The Optimal Fitting Model for Aging-related Receptive Field Size Curve of Macaque V1 Neurons

Visual function in humans degrades during the early stage of senescence beginning from middle 50s to 60s. Generally, it may derive from the general decline of cortex inhibition, which destroys the balance between excitation and inhibition system in the brain. To date, the optimal fitting model of receptive field size curve is not clear during different age groups. To address this issue, firstly, we carried out extracellular single-unit studies of the receptive field properties of cells in the primary visual cortex(v1) in young and old rhesus monkeys. By IGOR, we obtain the original data of receptive field size curve. Secondly, we use the existing models of Gaussian, DOG (subtractive) and a normalization (divisive) model to fit the data. After that, we found clear indications: The fitting goodness of DOG has a high degree during different age groups and the DOG model has better adaptability and flexibility. In addition, we can draw a conclusion: In aging process, the turning curvature of receptive field size curve of V1 cells changes obviously, and the surround suppression of the receptive field decreases clearly.