ABSTRACT
The effects of low-level hippocampal stimulation on the development of latent inhibition were investigated employing classical conditioning of the nictitating membrane response of rabbits. Four groups were given either (a) no preexposure of the to-be-CS, (b) preexposure, (c) preexposure overlapped by hippocampal stimulation or (d) preexposure overlapped by cortical stimulation, followed by 300 conditioning trials for each group. After conditioning, the hippocampal group was divided into two groups designated HS-1 and HS-2 by means of a post-hoc test for stimulation effects. Conditioning was found to be retarded in all three preexposed groups, with significantly greater retardation (augmentation of latent inhibition) in Group HS-2. The results support a general conception that the hippocampal stimulation produced its effects through the modulation of sensory input.
Subject(s)
Conditioning, Classical/physiology , Hippocampus/physiology , Neural Inhibition , Animals , Attention/physiology , Conditioning, Eyelid/physiology , Electric Stimulation , Extinction, Psychological/physiology , Female , Male , Mental Recall/physiology , RabbitsABSTRACT
The effects of hippocampal stimulation on the development and expression of latent inhibition were investigated employing classical conditioning of the nictitating membrane response of rabbits. Hippocampal stimulation overlapping conditioned stimulus preexposure produced attenuation of latent inhibition, as did stimulation presented during conditioning after preexposure. However, hippocampal stimulation during conditioning in the absence of preexposure had little effect. The results support the hypotheses that in classical conditioning a major function of the hippocampus is the modulation of sensory input, especially input involved in the learned irrelevance of stimuli.
Subject(s)
Conditioning, Classical/physiology , Hippocampus/physiology , Inhibition, Psychological , Animals , Electric Stimulation , Female , Male , Nictitating Membrane/physiology , Rabbits , Reflex/physiologyABSTRACT
The nictitating membrane response of rabbits was conditioned at a 200 msec interstimulus interval (ISI) with either circumorbital (C) or paraorbital (P) shock as the unconditional-stimulus locus. After 3 acquisition days half of each group was shifted to a 700 msec interstimuls interval. Results indicated: (1) more rapid acquisition for Group C, (2) postshift response decrements for both groups, (3) more rapid and stable, as well as complete return to preshift performance levels for Group C. Results were discussed in terms of the response-shaping hypothesis and the contiguity-substitution hypothesis in explaining both conditional response emergence and subsequent modifications of CR topography.
Subject(s)
Conditioning, Eyelid , Animals , Electroshock , Female , Male , Practice, Psychological , Rabbits , Reaction Time , Time FactorsABSTRACT
An apparatus which employs standard behavioral programming equipment is described. It enables the experimenter to program in advance with variables as auditory and visual instructional cues, delay intervals, and response mode, and to monitor response latency automatically. The apparatus is easily constructed, easily operated, and markedly increases the control of variables in tactile form perception experiments.
