Deficits in executive functioning are a common feature of Alzheimer\'s disease (AD) and result from impairment in the central executive system. As a result, elderly patients with early stage AD may require interventions that are more cognitively intense than traditional interventions. To address this need, in this multiple case study, we explored a dual-task-based music therapy intervention that involved drum playing and singing designed to induce attentional and motor controls. Three octogenarians diagnosed with early stage AD participated in 12 dual-task-based music therapy sessions over 6 weeks. Measures of executive functioning and the performance of a bimanual drum tapping task were evaluated before and after the intervention. Improvements in executive functioning were observed for participants A and C. After the intervention, reduced mean synchronization errors were found for the simultaneous tapping condition for all three participants. Although there was variability in the functional changes between participants, it is noteworthy that positive improvements in the elderly patients with early stage AD were obtained following dual-task-based music therapy. The results suggest that music therapy integrated into the dual-task paradigm can be an effective way to address degenerative cognitive deficits among elderly patients with early stage AD.

UNASSIGNED: To compare gait and cognitive performance conducted separately as a single- (ST) and simultaneously as a dual-task (DT), ie, when a cognitive task was added, among community-dwelling older adults with and without insomnia.
UNASSIGNED: Participants included: 39 (28 females) community-dwelling older adults with insomnia, 34 (21 females) controls without insomnia. Subject groups were matched for age, gender, and education. Sleep quality was evaluated based on two-week actigraphy. Gait speed and cognition were assessed as ST and DT performance. DT costs (DTCs) were calculated for both tasks. Outcomes were compared via independent samples t-tests or Mann-Whitney U-tests.
UNASSIGNED: Older adults with insomnia demonstrated significantly slower gait speed during ST (1 ± 0.29 vs 1.27 ± 0.17 m/s, p<0.001) and DT (0.77 ± 0.26 vs 1.14 ± 0.20 m/s, p<0.001) and fewer correct responses in the cognitive task during ST (21 ± 7 vs 27 ± 11, p=0.009) and DT (19 ± 7 vs 23 ± 9, p=0.015) compared to control group. DTC for the gait task was higher among older adults with insomnia (18.32%, IQR: 9.48-30.93 vs 7.81% IQR: 4.43-14.82, p<0.001). However, no significant difference was observed in DTC for the cognitive task (14.71%, IQR: -0.89-38.84 vs 15%, IQR: -0.89-38.84%, p=0.599).
UNASSIGNED: Older adults with insomnia have lower gait speed and poorer cognitive performance during ST and DT and an inefficient pattern of task prioritization during walking, compared to counterparts without insomnia. These findings may explain the higher risk of falls among older adults with insomnia. Geriatric professionals should be aware of potential interrelationships between sleep and gait.

Numerous investigations suggest mild traumatic brain injury (mTBI) may result in persistent gait balance control deficits. Furthermore, military Veterans with symptoms of chronic mTBI often present with physical symptoms that may be associated with impaired gait balance control which may lead to prolonged recovery, difficulty performing activities of daily living, and increased disability. It is therefore important to objectively quantify gait balance deficits in Veterans with chronic mTBI.
Is gait balance control impaired in a group of Veterans with chronic symptoms of mTBI when compared to healthy matched Veterans?
Eight Veterans with symptoms of chronic mTBI (1 F/7 M) and eight healthy matched Veterans (1 F/7 M) completed a gait balance assessment under single- (ST) and dual-task (DT) conditions. Gait balance control was quantified with whole body center of mass (COM) total medial-lateral (ML) displacement and peak ML velocity, which were calculated from camera-based motion capture.
Veterans with chronic mTBI walked with greater ML COM displacement (approximately 25 % increase) in both ST and DT walking (main effect of group, p = 0.018) when compared to healthy Veterans. The peak ML COM velocity was affected for both groups by performing a concurrent cognitive task (interaction effect, p =  .012). Slower ML COM velocities in healthy Veterans suggest the adoption of a conservative balance control strategy, while faster ML COM velocities for Veterans with chronic mTBI may indicate a diminished ability to control ML momentum.
Increased frontal plane COM motion under both ST and DT walking was observed in Veterans with chronic mTBI symptoms many years after injury. This suggests gait balance control may be adversely affected during divided attention gait and highlights the need for comprehensive gait analysis in the management of these individuals.

There is a known introspective limitation in the Psychological Refractory Period (PRP) paradigm - people underestimate the dual-task costs on their second reaction time. The prevailing explanation for this is that conscious awareness of the second stimulus is delayed in time until the first task has been centrally processed. Here, we examined this effect in more detail, by comparing reaction time estimates after processing a PRP task, and after passively experiencing \'replays\' of PRP trials. Even when participants had no dual-task processing demands, they did not accurately report the reaction time intervals using a visual analogue scale (the original reporting method of most introspective PRP experiments), but they did when placing markers that represent each event on a timeline. Thus, the timeline seems to better represent participants\' introspective representation of the trial. Importantly, introspection limitations still existed when participants processed the PRP task and then recreated it on a timeline.

Reports of introspective reaction times (iRTs) have been used to investigate conscious awareness during dual-task situations. Previous studies showed that dual-task costs in RTs (the psychological refractory period, PRP, effect) are not reflected in participants\' introspective reports. This finding has been attributed to conscious awareness of Task 2 being delayed while Task 1 is centrally processed. Here, we test this Temporal model and compare it to an alternative that assumes participants base their iRTs on experienced difficulty. We collected iRTs and difficulty estimates after each trial of a PRP paradigm in which the perceptual difficulty of either Task 2 (Experiment 1) or Task 1 (Experiment 2) was manipulated. Our results largely support the difficulty-based account, suggesting that in a dual-task situation, iRTs do not reflect timing of cognitive processes but are strongly influenced by the experience of difficulty.

BACKGROUND: Decrease of dual-task (DT) ability is known to be one of the risk factors for falls. We developed a new game concept, Dual-Task Tai Chi (DTTC), using Microsoft\'s motion-capture device Kinect, and demonstrated that the DTTC test can quantitatively evaluate various functions that are known risk factors for falling in elderly adults. Moreover, DT training has been attracting attention as a way to improve balance and DT ability. However, only a few studies have reported that it improves cognitive performance.
OBJECTIVE: The purpose of this study was to demonstrate whether or not a 12-week program of DTTC training would effectively improve cognitive functions.
METHODS: This study examined cognitive functions in community-dwelling older adults before and after 12 weeks of DTTC training (training group [TG]) or standardized training (control group [CG]). Primary end points were based on the difference in cognitive functions between the TG and the CG. Cognitive functions were evaluated using the trail-making test (part A and part B) and verbal fluency test.
RESULTS: A total of 41 elderly individuals (TG: n=26, CG: n=15) participated in this study and their cognitive functions were assessed before and after DTTC training. Significant differences were observed between the two groups with significant group × time interactions for the executive cognitive function measure, the delta-trail-making test (part B-part A; F1,36=4.94, P=.03; TG: pre mean 48.8 [SD 43.9], post mean 42.2 [SD 29.0]; CG: pre mean 49.5 [SD 51.8], post mean 64.9 [SD 54.7]).
CONCLUSIONS: The results suggest that DTTC training is effective for improving executive cognitive functions.
BACKGROUND: Japan Medical Association Clinical Trial Registration Number: JMA-IIA00092; https://dbcentre3.jmacct.med.or.jp/jmactr/App/JMACTRS06/JMACTRS06.aspx?seqno=2682 (Archived by WebCite at http://www.webcitation.org/6NRtOkZFh).