title: Perceptual decision related activity in the lateral geniculate nucleus.
abstract: Fundamental to neuroscience is the understanding of how the language of neurons relates to behavior. In the lateral geniculate nucleus (LGN), cells show distinct properties such as selectivity for particular wavelengths, increments or decrements in contrast, or preference for fine detail versus rapid motion. No studies, however, have measured how LGN cells respond when an animal is challenged to make a perceptual decision using information within the receptive fields of those LGN cells. In this study we measured neural activity in the macaque LGN during a two-alternative, forced-choice (2AFC) contrast detection task or during a passive fixation task and found that a small proportion (13.5%) of single LGN parvocellular (P) and magnocellular (M) neurons matched the psychophysical performance of the monkey. The majority of LGN neurons measured in both tasks were not as sensitive as the monkey. The covariation between neural response and behavior (quantified as choice probability) was significantly above chance during active detection, even when there was no external stimulus. Interneuronal correlations and task-related gain modulations were negligible under the same condition. A bottom-up pooling model that used sensory neural responses to compute perceptual choices in the absence of interneuronal correlations could fully explain these results at the level of the LGN, supporting the hypothesis that the perceptual decision pool consists of multiple sensory neurons and that response fluctuations in these neurons can influence perception.
authors.affiliation: Department of Psychology, Vanderbilt University, Nashville, Tennessee;
authors.forename: Yaoguang
authors.initials: Y
authors.lastname: Jiang
authors.affiliation: Department of Cell and Developmental Biology, Vanderbilt University, Nashville, Tennessee; and.
authors.forename: Dmitry
authors.initials: D
authors.lastname: Yampolsky
authors.affiliation: Department of Cell and Developmental Biology, Vanderbilt University, Nashville, Tennessee; and.
authors.forename: Gopathy
authors.initials: G
authors.lastname: Purushothaman
authors.affiliation: Department of Psychology, Vanderbilt University, Nashville, Tennessee; Department of Cell and Developmental Biology, Vanderbilt University, Nashville, Tennessee; and Department of Ophthalmology and Visual Sciences, Vanderbilt University, Nashville, Tennessee vivien.casagrande@vanderbilt.edu.
authors.forename: Vivien A
authors.initials: VA
authors.lastname: Casagrande
mesh_terms: D000818:Animals; D003657:Decision Making / Q000502:physiology*; D053483:Eye Movement Measurements; D005403:Fixation, Ocular / Q000502:physiology; D005829:Geniculate Bodies / Q000502:physiology*; D008253:Macaca mulatta; D008255:Macaca radiata; D008297:Male; D008959:Models, Neurological; D009474:Neurons / Q000502:physiology*; D009483:Neuropsychological Tests; D010775:Photic Stimulation; D011594:Psychometrics; D011601:Psychophysics; D014796:Visual Perception / Q000502:physiology
keywords: choice probability; perceptual decision; thalamus; vision