These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Overshadowing and summation in compound stimulus conditioning of the rabbit's nictitating membrane response.
    Author: Kehoe EJ.
    Journal: J Exp Psychol Anim Behav Process; 1982 Oct; 8(4):313-28. PubMed ID: 7175444.
    Abstract:
    The present experiments examined acquisition of the rabbit's nictitating membrane response to a light + tone simultaneous compound stimulus and its components as a function of the intensity of the tone. In Experiment 1, the tone intensity was varied across the values of 85, 89, and 93 dB, and the CS-US (conditioned stimulus-unconditioned stimulus) interval was 400 msec. In Experiment 2, the tone intensities were 73, 85, and 93 dB, and the CS-US interval was 800 msec. Experiments 3 and 4 further examined the effects of the 73-dB tone at CS-US intervals of 400 and 800 msec, respectively. All experiments included control groups, which were trained with either a light or a tone CS. In brief, the experiments revealed repeated instances of overshadowing, i.e., the impairment of conditioned response (CR) acquisition to one or both of the components of a compound. Moreover, two types of summation were obtained: within-subjects summation, in which rabbits trained with a compound showed a higher level of responding to the compound than to either of its component CSs (Experiments 2, 3, and 4), and between-groups summation, in which a group trained with a compound showed faster CR acquisition than either of its corresponding control groups trained with a single CS (Experiments 1 and 2). The results are discussed in terms of perceptual and distributive processing models of compound stimulus conditioning.
    [Abstract] [Full Text] [Related] [New Search]