title: A Decline in Response Variability Improves Neural Signal Detection during Auditory Task Performance.
abstract: The detection of a sensory stimulus arises from a significant change in neural activity, but a sensory neuron's response is rarely identical to successive presentations of the same stimulus. Large trial-to-trial variability would limit the central nervous system's ability to reliably detect a stimulus, presumably affecting perceptual performance. However, if response variability were to decrease while firing rate remained constant, then neural sensitivity could improve. Here, we asked whether engagement in an auditory detection task can modulate response variability, thereby increasing neural sensitivity. We recorded telemetrically from the core auditory cortex of gerbils, both while they engaged in an amplitude-modulation detection task and while they sat quietly listening to the identical stimuli. Using a signal detection theory framework, we found that neural sensitivity was improved during task performance, and this improvement was closely associated with a decrease in response variability. Moreover, units with the greatest change in response variability had absolute neural thresholds most closely aligned with simultaneously measured perceptual thresholds. Our findings suggest that the limitations imposed by response variability diminish during task performance, thereby improving the sensitivity of neural encoding and potentially leading to better perceptual sensitivity.
  
  
  
  The detection of a sensory stimulus arises from a significant change in neural activity. However, trial-to-trial variability of the neural response may limit perceptual performance. If the neural response to a stimulus is quite variable, then the response on a given trial could be confused with the pattern of neural activity generated when the stimulus is absent. Therefore, a neural mechanism that served to reduce response variability would allow for better stimulus detection. By recording from the cortex of freely moving animals engaged in an auditory detection task, we found that variability of the neural response becomes smaller during task performance, thereby improving neural detection thresholds.
authors: Center for Neural Science, g.vontrapp@nyu.edu.
authors: Gardiner
authors: G
authors: von Trapp
authors: Center for Neural Science.
authors: Bradley N
authors: 0000-0002-9864-7798
authors: BN
authors: Buran
authors: Department of Biomedical Engineering, College of Engineering, Boston University, Boston, Massachusetts 02215.
authors: Kamal
authors: K
authors: Sen
authors: Center for Neural Science.|Department of Psychology, and.
authors: Malcolm N
authors: 0000-0001-9491-146X
authors: MN
authors: Semple
authors: Center for Neural Science.|Department of Psychology, and.|Department of Biology, New York University, New York, New York 10003, and.
authors: Dan H
authors: DH
authors: Sanes
mesh_terms: D000818:Animals; D001303:Auditory Cortex / Q000502:physiology*; D001307:Auditory Perception / Q000502:physiology*; D000066670:Cell Plasticity / Q000502:physiology*; D005849:Gerbillinae; D008297:Male; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D011984:Sensory Receptor Cells / Q000502:physiology*; D013647:Task Performance and Analysis
keywords: amplitude modulation; attention; auditory cortex; neurometric; signal detection theory