These factor may be important in the context of products that may be used in, for example, circumstance of extremely low or high psychological arousal. Consider, for example, radar operators. These people may have to monitor radar screens for long periods of time, during which they may become bored, tired and under-stimulated. In order to design radar systems that are readable under such circumstances, it is important to have an understanding of how people's signal detection performance is likely to be affected by such factors. This is an area that has received a great deal of attention from psychologists and human-factors specialists see.