Contribution of Sensory Encoding to Measured Bias

Area of Science:

• Neuroscience
• Cognitive Science
• Computational Neuroscience

Background:

• Signal detection theory (SDT) is a framework for perceptual decision-making, yielding sensitivity (d') and bias (c).
• Bias is influenced by both decision criteria and sensory encoding, but the direct impact of sensory encoding on bias is not fully understood.

Purpose of the Study:

• To investigate whether sensory encoding processes in the primary visual cortex (V1) can directly influence behavioral bias measured by SDT.
• To determine if manipulating V1 neuronal excitability affects both behavioral and neuronal measures of bias.

Main Methods:

• Optogenetic manipulation of neuronal excitability in mouse V1 during orientation discrimination and contrast detection tasks.
• Extracellular recordings from V1 neurons in passively viewing mice to assess neuronal bias.
• Modulation of V1 encoding quality via stimulus contrast and interstimulus interval.

Main Results:

• Increased V1 excitability decreased behavioral bias; decreased excitability increased bias.
• Optogenetic manipulation shifted neuronal bias in V1 in the same direction as behavioral bias.
• Changes in stimulus contrast or interval consistently altered both behavioral and neuronal bias.

Conclusions:

• Sensory encoding processes in V1 are sufficient to drive changes in bias measured by SDT.
• Neuronal bias in sensory areas directly contributes to behavioral bias.
• SDT bias is sensitive to alterations in sensory encoding, independent of sensitivity changes.