Schreurs B G, Oh M M, Hirashima C, Alkon D L
Laboratory of Adaptive Systems, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland 20892, USA.
Behav Neurosci. 1995 Feb;109(1):24-33. doi: 10.1037//0735-7044.109.1.24.
Robust classical conditioning modifies responding to the unconditioned stimulus (US) in the absence of the conditioned stimulus (CS), a phenomenon the researchers called conditioning-specific reflex modification. Unconditioned responses (URs) to periorbital stimulation varying in intensity and duration were assessed before and after 1, 3, or 6 days of paired, explicitly unpaired, or no presentations of tone and electrical stimulation. After 3 days of pairings, conditioned responding (CRs) reached 94%, and there was an increase in latency to the peak of URs. The peak latency increase was replicated in a second experiment where rabbits reached asymptotic conditioning during 6 days of pairings. There was also a conditioning-specific increase in the amplitude of URs. There were no UR changes as a function of low level of CRs following 1 day of pairings. Data suggest that there are learning-specific changes in pathways mediating the US/UR, as well as in those mediating the CS/CR.
强健的经典条件反射会在没有条件刺激（CS）的情况下改变对无条件刺激（US）的反应，研究人员将这种现象称为条件特异性反射改变。在对音调与电刺激进行1天、3天或6天的配对、明确不配对或不呈现之后，评估了对强度和持续时间不同的眶周刺激的无条件反应（URs）。配对3天后，条件反应（CRs）达到94%，并且URs峰值的潜伏期增加。在第二个实验中重复了峰值潜伏期的增加，在该实验中兔子在6天的配对过程中达到渐近条件反射。URs的幅度也有条件特异性增加。配对1天后，随着低水平CRs的出现，URs没有变化。数据表明，在介导US/UR的通路以及介导CS/CR的通路中存在学习特异性变化。
