An Information Theoretical Analysis of neural coding of reach-to-grasp

FERNANDO MONTANI, ANDREY OLEYNIK, LUANA CASELLI, CESARE MAGRI, STEFANO PANZERI AND LUCIANO FADIGA

Pilsen, Czech Republic

Conferencia; 2nd INCF Congress of Neuroinformatics; 2009

Grasping is one the most evolved types of primate behavior, resulting from the transformation of a complex visuomotor process into specific motor commands required to reach-to-grasp an object. Higher order sensory and motor representations required in the process to reach and grasp an object appear to emerge from the neuronal firing rate. But, it has yet to be determined whether pre-motor and motor neurons encode information just in the numbers of spikes each neuron emits or also in the relative time of firing of the different neurons that might reflect synchronization. To address this question, we have applied an Information Theoretic approach to neuronal responses recorded in premotor and motor cortex to four different Light stimulus conditions throughout the process of reach-to-grasp an object. We considered first how complex neuronal representations of sensory and motor information are constructed from the activities of individual neurons. Averaged Mutual Information values provided by individual cells across the population, taking stimuli combinations with or without “Full Light condition”, allow us to classify cells without imposing a metric on the space of stimuli or responses. Second, we investigated if the synchronized firing of nearby neurons inside the pre-motor and motor cortex area can carry additional information about stimuli representation. Our findings show that synchrony within premotor and motor area is prevalent and informative. This suggests that interactions between neurons might be involved in the encoding of motor commands relevant to the process of reach-to-grasp.