Repeated exposure to the threat of perturbation induces emotional, cognitive, and postural adaptations in young and older adults.

This study examined the effects of initial and repeated postural threat exposure on emotional, cognitive, and postural responses. Twenty-seven young and twenty-seven older adults stood on a force plate fixed to a translating platform. Threat was manipulated through expectation of a temporally and directionally (left or right) unpredictable platform perturbation. Participants completed one 60s stance trial with no expectation of perturbation (No Threat) followed by 24 trials with threat of perturbation (Threat). The stance period before each perturbation varied (5-60s) except on an early Threat trial and the last Threat trial (60s), which were used for analysis. Postural threat elicited similar emotional, cognitive, and postural changes in young and older adults. With initial threat exposure, participants reported increases in self-reported anxiety and physiological arousal, as well as broad changes in attention focus. Participants also significantly increased centre of pressure (COP) amplitude and frequency, and COP power within medium and high frequencies. With repeated threat exposure, anxiety, arousal, and some threat-induced changes in attention focus significantly adapted. These changes were accompanied by significant reductions in COP frequency and COP power within medium frequencies. Some emotional and cognitive outcomes returned to no threat levels while postural outcomes did not. This study suggests that some threat-related changes in standing postural control may be...

Source: Experimental Gerontology - April 23, 2019 Category: Geriatrics Authors: Johnson KJ, Zaback M, Tokuno CD, Carpenter MG, Adkin AL Tags: Exp Gerontol Source Type: research