Classical conditioning model of panic disorder: response to Wolpe and Rowan

We refute Wolpe and Rowan's (1989) classical conditioning theory of panic disorder based upon several lines of evidence presented above. While there is no doubt that hyperventilation and conditioning are important factors in the production of panic attacks, Wolpe and Rowan's (1989) hypothesis is inconsistent with recent data concerning the limited role of hyperventilation and the importance of cognitive mediation in the production of panic attacks.     

Classical conditioning of the nictitating membrane response of the lemon shark (Negaprion brevirostris)

An experimental group of lemon sharks received 100 daily presentations of light flash as the conditioned stimulus (CS) and electric shock as the unconditioned stimulus (US) in a classical conditioning situation. The conditioned responses (CRs) and unconditioned responses (URs) under observation consisted of extensions of the nictitating membrane. Separate control groups received either (a) no CS or US, (b) CS-alone, or (c) completely random presentations of CS and US. Few CRs occurred in the experimental group at the outset of conditioning, but the percentage of CRs during the second half of the first acquisition session exceeded 95%. Conditioning stabilized above 95% CRs during Acquisition Sessions 3 through 7. These responses could not be attributed to pseudoconditioning, sensitization, or other nonassociative factors. When the experimental group was subsequently given six CS-alone sessions, the course of extinction was gradual. Most results seemed similar to those previously obtained during classical conditioning of the nictitating membrane in rabbits.     

Classical conditioning of pupillary constriction

Previous attempts to condition classically the pupillary response have resulted in mixed outcome. Studies using light as the UCS have generally been unsuccessful while those studies using shock as the UCS have been more successful. In the present study six subjects were visually presented 15 CVC trigrams while their pupil sizes were monitored. Five of the CVCs had been previously presented, five had been previously presented while paired with shock, and five had not been previously presented. Analysis indicated that more pupillary constriction occurred to the five CVCs paired with shock than those presented without shock or those not previously presented. The resulting classically conditioned pupillary constriction is discussed in terms of the development of meaning through classical conditioning.     

Classical conditioning of goldfish in the shuttlebox

Goldfish trained in a shuttlebox with light as CS and brief shock as US acquire the shuttling response to light whether or not an avoidance contingency is in effect. That the change in behavior produced by the classical procedure is not due merely to sensitization is demonstrated by a discriminative control. The results suggest the usefulness of the shuttlebox for the study of classical conditioning in goldfish and call into question the instrumental interpretation of the change in behavior produced by the avoidance procedure.     

Classical discrimination conditioning of the rabbit's eyelid response using pontine stimulation as a conditioned stimulus

Classical discrimination conditioning of the nictitating membrane/eyelid response was performed on seven rabbits using stimulation of the pontine nuclei or middle cerebellar peduncle as the conditioned stimulus (CS) and an air puff as the unconditioned stimulus (US). The rabbits learned to discriminate between a CS paired with a US and delivered to one pontine nucleus (the CS+) and a CS presented alone and delivered to the contralateral pontine nucleus (the CS-). Subsequent reversal of the discrimination was also achieved when the CS+ and CS- stimulation sites were interchanged. The results are interpreted as support for the idea that essential plasticity for classical eyelid conditioning occurs efferent to the pontine nuclei, possibly in regions of the cerebellum.     

Classical conditioning of beginning reading responses

The present study describes the first demonstration that laboratory-controlled experimental procedures can lead to the successful acquisition and subsequent retention of classically conditioned beginning reading responses (CCBRRs) in children of both sexes and mean age of 4 yr. Anticipatory instructions combined with higher-order classical conditioning temporally arranged into a trace conditioning paradigm presented for 10 trials for each response to be learned led to beginning reading responses being successfully acquired by 20 children during 95% of the 2,220 total acquisition learning trials and subsequently correctly recalled on 114 of the 222 retention test trials. Findings support the view that perhaps the relatively sudden and sustained acquisition learning curves for reading responses on the second-signalling-system level of behavior in the present study may be quite different from the relatively slow and incremental learning curves usually obtained in classical conditioning of the autonomic type which occur on the first-signalling-system level.     

Classical conditioning and retention of the infant's eyelid response: effects of age and interstimulus interval

Independent groups of 10-,20-, and 30-day-old infants were subjected to a classical eyelid conditioning procedure involving either a 500- or a 1500-msec interstimulus interval (ISI). Ten days later, all received a second conditioning session. A reliable increase in conditioned responding was observed at all ages but only by infants receiving the 1500-msec ISI. Although age was not a significant factor in any conditioning measure except final performance level, which was greater for the oldest than for the youngest group, it did influence long-term retention. A reliable memory component was observed in the Session 2 performance of infants initially trained at 20 and 30 days but not at 10 days. These data demonstrate the importance of temporal parameters in the formation of conditioned associations very early in infancy and provide evidence for the long-term behavioral consequences of those associations.     

Classical conditioning of the eyeblink response in the delay paradigm in adults aged 18-83 years

To determine if age differences in classical conditioning of the eyelid response begin to appear in middle age in humans as they do in animals, adult subjects aged 18-83 years were trained in the delay conditioning paradigm. Large age effects occurred. Statistically significant differences first appeared in the decade of the 40s. Within-age-group variability was large. To reduce variability, subjects were classified by the magnitude of their unconditioned response (UR). Regardless of age, subjects with low amplitude URs conditioned poorly. In the normal UR amplitude group, the correlation between age and total percentage conditioned responses (CRs) was -.58. Eyeblink rate and voluntary responding did not account for age differences in conditioning, and it was unlikely that hearing acuity or corneal sensitivity caused the differences. Parallels between human and animal eyelid conditioning are considered, and it is suggested that age changes in the cerebellum may affect conditioning in aging mammals, including humans.     

Classical conditioning of the rabbit's nictitating membrane response under fixed and mixed CS-US intervals

The rabbit's nictitating membrane response was classically conditioned to a tone CS, followed by an electric shock US, at two randomly alternating CS-US interstimulus intervals (ISIs). Different groups were exposed to different proportions of 200- and 700-msec ISIs. The study revealed: (a) CR percentage was a direct function of the proportion of 200-msec ISIs; (b) trials to the first test-trial CR were an inverse function of the proportion of 200-msec ISIs; (c) CR onset latencies decreased over training; (d) CR peak latencies coincided with the temporal loci of the US; and (e) groups exposed to both ISIs acquired double-peaked CRs. Moreover, the amplitudes of nictitating membrane responses in the present experiment paralleled certain quantitative aspects of the free operant key peck response rates of pigeons trained under two mixed inter-reinforcement intervals. The results were discussed with respect to the micromolar response shaping and macromolecular CS-trace accounts of classical conditioning.