Open Collections

The effects of changing the interstimulus interval during habituation in Caeorhaditis elegans

University of British Columbia

Although habituation is one of the simplest forms of non-associative learning, its underlying neural mechanisms are still not well understood. One factor that plays a key role in habituation is interstimulus interval (ISI). Understanding, at a behavioural level, the effects that ISI has on habituation may provide important insights into the cellular events involved in this form of learning. The experiments in this thesis further explored the role of ISI in habituation of the reversal response of the nematode Caenorhabditis elegans by examining the effect of changing the ISI during habituation training. The effect of ISI change was examined in terms of both its impact on habituation and its impact on spontaneous recovery from habituation. One type of ISI change tested was continual variation in the ISI used during habituation. When habituation stimuli were delivered at variable ISIs having an overall average of 10 s the recovery from habituation observed was slower than that seen when habituation stimuli were given at regular 10 s intervals. A comparison of fixed and variable stimulation during habituation with a 60-s ISI revealed no differences in recovery rate. Thus, the impact of variable ISIs during habituation on recovery from habituation was noticeable at a 10-s ISI, but not a 60-s ISI. In a second experiment, the effect of shifting to a different ISI part-way through habituation training was explored. Whether the shift was from a 10-s ISI to a 60-s ISI or a 60- to a 10-s ISI, in both cases the recovery rate (which is typically different for each ISI on its own) observed after habituation was primarily determined by the ISI given in the last half of the habituation treatment. Examination of the impact on response patterns resulting from variation or change in ISI generated a model of how response potential may interact with ISI that can be used to further understand the relationship between ISI and response magnitude during habituation.

Thesis/Dissertation

application/pdf

2008-09-09

For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.

http://hdl.handle.net/2429/1726

Psychology

University of British Columbia

UBCV

DSpace