Study 1 - A Guinea pig's Immobility Response to Sound
If a novel stimulus was introduced into an environment, like a sound or loud noise, it is likely that a guinea pig will stop what it is doing and freeze movement, and perform what is called a immobility response. An abbreviation of this would be IR.
An IR(at least for a guinea pig), “varies from a brief pause in ongoing activity to a full-blown response with a characteristic posture in which the back is arched, the head is up, and the front legs are extended” (Miller & Murray 1966).
While the pause time for a guinea pig varies, it usually depends on whether or not they have adjusted to a given environment and it depends on the type of noise that was being observed by the animal, but for each pig it could differ.
6 short-hair guinea pigs, three were 1 month old and 3 were 5 months during this study.
This table shows how many decibels it takes for a guinea pig to respond to a designated tone.
In the study, the procedure performed was presenting tones with frequencies ranging from .125 to 32.0 kc. And to see what effect (noise level) it would take for the guinea pigs to stop chewing on lettuce.
S was placed into a cloth cage that was also sound proof. They faced the sound sources when played and stopped eating, which were on level with the head and at a distance of 3ft from the guinea pig.
For this specific experiment the auditory sensitivity of a guinea pig can be inferred to be similar and slightly worse to a man’s up to about 10 kc.
Unlike man, however, the guinea pig’s upper limit of hearing extends to at least 32 kc. And perhaps as high as 50 kc.
2 groups of 77-db and 47-db show IR on a graph to Tone or No Tone playing
20 short-haired guinea pigs were 120-200 days old and weighed about 1.5 pounds, but 9 were not used in this second experiment because they failed to drink water during the testing.
In 37 days of training, instead if a lettuce magazine a water cup was used to test guinea pigs response to tones while drinking water from a water cup at a continuous rate, after 23 and a half hours of water deprivation to stimulate drinking activity within the subject.
All of the sessions were held one after the other daily, and the cessation of drinking water from the guinea pig was usually followed by a head tilt up, with an immediate repetition of stopped movement.
Additional Information + Results
“The generalization of habituation along the frequency dimension for the high-level
group fits the view that habituation and extinction are similar processes and that both show the familiar generalization phenomena of conditioning, while the asymmetrical gradient for the low-level group is unexplained. (Miller & Murray 1966).
Staying still allows the guinea pig to “offer predators fewer stimuli” which in turn gives the guinea pig time to observe their own surroundings and plan an escape.
With respect to auditory function, long-term experimentation with guinea pigs is difficult because these animals are highly susceptible to conductive hearing losses produced by pathological bone growth in crucial locations in the middle ear,
Lastly, in future experimental designs it should be possible to use the IR as an indicator of sensory function, pattern recognition, memory function, or emotionality in a guinea pig.