The use of reaction time as a measure of information processing has a long-standing tradition in human experimental psychology. A great advantage of this parameter is that it directly reflects the assumed underlying psychological/ neuronal processes. Although the use of reaction time paradigms has been very powerful in studying human information processing, this parameter has not received much attention in animal research. It is assumed that valid reaction time paradigms in rodents can be valuable tools in studying the neurobiological mechanisms underlying elementary aspects of information processing.

Data will be presented in which the performance of rats is analyzed in a simple and choice reaction time task that was performed in an operant conditioning chamber. First, rats are pre-trained to push a hinged panel located in front of a food magazine to obtain a food reward. Then the rats first have to press the hinged panel and then a lever to obtain the reward. After acquiring this, the rats had to poke their nose for a variable period (i.e., hold duration) in the magazine and wait for a tone. The final stage of this task consisted of the following sequence. A trial was initiated by a rat by poking its nose into the food magazine. The rat had to hold it's nose in the magazine until a tone was switched on, which was presented after a variable hold duration (ranging from 0.5-1.5 s). If a rat withdrew its nose form the magazine before the tone was switched on, the trial was re-started and a premature response was scored. Responses after the tone were regarded as reaction responses to the stimulus, provided that the response was above 100 ms and faster than 1500 ms. Training in this task takes about 3-4 weeks. In the simple reaction time task only a high tone was presented and in the choice reaction time task either a high or a low tone was presented. If a low tone was presented the rat had to respond to the right lever and if a high tone was presented the rat had to respond to the other lever.

Based on mean reaction times and comparison between task conditions, it appeared that only the choice reaction time could validly be assessed in rats. The validity of this reaction time paradigm was also demonstrated by other characteristics of the behavioral performance of animals in this task. Thus, the evaluation of the variation of reaction times of (individual) animals provides evidence that these correspond with observations in human studies. Further validation of this reaction time paradigm was obtained by pharmacological and electrophysiological studies.

It is concluded that reaction times can be assessed in a Skinner box in rats but that there are several constraints. Further, a detailed behavioral analysis is required to assure that the responses reflect true reaction times. Finally, it is claimed that this type of paradigm provides a new approach in studying neurobiological mechanisms underlying information processing in rodents.

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