List of Past Events
Multimodal sensory control of hands in object manipulation
Dr. Roland S. Johansson
From Thursday, May 05, 2005 - 11:00am
To Wednesday, May 04, 2005 - 12:00am
Ume� University, Sweden
Any purposeful action reflects a desire to turn from the current sensory state to a more advantageous sensory state, which thus represents the goal of the action. Natural object manipulations involve action plans composed of sequences of action phases whose goals are organized around contact events involving the hands and manipulated objects. The prediction of useful motor commands for each action phase uses different types of sensorimotor `initial state' information. In conjunction with memory mechanisms, visual and tactile modalities identify important hand-object relations and physical properties of objects involved, such as shape, surface friction, mass, and distribution of mass. Furthermore, learning and maintenance of sensorimotor correlations that underlie predictions of suitable motor commands requires that the brain monitors and evaluates the sensory consequences of executed motor commands.
To this end, current evidence suggest that the brain establishes checkpoints that correspond to predicted alignments in space and time between haptic and gaze events that correspond to goal completion of task phases. This multimodal sensory information, when put in register with corresponding efferent copy, proprioceptive and sometimes auditory signals, presumably supports learning and upholding of the correlations required between `initial state' information and suitable motor commands. In the framework of this general control scheme, I will discuss encoding of important fingertip events by tactile afferents and the capturing of visual information as reflected by gaze behaviour and eye-hand coordination.
Dr. Roland S. Johansson
