en Clinical Neuroscience Clinical Neuroscience Original Original <strong>Introduction</strong>: The neural substrates of temporal processing are not still fully known. The majority of interval timing studies have dealt with this subject in the context of &ldquo;Explicit timing&rdquo; (computing the time intervals explicitly). The hypothesis &ldquo;Implicit timing&rdquo; (implicitly using temporal processing to improve function) has also proposed. This lesion study addressed explicit and implicit timing paradigms simultaneously using identical experimental tasks.<br> <strong>Methods</strong>: In this case-control study, 15 patients with Right Hemisphere Damage (RHD) and 15 patients with Left Hemisphere Damage (LHD) and 15 age-matched normal subjects were included. Participants performed a temporal reproduction task (assessing explicit timing) and a temporal prediction task (assessing implicit timing) in two sub- and supra-second intervals.<br> <strong>Results</strong>: Our results showed that RHD can lead to significantly lower accuracy in the temporal reproduction task in sub-second (p=0.005) and supra-second (p=0.001) intervals, compared with the normal subjects. Also, LHD led to perturbation in temporal prediction task by an increase in reaction time (lower accuracy) in sub- (p=0.011) and supra-second (p=0.006) time intervals than the normal subjects.&nbsp;<br> <strong>Conclusion</strong>: Overall, our findings suggested that there is a right hemispheric bias in the neural substrate of explicit timing, in both sub- and supra-second intervals. Furthermore, for the first time in a lesion study, we showed the evidence of left-hemispheric bias in neural substrates of implicit timing. Lesion study, Interval timing, Explicit timing, Implicit timing 301 312 http://bcn.iums.ac.ir/browse.php?a_code=A-10-1324-1&slc_lang=en&sid=1 Ali Hosseini 13700319475328460027191 13700319475328460027191 No Department of Biomedical Sciences, Faculty of Pharmaceutical, Biomedical and Veterinary Sciences, Universiteitsplein, Antwerp, Belgium. Sajjad Rezaei 13700319475328460027192 13700319475328460027192 No Department of Psychology, Faculty of Literature and Humanities, University of Guilan, Rasht, Iran. Alia Saberi alia.saberi.1@gmail.com 13700319475328460027193 13700319475328460027193 Yes eurosciences Research Center, Neurology Department, Pouursina Hospital, School of Medicine, Guilan University of Medical Sciences, Rasht, Iran.