Nr. Burns et al., TESTING THE INTERPRETATION OF INSPECTION TIME AS A MEASURE OF SPEED OF SENSORY PROCESSING, Personality and individual differences, 24(1), 1998, pp. 25-39
Explaining the relationship between inspection time (IT) and IQ depend
s on understanding the psychophysics of IT. White's (1996, Personality
and Individual Differences, 20, 351-363) argument that IT is a measur
e of temporal resolution within the visual system was tested. Two pred
ictions were made on the basis of White's argument that IT does not de
pend on line-length discriminations but on discriminating target from
mask. First,;radically different target-mask configurations would resu
lt in the same response outcome. Second, increasing the number of alte
rnative targets would not increase IT. Three subjects performed four p
attern masking tasks presented on a LED display with stimulus onset as
ynchronies (SOAs) ranging from 0-75 msec and using three configuration
s of backward mask. Results met the predictions. Psychometric function
s for different tasks were near identical and IT estimates did not inc
rease as the number of targets was increased. It is therefore possible
that the IT-IQ relationship applies generally to pattern backward mas
king tasks. Results also confirmed the prediction (Levy, 1992, Persona
lity and Individual Differences, 13, 987-1002; White, 1996, Personalit
y and Individual Differences, 20, 351-363) that discriminative accurac
y does not rise above chance level until after some small, non-zero SO
A. (C) 1998 Elsevier Science Ltd. All rights reserved.