Civil Engineering Reference
In-Depth Information
The average time to process information in the 3 processors is as follows: 100 ms for
perception; 70 ms for cognition; and 70 ms for action. These numbers depend upon the
task; a complex target with many details takes a longer time to process than a simple
target. For motor processors, however, the variability in time is not
FIGURE 5.3
Human information
processing. Adapted from a model by
Card, Moran, and Newell (1982).
HT=half-time of memory;
Cap=capacity; T=average processing
time.
so large; once a decision has been made, it takes a relatively short time to act upon it.
Taking these issues into consideration, the range of variability in perceptual and cognitive
processors is about 25-200 ms, and in motor processors about 30-100 ms (Card et al.,
1983).
At the top of the figure is the long-term memory (LTM). The LTM supposedly has
unlimited storage capability. This is probably not true—people do forget things that are
of less relevance, although under hypnosis and in dreams, information which has not
been retrieved for years can surface.
The mode of information in LTM is semantic; that is, it consists of concepts. Most
people store and retrieve information from LTM in terms of concepts. For example, you
can teach a child how to read a watch, no matter whether the face of watch has numbers
or markers.
