Abstract
Normal aging is thought to be associated with specific decline in attention mechanisms of suppression (e.g., Schmitz et al., 2010). In particular, we have previously reported (Tzvetanov et al. 2013) reduced suppression in old age in a salience suppression task that has been shown to rely on proactive suppression in the left IPS (Mevorach et al., 2009). The effect of aging has also been documented in the motor control domain (e.g., Seidler et al., 2010) but the link between decline in attention and motor control is still poorly understood. In the present study we investigated the relation between reduced suppression in old age (as in Tsvetanov et al., 2013) and reduced motor control in a simple reaching task. Young and old participants had to reach for a predefined target as quickly and as accurately as possible. In certain blocks of trials distractors also appeared adjacent to the target. In addition, participants also performed a visual attention task using hierarchical letter stimuli. We found that young and old participants differed in their movement accuracy as well as in their ability to suppress distractors in the hierarchical letter task. Specifically, older adults showed increased movement error in the presence of distractors (but not when distractors were absent). Interestingly, the errors exhibited by the older participants reflected greater avoidance of the distractor in reaching for the target (i.e., older adults tended to reach away from the distractor in an exaggerated manner compared to young participants). Moreover, we also found a correlation (controlling for age) between a measure of attention suppression in the hierarchical letter task and the size of the reaching error. We suggest that motor control in the presence of distractors relies on suppression of the visual representation of the distractors (cf. Chapman et al., 2012) which may decline with age.
Meeting abstract presented at VSS 2016