An attempt to condition components of urine formation in dogs

Previous research on the renal conditional reflex (CR) has resulted in contradictory data. The work of Bykov with dogs and of Hoferet al. with humans indicated that a renal CR is possible, but the experiments of Corsonet al. and Watt and Gantt with dogs having normal or transplanted cervical kidneys showed no clear-cut renal CR’s. The present work supports the latter finding. Three female mongrel dogs were used. One dog (normal) had an externalized ureter; the other two (experimental) had denervated cervical kidneys (autografts). In 155 days of experiments, the investigators found diuresis to occur only on unconditional stimulus,i.e., only when a dog drank diluted milk (one part milk to four parts water)ad lib.; the dogs drank an average of between 500 and 1,100 ml. No diuresis occurred when 30 ml. of the mixture were given (conditional stimulus). Urinalysis indicated a lack of renal conditioning with respect to the excretion rates and the concentrations of creatinine and electrolytes, except for the sodium concentration in the normal dog’s urine, which decreased on bothad lib and test (30 ml) days; the volume was not affected. Conclusion: Drinking a small quantity of diluted milk as a conditional stimulus did not produce a conditional diuretic response either in the normal dog or in the two dogs with transplanted kidneys.     

Eyeblink conditioning in rats using pontine stimulation as a conditioned stimulus

Previous studies using rabbits and ferrets found that electrical stimulation of the pontine nuclei or middle cerebellar peduncle could serve as a conditioned stimulus (CS) in eyeblink conditioning (Bao, Chen, & Thompson, 2000; Hesslow, Svensson, & Ivarsson, 1999; Steinmetz, 1990; Steinmetz, Lavond, & Thompson, 1985; 1989; Steinmetz et al., 1986; Tracy, Thompson, Krupa, & Thompson, 1998). The current study used electrical stimulation of the pontine nuclei as a CS to establish eyeblink conditioning in rats. The goals of this study were to develop a method for directly activating the CS pathway in rodents and to compare the neural circuity underlying eyeblink conditioning in different mammalian species. Rats were given electrical stimulation through a bipolar electrode implanted in the pontine nuclei paired with a periorbital shock unconditioned stimulus (US). Paired training was followed by extinction training. A subset of rats was given a test session of paired training after receiving an infusion of muscimol into the anterior interpositus nucleus. Rats given paired presentations of the stimulation CS and US developed CRs rapidly and showed extinction. Muscimol infusion prior to the test session resulted in a reversible loss of the eyeblink CR. The results demonstrate that electrical stimulation of the pontine nuclei can be used as a CS in rodents and that the CS pathway is similar in rats, rabbits, and ferrets. In addition, the loss of CRs following muscimol inactivation shows that the conditioning produced with pontine stimulation depends on cerebellar mechanisms.     

The use of an unpleasant sound as the unconditional stimulus in aversive Pavlovian conditioning experiments that involve children and adolescent participants

Ethical considerations can prohibit the use of traditional unconditional stimuli (USs), such as electric shocks or loud tones, when children or adolescents participate in aversive Pavlovian conditioning experiments. The present study evaluated whether an unpleasant sound provides a viable alternative. Fifteen boys and girls aged 13 to 17 years completed a differential Pavlovian conditioning procedure in which a conditional stimulus (CS) was followed by the sound of metal scraping on slate. Acquisition of conditioned responses was found in startle blink magnitude, expectancy judgments of the sound, and skin conductance responses. Extinction of conditioned responses was found in all measures when the CS was no longer followed by the unpleasant sound. Subjective ratings and skin conductance responses indicated that the sound was unpleasant because of its qualitative features, rather than its intensity. The results support the use of an unpleasant sound as a low-risk alternative to traditional USs in aversive Pavlovian conditioning experiments with children and adolescents.     

An n-back task using vibrotactile stimulation with comparison to an auditory analogue

We report a vibrotactile version of the common n-back task used to study working memory. Subjects wore vibrotactile stimulators on three fingers of one hand, and they responded by pressing a button with the other hand whenever the current finger matched the one stimulated n items back. Experiment 1 showed a steep decline in performance as n increased from 1 to 3; each additional level ofn decreased performance by 1.5 d' units on average. Experiment 2 supported a central capacity locus for the vibrotactile task by showing that it correlated strongly with an auditory analogue; both tasks were also related to standard digit span. The vibrotactile version of n-back may be particularly useful in dual-task contexts. It allows the assessment of cognitive capacity in sensory-impaired populations in which touch remains intact, and it may find use in brain-imaging studies in which vibrotactile stimuli impose a memory load.     

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.     

Unconscious phantasy as an obstacle and as a stimulus to knowledge

This paper underlines and explores the connections between emotional and cognitive development at a very early stage, starting from the psychoanalytic psychotherapy of a 4-year-old boy with autistic features. Development of the personality and development of the mind are shown to proceed together and to be interwoven when the therapist starts to help the child to modulate the terror and the rage related to separation. The development of the idea of a good nipple and the Introjection of it as a mental structure is considered an important step on the way towards separation between mother and baby and towards the formation within the baby self of a space where symbols of the external world can be placed. Autistic features are considered as an extreme form of denial of both internal and external reality.     

An evaluation of differential reinforcement with stimulus fading as an intervention for medical compliance

Individuals with autism spectrum disorder (ASD) often exhibit noncompliance during medical exams. One intervention used to address this concern is differential reinforcement. Although differential reinforcement includes extinction, it may not be feasible or safe to implement extinction during medical exams. In the current study, we evaluated differential reinforcement without extinction and differential reinforcement without extinction plus stimulus fading, for increasing compliance during routine medical exams exhibited by 4 individuals with ASD. An indirect assessment identified problematic medical procedures, and a functional analysis showed that participants' disruptive behavior was maintained by escape from medical tasks. Differential reinforcement without extinction was insufficient in increasing medical compliance with 3 of 4 participants. The addition of a modified stimulus fading procedure that involved gradually introducing smaller components of problematic exam steps was effective in increasing medical compliance with all exam steps.