| |
Abstract:
Abstract: Reaction time (RT) that increases as movement
difficulty increases is considered to be strong support for the
motor program construct (Henry & Rogers, 1960). In this
context, since all movement specifications are provided prior to
the RT stimulus, increases in RT are attributed to the time it
takes to "load" or "unload" a more "detailed" motor program.
However, underlying anatomical constraints may simply increase as
task complexity increases. Here, RT costs may be explained by the
time it takes to activate brain mechanisms with increased
constraints. In the present experiment, visual stimuli were mapped
to hand/foot dual-responses. Dual ipsilateral hand/foot RTs were
70ms faster than dual contralateral hand/foot RTs. In principle,
ipsilateral dual-responses were controlled by a single hemisphere
and contralateral dual-responses were controlled by both
hemispheres. Hence, since (motor program) hand/foot task complexity
was held constant across laterality conditions, the difference in
RT is attributed to time costs associated with activating increased
(anatomical) control constraints.
|
