Examining links between anxiety, reinvestment and walking when talking by older adults during adaptive gait

Abstract

Falls by older adults often result in reduced quality of life and debilitating fear of further falls. Stopping walking when talking (SWWT) is a significant predictor of future falls by older adults and is thought to reflect age-related increases in attentional demands of walking. We examine whether SWWT is associated with use of explicit movement cues during locomotion, and evaluate if conscious control (i.e. movement specific reinvestment) is causally linked to fall-related anxiety during a complex walking task. We observed whether twenty-four older adults stopped walking when talking when asked a question during an adaptive gait task. After certain trials, participants completed a visuospatial recall task regarding walkway features, or answered questions about their movements during the walk. In a subsequent experimental condition, participants completed the walking task under conditions of raised postural threat. Compared to a control group, participants who SWWT reported higher scores for aspects of reinvestment relating to conscious motor processing but not movement self-consciousness. The higher scores for conscious motor processing were preserved when scores representing cognitive function were included as a covariate. There were no group differences in measures of general cognitive function, visuospatial working memory or balance confidence. However, the SWWT group reported higher scores on a test of external awareness when walking, indicating allocation of attention away from task-relevant environmental features. Under conditions of increased threat, participants self-reported significantly greater state anxiety and reinvestment and displayed more accurate responses about their movements during the task. SWWT is not associated solely with age-related cognitive decline or generic increases in age-related attentional demands of walking. SWWT may be caused by competition for phonological resources of working memory associated with consciously processing motor actions and appears to be causally linked with fall-related anxiety and increased vigilance.

Keywords: Attention; Conscious motor processing; Falls; Fear of falling; Movement self-consciousness; Stops walking when talking; Working memory.

Fig. 1

a Schematic of path sequences and direction of walking. The dotted line in Path 1 indicates the route that participants took (returning on the left side of the walkway in all trials). The small dashed arrows in Paths 2 and 3 indicate the first and last blocks in the walkway along with the direction of walking. The solid grey arrows in Path 2 show example locations of collapsible black blocks, along with the approximate layout of the nylon wire that was used by experimenters to ‘trigger’ the block to collapse during false trials. For the VSR task, participants were presented with pen-and-paper task where, directly after walking, they were asked to mark the position of the white path on a blank 4 × 6 grid with the start position of the walkway identified. The VSR task was scored using the following rules: (a) 1 point for each block correctly marked; (b) subtract 0.5 points for each block where no attempt was made to mark that area of the path; (c) 1 point for each turn in the walkway correctly identified. Finally, as there were eight white blocks in every path sequence, if a participant marked more than eight blocks, 1 point was deducted for every block marked over the total of eight. Possible scores ranged from −8 to +10. b A cross-sectional schematic of the collapsible block mechanism. The distance between the magnets was adjusted so that experimenters only needed to impart a small amount of force to cause the support surface to fall (vertical distance of fall = 18 cm)

Fig. 2

Bar plot showing scores from the two dimensions of the Movement Specific Reinvestment Scale: movement self-consciousness and conscious motor processing. Error bars represent standard error of the mean. *p < 0.05, **p < 0.005

Fig. 3

(SA) Shortened version of Spielberger’s State anxiety questionnaire (Spielberger 1975). Three items: (1) I feel calm when completing the task (negatively scored as per original questionnaire); (2) I feel tense when completing the task; (3) I am worried that I may lose my balance. Possible responses were: 0 = Not at all; 1 = Somewhat; 2 = Moderately; 3 = Very much (maximum range of possible scores = 0–9). (MSRS) Shortened version of the Movement Specific Reinvestment Scale comprised two items from each dimension of movement self-consciousness (sh-MSRSmsc): (1) I am self-conscious about the way I look when I am moving; (2) I sometimes have the feeling that I am watching myself move, and conscious motor processing (sh-MSRScmp): (1) I am always trying to think about my movements when I carry them out; (2) I am aware of the way my body moves when I carry out a movement. These four items were selected from the total of 10 items in the original MSRS scale as they were deemed by the authors to be most strongly suited to measure state reinvestment during gait. Possible responses were: 0 = Extremely uncharacteristic; 1 = Uncharacteristic; 2 = Neutral; 3 = Characteristic; 4 = Extremely characteristic (maximum range of possible scores = 0–8 for each factor). For measures of sh-SA, sh-MSRSmsc and sh-MSRScmp, scores represent the mean of three administrations of each questionnaire after the final trial within each path sequence, in both Baseline and Threat conditions. Error bars represent standard error of the mean. *p < 0.05, **p < 0.005