title: Extended LATER model can account for trial-by-trial variability of both pre- and post-processes.
abstract: We present a new decision-making model that can account for trial-by-trial variability induced by a process ("pre-process") that occurs before an explicit sensory signal specifying a later motor response. A process after explicit sensory signals, referred to herein as the "post-process", has been investigated by a variety of so-called rise-to-threshold models including the LATER model. The LATER model formulates post-process variability but treats the pre-process as fixed within a block of an experiment. We propose an extension of the LATER model, which we call the extended LATER (ELATER) model, to account for trial-by-trial variability of both pre- and post-processes together. We present the mathematical formulation of the ELATER model and analyze its characteristics, including numerical examples and an example of saccade latency data in reward-manipulated conditions with caudate activity. The ELATER model is useful for investigating decision making by taking account of trial-by-trial variability of both pre- and post-processes.
authors.affiliation: Laboratory for Integrated Theoretical Neuroscience, RIKEN Brain Science Institute, 2-1 Hirosawa, Wako, Saitama, Japan. hn@brain.riken.jp
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Nakahara
authors.forename: Kae
authors.initials: K
authors.lastname: Nakamura
authors.forename: Okihide
authors.initials: O
authors.lastname: Hikosaka
mesh_terms: D000818:Animals; D003657:Decision Making; D004192:Discrimination, Psychological / Q000502:physiology*; D006801:Humans; D008960:Models, Psychological; D009474:Neurons / Q000502:physiology; D011336:Probability; D011930:Reaction Time / Q000502:physiology*; D015203:Reproducibility of Results; D012201:Reward; D012438:Saccades / Q000502:physiology; D012684:Sensory Thresholds / Q000502:physiology