Covert judgements are sufficient to trigger subsequent task-switching costs.

This research examines whether we have a tendency to repeat mental processes leading to decisions or judgements that are not accompanied by overt behaviours. We adapted the task-switching paradigm so that on selected trials task processing would be terminated prior to response execution. Switch costs were present subsequent to trials where task processing was terminated either at the stage of response selection or at the earlier stage of making a covert judgement (a mental decision) about the target stimulus. These costs were residual, as they occurred despite long preparation intervals, and they did not result from cue-switching or feature-repetition effects. We conclude that the same type of control mechanism may be recruited to select between potential alternative tasks whenever a stimulus needs to be processed in a task-specific way, regardless of whether or not an overt response is required.