This study investigated the mechanisms of flicker detection suppression by measuring mesopic rod and cone critical flicker frequencies (CFFs) at different center and surround illuminance levels. Stimuli were generated with a four-primary photostimulator that provided independent control of rod and cone excitations. The results showed that dim surrounds ≤0.2 Td suppressed cone-mediated CFFs at ≥...

Operant conditioning of the skin resistance response was obtained using a dim flash of white light as the reinforcing stimulus. The results confirm earlier reports using similar procedures from another laboratory, show no differential effect of the illuminance of a reinforcing light, and contrast sharply with a study which failed to replicate previous studies using light flashes as the reinforc...