Touchscreen-based visual temporal discrimination task in the behaving mouse by the constant method

Abstract

Purpose : Critical fusion frequency(CFF), defined as the frequency at which a flickering light is perceived as a continuous light, is useful for assessing the temporal characteristics of the visual system. Using electrophysiological analysis such as flicker electroretinogram (ERG) and visual evoked potential (VEP), CFF has been studied (Ridder and Nusinowitz, 2006, Nusinowitz et al., 2007). However, the CFF has not been studied yet in terms of behavioral performance. Here we established a behavioral method for evaluating CFF of mice using the constant method that is one of the psychophysical techniques used for determining thresholds of various sensory functions.

Methods : C57BL/6 mice were trained to perform a two-alternative forced choice task in which steady (250Hz) light and flickering (4-20Hz) light were presented on a green light emitting diode (green LED, 508nm) screen. The temporal frequency of flickering stimulus was randomly chosen on each trial. Mice responded to steady light by making nose-poke toward touchscreen. The proportions of correct responses (PCRs) were measured.

Results : Results showed that PCRs became lower with increasing temporal frequency of flickering stimulus. In the 20Hz condition, PCRs were close to chance level. From the data obtained, we calculated a threshold. The results suggest that CFF in behaving mice is approximately 14Hz.

Conclusions : We established the method to evaluate temporal resolution of ON and OFF pathway-mediated vision in the behaving mice. This behavioral assay of mouse model could contribute to development of diagnosis of human retinal disease by applying genetically manipulated mice.

This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.