Switching between simple cognitive tasks: the interaction of top-down and bottom-up factors.
How do top-down factors (e.g., task expectancy) and bottom-up factors (e.g., task recency) interact to produce an overall level of task readiness? This question was addressed by factorially manipulating task expectancy and task repetition in a task-switching paradigm. The effects of expectancy and repetition on response time tended to interact underadditively, but only because the traditional binary task-repetition variable lumps together all switch trials, ignoring variation in task lag. When the task-recency variable was scaled continuously, all 4 experiments instead showed additivity between expectancy and recency. The results indicated that expectancy and recency influence different stages of mental processing. One specific possibility (the configuration-execution model) is that task expectancy affects the time required to configure upcoming central operations, whereas task recency affects the time required to actually execute those central operations.
Ruthruff
E
E
National Aeronautics and Space Administration-Ames Research Center, Moffett Field, California 94035, USA. eruthruff@mail.arc.nasa.gov
Remington
R W
RW
Johnston
J C
JC
D003071:Cognition; D006801:Humans; D011597:Psychomotor Performance; D011930:Reaction Time