Habituation-dishabituation

The principal benefits of the habituation-dishabituation test arise from the speed of testing and the minimal need for equipment. Each animal may complete a nine trial session in less then 30 minutes. An additional advantage comes with the sequential presentation of the stimuli as this methodology avoids the problems associated with the mixing of vapours from different odour stimuli if the odours are presented simultaneously. The test is particularly well suited for field work as the stimuli may be presented on a substrate that the subject normally investigates, thus elicting a more natural response than one might encounter in a lab environment. 

If a null result ensues, subsequent replication of the experiment is one way to feel more confident that the results are reliable. Alternatively, the animals may be trained in a conditioned odour preference task as described below. This would enable the investigator to further understand why the subjects did not respond in the habituation-dishabituation task. Videotaping the results should also become standard practice. As well as creating a permanent record that enables behavioural... 

Schellinck, H.M., Rooney, E. and Brown, R.E. (1995) Odors of individuality of germfree mice are not discriminated by rats in a habituation-dishabituation procedure. Physiol. Behav. 57,... 

Four main experimental paradigms have been used in the study of MHC-associated odours (Eggert et al., 1999). These are mate choice pregnancy block (the Bruce effect) trained discrimination and habituation-dishabituation. 

The habituation-dishabituation method suffers from some of the problems associated with the trained discrimination procedure principally that it lacks a known functional context. However there is another important fundamental limitation in the habituation-dishabituation paradigm, which is that it relies entirely on an investigation response. As we discuss in Section 3, investigation alone can never be a definitive measure of individual recognition. 

In both the mate choice studies (where mating is prevented) and the habituation-dishabituation test, investigation of an odour source is measured as the behavioural response. However, little attention is usually paid to the functional meaning of investigation in these contexts. We believe that investigation is of limited value in studies of individual recognition, because it is not a specific functional response. 

I use the term discrimination to refer to the basic sensory ability to distinguish between two odors, in this case the odors of two individuals. These abilities can be directly assessed by a number of methods, but the most common are trained discriminations and habituation-dishabituation methods. 

We collected the odors of MHC-congenic rats ( PVG PVG.Rl) maintained on a standard lab chow (Purina) or on a test diet designed to prevent the growth of caecal bacteria (Teklad TD 69466). Rats tested in the habituation-dishabituation task could discriminate between the urinary odors of genetically identical rats after the change from Purina to... 

To determine if the results of either the habituation-dishabituation task or the operant-olfactometer paradigm are relevant to the processes adopted by rats and mice in recognizing individual conspecifics, it will be necessary to examine the relationship among genetic and dietary factors in semi-natural populations. The procedure used by Manning, Wakeland Potts (1992) provides a model for such experiments. 

Habituation-dishabituation tests are based on the premise that successive presentations of a stimulus odor to a subject result in habituation of the behavioral response to that odor (Schellinck Brown 1995). Subjects will respond, however, to a different or novel odor. A change in behavior indicates that the second odor can be discriminated from the first. Lack of response is sometimes taken to indicate a lack of discrimination. However, as we have discussed previously, the failure to display an unlearned response can not be taken as certain evidence against either recognition or discrimination. 

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