Abstract
In a blind walking task, participants can be induced to under or overestimate the distances to visual targets by training them with mismatching viewed and walked distances (Ellard & Thompson, VSS 2002). This may indicate that participants have recalibrated the relationship between visual space and action space, or it might mean that they have learned a series of associations between the appearance of a target and the effort required to walk to it. In order to distinguish between these possibilities, we conducted new studies in which we trained participants using mismatched visual and walked target locations, and then tested them by asking them to either throw a ball at a visual target or to complete a spatial updating task. In both cases, the training consisted of 21 blindwalking trials at distances ranging from 8 to 16 m. On each trial, the participant was asked to view the target and then, while blindfolded, they were led to a location that they were told corresponded to the visual target location. In conflict conditions, the walked location was either 20% closer (−20 condition) or 20% further away (+20 condition) than the visual target location. Following training, some participants were required to throw a ball at a visual target. Other participants were presented with a spatial updating task in which they were asked to briefly view an offset visual target, walk forward without vision until told to stop, and then turn to face the target Results from both the ball throwing and the updating task showed that the conflict training exerted an effect on responses in the predicted directions, but the −20 condition exerted a much stronger effect than the +20 condition. These findings provide preliminiary evidence that our training procedure recalibrated the relationship between visual space and action space.