Electrocortical Activity in Older Adults Is More Influenced by Cognitive Task Complexity Than Concurrent Walking

Figures

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  FIGURE 1. Grand averaged EEG signals from channel Pz for the younger (n = 21, blue) and older adults (n = 19, green) while performing the response time task in four different conditions: single stimulus while standing (SINGLE-STAND), single stimulus while walking (SINGLE-WALK), double stimuli while standing (DOUBLE-STAND), double stimuli while walking (DOUBLE-WALK). The thick line represents the average, and the shaded area represents ± 1 standard deviation.

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  FIGURE 2. Mean (SD) and individual values of response time in four conditions: single stimulus while standing (SINGLE-STAND), single stimulus while walking (SINGLE-WALK), double stimuli while standing (DOUBLE-STAND), double stimuli while walking (DOUBLE-WALK) for younger and older adults. *Denotes significant difference between SINGLE and DOUBLE stimuli (p < 0.0001). †Denotes significant difference in relation to single stimuli condition for older adults, and single and double stimuli conditions for young adults (p < 0.001). #Denotes significant difference in relation to walking conditions for the same group (p < 0.05).

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  FIGURE 3. Mean (SD) and individual values of stride frequency (A) and the coefficient of variation of the step frequency (B) before (SNG-PRE) and after single stimuli (SNG-POST), as well as before (DBL-PRE) and after double stimuli (DBL-POST) for younger (blue) and older adults (green). *Denotes significant difference in relation to PRE (p < 0.001). †Denotes significant difference in relation to DBL-POST, as well as SNG-PRE and SNG-POST (p < 0.0001). ‡Denotes significant difference from PRE to POST for the older adult group (p = 0.001).

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  FIGURE 4. Mean (SD) and individual values of N200 peak (A), N200 latency (B), P300 peak (C), and P300 latency (D) in four conditions for the channel Fz: single stimulus while standing (SINGLE-STAND), single stimulus while walking (SINGLE-WALK), double stimuli while standing (DOUBLE-STAND), double stimuli while walking (DOUBLE-WALK) for younger and older adults. *Denotes significant difference in relation to older adults (p < 0.0005). †Denotes significant difference in relation to single stimuli conditions for the same group (p < 0.05).

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  FIGURE 5. Mean (SD) and individual values of N200 peak (A), N200 latency (B), P300 peak (C), and P300 latency (D) in four conditions for the averaged central channels (C3, Cz, and C4): single stimulus while standing (SINGLE-STAND), single stimulus while walking (SINGLE-WALK), double stimuli while standing (DOUBLE-STAND), double stimuli while walking (DOUBLE-WALK) for younger and older adults. *Denotes significant difference in relation to older adults (p < 0.05). †Denotes significant difference in relation to single stimuli conditions for the same group (p < 0.005).

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  FIGURE 6. Mean (SD) and individual values of N200 peak (A), N200 latency (B), P300 peak (C), and P300 latency (D) in four conditions for the channel Pz: single stimulus while standing (SINGLE-STAND), single stimulus while walking (SINGLE-WALK), double stimuli while standing (DOUBLE-STAND), double stimuli while walking (DOUBLE-WALK) for younger and older adults. *Denotes significant difference in relation to older adults (p < 0.05). †Denotes significant difference in relation to single stimuli conditions for the same group (p < 0.05). #Denotes significant difference in relation to walking conditions for the same group (p < 0.05).