Abstract
Choice reaction time and movement time were measured in a discrete visuo-manual pointing task. Two movement amplitudes (7.5 cm and 30 cm) and two target widths (1.5 cm and 6 cm) were used in all possible combinations. Movement time varied according to movement amplitude and to target width. However, some departure from the linear relationship between movement difficulty and movement time, known as the Fins' law, was observed. Choice RT varied according to movement amplitude, whereas target width influenced choice RT for short-amplitude movements but not for long-amplitude movements. It is concluded that the previously reported relationship between movement difficulty and choice RT primarily results from variations in movement amplitude.
Get full access to this article
View all access options for this article.