Function Of Retention Interval Research Articles

Twisted memories: Addiction-related engrams are strengthened by desire thinking

Associative learning plays a central role in addiction by reinforcing associations between environmental cues and addiction-related information. Unsupervised learning models posit that memories are adjusted based on how strongly these representations are coactivated during the retrieval process. From a different perspective, clinical models of addiction posit that the escalation and persistence of craving may depend on desire thinking, a thinking style orienting to prefigure information about positive addiction-related experiences. In the present work, we tested the main hypothesis that desire thinking is a key factor in the strengthening of addiction-related associations. A group of adult smoking volunteers (N = 26) engaged in a period of desire thinking before performing an associative learning task in which neutral words (cues) were shown along with images (smoking-related vs. neutral context) at different frequencies. Two retrieval tests were administered, one immediately after encoding and the other after 24 h, to test how the recall of associations changed as a function of retention interval. Two control groups, smokers (N = 21) and non-smokers (N = 22), performed a similar procedure, with a neutral imagination task replacing desire thinking. Participants who engaged in desire thinking increased their performance from the first to the second retrieval test only for the most frequent smoking-related associations. Crucially, this selective effect was not observed in the two control groups. These results provide behavioral evidence in support of the idea that desire thinking plays a role in strengthening addiction-related associations. Thus, this thinking process may be considered a target for reconsolidation-based conceptualizations of, and treatments for, addiction.

The Effect of Blindness on Long-Term Episodic Memory for Odors and Sounds.

We recently showed that compared with sighted, early blind individuals have better episodic memory for environmental sounds, but not odors, after a short retention interval (∼ 8 – 9 min). Few studies have investigated potential effects of blindness on memory across long time frames, such as months or years. Consequently, it was unclear whether compensatory effects may vary as a function of retention interval. In this study, we followed-up participants (N = 57 out of 60) approximately 1 year after the initial testing and retested episodic recognition for environmental sounds and odors, and identification ability. In contrast to our previous findings, the early blind participants (n = 14) performed at a similar level as the late blind (n = 13) and sighted (n = 30) participants for sound recognition. Moreover, the groups had similar recognition performance of odors and identification ability of odors and sounds. These findings suggest that episodic odor memory is unaffected by blindness after both short and long retention intervals. However, the effect of blindness on episodic memory for sounds may vary as a function of retention interval, such that early blind individuals have an advantage over sighted across short but not long time frames. We speculate that the finding of a differential effect of blindness on auditory episodic memory across retention intervals may be related to different memory strategies at initial and follow-up assessments. In conclusion, this study suggests that blindness does not influence auditory or olfactory episodic memory as assessed after a long retention interval.

Sex differences in the generalization of fear as a function of retention intervals

In previous studies using male rodents, context change disrupted a fear response at a short, but not a long, retention interval. Here, we examined the effects of context changes on fear responses as a function of time in male and female rats. Males displayed context discrimination at all intervals, whereas females exhibited generalization by 5 d. Ovariectomized females with no hormone replacement displayed context discrimination at 5 d, whereas those receiving 17β-estradiol generalized their fear response to a neutral context. These results demonstrate that fear generalization for contextual cues occurs faster in female rats and is mediated, in part, by estrogens.

Examination of the Effect of Mental Reinstatement of Context Across Developmental Level, Retention Interval and Type of Mnemonic Instruction

The effect of mental reinstatement of context was examined using a 4*5*2 factorial design incorporating four age groups (6-year-olds, 8-year-olds, 11-year-olds and adults), two retention intervals (1 day and 2 weeks after the stimulus event) and five interview conditions. The interview conditions included; free recall, mental reinstatement-environment (where the setting was reinstated but no event-related detail was provided in the mnemonic instruction), mental reinstatement-event (where specific event-related content was provided), mental reinstatement-combined (a combination of the two above-mentioned methods) and specific questions. Overall, mental reinstatement (irrespective of the type) was found to enhance correct recall performance compared to free recall and (unlike specific questions) it did not lead to greater number of commission errors. Contrary to our initial predictions, however, there was no evidence of any special benefit of mental reinstatement for children and the effect of the technique did not vary consistently as a function of retention interval.

Persistent expression of methamphetamine-induced CTA in periadolescent rats

It is well documented that the transition from periadolescence to adulthood produces profound changes in motivated behavior, and furthermore, attenuates the aversive experience of abused drugs. Little is known, however, about adolescent memory for the conditioned aversive effects of abused drugs following retention intervals that span this developmental transition. The present experiment investigated methamphetamine-induced conditioned taste aversion (CTA) in periadolescent rats to determine if the magnitude of conditioning was altered following retention intervals that extend to adulthood. Rats consumed saccharin (0.1%, w/v) and were immediately injected with saline or methamphetamine (3.0 mg/kg) either once (PND 40) or three times (PND 38–40), and memory was assessed one or 50 days later on post natal days 41 or 90, respectively. Rats exhibited robust methamphetamine-induced CTA one and 50 days after conditioning, and the strength of responding did not change as a function of retention interval, regardless if animals were trained with one or three saccharin–methamphetamine pairings. These findings indicate that the expression of memory for the aversive effects of methamphetamine was resistant to degradation throughout the developmental period of periadolescence to adulthood.

Episodic-like Memory in the Rat

A fundamental question in comparative cognition is whether animals remember unique, personal past experiences. It has long been argued that memories for specific events (referred to as episodic memory) are unique to humans. Recently, considerable evidence has accumulated to show that food-storing birds possess critical behavioral elements of episodic memory, referred to as episodic-like memory in acknowledgment of the fact that behavioral criteria do not assess subjective experiences. Here we show that rats have a detailed representation of remembered events and meet behavioral criteria for episodic-like memory. We provided rats with access to locations baited with distinctive (e.g., grape and raspberry) or nondistinctive (regular chow) flavors. Locations with a distinctive flavor replenished after a long but not a short delay, and locations with the nondistinctive flavor never replenished. One distinctive flavor was devalued after encoding its location by prefeeding that flavor (satiation) or by pairing it with lithium chloride (acquired taste aversion), while the other distinctive flavor was not devalued. The rats selectively decreased revisits to the devalued distinctive flavor but not to the nondevalued distinctive flavor. The present studies demonstrate that rats selectively encode the content of episodic-like memories.

The Hippocampus Supports both the Recollection and the Familiarity Components of Recognition Memory

The receiver operating characteristic (ROC) has been used to investigate the component processes of recognition memory. Some studies with this technique have been taken to indicate that the hippocampus selectively supports the process of recollection, whereas adjacent cortex in the parahippocampal gyrus supports the process of familiarity. We analyzed ROC data from young adults, memory-impaired patients with limited hippocampal lesions, and age-matched controls. The shape of the ROC changed in similar ways from asymmetric to symmetric, as a function of the strength of memory (strong to weak) in both the young adults and the patients. Moreover, once overall memory strength was similar, the shape of the patient ROC was asymmetric and matched the control ROC. These results suggest that the component processes that determine the shape of the ROC are operative in the absence of the hippocampus, and they argue against the idea that the hippocampus selectively supports the recollection process.

Proactive and retroactive effects of negative suggestion.

The negative effects of false information presented either prior to (proactive interference; PI) or following (retroactive interference; RI) true information was examined with word definitions (Experiment 1) and trivia facts (Experiment 2). Participants were explicitly aware of which information was true and false when shown, and true-false discrimination was evaluated via multiple-choice tests. Negative suggestion, defined as poorer performance on interference items than noninterference (control) items, consistently occurred when the wrong information followed the correct information (RI) but not when it preceded the correct information (PI). These effects did not change as a function of retention interval (immediate, 1 week, or 3 weeks) or number of incorrect alternatives (1 or 3). Implications of this outcome for experiencing incorrect information in both academic and nonacademic situations are considered.

The effect of reinforcer delays on the form of the forgetting function.

Pigeons were trained in a matching-to-sample procedure with retention intervals of 0, 2, 4, 6, and 8 s mixed within each session. In different conditions, reinforcement was delayed by 0, 1, 2, 4, 6, or 8 s from correct choice responses. Discriminability decreased with increasing retention-interval duration and with increasing reinforcer delay. Exponential forgetting functions were fitted to discriminability measures plotted as a function of retention interval. Initial discriminability (intercept of the fitted functions) decreased with increasing reinforcer delay. Rate of forgetting (slope of the fitted functions) increased with reinforcer delay, suggesting an interaction between the effects of reinforcer delay and retention interval. The data were well described by multiplying an exponential function describing the effects of retention interval by a hyperbolic function describing the effect of reinforcer delay. This description included an interaction term that allowed for a greater effect of reinforcer delay at longer retention intervals.

A fuzzy trace analysis of categorical inferences and instantial associations as a function of retention interval

Two experiments on children's inferences and associative memory provided a test of predictions from fuzzy-trace theory. Specifically, it was expected that gist-based false recognitions would increase with age and that false recognitions would be uncorrelated with verbatim memory. In Experiment 1, children in Grades 1 through 5 heard lists of category labels, clustered instances from categories, and individual instances. On an immediate test, children indicated whether or not they had previously heard a series of individually presented test words. This list consisted of old words, new words, or words that were categorically or semantically related to the studied word clusters. Children made more false recognition errors for instances than for categories. Verbatim memory and inferences were unrelated. In Experiment 2, the effect of a test delay on categorical inferences and associated instances was examined with children in Grades 1 to 6. With delay, false recognition of associated instances declined for children at all grade levels. In contrast, categorical inferences increased with delay for older children. Verbatim memory and inferences were uncorrelated under immediate and 1-day delay conditions, but there were some low but significant correlations across grades under the 7-day delay. The results of the two experiments are interpreted as supporting fuzzy-trace theory.

The influence of experimental design: The example of the Brown-Peterson paradigm.

Abstract The results that are found in an experiment may depend upon whether the independent variable is manipulated in a between - subjects or a within - subjects fashion. This is illustrated here using the Brown - Peterson short - term temporory distractor paradigm. The traditional finding of rapid memory loss as a function of retention interval was found only when retention interval was manipulated within subjects. No effects of retention interval was found when retention interval was manipulated between subjects. Perhaps the most basic distinction among kinds of experimental design is that between within - subject (repeated - measures) and between - subject (separate - group) designs. Within - subjects designs have long been popular in experimental psychology, and they have become even more widely used in recent decades (Poulton, 1982). In some domains, this may reflect greater ecological validity for within - subjects designs insofar as people may experience a number of levels of a particular variable in everyday life (Greenwald, 1976). However, a major reason for the popularity of within - subjects designs is that they are more statistically powerful than between - subjects designs. In memory research, several variables of current interest have been shown to yield different patterns of effects in within - subjects and between - subjects experiments. The effects of stimulus generation (Begg & Snider, 1987; Slamecka & Katsaiti, 1987), imagery bizarreness (McDaniel & Einstein, 1986), levels of processing (Challis & Brodbeck, 1992; Thapar & Greene, 1994), and presentation modality (Greene, 1989) may each be modified by the nature of the experimental design. The purpose of this study is to demonstrate that even the most classic findings of memory research are not necessarily immune to the effects of design. One of the most heavily studied memory paradigms is the Brown - Peterson (or distractor) short - term memory task (for a review, see Greene, 1992). On each trial, subjects are given a short list of items and then engage in a rehearsal - preventing activity during the retention interval. At the conclusion of the retention interval, subjects are asked for recall of the items (usually in order). The classic finding (first discovered by Daniels, 1895, and later reported by Peterson & Peterson, 1959) is that recall is quite accurate at short retention intervals but drops rapidly, reaching asymptote when the retention interval is approximately 15 - 25 s. Two aspects of the procedure of Daniels (1895) and Peterson and Peterson (1959) that have been followed by most later researchers are that each subject goes through multiple trials and that the duration of the retention interval is varied randomly within subjects. A rare exception to this pattern is an experiment by Turvey, Brick, and Osborn (1970), who performed an experiment in which, for the first four trials, each subject experienced only one duration of the retention interval. Different groups underwent 5, 10, 15, 20, or 25 s of distraction on each trial. An examination of Turvey et al.'s (1970) data reveals no tendency for longer retention intervals to lead to poorer memory; in fact, there was a slight tendency in the opposite direction. Perhaps because this experiment was not carried out to study the effects of retention interval, this aspect of the data was given little attention by Turvey et al. (1970) and has been rarely discussed in subsequent studies. Turvey et al.'s (1970) data are reminiscent of Keppel and Underwood's (1962) finding that performance on the first trial of a Brown - Peterson task was unaffected by the duration of the retention interval. Keppel and Underwood's (1962) data are often dismissed as being uninterpretable due to ceiling effects on first - trial performance (see, e.g., Baddeley, 1990, p. 48; Crowder, 1989, p. 278). Turvey et al.'s (1970) results suggest that null effects of retention interval are not necessarily always due to ceiling effects. …

The Persistence of False Memories in List Recall

Roediger and McDermott (1995) recently re-introduced a paradigm to study the creation of false memories. Subjects hear short lists of related words (e.g., thread, pin, eye, sewing, etc.), all of which are associates of a critical nonpresented word (e.g., needle); on a free recall test given immediately after list presentation, subjects often erroneously recall the critical nonpresented word. The experiments reported here explore (a) the effect of test delay on false recall and (b) whether multiple study/test opportunities reduce the proportion of critical items erroneously recalled. In Experiment 1, introduction of a 2-day delay between study and test produced probabilities of false recall that exceeded those of veridical recall. In addition, prior testing of the list enhanced false recall, much like testing enhances later recall of studied items (the testing effect). In Experiment 2, an attempt was made to reduce or eliminate the false recall effect by using a multitrial study/test procedure. Although subjects were able to reduce the proportion of critical nonpresented words erroneously recalled, they were unable to eliminate the false recall effect, even after 5 study-test trials. An interaction occurred between accurate and false recall as a function of retention interval: after a one-day delay, false recall levels rose, whereas accurate recall decreased. Results of both experiments demonstrate the persistence of this memory illusion.

Effects of elements or compound preexposure on conditioned taste aversion as a function of retention interval

The effects of element or compound preexposure and retention interval were examined in three experiments with the taste-aversion paradigm. In Experiment 1, preexposure to the elements of a compound flavor produced less latent inhibition to the compound than did preexposure to the compound itself when a 1-day preexposure-conditioning interval was used. However, preexposing the elements or the compound resulted in equivalent latent inhibition effects when a 21-day retention interval was used. In Experiment 2, a similar pattern of results was observed when the conditioning-test interval was manipulated. Experiment 3 explored the effect of element or compound preexposure when preexposure and test were carried out in different contexts. Attenuated latent inhibition following preexposure to the elements was found when preexposure and test were carried out in the same context. In contrast, preexposure to the elements resulted in as much latent inhibition as did preexposure to the compound when the context was switched from preexposure to testing. The implications of these findings for a retrieval-oriented view of latent inhibition are discussed.

The effect of nonreinforced stimulus exposure on the strength of a conditioned taste aversion as a function of retention interval: Do latent inhibition and extinction involve a shared process?

Two experiments examined the effects of nonreinforced flavor exposure on the strength of a conditioned taste aversion. Rats were conditioned by pairing maple flavor with LiC1. Prior to or subsequent to this pairing, some animals received nonreinforced exposure to either maple or saccharin. In separate subjects, preference for maple was tested 1 or 21 days after the last training episode. In the first experiment, the nonreinforced stimulus exposure occurred before conditioning (latent inhibition, or LI, procedure); in the second experiment, the nonreinforced exposure occurred after conditioning (extinction, or EXT, training). In both experiments, nonreinforced exposure to maple or saccharin reduced the magnitude of a conditioned maple aversion when testing occurred soon after conditioning. When testing was delayed, however, the attenuation due to nonreinforced saccharin exposure dissipated, both with the LI procedure and with EXT. In contrast, the nonreinforced exposure to maple was found to attenuate conditioned reactions at both short and long retention intervals. The release from generalized LI and spontaneous recovery following generalized EXT training are discussed in terms of retrieval processing. The possibility that the same mechanism may underlie LI and EXT is considered.

Two-year-old talk about the past

Children between 29 and 35 months of age were interviewed in order to determine how much they remember about their past experiences, how they organize what they remember, and how long they are able to retain memories of past events. Children readily participated in the conversations, and recalled a great deal of accurate information about events they had experienced both in the recent past (up to 3 months ago) and the distant past (more than 3 months ago). The mean number of conversational turns, the number and type of questions asked (prompts, probes, yes/no), and the amount and type of information provided by the child about the events under discussion did not differ significantly for the two retention intervals. Children organized their recall in one of two ways, in a question/answer form or a narrative form, but this was neither an individual difference nor a function of retention interval. The results are discussed along with other recent findings about young children's memory abilities, and directions for future research are suggested.

Why do Socratic stimuli produce hypermnesia?

Socratic stimuli, giving a description of a word without presenting the word itself, increase recall as a function of retention interval (see the studies on hypermnesia in Erdelyi, Buschke, & Finkelstein, 1977). In the present study, one lengthy recall task (20 min) or four consecutive recall trials of 5 min followed the presentation of either Socratic descriptions of words or words themselves, which were either of high or low imagery value (Experiment 1). The recall task used the impaired feedback technique (Gardiner, Passmore, Herriot, & Klee, 1977) leaving the already retrieved items unavailable during the remaining time of the recall trial or trials. The nature of the recall task did not affect recall performance, and only Socratic descriptions of high imagery words produced a recall increase. In Experiment 2, two possible sources of hypermnesia with Socratic stimuli were further explored: imagery and the generation effect. Generation failed to produce hypermnesia, while Socratic descriptions of high and low imagery words produced significant effects. Moreover, high imagery words without Socratic descriptions also led to hypermnesia. An encoding context that improves a unique semantic processing is likely to be critical for obtaining hypermnesia.

Subtest scores of a comprehensive examination of medical knowledge as a function of retention interval.

It was hypothesized that performance on particular subtests of a comprehensive examination of medical knowledge would be a function of the length of time between completion of the respective medical training and the administration of the comprehensive examination. Two samples of graduates of the Jefferson Medical College including 1086 students who graduated between 1975 and 1979, and 877 who graduated in 1980 through 1983 were studied. Each student in the junior year of medical school had been assigned to one of four groups. Each group took the required clerkship training in internal medicine, obstetrics/gynecology, pediatrics, psychiatry and surgery in a different rotational sequence. Statistical analyses indicated that there were no statistically significant differences among the four groups in the two samples, before and after the junior year on total comprehensive medical examination scores. However, an expected linear trend was found in scores on subtests of psychiatry, obstetrics/gynecology, and surgery in both samples. The observed trend indicated that the shorter the retention interval between clerkship training and the respective examination, the higher the score on that examination. Data were analyzed in terms of some hypotheses from learning theories, and implications for medical education were discussed.

Normalization in paraphrase and recall: Effects of processing, grammatical article type, and retention interval

Investigations of semantic normalization of discourse have not generally controlled for perceived connectiveness of materials, depth of processing, and retention interval. The current experiment investigated semantic normalization in paraphrase and recall as a function of whether sentences were paraphrased or merely copied, of whether sentences were perceived by subjects to be connected or unrelated, and of retention interval. Results indicated that significantly more normalization occurred in paraphrase than in recall, that more normalization and better recall occurred when sentences were perceived as related, and that there was more normalization and better recall when sentences were paraphrased than when they were copied. No significant differences in normalization were found as a function of retention interval. Results are discussed in terms of depth of processing and a need for learners to integrate congruent and discrepant material into cohesive entities by use of grammatical articles, article changes, and intrusions that psychologically connect unrelated sentences.

The Effect of Electric Shock and Fear Conditioning on KAMIN Effect in Rats

The question of what causes KAMIN effect is still remained. Recently, it is popularly thought that KAMIN effect is “shock-induced” phenomenon. There are, however, some researchers who do not agree to this explanation. One of my purposes is to investigate whether KAMIN effect is induced only by electric shocks. Another is to try to get an alternative explanation of KAMIN effect by comparing avoidance respones as an index of external behavior with heart rate changes as an index of internal behavior. Subjects were 54 male albino rats. They were given one of two preceding procedures of fear conditionning and electric shock trial, and then were ramdomly divided into one of four retention interval groups (0, 1, 3, 24 hrs.). After their retention intervals, they were tasked one-way avoidance training. The number of avoidance responses of the rats given the preceding procedure of fear conditioning showed a typical V-shaped curve as function of retention intervals, but that of the rats given only shocks did not showed a typical curve, but a modified-V-shaped curve with a rising end. This means that the avoidance responses have not been facilitated immediately after administration of electric shocks. Since the results of HR changes to the CS and the shuttle box situation did not revealed specific changes in the one-hour groups, as compared with 3 and 24 hour groups, the present results could not be explaned by either memory or drive theory. It might be thought that the first part of V-shaped curve in KAMIN effect is made by facilitating effect of avoidance response immediately after learning of CS-UCS relationship, and that the middle and last parts are produced only by effect of electric shocks.

Storage-retrieval analysis of acoustic similarity

A statistical procedure that separates storage from retrieval was used to study the acoustic similarity effect as a function of retention interval in the Brown-Peterson paradigm. Both storage and retrieval components showed reliable and independent changes with retention interval, but only the storage component was affected by acoustic similarity. Hence, acoustic similarity affects trace durability and retrieval plays no essential role in the similarity effect. This finding is inconsistent with the address hypothesis (cf. Baddeley, 1968). It is argued that acoustic similarity induces subjects to encode the target item in a confused fashion, particularly in regard to order information.