Sex Differences in Certain Mental Disorders Among Whites and Negroes in Georgia During the Decade 1923-1932

In two three-interval temporal forced-choice experiments eight subjects were tested to determine the effect of a cue on the rate of detection of a signal when both cue and detection stimulus were of very brief duration and were separated by randomly varied temporal intervals (delta ts). Delta ts ranged from a cue precedence of 900 msec, through simultaneous presentation, to a detection-stimulus precedence of 900 msec.

A significant quadratic trend was found in the delta-t variable, with maximum detection when cue and detection stimulus were simultaneous, and there was an indication that the quadratic trend differed between the two stimulus combinations. An attempt was made to distinguish between attentional effects linked to the time of occurrence of the cue and attentional effects linked to the time of occurrence of the detection stimulus.