Low Contrast-Preferring Neurons in V1 Maintain Perception of Familiar Objects in Contrast Variability

Article: How can our brain still perceive familiar objects even when they become indistinct?
Source: National Institute for Physiological Sciences (Japan)
Published: November 27, 2021 

After repeated experience, a subset of neurons in V1
exhibits strong responses to low-contrast visual stimuli

The appearance of objects can change in different lighting conditions, such as decreases to contrast in dim lighting or foggy weather. Yet, the brain perceives the object as the same object even when its features become less distinct. Researchers in Japan sought to investigate the mechanism behind the visual system's flexible representation of information, specifically how it maintains perception of low-contrast familiar objects. The prevailing thought is that the primary visual cortex (V1) processes visual information as a direct reflection of the strength of external stimuli; as such, high-contrast stimuli elicit stronger responses, and vice versa for low-contrast stimuli. In the present study, the scientists discovered that a number of neurons in V1 of the mouse visual cortex preferentially respond to low-contrast stimuli after repeated experience, such that low-contrast stimuli elicit stronger responses and high-contrast stimuli elicit weaker responses. The activity of these low contrast-preferring neurons fired more frequently in correct-choice than incorrect-choice trials, and were rare during passive viewing without training, demonstrating the influence of experience in strengthening the neural connections. A change in neuronal excitation-inhibition balance might also play a role. One of the authors states, "This flexible information representation may enable a consistent perception of familiar objects with any contrast." They suggest that artificial neural networks could better model vision by incorporating not only high contrast-preferring neurons but also low contrast-preferring neurons to improve discrimination of visual stimuli.

My rating of this study: ⭐⭐ 

Kimura R and Yoshimura Y. "The contribution of low contrast–preferring neurons to information representation in the primary visual cortex after learning." Science Advances.  7(48). 26 November 2021. https://doi.org/10.1126/sciadv.abj9976