Sensory information passed through the attentional filter resides temporarily in a processing stage called °working'. or short-term memory. Working memory is like a scratch pad where people collect the information (visual, auditory, knowledge stored in the permanent long-term memory) needed to interpret sensory input and to make decisions. Working memory, however, has two severe limits that often play a role in accidents:
Information remains in working memory for a short time, maybe 30 seconds, if it is not used or refreshed. The cyclist could refresh working memory, for example, by continuously looking at the blue blob. Once the cyclist looks away, the blue blob must be processed or it will be lost within a very short time.
Older Information may be flushed out at any time by to input. Working memory has very low capacity, 0new information may chase out old. For example, several studies show that recall of road signs is remarkably poor. The researchers stopped drivers a few hundred yards after a road sign and found that recall was as low as 18%. although the signs had been seen only seconds before. Presumably, new information had pushed the signs out of working memory. Since working memory records all sorts of information, a few words from radio or cell phone, could also fill it up and cause other objects to be forgotten.