Abstract - Klooster

Gestures make memories, but what kind? The cognitive and neural mechanisms of hand gesture

Abstract: Gestures influence communication by transmitting ideas from speakers to listeners. Gestures have been shown to help people learn and remember new information, suggesting that gestures impact cognition beyond supporting the expression of already-formed ideas. The cognitive and neural mechanisms that support gesture, however, are unknown. To investigate these mechanisms we will study participants who have different patterns of intact and impaired memory systems: patients with bilateral hippocampal damage who have severe and selective impairments in declarative memory; patients with Parkinson's disease with striatal dysfunction and impairments in non-declarative memory; and demographically matched healthy comparison participants who have no memory impairment. Participants will view a video of someone explaining how to solve the Tower of Hanoi, and then will solve it themselves on a computer. Their mouse trajectories will be recorded to see if they match either the large arching or flat sideways hand gestures seen in the videos. If viewing gestures affects amnesics' later actions, this will be strong evidence that a healthy hippocampus and intact declarative memory are not necessary for the comprehension and mental representation of gesture. Conversely, if Parkinson's patients' later actions reflect the gestures they viewed, this will show that a normally functioning striatum and normal procedural memory are not necessary for the comprehension and mental representation of gesture. (Nate Klooster, collaborating with Melissa Duff and Susan Wagner Cook).