Henry Kennedy has invited Mathew Diamond from SISSA (Trieste, Italy) to come and give a talk on:
Unified framework for perception of stimulus intensity and perception of time in human and rats:
Demonstration of sensory integration in behavior implies the existence of at least two levels of neuronal processing – stages at which the instantaneous quantity of the stimulus is reliably encoded and further stages at which information is integrated over time. However, the neuronal circuitry by which evidence is accumulated remains to be identified. We are examining how a touch percept evolves over time, and the neuronal basis of this evolution. Our experiments show that the perception of stimulus intensity is confounded by stimulus duration, and the confound may originate in a neuronal population of frontal cortex that multiplexes intensity and duration. Further experiments show that the confusion is symmetrical: both humans and rats are confounded stimulus intensity when they attempt to estimate stimulus duration. This motivates to our attempt to form a unified model for time and magnitude estimation. Neurons in rat somatosensory cortex encode ongoing speed values, whereas neurons in premotor cortex encode speed integrated over time. In conclusion, in rats and humans touch is accumulated, not averaged, an operation that leads to confusion between duration and magnitude; premotor cortex is a critical center for accumulation.
ISC Amphi - 11 til 1pm