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Do aging and dual-tasking impair the capacity to store and retrieve visuospatial information needed to guide perturbation-evoked reach-to-grasp reactions?

Cheng KC, Pratt J, Maki BE - PLoS ONE (2013)

Bottom Line: Ten healthy older adults were tested with the previous protocol and compared with the previously-tested young adults.Both age groups showed similar reduction in medio-lateral end-point accuracy when recall-delay was longest (10 s), but differed in the effect of recall delay on vertical hand elevation.For both age groups, engaging in either the non-spatial or spatial-memory task had similar (slowing) effects on the arm reactions; however, the older adults also showed a dual-task interference effect (poorer cognitive-task performance) that was specific to the spatial-memory task.

View Article: PubMed Central - PubMed

Affiliation: Toronto Rehabilitation Institute, University Health Network, Toronto, Ontario, Canada ; Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada ; Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada.

ABSTRACT
A recent study involving young adults showed that rapid perturbation-evoked reach-to-grasp balance-recovery reactions can be guided successfully with visuospatial-information (VSI) retained in memory despite: 1) a reduction in endpoint accuracy due to recall-delay (time between visual occlusion and perturbation-onset, PO) and 2) slowing of the reaction when performing a concurrent cognitive task during the recall-delay interval. The present study aimed to determine whether this capacity is compromised by effects of aging. Ten healthy older adults were tested with the previous protocol and compared with the previously-tested young adults. Reactions to recover balance by grasping a small handhold were evoked by unpredictable antero-posterior platform-translation (barriers deterred stepping reactions), while using liquid-crystal goggles to occlude vision post-PO and for varying recall-delay times (0-10 s) prior to PO (the handhold was moved unpredictably to one of four locations 2 s prior to vision-occlusion). Subjects also performed a spatial- or non-spatial-memory cognitive task during the delay-time in a subset of trials. Results showed that older adults had slower reactions than the young across all experimental conditions. Both age groups showed similar reduction in medio-lateral end-point accuracy when recall-delay was longest (10 s), but differed in the effect of recall delay on vertical hand elevation. For both age groups, engaging in either the non-spatial or spatial-memory task had similar (slowing) effects on the arm reactions; however, the older adults also showed a dual-task interference effect (poorer cognitive-task performance) that was specific to the spatial-memory task. This provides new evidence that spatial working memory plays a role in the control of perturbation-evoked balance-recovery reactions. The delays in completing the reaction that occurred when performing either cognitive task suggest that such dual-task situations in daily life could increase risk of falling in seniors, particularly when combined with the general age-related slowing that was observed across all experimental conditions.

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Cognitive tasks.(A) For the non-spatial-memory task, subjects were asked to add a series of auditorily-presented random numbers and to report the final sum after the end of the trial. Difficulty of the task was adjusted by changing the range of numbers (i.e. 1-to-3, 1-to-5, 1-to-9, or 4-to-12) to be added. Starting at the number “3”, subjects were instructed to sequentially add a series of random numbers delivered (via headphones) every 1.25s. As an example, the figure shows the correct response (3+5+3+2+4=17) to the sequence of numbers shown (2–5). (B) For the spatial-memory task, subjects were instructed to imagine a highlighted square moving around in an N×N matrix and to report the final position of the highlighted square within the matrix. Difficulty of the task was adjusted by changing the size of the matrix (i.e. 3×3, 4×4, 5×5, 6×6, or 7×7). Starting at or near the center cell, a random verbal command to move up, down, left or right was given every 1.25s. As an example, the gray arrows in the figure show the correct responses to a sequence of commands to “move up,” “move right,” “move right,” and “move down,” after starting at cell “F”. Subjects were shown the matrix after each trial and asked to identify the correct final response (cell “H” in the example shown).
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pone-0079401-g003: Cognitive tasks.(A) For the non-spatial-memory task, subjects were asked to add a series of auditorily-presented random numbers and to report the final sum after the end of the trial. Difficulty of the task was adjusted by changing the range of numbers (i.e. 1-to-3, 1-to-5, 1-to-9, or 4-to-12) to be added. Starting at the number “3”, subjects were instructed to sequentially add a series of random numbers delivered (via headphones) every 1.25s. As an example, the figure shows the correct response (3+5+3+2+4=17) to the sequence of numbers shown (2–5). (B) For the spatial-memory task, subjects were instructed to imagine a highlighted square moving around in an N×N matrix and to report the final position of the highlighted square within the matrix. Difficulty of the task was adjusted by changing the size of the matrix (i.e. 3×3, 4×4, 5×5, 6×6, or 7×7). Starting at or near the center cell, a random verbal command to move up, down, left or right was given every 1.25s. As an example, the gray arrows in the figure show the correct responses to a sequence of commands to “move up,” “move right,” “move right,” and “move down,” after starting at cell “F”. Subjects were shown the matrix after each trial and asked to identify the correct final response (cell “H” in the example shown).

Mentions: For the trials with recall-delays of 5s and 10s, subjects performed a spatial-memory task (modified Brooks spatial task) or a non-spatial memory (mental arithmetic) task during the recall-delay interval, or performed no cognitive task at all (see 8 and Figure 3A and 3B for details). Note that the secondary tasks could not be performed in the absence of any recall-delay interval (i.e. in the trials where recall-delay time = 0s) and were also not included in the trials with a 2s recall-delay time because the 2s interval would have permitted only one mental computation (since each auditory number/instruction was given every 1.25s) and hence would not have allowed meaningful assessment of cognitive-task performance.


Do aging and dual-tasking impair the capacity to store and retrieve visuospatial information needed to guide perturbation-evoked reach-to-grasp reactions?

Cheng KC, Pratt J, Maki BE - PLoS ONE (2013)

Cognitive tasks.(A) For the non-spatial-memory task, subjects were asked to add a series of auditorily-presented random numbers and to report the final sum after the end of the trial. Difficulty of the task was adjusted by changing the range of numbers (i.e. 1-to-3, 1-to-5, 1-to-9, or 4-to-12) to be added. Starting at the number “3”, subjects were instructed to sequentially add a series of random numbers delivered (via headphones) every 1.25s. As an example, the figure shows the correct response (3+5+3+2+4=17) to the sequence of numbers shown (2–5). (B) For the spatial-memory task, subjects were instructed to imagine a highlighted square moving around in an N×N matrix and to report the final position of the highlighted square within the matrix. Difficulty of the task was adjusted by changing the size of the matrix (i.e. 3×3, 4×4, 5×5, 6×6, or 7×7). Starting at or near the center cell, a random verbal command to move up, down, left or right was given every 1.25s. As an example, the gray arrows in the figure show the correct responses to a sequence of commands to “move up,” “move right,” “move right,” and “move down,” after starting at cell “F”. Subjects were shown the matrix after each trial and asked to identify the correct final response (cell “H” in the example shown).
© Copyright Policy
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC3818305&req=5

pone-0079401-g003: Cognitive tasks.(A) For the non-spatial-memory task, subjects were asked to add a series of auditorily-presented random numbers and to report the final sum after the end of the trial. Difficulty of the task was adjusted by changing the range of numbers (i.e. 1-to-3, 1-to-5, 1-to-9, or 4-to-12) to be added. Starting at the number “3”, subjects were instructed to sequentially add a series of random numbers delivered (via headphones) every 1.25s. As an example, the figure shows the correct response (3+5+3+2+4=17) to the sequence of numbers shown (2–5). (B) For the spatial-memory task, subjects were instructed to imagine a highlighted square moving around in an N×N matrix and to report the final position of the highlighted square within the matrix. Difficulty of the task was adjusted by changing the size of the matrix (i.e. 3×3, 4×4, 5×5, 6×6, or 7×7). Starting at or near the center cell, a random verbal command to move up, down, left or right was given every 1.25s. As an example, the gray arrows in the figure show the correct responses to a sequence of commands to “move up,” “move right,” “move right,” and “move down,” after starting at cell “F”. Subjects were shown the matrix after each trial and asked to identify the correct final response (cell “H” in the example shown).
Mentions: For the trials with recall-delays of 5s and 10s, subjects performed a spatial-memory task (modified Brooks spatial task) or a non-spatial memory (mental arithmetic) task during the recall-delay interval, or performed no cognitive task at all (see 8 and Figure 3A and 3B for details). Note that the secondary tasks could not be performed in the absence of any recall-delay interval (i.e. in the trials where recall-delay time = 0s) and were also not included in the trials with a 2s recall-delay time because the 2s interval would have permitted only one mental computation (since each auditory number/instruction was given every 1.25s) and hence would not have allowed meaningful assessment of cognitive-task performance.

Bottom Line: Ten healthy older adults were tested with the previous protocol and compared with the previously-tested young adults.Both age groups showed similar reduction in medio-lateral end-point accuracy when recall-delay was longest (10 s), but differed in the effect of recall delay on vertical hand elevation.For both age groups, engaging in either the non-spatial or spatial-memory task had similar (slowing) effects on the arm reactions; however, the older adults also showed a dual-task interference effect (poorer cognitive-task performance) that was specific to the spatial-memory task.

View Article: PubMed Central - PubMed

Affiliation: Toronto Rehabilitation Institute, University Health Network, Toronto, Ontario, Canada ; Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada ; Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada.

ABSTRACT
A recent study involving young adults showed that rapid perturbation-evoked reach-to-grasp balance-recovery reactions can be guided successfully with visuospatial-information (VSI) retained in memory despite: 1) a reduction in endpoint accuracy due to recall-delay (time between visual occlusion and perturbation-onset, PO) and 2) slowing of the reaction when performing a concurrent cognitive task during the recall-delay interval. The present study aimed to determine whether this capacity is compromised by effects of aging. Ten healthy older adults were tested with the previous protocol and compared with the previously-tested young adults. Reactions to recover balance by grasping a small handhold were evoked by unpredictable antero-posterior platform-translation (barriers deterred stepping reactions), while using liquid-crystal goggles to occlude vision post-PO and for varying recall-delay times (0-10 s) prior to PO (the handhold was moved unpredictably to one of four locations 2 s prior to vision-occlusion). Subjects also performed a spatial- or non-spatial-memory cognitive task during the delay-time in a subset of trials. Results showed that older adults had slower reactions than the young across all experimental conditions. Both age groups showed similar reduction in medio-lateral end-point accuracy when recall-delay was longest (10 s), but differed in the effect of recall delay on vertical hand elevation. For both age groups, engaging in either the non-spatial or spatial-memory task had similar (slowing) effects on the arm reactions; however, the older adults also showed a dual-task interference effect (poorer cognitive-task performance) that was specific to the spatial-memory task. This provides new evidence that spatial working memory plays a role in the control of perturbation-evoked balance-recovery reactions. The delays in completing the reaction that occurred when performing either cognitive task suggest that such dual-task situations in daily life could increase risk of falling in seniors, particularly when combined with the general age-related slowing that was observed across all experimental conditions.

Show MeSH
Related in: MedlinePlus