The temporal parameters of visual-proprioceptive intermodal integration in infants and adults

Proprioception, or the internal sense of the position and movement of body parts, is to a large extent the forgotten sense. Yet, it is as important for the organization of goal-directed action as the other, externally oriented senses, such as vision and audition. In this research program proposed here, we intend to study proprioception in both infants and adults by examining the temporal window over which proprioceptive awareness occurs. Using a video delay device, we present visual feedback of hidden body movements. We can then investigate the degree of delay that is required before participants recognize that there is a delay and also the degree of delay over which participants can still detect a correspondence between the internal feeling of movement and the visual feedback of that movement. In this way, we can assess proprioception by studying the integration of proprioception and vision in perception and in short term memory. With infants as young as 6 months of age, we will use an intermodal visual preference procedure whereby infants are shown video of their own hidden leg movements. We will record the infants' looking time to video that is live versus delayed. We will also compare relative looking time to video that is delayed by different amounts of time. With adults, we will also present video of hidden movements (in this case arm movements). To study adults' ability to perceive the correspondence between visual and proprioceptive stimulation, we will request judgements of whether the video is live or delayed. With adults, we will also manipulate the type of movements they perform. To study adults' proprioceptive short-term memory, we will present video delayed by different amounts of time and request judgements of whether the video is a playback of their own movements or a recording of another actor. This program of research will be the first comprehensive examination, focusing on the temporal characteristics, of both adults' and infants' perception and short-term memory of proprioceptive information.