Conditioning: A Historical Note.

In the controversy over the Estes Park Report contradictory assertions have been made about Pavlov's involvement in the phenomenon variously labeled as "psychic reflex" and "conditioned reflex." A reconciliation between the apparently contradictory views may be brought about through recognition that the labels are not interchangeable, even though they refer to the same phenomenon. The difference is in the implied theoretical interpretations. It may also be of value to recall that in the early observations of the phenomenon Pavlov's theoretical position had not been consistent. The following quotations are presented as supporting evidence in the interest of accuracy in the historical record. The source is F. P. Maiorov's authoritative monograph Istoriia Ucheniia ob Uslovnykh Refleksakh (see record 1952-01235-000). (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Conditioning to complex stimuli.

A research program is described dealing with behavior in a classical GSR conditioning situation. The empirical program is related "to the broader perspective of psychology in general." The research "affords a slim—but I hope stable—bridge between S-R learning theory and whatever is meant by perceptual theory." A rationale of assumptions is developed and on the basis of analysis predictions are formulated. "The present results are eminently consonant with an S-S interpretation of behavior… though I have attempted to make it consonant with S-R contiguity theory by employing the notion of internalized stimuli generated by responses to the conditioned stimulus." (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The importance of time as stimulus of conditioned reflex activity.

"The formation of conditioned reflexes to time plays an important part in the systemic activity of the cerebral cortex, in the development of definite periodicity in physiological functions, and in the establishment of rhythmical pattern reactions in the working activity of man. By virtue thereof the question of the cortical mechanisms involved in the process of formation of conditioned reflexes to time acquires considerable theoretical and practical importance." Studies, from Russian laboratories, employing a variety of experimental animals, and man, are cited. Experimental variables are systematically described as well as the many theoretical issues. 34 refs. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Amygdala lesions block conditioned enhancement of the early component of the rat eyeblink reflex.

A tone-conditioned stimulus (CS) previously paired with a grid shock unconditioned stimulus (US) can greatly enhance the early electromyographic (EMG) component (RI) of the rat eyeblink reflex. The hypothesis that the central nucleus of the amygdala (ACe) is an essential part of the circuitry mediating conditioned RI enhancement was tested. After bilateral ACe lesions (L) or a sham operation (S), rats received paired presentations of the CS and US (P) or explicitly unpaired CS and US presentations (U), resulting in 4 groups: P/S, P/L, U/S, and U/L. ACe lesions completely prevented conditioned RI enhancement, which was only exhibited in Group P/S. In the latter group, the "preextinction" conditioned enhancement effect was roughly a 2-fold increase in the RI magnitude. Circuit-level mechanisms are discussed, and some advantages of the eyeblink EMG response in this general conditioning paradigm are considered. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Differential Effects of 8-OH-DPAT on Two Forms of Appetitive Pavlovian Conditioning in the Rat.

Rats were trained on an appetitive Pavlovian conditioning task in which the conditioned stimulus (CS) was either localized (a light in the food tray) or nonlocalized (an increase in the general level of illumination). The conditioned response (CR) of approaching the site of food delivery in the presence of the CS was monitored. Presession treatment with the 5-HT1A agonist 8-OH-DPAT (subcutaneous injections at a dose of 0.15 mg/kg) retarded acquisition of the CR, but only when the localized CS was used. The results confirm the general proposal that serotonergic processes are involved in learning. The selective effect of the drug is not to be explained in terms of its motor effects and is consistent with the specific suggestion that systemic administration of 8-OH-DPAT is especially effective in disrupting learning tasks mediated by hippocampal mechanisms. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Conditioning following repeated exposure to MDMA in rats: Role in the maintenance of MDMA self-administration.

There has been some controversy in the literature concerning the ability of ±3,4 methylenedioxymethamphetamine (MDMA) to reinforce operant responding in rats. In the present study, operant responding maintained by intravenous MDMA infusions increased when the fixed ratio schedule was increased from 1 to 5, decreased when saline was substituted for MDMA, and increased again when MDMA was reintroduced. During self-administration training, each infusion of MDMA was paired with the illumination of a light stimulus. The role of the continued presentation of this drug-associated stimulus in operant responding was measured in groups of rats that had received comparable exposure (average 19 daily test sessions) to MDMA during training. When either the light stimulus or the drug infusion was omitted, operant responding decreased gradually over the 15-day test period following training. When both the light stimulus and the MDMA infusion were omitted, there was a dramatic decrease in operant responding that persisted for the entire 15-day test period. These findings suggest that cues associated with MDMA develop conditioned properties that might contribute to drug taking. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Motivational Control of Second-Order Conditioning.

Two experiments examined the motivational specificity of the associations that support 2nd-order conditioning. In the 1st phase of each experiment rats were exposed to 2 visual conditioned stimuli (CSs) paired with either a saline or food pellet unconditioned stimulus (US) prior to exposure to 2nd-order conditioning using 2 auditory CSs, 1 paired with each visual CS. Rats' motivational state was then shifted prior to a test such that if and only if specific motivational features of the 1st-order training US played a role in the 2nd-order associative structure would responding to the 2nd-order cues shift appropriately with the state change. Even when the US was irrelevant to the training motivational state, shifts in state revealed that it was encoded within the associative structure supporting 2nd-order responding. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Opioid Receptors Regulate the Extinction of Pavlovian Fear Conditioning.

Rats received a single pairing of an auditory conditioned stimulus (CS) with a footshock unconditioned stimulus (US). The fear (freezing) that had accrued to the CS was then extinguished. Injection of naloxone prior to this extinction significantly impaired the development of extinction. This impairment was mediated by opioid receptors in the brain and was not observed when naloxone was injected after extinction training. Finally, an injection of naloxone on test failed to reinstate extinguished responding that had already accrued to the CS. These experiments show that opioid receptors regulate the development, but not the expression, of fear extinction and are discussed with reference to the roles of opioid receptors in US processing, memory, and appetitive motivation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Conditioned brain-stimulation reward attenuates the acoustic startle reflex in rats.

The acoustic startle reflex (ASR) in rats is attenuated by a light paired with food or, in humans, by "pleasant" pictures. Rats were trained to barpress for lateral hypothalamus (LH) stimulation. ASR amplitudes were then measured at 4 intensities, with or without a light. Control rats that did not receive brain-stimulation reward (BSR) showed initially lower ASR amplitudes than did rats exposed to BSR, but both groups responded similarly with or without light. Next, experimental rats were given BSR in the presence of light but not in its absence. After conditioning, ASR amplitudes were reduced, and ASR thresholds were raised by a mean of 2.6 dB in the light but remained at preconditioning levels without light. No such change was found for control rats or rats with placements outside the LH. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Anticipating the Attack: Temporal Conditioning During Amygdala Kindling in Rats.

The present study showed that amygdala-kindled rats use short-interval timing superimposed on phase or ordinal timing to predict when a convulsion will occur. In 2 experiments, rats received 1 stimulation and 1 sham stimulation each day, always at the same times (conditioned stimulus [CS]+ and CS- times, respectively) and 150 s after rats had been placed in the testing chamber (the preadministration interval). As kindling progressed, the rats displayed more defensive behavior at the CS+ time than at the CS- time. Then, a stimulation-free peak-procedure test was conducted: At the CS+ time, but not at the CS- time, defensive behavior increased progressively as the 150-s preadministration interval elapsed, and then it gradually declined. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A Role for CS-US Contingency in Pavlovian Conditioning.

Two experiments evaluated the role of conditioned stimulus-unconditioned stimulus (CS-US) contingency in appetitive Pavlovian conditioning in rats. In both experiments, some groups received a positively contingent CS signaling an increased likelihood of the US relative to the absence of the CS. These groups were compared with control treatments in which the likelihood of the US was the same in the presence and absence of the CS. A trial marker served as a trial context. Experiment 1 found contingency sensitivity. There was a reciprocal relationship between responding to the CS and the trial marker. Experiment 2 showed that this result was not stimulus or response specific. These results are consistent with associative explanations and the idea that rats are sensitive to CS-US contingency. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Conditioning of ictal and interictal behaviors in rats by amygdala kindling: Context as the conditional stimulus.

The authors showed that conditional effects of the stimulation environment modulate both the ictal and interictal behaviors of rats subjected to amygdala kindling. Rats received 53 stimulations to the left basolateral amygdala in 1 conditional stimulus (CS) context (CS+) and 53 sham stimulations (the stimulation lead was attached but no current was delivered) in another context (CS-), quasirandomly over 54 days. Three kinds of conditional effects were observed, First, after several stimulations, less ambulatory activity, more freezing, and less rearing reliably occurred in the CS + context than in the CS context. Second, after 45 stimulations, all of the rats chose the CS - context over the CS + context in a conditioned place preference test. Third, when the rats were finally stimulated in the CS- context, their motor seizures were less severe: Latencies were longer, motor seizures were shorter, convulsive patterns were of a lower class, and there were fewer falls. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Impact of Healthy Aging on Awareness and Fear Conditioning.

Fear conditioning has provided a useful model system for studying associative emotional learning, but the impact of healthy aging has gone relatively unexplored. The present study investigated fear conditioning across the adult life span in humans. A delay discrimination task was employed using visual conditioned stimuli and an auditory unconditioned stimulus. Awareness of the reinforcement contingencies was assessed in a postexperimental interview. Compared with young adult participants, middle-aged and older adults displayed reductions in unconditioned responding, discriminant conditioning, and contingency awareness. When awareness and overall arousability were taken into consideration, there were no residual effects of aging on conditioning. These results highlight the importance of considering the influence of declarative knowledge when interpreting age-associated changes in discriminative conditioned learning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Independent Manipulation of Emotion in an Emotional Stroop Task Using Classical Conditioning.

The effects of emotional connotation on emotional Stroop interference in anxiety were examined. First, a classical conditioning paradigm was used in which neutral words and nonwords were paired with either negative or neutral pictures. These conditioned stimuli were then presented in an emotional Stroop paradigm. Finally, participants rated each word and nonword for emotional connotation. The high-anxious group demonstrated significant interference for the nonwords that had been negatively conditioned, and these effects did not dissipate over time. The affective rating data supported the view that nonwords, but not the words had been successfully conditioned in the high-anxious group. This experiment provides evidence for the importance of emotional connotation rather than confounded semantic factors in the emotional Stroop effect. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

NMDA Receptor Modulation of Incidental Learning in Pavlovian Context Conditioning.

Rats exposed to a footshock show conditional fear when reexposed to the shock context. Immediate presentation of shock after placement in the context significantly reduces this fear. Preexposure to the context in the absence of shock, coupled with a minimum preshock interval during training, overcomes this immediate shock deficit. Because rats learn about the context during preexposure and express that learning after being reinforced, the context preexposure effect is an aversive analogue of latent learning. The authors examined the effect of the N-methyl-D-aspartate (NMDA) receptor antagonist D,L-2-amino-5-phosphovalerate (APV) on the facilitatory effect of context preexposure. Rats were preexposed to a chamber after APV administration. The next day they were placed in the same chamber without drug and received shock 35 s later. APV blocked the facilitatory effect of preexposure. Therefore NMDA receptors are important for contextual latent learning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Temporal Encoding in Fear Conditioning Revealed Through Associative Reflex Facilitation.

[Correction Notice: An erratum for this article was reported in Vol 118(3) of Behavioral Neuroscience (see record 2007-16851-001). The article contained several errors. On page 396, second paragraph, the sentence beginning on line 6 should read as follows: "Having a stable baseline is critical for studies of reflex facilitation because the experimental designs invariably entail repetitive CR testing, if only to achieve reasonable statistical power (see Choi et al., 2001b; Lindquist & Brown, 2004)." On page 400, the first heading should read as follows: "Comparison of New and Old Reflex Facilitation Procedures". On page 400, the first sentence under the abovementioned heading should read as follows: "We decided not to use the original measure of reflex facilitation, developed by J. S. Brown et al. (1951), because it suffers from severe interpretational limitations, elaborated in detail elsewhere (Choi et al., 2001b; Leaton & Cranney, 1990; Lindquist & Brown, 2004)."] Temporal encoding in Pavlovian fear conditioning was examined through conditional facilitation of the short-latency (Rl) component of the rat eyeblink reflex. Rats were fear-conditioned to a tone conditional stimulus (CS) with either a 3- or 9-s interstimulus interval (ISI) between CS onset and the onset of the grid-shock unconditional stimulus (US). Rl facilitation was tested over 2 days, in counterbalanced order, at a latency of 3 s and 9 s from CS onset. CS-produced Rl facilitation, the conditional response (CR), was 3-4 times larger when the test latency equaled the conditioning ISI. These results, coupled with the known neurophysiology of Rl facilitation, suggest that this CR could disclose differences in the time course of CS-generated output from the amygdala when driven by cortical versus subcortical CS-CR pathways. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

"Stimulus Selection in Eyelid Conditioning in the Rabbit (Oryctolagus cuniculus)": Erratum.

Reports an error in the original article by Perry S. Kinkaide (Journal of Comparative and Physiological Psychology, 1974[Jun], 86[6], 1132-1140). The lower portion of Figure 3 on page 1138 should have represented the last two conditions for Group T as Test AV and reTest AV. The last sentence of the caption should have been deleted. (The following abstract of this article originally appeared in record 1979-05368-001) Conducted 2 experiments, using a total of 24 female New Zealand white rabbits, in which a "visual" stimulus (V), either flashes or electrical stimulation of the optic chiasma, was reinforced in compound with a differentially reinforced (CS+) or nonreinforced (CS-) nonvisual stimulus. Visual stimulus control of conditioned eyeblink activity was acquired if V was reinforced in compound with CS- but was "blocked" when reinforced in compound with CS+. Both effects were demonstrable within Ss and were independent of the method of visual stimulation. Extinction and backward conditioning of chiasmic stimulation preceded retraining of 6 Ss. The establishment and blocking of visual stimulus control were again evident within Ss. The data are interpretable in terms of either attentional or associative theory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The challenge of diversity in modern psychoanalysis.

The articles in this special section have pointed to the need for reexamination of theory and technique, if psychoanalytic treatment is to remain relevant for diverse patient groups. Some clinical assumptions, including both theories of psychosexual development and theories of object relations, and some assumptions as to mutative factors and therapeutic goals, are culture bound in unacknowledged ways. A modern psychological theory of psychic organization and psychic change is needed to account for common factors in the psychoanalytic approach that apply across cultures to enable specific applications for particular patient groups and to serve as a framework for research. The issues of diversity raise a challenge for psychoanalysis but also offer an opportunity to revitalize the field. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Eyeblink Classical Conditioning to Auditory and Olfactory Stimuli: Performance Among Older Adults With and Without the Apolipoprotein E ε4 Allele.

Patients with Alzheimer's disease (AD) demonstrate slowed acquisition of the conditioned response (CR) in eyeblink classical conditioning paradigms (EBCC), although it is unknown how early in the course of the disease CR acquisition is affected. This study investigated whether changes in the rate of CR acquisition were apparent in nondemented older adults at greater genetic risk for developing AD (i.e., carriers of the apolipoprotein E [APOE] ε4 allele). Both ε4+ and ε4- participants demonstrated CR acquisition to auditory and olfactory CSs; however, rate of acquisition to the olfactory CS was significantly slower in ε4+ persons. Both groups acquired the CR to an auditory CS at the same rate. Results support olfactory compromise in the earliest stages of the AD disease process. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Dissociating the conditioning and the anorectic effects of estradiol in female rats.

The present series of experiments challenges the ability of the hormone estradiol to act as an unconditioned stimulus in the conditioned taste avoidance (CTA) learning paradigm. We hypothesize that reductions in sucrose consumption observed after pairing it with estradiol are not indicative of associative learning, but due to the unconditioned expression of estradiol’s anorectic effects during the time of CTA assessment. Three experiments in which a sucrose solution was paired with estradiol were conducted to test this hypothesis. Experiment 1 demonstrated that female rats expressed a reduction in post-pairing sucrose consumption even though the anorectic effects of estradiol had subsided. Experiment 2 showed that although a low dose of estradiol produced anorexia, it did not elicit post-pairing reductions in sucrose consumption. Experiment 3 revealed that contingent pairing was a requirement for post-pairing reduction in sucrose consumption even when testing was done at a time when anorexia is expressed. These findings demonstrate the dissociability of the conditioning and anorectic effects of estradiol, providing evidence against the hypothesis. The results are discussed in terms of independent neural mechanisms underlying the disparate behaviors. (PsycINFO Database Record (c) 2010 APA, all rights reserved)