Auditory inspection time and intelligence: A new spatial localization task

Sixty-seven university undergraduates were tested on a new auditory inspection time (AIT) task based on the ability of human subjects to locate the left or right position of a stereophonic source and on a modified version of the Raven's Progressive Matrices (MRPM). The AIT task required subjects to locate the spatial position of a dichotic phantom lateralized by a phase difference to their left or right side that was backward masked by a high intensity source located in the midline of the head. Unlike previously described AIT tasks all subjects were able to perform the task. The log of AIT threshold was significantly correlated with the MRPM (r = -0.37). In a further sample (n = 41) an r of -0.61 was observed; this latter sample was retested, with a delay of between 3 and 10 days and an r of -0.57 was obtained on this second occasion. In comparison. the correlation between visual inspection time (VIT) and MRPM in this sample was -0.41 and -0.21 on retest. Test-retest reliability for AIT was high (0.82) and comparable to that obtained in the same sample for VIT (0.76). It is concluded that this new AIT task appears to be accessible to a wider range of subjects than the successive frequency discrimination tasks employed by others.