Memory for time intervals is impaired in left hemi-Parkinson patients

The basal ganglia have been proposed as one of the neural correlates of timekeeping functions. Both encoding and memory retrievalcomponents for time perception are impaired in Parkinson’s disease (PD). The aim of our study was to investigate in hemi-Parkinsonianpatients the existence of a specific alteration in memory for time depending on the affected side, to better understand the contribution of theleft or right basal ganglia circuits in different components of time perception. Right and left hemi-PD patients performed a time reproductiontask in which they were required to reproduce in the same session short (5 s) and long (15 s) time intervals, in off- and on-therapy condition.While the right hemi-PD patients overestimated the shorter interval, only the left hemi-PD group showed the memory migration effect,overestimating the shorter and underestimating the longer time intervals. These results argue for a critical involvement of the right basalganglia in memory retrieval for time intervals, in the range of seconds