Schettino, L. F., *Pallottie, A., *Borland, C., *Nessa, S.,* Nawroj, A., Yu, Y.-C. (2013) The organization of digit contact timing during grasping . Experimental Brain Research, 227, 477-486.
*denotes research students
My students and I, in collaboration with Professor Yih-Choung Yu of Electrical and Computer Engineering, have recently published the first detailed study looking at the organization of finger contact timing during grasping. In order to capture the time at which each finger makes contact with a target object, we designed and implemented an instrumented glove that captures data at 1000 points per second. Our results show that normal human adults tend to employ a radial to ulnar ordering (from index finger to little finger) that is modified according to task constraints. Furthermore, we found evidence to support the notion that the index finger has an important role to play during a grasp. We have suggested that such role, at least in part, may be due to a need to capture haptic information (tactile and proprioceptive information produced during movement).
The relevance of this work comes from the realization that in order to understand how the brain coordinates complex movements, we need to understand the natural statistics of the motor output at all levels. Continuing research in my lab and through collaborations allows us to ask questions at the behavioral, somatic and neural level.
The distribution of digit contact ordering patterns for all trials for each of the 120 possible permutations of 5 digits, starting with 1-2-3-4-5 and ending with 5-4-3-2-1. Letters a-h mark the permutations with the highest trial counts (defined in the inset). As can be observed, there are clear preferences for a reduced number of permutations containing an even smaller number of four-digit patterns. The dashed line represents chance level.