For example, they may talk to another witness and use information from the conversation to fill in their reconstruction of the events. Again, it should be emphasized that people do this automatically and unconsciously and that it is not necessarily a purposeful attempt to deceive. Memory systematically distorts perception Memory tends to distort perception in systematic ways. For example, people tend to remember colors as being brighter and more saturated than they actually were. Other studies show that people asked to recall vehicle speed tend to overestimate slow speeds and to underestimate fast ones.
Additional studies show systematic basises in remembering distance and size.
Lastly, as noted above, memory also biases toward expected events.