Habituation in the jumping spider Trite planiceps
Degree GrantorUniversity of Canterbury
Degree NameMaster of Science
The ability to filter out repetitive, irrelevant, background stimuli prevents the nervous system from being flooded with information. However, animals must be particular to which stimuli they attend to and those that they ignore, as mistakes could have a high cost. One of the most fundamental forms of learning is habituation. Habituation is a form of non-associative learning, meaning that it is not linked with any other stimuli - it is simply the repetition of the same stimulus. I explored several characteristics of habituation with the New Zealand jumping spider Trite planiceps. These salticids are highly visual, and I used a visual stimulus in all experiments, as moving visual stimuli trigger a readily observable optomotor response. Firstly, I exposed T. planiceps to a repetitive visual stimulus, either in alternating or random fashion, and found that after only fifteen repetitions the orientation responses had dropped below 50%. I then explored the effect of interstimulus interval (ISI), using either an ISI of 10 s or 20 s between stimulus presentations. T. planiceps showed a significant difference in response decrement to repeated visual stimulation between the two ISIs, as found in other arthropods. Finally, I tested dishabituation, which is the recovery of the habituated response after the presentation of a novel stimulus, using a double air puff as the novel stimulus. Surprisingly, I got only a small response from T. planiceps, which was quite unlike the comparative literature of dishabituation on arthropods. I explain the possible reasons for this response in detail. While my data suggest that T. planiceps does habituate to repeated presentation of a visual stimulus, further testing is required before firm conclusions can be made.