Abstract
Conditioning of a target cue is blocked when it occurs in compound with another cue (blocking cue) that has already received conditioning. Although blocking of appetitive conditioning is commonly used in rodents as a test of selective learning, it has been demonstrated rarely in mice. In order to investigate the conditions that result in blocking in mice two studies tested the effect of the extent of prior blocking cue training on blocking of appetitive conditioning. Mice received either 80 or 200 trials of blocking cue training prior to compound conditioning. A control group received only compound training. Experiment 1 assessed the ability of a visual cue to block conditioning to an auditory target cue. Exposure to the context and the unconditioned stimulus, sucrose pellets, was equated across groups. Blocking was evident in mice that received 200, but not 80 training trials with the visual blocking cue. Responding to the blocking cue was similar across groups. Experiment 2 assessed the ability of an auditory cue to block conditioning to a visual target cue. Blocking was evident in mice trained with 80 and 200 auditory blocking cue trials. The results demonstrate that the strength of blocking in mice is dependent on the modality and experience of the blocking cue. Furthermore, prolonged training of the blocking cue after asymptotic levels of conditioned responding have been reached is necessary for blocking to occur under certain conditions suggesting that the strength of conditioned responding is a limited measure of learning.
Highlights
In a conditioning procedure a cue that has been paired with an unconditioned stimulus (US) may fail to elicit conditioned responding if the cue has been conditioned in compound with another cue that has previously been paired with the unconditioned stimulus (Kamin, 1969)
One of the most common ways of assessing learning in rodents is by appetitive conditioning of magazine approach behaviour, in which pairing a cue with food reward results in rodents making anticipatory head entries, during the conditioned stimulus (CS), into the magazine, where food is dispensed
The results demonstrate that blocking of appetitive conditioning in mice is dependent on the modality of the blocking cue, and, depending on the particular modality, is dependent on the amount of training with the blocking cue despite the fact that the extent of training did not affect the strength of conditioned responding to the blocking cue
Summary
In a conditioning procedure a cue that has been paired with an unconditioned stimulus (US) may fail to elicit conditioned responding if the cue has been conditioned in compound with another cue that has previously been paired with the unconditioned stimulus (Kamin, 1969). This blocking effect provides an example of the failure of temporal contiguity between events to be sufficient for conditioning. At test mice that received the light conditioning trials showed lower levels of magazine approach behaviour to the clicker compared to the control group
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
