Psychomotor Skills Psychomotor skills are the mental and physical skills needed to perform a task. It is simply the ability to plan and control movements. Reaction Time They say ‘TIME IS MONEY’!! Human factors specialists help the human operator respond more rapidly to system demands. Question: Why people are slow in some situations and fast or too fast in others? Donders (a Dutch physiologist) established three different reaction times (A,B, and C): 1. A Reaction time: only one stimulus and one response. It is called a simple reaction. The time between the onset of the stimulus and the response is called simple reaction time. It only require nervous system conduction time.

2. B Reaction time: More than one stimulus and each stimulus has its own unique response. It is called a choice reaction situation because it requires identifying one of several possible stimuli and choosing the correct response. 3. C Reaction time: Several stimuli but only a single response. It requires identification of stimuli but no response selection. Based on information theory; there is no information present with only a single alternative. There is no response information but there is a stimulus information. If A is subtracted from C; the result is an estimate of the time needed for mental identification (stimulus identification time). If C is subtracted from B ; the result is an estimate of the time needed for mental selection (response selection time). B requires both stimulus identification and response selection, C requires stimulus identification, and A does not require any response selection or stimulus identification. A RT < C RT< B RT