Duration of Experienced Lengthening and Shortening of Straight Lines
The stimulus was a vertical, straight, red line which for 60 msec. was projected onto a medium grey screen 2 m. from S. In Exp. I the line was 8.5 cm. long and 2 mm. wide; in Exp. II the line was 17 cm. long and 2 mm. wide. Fixating the nethermost point of the short and long lines, respectively, Ss reported experiencing the line as lengthening from the point of fixation to full length and then shortening to the point of fixation. Ss' durations of experienced lengthening-shortening were measured (in msec.). For a given S the durations of lengthening-shortening of the 8.5-cm. line and the 17-cm. line were identical. Ss reported that the velocity of the experienced movement (lengthening-shortening) of the long line was greater than that of the short line. When 12 Ss were retested from 6 to 8 mo. later, their durations remained constant. Barbiturate caused a significant increase in durations of lengthening-shortening. This is consistent with the notion that the source of experienced lengthening-shortening is to be found in cortical brain processes. An electronic explanation of the experienced movement as a working hypothesis is offered.