The purpose of this study is to evaluate the roles of various brain regions in temporal-discrimination learning by using electrophysiological activity. Temporal-discrimination learning which include in timing is one of the most important properties of behavior. There are three major methods to study time perception in animals, this is, temporal-discrimination or temporal-bisection procedure, temporal-differentiation procedure (e. g. DRL, DRLL), and peak-interval (PI) procedure. I had three experiments that were temporal-discrimination between 2-sec and 8-sec, DRLL 4 sec schedule, and peak-interval 30-sec procedure. I had the results that all method could reach the criterion in learning without any problem. I published an article in Japanese Physiological Psychology and Psychophysiology in April 2003.
EEG is reflected by the brain activity associated with certain temporal decision processes. Changes in brain responsiveness to an external stimulus can be investigated by the measurement of evoked potentials. An internal stimulus such as the judgment of a temporal criterion will evoke an even-related potential (ERP). The stimulus onset ERPs consisted of P2, N2, and P3-like components. P3-like component was consistently observed for the frontal cortex and hippocampal CAI. Significantly greater amplitudes of the P3-like components was observed during the temporal-discrimination task when compared to the simple reaction-time task. At the stimulus offset, P2, N2, and P3-like components were elicited as well as the stimulus onset. P3-like component in the frontal cortex at the stimulus offset was larger for the temporal-discrimination task than for the simple reaction-time task. I also calculated hippocampal power spectra. The hippocampal theta power increased more in the temporal-discrimination task than in the temporal control task at the onset of the auditory stimuli. I presented at the neuroscience meeting in 2002 entitled timing behavior and photic driving on EEG in rats. I published a paper dealing with working memory and processing of temporal information.