This pattern can be explained by the notion of competing pathways for pro- and antisaccades in findings of others. In experiment 3, we further explored the degrees of modulation of location probability by decreasing the magnitude of high probability from 75 to 65%. We again observed a pattern similar to that seen in experiment 2 but with smaller modulation effects. Together, these experiments indicate that the reorienting process is a critical factor in producing the antisaccade cost. Furthermore, the antisaccade cost can be modulated by probabilistic contextual information such as location probabilities.

Test-retest reliability and minimal detectable change of the Contextual Memory Test in older adults with and without mild cognitive impairment.

BACKGROUND: The ability to detect one's own memory capacity and develop strategies based on daily contexts is important for daily activities. The Contextual Memory Test (CMT) assesses self-awareness, self-efficacy, self-perception/evaluation of performance, recall, and strategy use that are associated with daily contexts, and could be a potentially suitable measurement for assessing memory and meta-memory in older adults with and without cognitive impairment. Nevertheless, the test-retest reliability and minimal detectable change (MDC) remain unknown in these individuals. OBJECTIVE: The purpose of this study was to examine test-retest reliability and calculate MDC of the CMT in healthy older adults and those with mild cognitive impairment (MCI). METHODS: Eighty-three participants completed the CMT twice with a one-month interval. Test-retest reliability was examined using intraclass correlation coefficient (ICC) in all seven domains of the CMT and the recognition subtest. The standard error of measurement (SEM) and MDC were calculated. The Bland-Altman analysis was performed to evaluate the degree of agreement between measurements. RESULTS: The ICC of five domains (self-awareness, self-perception/evaluation of performance, immediate/delayed/total recall) and the recognition subtest were good to excellent (ICC = 0.63-0.94) in healthy and MCI participants and the MDC% were less than 30% The ICC of the other two domains (self-efficacy and total strategy use, TSS) were low (ICC = 0.07-0.59) and the MDC% exceeded 30%. The Bland-Altman analysis showed generally better performance in the 2nd than the 1st measurement in most CMT domains. CONCLUSIONS: Our results revealed sufficient test-retest reliability and acceptable MDC in most CMT domains in healthy and MCI participants. Only the self-efficacy and TSS domains demonstrated low ICC and large MDC. Possible practice effects were found between repeated measurements. Clinicians should be cautious when evaluating self-efficacy and strategy use using the CMT in older adults. Further improvements are needed for these two domains.

The dorsal attentional system in oculomotor learning of predictive information.

The dorsal attentional network is known for its role in directing top-down visual attention toward task-relevant stimuli. This goal-directed nature of the dorsal network makes it a suitable candidate for processing and extracting predictive information from the visual environment. In this review we briefly summarize some of the findings that delineate the neural substrates that contribute to predictive learning at both levels within the dorsal attentional system: including the frontal eye field (FEF) and posterior parietal cortex (PPC). We also discuss the similarities and differences between these two regions when it comes to learning predictive information. The current findings from the literature suggest that the FEFs may be more involved in top-down spatial attention, whereas the parietal cortex is involved in processing task-relevant attentional influences driven by stimulus salience, both contribute to the processing of predictive cues at different time points.