<P> Participants are asked to identify which of several items (two to four) is correct . One of the presented items is the target--a previously presented item . The other items are similar, and act as distractors . This allows the experimenter a degree of manipulation and control in item similarity or item resemblance . This helps provide a better understanding of retrieval, and what kinds of existing knowledge people use to decide based on memory . </P> <P> When response time is recorded (in milliseconds or seconds), a faster speed is thought to reflect a simpler process, whereas slower times reflect more complex physiological processes . </P> <P> Hermann von Helmholtz was the first psychologist to inquire whether the velocity of a nerve impulse could be a speed that is measurable . He devised an experimental set - up for measuring psychological processes with a very precise and critical time - scale . The birth of mental chronometry is attributed to an experiment by Helmholtz's colleague, Franciscus Donders . In the experiment, he attached electrodes to both feet of the subject . He then administered a mild shock to either the left or right foot, and told the subject to move the hand on the same side--which turned the stimulus (the shock) off . In a different condition, the subject was not told which foot the stimulus would act on . The time difference between these conditions was measured as one - fifteenth of a second . This was a significant finding in early experimental psychology, because researchers previously thought that psychological processes were too fast to measure . </P> <P> An early model of dual process theories was suggested by Atkinson and Juola's (1973) model . In this theory, the familiarity process would be the first activated as a fast search for recognition . If that is unsuccessful in retrieving the memory trace, then there is a more forced search into the long - term memory store . </P>

When is the hippocampus involved in recognition memory