Jeroen van Boxtel¹ (), Pratik Raul¹, Richard Barry², Faran Sabeti¹; ¹University of Canberra, Bruce, Australia, ²Blink Eye Clinic, Canberra, Australia

Stimulus noise is generally considered detrimental to performance. However, under some conditions noise can actually improve performance, an effect called stochastic resonance, or stochastic facilitation. Past research on the beneficial (and detrimental) effects of noise on perception has strongly focused on white pixel noise. However, some research indicates that noise with different spatio-temporal content (e.g., pink noise, or brown noise) may be more beneficial to performance. Here, we compared the impact of different colours of noise, both beneficial and detrimental, in a letter discrimination task. Stimuli were 10 letters – one per trial – embedded in noise, presented on a gray background. A staircase was run to determine threshold letter size (i.e., visual acuity) in a 10 alternative choice task, performed at 7 levels of pixel noise (0, 0.25, 0.75, 2.3, 7, 21, 64 sigma in pixel intensity). We found small beneficial effects of noise for all noise colours, at low levels of stimulus noise (0.25, and 0.75), i.e. stochastic resonance. At higher levels of stimulus noise, performance deteriorated, but to a significantly lesser degree for brown noise. Otherwise, there was no difference between the different colours of noise. These findings suggest that noise can indeed improve performance, and that the spatio-temporal composition of the noise does not strongly influence the beneficial effects of noise in a letter discrimination task.

Acknowledgements: This research was partially funded by the Australian Government through the Australian Research Council Discovery Project (project number DP220100406).