A signal-detection approach to subception: Concomitant verbal and finger-latency responses in metacontrast

Metacontrast conditions were created by the onset of flanking lights designed to mask the prior blink of an otherwise steady center light. For pseudometacontrast trials, the center light did not blink in advance of the flanking lights. Responses were an immediate finger-key release to the first detectable change in the visual display followed by a statement of whether the center light had been doused. A signal-detection analysis was used to avoid both threshold and response-criterion problems. Verbal report was, on the average, more sensitive than finger latency in detecting the masked blinks. However, there were large and consistent individual differences; reaction time was the more sensitive for a few subjects. Data analysis revealed that each response system showed detection with the other system “partialed out.” A model was offered in which verbal- and finger-response systems act in parallel, with uncorrelated variability between systems accounting for the subception effect.