Reminder-induced recovery of associations to an overshadowed stimulus

The possibility of reversing the deficit produced by overshadowing through the use of memory reactivation was investigated. Using lick suppression as a measure of associative strength, water-deprived rats were conditioned in a Pavlovian paradigm which produced reliable overshadowing of a flashing light by a tone. It was found, however, that exposure to the overshadowed stimulus outside of the conditioning context during the retention interval (reminder treatment) caused an increase in lick suppression during testing in animals that had undergone overshadowing, relative to nonreminded overshadowed animals. Subjects that received the reminder treatment but were conditioned without overshadowing showed no increase in lick suppression. Additional control groups ensured that the increase in suppression observed in the overshadowed subjects following reminder treatment was not due to nonspecific fear. The results suggest that the performance deficit produced by overshadowing is due at least in part to a reversible failure to efficiently retrieve associations to the overshadowed stimulus at the time of testing, rather than a failure to form those associations during conditioning.     

Reminder-induced recovery from blocking as a function of the number of compound trials

Conditioned lick suppression in rats was employed to examine changes in the associative status of a blocked stimulus as a function of the number of compound stimulus conditioning trials. In each of two experiments, prior tone-footshock pairings produced similar blocking of conditioned responding to the light element of a tone-light compound when either two or six compound trials were used. In experiment 1, two exposures to the light alone in a dissimilar context during the retention interval, i.e., a reminder treatment, resulted in a restoration of responding to the light which was complete and similar for animals receiving two or six compound trials. This indicated that latent acquisition with respect to the blocked stimulus was largely complete after two compound trials. Because of a potential ceiling effect for reminder-induced recovery from blocking, Experiment 2 employed an attenuated reminder (one light exposure). This reminder reversed the blocking when six, but not when two, compound trials were used. These results suggest that, after latent acquisition to the blocked stimulus is complete, the blocked stimulus continues to be processed during additional compound stimulus conditioning trials, with a consequent latent facilitation of retrieval of associations to the blocked stimulus.     

The effectiveness of imagery and sentence strategy instructions as a function of visual and auditory processing in young school-age children

The relationship between auditory and visual processing modality and strategy instructions was examined in first- and second-grade children. A Pictograph Sentence Memory Test was used to determine dominant processing modality as well as to assess instructional effects. The pictograph task was given first followed by auditory or visual interference. Children who were disrupted more by visual interference were classed as visual processors and those more disrupted by auditory interference were classed as auditory processors. Auditory and visual processors were then assigned to one of three conditions: interactive imagery strategy, sentence strategy, or a control group. Children in the imagery and sentence strategy groups were briefly taught to integrate the pictographs in order to remember them better. The sentence strategy was found to be effective for both auditory and visual processors, whereas the interactive imagery strategy was effective only for auditory processors.     

Reactivation-induced interference in a short-term retention paradigm

In Experiment 1 it was demonstrated that interference with a rat's retention of a target spatial cue decreases as the interval between prior conflicting cues and the target increases. Experiment 2 showed that interference can occur even when the interstimulus interval is long, if the memory of a conflicting cue is reactivated just prior to exposing an animal to the target cue. A third experiment suggested that these findings could not be easily interpreted in terms of a stimulus satiation effect. The implications of these findings for a trace decay model of short-term retention were discussed.     

Forgetting of recently acquired or recently reactivated memories

Four experiments compared the rates of forgetting following acquisition of a conditioned aversion and following a reactivation treatment given long after conditioning had been completed. The “reactivation treatment” consisted of a single presentation of the unconditioned stimulus, a procedure known to reinstate, following substantial forgetting, the behavior seen immediately after conditioning. It was first determined that the decrement in performance 1, 3, or 7 days later tended to be more rapid just after original conditioning than following a reactivation treatment given 27 days after conditioning. Subsequent experiments confirmed that the forgetting seen 3 or 7 days after original conditioning was in fact greater than forgetting 3 or 7 days after the reactivation treatment that had followed conditioning by 27 days; also, tests permitted rejection of the hypothesis that this effect could be attributed to nonassociative (systemic) consequences of the conditioning situation. Finally, tests indicated that retention 24 hr after a reactivation treatment was significantly better if the reactivation treatment followed conditioning by 27 days than if it were given just 3 min or 24 hr after conditioning. The central observation emerging from this study, that forgetting is more rapid following original learning than following a temporally remote reactivation treatment, was discussed in terms of potential interactions between the age (or accessibility) of a memory and processes that might be instigated by a reactivation treatment.     

An ethological analysis of open-field behavior in rats and mice

In our view open-field testing entails both a predatory encounter, which occurs as a consequence of handling and placement of subjects into the testing apparatus, and sudden social separation from conspecifics. We hypothesize, therefore, that open-field behavior represents a compromise between responses aimed at minimizing detectability as a predator evasion tactic, and those which are motivated by attempts to reinstate contact with companions. Six experiments were conducted using rats and mice to test various implications of this model. Pretest shock and the presence of a human observer each retarded the appearance of social reinstatement behaviors and enhanced responses which minimize detectability in both species. Likewise, because of diminished reinstatement tendencies animals tested in pairs froze longer than those tested individually. The applicability of this model to other aspects of open-field behavior in rodents was examined, and the contrast between this view and the general emotionality hypothesis was briefly discussed.     

Alleviating forgetting of active shock-avoidance by apparently unrelated food presentations

A series of four experiments investigated why forgetting of an active shock-avoidance response was reduced when an apparently unrelated appetitive experience occurred both prior to avoidance training and during the retention interval between training and testing. Experiments 1 and 2 demonstrated the reliability of the phenomenon and found that a sufficient condition for the effect was the presentation of food from a pellet dispenser (not an operant response per se). Experiment 3 demonstrated that the effect was not the result of enhanced activity. Experiment 4 showed that forgetting was still reduced when the appetitive experience occurred only prior to active avoidance or only during the retention interval. The results are discussed in regard to the reinstatement of the reinforcer representation.     

Contextual control of the extinction of conditioned fear

Rats received 15 pairings of a CS and shock in one context, and then a series of CS-alone trials in a second context. Even though this extinction procedure produced a complete loss of conditioned suppression, when the animals were returned to the site of original conditioning, suppression was renewed to a level comparable to that of animals that had not undergone extinction. Controls indicated that the renewed suppression was not due solely to pseudoconditioning, suggesting that the CS-US association had survived extinction. Renewed suppression was also demonstrated in a third context that was never associated with shock. Loss of suppression did not necessarily depend upon inhibitory conditioning of the extinction context. The data suggest that extinction of conditioned fear is specific to the context in which it occurs. They also suggest the possibility that animals might discriminate episodes in which a CS is reinforced and nonreinforced independently of the excitatory or inhibitory status of cues, like contextual stimuli, that are coincidentally present during those episodes.     

Alleviation of forgetting of discrimination learning

Reactivation treatments intended to alleviate forgetting in rats were tested in two discrimination tasks—instrumental learning with brightness or with spatial location as the discriminanda. For memories acquired 28 days earlier, forgetting was alleviated with both tasks when testing was preceded by certain reactivation treatments. Therefore, the generality of the effectiveness of reactivation treatments for alleviating forgetting is extended to include discrimination learning and response measures other than go, no-go behavior.     

The interaction of memories in the rat: Effects on short-term retention performance

In four experiments, rats were tested for short-term retention of a target spatial location either with or without prior exposures to alternate spatial locations in a T-maze. In all cases, exposure to alternate locations prior to exposure to the target location impaired retention of the target. This impairment increased as the number of exposures to the alternate location was increased, and the impairment decreased as the interval between alternate and target exposures was increased. In no case was the magnitude of the impairment found to increase as the retention interval was lengthened.     

Taste-mediated potentiation of noningestional stimuli in rats

Holtzman rats drank saccharin in a distinctive environmental chamber prior to lithium-induced toxicosis. This treatment was administered four times. These animals subsequently drank less water or familiar saline in the chamber than animals which received water in the environment during conditioning. In addition, these environmental stimuli blocked the formation of a lithium-mediated coffee aversion more if they were conditioned in the presence of saccharin than if they were conditioned in the presence of water. Such differential blocking provided further evidence that the presence of a taste during conditioning facilitated aversion learning to the environmental chamber.     

Social elicitation of infant vocal behavior.

The time course and the nature of social elicitation of vocalizations in 3-month-old infants were analyzed. Adult stimulation produced an immediate and significant increase in both the rate and the percent of bursts of vocal sounds of eight infants (Experiment 1). Both response-independent and response-dependent social stimulation were effective in producing increased rates of vocalizations, but only when each of four infants could see the eyes of the adult who delivered the social stimulus (Experiment 2).     

Alcohol consumption by college women following exposure to unsolvable problems: Learned helplessness or stress induced drinking?

Three experiments were intended to examine the relationship between alcohol, depression and learned helplessness. In Study I, more female undergraduate heavy drinkers than light drinkers were found to have critically elevated scores on a depression index. A sex difference in the relationship between drinking and depression is suggested since male depressives were equally distributed among drinking categories. In Studies II and III, female undergraduates were given unsolvable problems in a learned helplessness paradigm. Relative to controls these subjects reported increased depressive and hostile affect and drank more beer in a taste rating task. However, we failed to find deficits in anagram solution with those subjects given the learned helplessness manipulation. Specific questions are raised regarding the boundary conditions of learned helplessness while implications bearing on stress-related alcohol consumption are discussed.     

Effects of two types of response-contingent time-out on compliance and oppositional behavior of children.

The present study examined the effects of two time-out (TO) procedures, within-room and out-of-room, on compliance and oppositional behavior. Subjects were 24 nonclinic 5-year old children and their mothers. Mother-child pairs were assigned to one of three groups (within-room time-out, out-of-room time-out, or control) and observed in a laboratory setting under each of three experimental conditions: pretraining, training, and posttraining. The results indicated that, relative to the control group, both out-of-room and within-room TO reduced oppositional behavior and increased compliance. The two time-out procedures were equally effective in changing the two target behaviors; however, the within-room approach required significantly more administrations of time-out than the out-of-room technique.     

Impression management in the forced compliance situation: Two studies using the bogus pipeline

Two studies were performed to assess the interpersonal concerns of subjects in the forced compliance paradigm. The first study counterposed dissonance and impression management theory predictions in a 2 × 2 design by varying the public versus private nature of the counterattitudinal behavior and by assessing attitudes with the usual pencil-and-paper method or with a bogus pipeline technique designed to create strong pressures toward sincere reporting. Attitude change occurred only in the Public/Pencil-and-Paper condition and thus supported an interpersonal or impression management interpretation. The second study examined the effect of measuring the critical attitude a second time in the mode not experienced in the first assessment. This three-group design (Pencil-and-Paper/Bogus Pipeline, Bogus Pipeline/Pencil-and-Paper, Control) demonstrated that attitude change occurred only in the Pencil-and-Paper/Bogus Pipeline condition and was maintained on the second assessment when measured by the bogus pipeline. A common-factor analysis of the secondary measures in the second study demonstrated that the Pencil-and-Paper/Bogus Pipeline subjects reported a great deal of negative arousal such as embarrassment and guilt, while the subjects in the Bogus Pipeline/Pencil-and-Paper condition reported feeling manipulated and constrained. The findings of both studies were interpreted as consistent with impression management theory.