• Emotional, cognitive, and postural adaptations to repeated postural threat exposure

      Johnson, Kyle; Applied Health Sciences Program
      This thesis investigated initial threat-induced changes in emotional, cognitive, and postural control measures and adaptation of these measures to repeated threat exposure in healthy young and older adults. Twenty-seven young and twenty-seven older adults stood on a platform under no threat and threat conditions. Postural threat was manipulated by altering the expectation of a temporally and directionally unpredictable mediolateral support surface translation during quiet standing. Regardless of age, participants were more anxious, reported broad changes in attention focus, and increased centre of pressure (COP) amplitude and frequency with first threat exposure. With early threat exposure, participants were less anxious and increased COP frequency. With repeated threat exposure, participants were less anxious, reported reductions in threat-induced changes in attention focus, and decreased high frequency COP displacements. These results suggest young and older adults demonstrate similar patterns of emotional, cognitive, and postural adaptations to initial and repeated threat exposure.