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Results for “Conditioning, Classical”

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At least 433 records · Page 24Linked to original sources

PubMed1998

Classical conditioning to hypoxia using odors as conditioned stimuli in rats.

The authors performed a differential conditioning experiment in 30 rats, using 2 odors as the conditioned stimuli (CS+ and CS-) and hypoxia (8% O2) as the unconditioned stimulus. Vanillin was the CS+ and rose the CS- in half of the rats, and vice versa in the other half. Fifteen paired CS+/hypoxia trials and 15 CS- only trials were performed in random order, followed by 3 CS+ only and 3 CS- only trials to test for conditioning. The increase in ventilation from prestimulus levels averaged 116 +/- 85% in response to CS+ versus 55 +/- 36% in response to CS-. This effect was supported by the significant Pre-Post Stimulus x CS Type interaction for this variable (p < .003). The data confirm the sensitivity of breathing to conditioning processes and also indirectly support the hypothesis that feedforward responses may complement feedback reflex pathways in respiratory homeostasis.

Animals↗

PubMed1988

Classically conditioned cardiac responses in "old" and "young" Fischer 344 rats.

Male and female Fischer 344 rats, 12 or 26-28 months of age, received two sessions of Pavlovian heart rate conditioning, and were compared with same-sex and same-age controls receiving unpaired presentations of the tone conditional stimulus (CS) and the shock unconditional stimulus (US). Older rats of both sexes demonstrated slower acquisition of the heart rate (HR) conditioned response (CR), and smaller magnitude changes than did the younger animals. Control experiments in 6-, 12-, 24-, and 30-month-old animals indicated that these differences were not due to an impaired sensitivity to the CS or US in the older animals. Results are discussed in terms of their implications for use of this animal model in investigations of age-related deficits in associative learning.

Aging↗

PubMed1993

Concomitant eyeblink and heart rate classical conditioning in young, middle-aged, and elderly human subjects.

Pavlovian heart rate (HR) and eyeblink (EB) conditioning were assessed in 4 groups of Ss who differed in age: young = 19-33 years, young middle-aged = 35-48 years, old middle-aged = 50-63 years, and old = 66-78 years. A 100-ms corneal airpuff was the unconditioned stimulus and a 600-ms tone was the conditioned stimulus. A nonassociative control group received explicitly unpaired tone and airpuff presentations. All Ss were studied for 2 100-trial sessions separated by approximately 7 days. An impairment in acquisition of both the EB and HR responses occurred in the old and middle-age Ss, but all age groups showed significantly greater conditioning than did the control group. Slight increases in performance resulted from a 2nd session of training. These findings suggest an age-related impairment in a general associative process.

Adult↗

PubMed2004

Effects of a corneal anesthetic on extinction of the classically conditioned nictitating membrane response in the rabbit (Oryctolagus cuniculus).

Rabbits (Oryctolagus cuniculus) were presented with 7 daily sessions of tone-alone training after conditioning. Before the beginning of each of the first 4 extinction sessions, an artificial tear solution or tetracaine hydrochloride was administered to the cornea of rabbits in the control group (n = 6) and experimental group (n = 7), respectively. There were no between-group differences in the percentage of conditioned responses between both groups. However, the amplitude of the conditioned response was notably reduced in the tetracaine group (M = 0.40, SEM +/- 0.216) relative to the control group (M = 1.32, SEM +/- 0.639) early in extinction. Results seem to suggest that although motor output has been found to play an important role in extinction, corneal sensory feedback is not necessary.

Anesthetics↗

PubMed2005

Acquisition of differential delay eyeblink classical conditioning is independent of awareness.

There has been debate about whether differential delay eyeblink conditioning can be acquired without awareness of the stimulus contingencies. In 4 experiments, the authors reexamined this question. Older participants were tested with a tone and white noise (Experiment 1) or with 2 tones (Experiment 2). In addition, younger participants were tested with 2 tones (Experiment 3) or with 2 tones plus the parameters from an earlier study that had reported a relationship between conditioning and awareness (Experiment 4). Participants who were designated aware of the stimulus contingencies and participants who were designated unaware exhibited equivalent levels of differential eyeblink conditioning. Awareness of stimulus contingencies is not required for differential delay eyeblink conditioning when simple conditioned stimuli are used.

Adult↗

PubMed2005

Amygdalar unit activity during three learning tasks: eyeblink classical conditioning, Pavlovian fear conditioning, and signaled avoidance conditioning.

Neural activity in central and basolateral amygdala nuclei (CeA and BLA, respectively) was recorded during delay eyeblink conditioning, Pavlovian fear conditioning, and signaled barpress avoidance. During paired training, the CeA exhibited robust learning-related excitatory activity during all 3 tasks. By contrast, the BLA exhibited minimal activity during eyeblink conditioning, while demonstrating pronounced increases in learning-related excitatory responsiveness during fear conditioning and barpress avoidance. In addition, the relative amount of amygdalar activation observed appeared to be related to the relative intensity of the unconditioned stimulus and somatic requirements of the task. Results suggest the CeA mediates the Pavlovian association between sensory stimuli and the BLA mediates the modulation of instrumental responding through the assignment of motivational value to the unconditioned stimulus.

Action Potentials↗

PubMed1967