Neuronal thresholds and choice-related activity of otolith afferent fibers during heading perception.
How activity of sensory neurons leads to perceptual decisions remains a challenge to understand. Correlations between choices and single neuron firing rates have been found early in vestibular processing, in the brainstem and cerebellum. To investigate the origins of choice-related activity, we have recorded from otolith afferent fibers while animals performed a fine heading discrimination task. We find that afferent fibers have similar discrimination thresholds as central cells, and the most sensitive fibers have thresholds that are only twofold or threefold greater than perceptual thresholds. Unlike brainstem and cerebellar nuclei neurons, spike counts from afferent fibers do not exhibit trial-by-trial correlations with perceptual decisions. This finding may reflect the fact that otolith afferent responses are poorly suited for driving heading perception because they fail to discriminate self-motion from changes in orientation relative to gravity. Alternatively, if choice probabilities reflect top-down inference signals, they are not relayed to the vestibular periphery.
Interdisciplinary Institute of Neuroscience and Technology, Qiushi Academy for Advanced Studies, Zhejiang University, Hangzhou, Zhejiang Province 310027, China; Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030; and yuxiongj@zju.edu.cn angelaki@bcm.edu.
Xiong-jie
XJ
Yu
Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030; and.
J David
JD
Dickman
Brain and Cognitive Sciences, University of Rochester, Rochester, NY 14627.
Gregory C
GC
DeAngelis
Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030; and yuxiongj@zju.edu.cn angelaki@bcm.edu.
Dora E
DE
Angelaki
D000344:Afferent Pathways / Q000502:physiology; D000818:Animals; D002755:Choice Behavior / Q000502:physiology*; D008253:Macaca mulatta; D008297:Male; D009039:Motion Perception / Q000502:physiology; D009949:Orientation / Q000502:physiology*; D010037:Otolithic Membrane / Q000294:innervation*; D012372:ROC Curve; D012684:Sensory Thresholds / Q000502:physiology*; D013028:Space Perception / Q000502:physiology*
choice probability; heading discrimination; neuronal threshold; otolith afferent; psychophysical threshold