Dual-task and electrophysiological markers of executive cognitive processing in older adult gait and fall-risk

Abstract

The role of cognition is becoming increasingly central to our understanding of the complexity of walking gait. In particular, higher-level executive functions are suggested to play a key role in gait and fall-risk, but the specific underlying neurocognitive processes remain unclear. Here, we report two experiments which investigated the cognitive and neural processes underlying older adult gait and falls. Experiment 1 employed a dual-task (DT) paradigm in young and older adults, to assess the relative effects of higher-level executive function tasks (n-Back, Serial Subtraction and visuo-spatial Clock task) in comparison to non-executive distracter tasks (motor response task and alphabet recitation) on gait. All DTs elicited changes in gait for both young and older adults, relative to baseline walking. Significantly greater DT costs were observed for the executive tasks in the older adult group. Experiment 2 compared normal walking gait, seated cognitive performances and concurrent event-related brain potentials (ERPs) in healthy young and older adults, to older adult fallers. No significant differences in cognitive performances were found between fallers and non-fallers. However, an initial late-positivity, considered a potential early P3a, was evident on the Stroop task for older non-fallers, which was notably absent in older fallers. We argue that executive control functions play a prominent role in walking and gait, but the use of neurocognitive processes as a predictor of fall-risk needs further investigation.

The interaction between cognition and motor control: A theoretical framework for dual-task interference effects on posture, gait initiation, gait and turning

“…Consequently, the resulting dual-task interference is greater than that related to a cognitive concomitant task, and performance decrements in both motor tasks are more pronounced. However, these results contrast with Walshe et al's (2015) report of higher DTCs for a concurrent task involving EF (relative to a nonexecutive motor task) [100]. It is difficult to draw firm conclusions about the difference in impact between a motor and a cognitive concurrent task because (i) the tasks' level of complexity and novelty influences the DTCs and biases the comparison, and (ii) motor tasks always feature a cognitive component to some extent.…”

Executive function is necessary for the regulation of the stepping activity when stepping in place in older adults

“…Recently, Walshe et al [22] reported a larger negative effect of dual tasking on gait, but even more so when the cognitive task targeted the executive functions. In their study, gait in both young and older adults was affected, but with a larger effect in older adults.…”

“…reciting the alphabet) [20, 22, 40]. Both cognitive tasks performed in this study are considered to rely mainly on the executive functions.…”

Does Combined Physical and Cognitive Training Improve Dual-Task Balance and Gait Outcomes in Sedentary Older Adults?

“…In addition, certain types of dual-task combinations can increase the dual-task interference (Fraser and Bherer, 2013). In particular cognitive tasks that are more executive in nature seem to interfere more with gait (Al-Yahya et al, 2011; Buracchio et al, 2011; Walshe et al, 2015). A systematic review and meta-analysis found that cognitive tasks with “mental tracking” (pg.…”