Storage and retrieval processes of alcohol-induced amnesia.

Used a technique that separates storage from retrieval in the Peterson paradigm to study the information-processing dynamics of alcohol-induced amnesia. An experiment with a 2–3 factorial design was performed with 38 normal male undergraduates; the factors were (a) drug group (632 ml/kg alcohol vs placebo), (b) organization (high vs low organization of target items), and (c) retention interval (4 sec vs 12 sec). Results show that the storage measure, all main effects and the Organization?×?Retention Interval interaction were significant. For the retrieval measure, all main effects and interactions were significant except the Drug Group?×?Retention Interval interaction. Because the storage and retrieval measures were independent, a 2-process explanation of alcohol-induced memory impairment is developed, using the theoretical notions of "depth of encoding" and "restriction of search set." Some clinical implications are discussed. (26 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Developmental differences in episodic retrieval: The role of differences in concept representations in semantic memory.

Developmental differences in the relative salience of features in concept representations in semantic memory and their contributions to differences in cued recall were examined in two experiments. For second graders, fifth graders, and college students, acquisition encoding of cue–target noun pair information was constrained by means of defining-, characteristic-, category-, and incidental-feature orienting questions. At retrieval, the encoding of cue information alone was constrained (Experiment 1) within subjects by means of the same (e.g., defining at acquisition and defining at retrieval) or related (e.g., defining at acquisition and characteristic at retrieval) retrieval questions or was unconstrained (Experiment 2). In both experiments, the acquisition presentation duration was manipulated (1 s or 5 s) in order to examine the spread of feature activation within concepts. The results showed that recall varied with feature salience, with the salience greatest for defining features. In addition, the results suggested that the relative salience of defining features was at least as great for the children as for the adults. The results offer no support for Keil and Batterman's (1984) hypothesis of a shift from characteristic to defining features in the development of word meaning representation in memory. (21 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effect of lysine-8-vasopressin on retention and retrieval of a discrimination reward task in the rat.

The effect of vasopressin on memory of a brightness discrimination reward task was investigated in 20 male Sprague-Dawley rats. Two measures of retention were used: resistance to extinction and savings scores on a reacquisition task given 45 days after the completion of extinction training. The effect of the peptide on both memory consolidation and retrieval was assessed. There were 2 major findings: (a) The peptide enhanced memory consolidation of the task whether measured after a short time interval (6 days) or after a long time interval (45 days after completion of extinction training) using a measure of trials to relearn the task, and (b) the peptide had no effect on memory retrieval. These results were compared to those of other studies designed to access memory consolidation and retrieval on appetitive tasks. The mechanisms of the peptide's effect on memory was briefly discussed with respect to three theories on the subject. This study extends the vasopressin research on memory consolidation by suggesting that it pertains to appetitive as well as to aversive tasks. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Verbal memory in drug-naive, newly diagnosed Parkinson's disease. The retrieval deficit hypothesis revisited.

Objective: The retrieval deficit hypothesis on memory impairment in patients with Parkinson's disease (PD) implies a selective impairment in recall of learned material with normal encoding, retention, and recognition. This hypothesis has been challenged by new data. We have therefore investigated verbal memory and learning in a large sample of newly diagnosed, drug na?ve, non-demented patients with PD. Method: From a sample of patients with PD from the Norwegian ParkWest study, 133 PD patients and 133 controls matched on sex, age, and education were included. The California Verbal Learning Test-2 (CVLT-2) was used to assess verbal memory. Results: Patients performed significantly worse than controls on free and cued recall as well as on recognition memory. Patients used the semantic clustering learning strategy significantly less extensively than the controls and the learning slope of the PD patients was significantly less steep. There was no difference in retention when controlling for encoding. Patients did not perform better on the recognition measure or on cued recall (d-prime), as compared to free recall. Executive functions explained a substantial part of the memory deficits. Conclusions: This study suggests that memory impairment in drug na?ve early PD to a large degree is a deficit of learning/ encoding and not of retention or retrieval. An implication is that the retrieval deficit hypothesis should be moderated in its general form. Executive deficits and less extensive use of the efficient semantic clustering learning strategy had a strong impact on learning and memory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Tower of Hanoi: Evidence for the cost of goal retrieval.

Past research on the Tower of Hanoi problem has provided clear evidence for the importance of goal–subgoal structures in problem solving. However, the nature of the traditional Tower of Hanoi problem makes it impossible to determine whether there is any special cost associated with storing or retrieving goals. A variation of the Tower of Hanoi problem is described that allows one to determine separately if there is an effect of how long a goal has to be retained on storage time or how long ago it was formed on retrieval time. This paradigm provides evidence for an effect of retention interval on retrieval time and not on storage time. An ACT–R (Adaptive Control of Thought–Rational; J. R. Anderson & C. Lebiere, 1998) simulation of these data is described, which treats goal memory as no different from other memories. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Enhancement and impairment of memory retrieval by a vasopressin metabolite: An interaction with the accessibility of the memory.

A series of 3 experiments was conducted to determine the generalizability of the improved recall seen with pretest administration of vasopressin in aversively motivated tasks. The learning paradigm selected for this purpose assessed the transmission of a food preference between rats; retention intervals of 8, 10, and 14 days were used in the 3 experiments, respectively. Pretest sc injection of a vasopression metabolite, AVP4–9, significantly improved recall under conditions in which memory was poor in vehicle-treated rats but significantly impaired memory at a time when good recall was evident in controls. These findings support the postulate that administration of vasopressin or its metabolites modulate memory retrieval processes and suggest that the nature of this effect depends on the degree of forgetting that has occurred. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Retention of order information for sounds and words.

In 4 experiments with a total of 160 undergraduates and 2 university staff members, short segments of naturalistic sounds were compared with their verbal labels in several tasks requiring retention of order information. Results of Exp I show that ordered recall of 7-item sequences of sounds was poorer than words with interstimulus intervals of 500 msec or shorter, while the difference disappeared with an interstimulus interval of 1 sec. Results of Exp II–IV, which extended the comparison to running memory span, serial probe, and probe recognition tasks, show a superiority of words over sounds in the recency component of the serial position curves in each case. Taken together, findings support the idea that verbal coding facilitates retention of order information, and discount interpretations of the sound–word difference based on higher-order processing strategies or retrieval problems. (French summary) (16 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Developmental invariance in distinctiveness effects in memory.

Improvements in 5- and 7-year-olds' acquisition and retention of related concept pairings were examined when additional similarities and differences between pair members were provided. Using a standard paired-associate learning paradigm, children learned 18 related picture pairs; some of the children either were given or produced additional similarities or differences between pair members at the time of learning. Three weeks after learning was complete, children attempted to recall the pairs. Using a model to determine the storage and retrieval loci of these effects, the results showed that (a) all children benefited from self-generated elaborations, regardless of whether these were similarities or differences, and these benefits were storage related, and (b) difference elaborations improved children's retention regardless of whether they were self- or experimenter-generated, and these effects were primarily retrieval based. These results are consistent with theories that (a) view retrieval as the locus of distinctiveness effects and (b) view storage as the locus of self-generated memory improvements. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Attentional limits in memory retrieval.

The hypothesis that episodic memory retrieval can occur in parallel with other cognitive processes was tested in 2 experiments. Participants memorized words and then performed speeded cued recall (Experiment 1) or speeded yes-no recognition (Experiment 2) in a dual-task situation. The psychological refractory period design was used: The participant was presented with a single test item at various stimulus onset asynchronies (SOAs; 50-1,000 ms) after a tone was presented in an auditory-manual 2-alternative choice reaction task. Reducing the SOA increased the memory task reaction times. This slowing was additive with the effect of variables slowing retrieval in the memory task. The results indicate that memory retrieval is delayed by central processes in the choice task, arguing that the central bottleneck responsible for dual-task interference encompasses memory retrieval as well as response selection. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Benzodiazepines alter cochleo-cochlear loop in humans

When administered soon before or after training, glucose facilitates memory in rodents and in several populations of humans, including healthy elderly people. Thus, glucose appears to enhance memory formation in a time- and dose-dependent manner. By assessing the effects of glucose at the time of memory tests, the present experiment examined the role of glucose on memory retrieval in healthy elderly people. On four sessions separated by a week, glucose or saccharin were administered immediately before hearing a narrative prose passage, as in previous experiments, or immediately before being tested for recall of the passage (24 h after training). Subjects recalled significantly more information after glucose ingestion than after saccharin ingestion whether the glucose was given before acquisition or memory tests. In addition, recall was significantly better in the preacquisition glucose condition relative to recall in the retrieval glucose condition. These findings provide evidence that glucose enhances both memory storage and retrieval.     

Cue strength as a moderator of the testing effect: The benefits of elaborative retrieval.

The current study explored the elaborative retrieval hypothesis as an explanation for the testing effect: the tendency for a memory test to enhance retention more than restudying. In particular, the retrieval process during testing may activate elaborative information related to the target response, thereby increasing the chances that activation of any of this information will facilitate later retrieval of the target. In a test of this view, participants learned cue–target pairs, which were strongly associated (e.g., Toast: Bread) or weakly associated (e.g., Basket: Bread), through either a cued recall test (Toast: _____) or a restudy opportunity (Toast: Bread). A final test requiring free recall of the targets revealed that tested items were retained better than restudied items, and although strong cues facilitated recall of tested items initially, items recalled from weak cues were retained better over time, such that this advantage was eliminated or reversed at the time of the final test. Restudied items were retained at similar rates on the final test regardless of the strength of the cue–target relationship. These results indicate that the activation of elaborative information—which would occur to a greater extent during testing than restudying—may be one mechanism that underlies the testing effect. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Neural correlates of cued recall with and without retrieval of source memory

A source memory procedure was used to investigate whether event-related potentials (ERPs) reflect the retrieval of episodic information (recollection) on tests of word-stem cued recall. 'Cued recall ERP effects' for recalled items were found to differ only in their magnitudes, and not their scalp distributions, according to the accuracy of source memory. This finding strongly supports the hypothesis that cued recall ERP effects reflect quantitative variation in the amount or quality of information which can be retrieved about recently experienced events. Topographic analyses also revealed that the distribution of the cued recall ERP effects changed over time, reflecting the activity of at least two temporally and neuroanatomically dissociable neural populations contributing to recollection on this task.     

Expression of renewal is dependent on the extinction-test interval rather than the acquisition-extinction interval.

A recent finding suggested that when extinction occurs shortly after acquisition, renewal of an extinguished fear response (fear-potentiated startle) to a light conditioned stimulus (CS) is diminished (Myers, Ressler, & Davis, 2006). The present study attempted to extend this finding using a white-noise CS and freezing as the behavioral measure of fear. In Experiments 1A and 1B, we observed renewal whether extinction occurred 10 min or 24 hr after acquisition. In contrast, renewal was not observed if test occurred 10 min after extinction (Experiment 2). Experiment 3 demonstrated that expression of extinction at the 10-min extinction-test interval was attenuated by a pretest subcutaneous injection of the γ-aminobutyric acid (GABA) inverse agonist FG7142. These findings suggest that renewal is influenced more by the extinction-test interval than the acquisition-extinction interval. Further, the failure to see renewal 10 min after extinction suggests that there is a separate context memory that undergoes a different consolidation function than the CS-no US memory formed during extinction. Finally, the expression of extinction appears to be GABA dependent regardless of the extinction-test interval or the test context. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Delayed extinction attenuates conditioned fear renewal and spontaneous recovery in humans.

This study investigated whether the retention interval after an aversive learning experience influences the return of fear after extinction training. After fear conditioning, participants underwent extinction training either 5 min or 1 day later and in either the same room (same context) or a different room (context shift). The next day, conditioned fear was tested in the original room. When extinction took place immediately, fear renewal was robust and prolonged for context-shift participants, and spontaneous recovery was observed in the same-context participants. Delayed extinction, by contrast, yielded a brief form of fear renewal that reextinguished within the testing session for context-shift participants, and there was no spontaneous recovery in the same-context participants. The authors conclude that the passage of time allows for memory consolidation processes to promote the formation of distinct yet flexible emotional memory traces that confer an ability to recall extinction, even in an alternate context, and minimize the return of fear. Furthermore, immediate extinction can yield spontaneous recovery and prolong fear renewal. These findings have potential implications for ameliorating fear relapse in anxiety disorders. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Spaced retrieval: Absolute spacing enhances learning regardless of relative spacing.

Repeated retrieval enhances long-term retention, and spaced repetition also enhances retention. A question with practical and theoretical significance is whether there are particular schedules of spaced retrieval (e.g., gradually expanding the interval between tests) that produce the best learning. In the present experiment, subjects studied and were tested on items until they could recall each one. They then practiced recalling the items on 3 repeated tests that were distributed according to one of several spacing schedules. Increasing the absolute (total) spacing of repeated tests produced large effects on long-term retention: Repeated retrieval with long intervals between each test produced a 200% improvement in long-term retention relative to repeated retrieval with no spacing between tests. However, there was no evidence that a particular relative spacing schedule (expanding, equal, or contracting) was inherently superior to another. Although expanding schedules afforded a pattern of increasing retrieval difficulty across repeated tests, this did not translate into gains in long-term retention. Repeated spaced retrieval had powerful effects on retention, but the relative schedule of repeated tests had no discernible impact. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Storage and retrieval of associative clusters: A stages-of-learning analysis of associative memory traces.

In this research, the assumptions underlying the unitary trace theory of item representation and acquisition were tested in two cued-recall experiments in which the degree of preexperimental knowledge (typicality) was manipulated. Subjects learned lists of word triads (each of which consisted of a single cue and two targets) to a stringent acquisition criterion. In Experiment 1, typicality was manipulated in the absence of semantic relationships between members of the associative clusters. In Experiment 2, semantic relationships were present among cluster members, and preexperimental knowledge was manipulated by varying the degree of intracluster category membership as measured by whether cue and target items were typical or atypical category exemplars. In both experiments a mathematical model that embodies stages-of-learning distinctions was used to analyze the acquisition data. The results indicated that (1) cues and targets were represented in a single holistic memory trace, and (2) the manipulation of the degree of preexperimental knowledge affected both trace storage and retrieval learning, but had only a minimal impact on retrieval performance between the time a trace was stored and the time retrieval learning was complete. It was argued that these findings are consistent with a single unitary trace interpretation, namely, the modified storage-retrieval model. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Expanding retrieval practice promotes short-term retention, but equally spaced retrieval enhances long-term retention.

Expanding retrieval practice (T. K. Landauer & R. A. Bjork, 1978) is regarded as a superior technique for promoting long-term retention relative to equally spaced retrieval practice. In Experiments 1 and 2, the authors found that expanding retrieval practice of vocabulary word pairs produced short-term benefits 10 min after learning, conceptually replicating Landauer and Bjork's results. However, equally spaced retrieval produced superior retention 2 days later. This pattern occurred both with and without feedback after test trials. In Experiment 3, the 1st test occurred immediately or after a brief delay, and repeated tests were expanding or equally spaced. Delaying the first test improved long-term retention, regardless of how the repeated tests were spaced. The important factor for promoting long-term retention is delaying initial retrieval to make it more difficult, as is done in equally spaced retrieval but not in expanding retrieval. Expanding the interval between repeated tests had little effect on long-term retention in 3 experiments. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Attention and retrieval from long-term memory.

Conducted 9 experiments with 152 female volunteers (mean age 44.4 yrs) to investigate the disrupting effect of a secondary task on retrieval from long-term memory. Exps I–V studied the influence of concurrent card sorting or digit span on free recall or paired-associate learning of word lists. Exp VI explored recall probability using a recognition paradigm in which accuracy and latency could be measured simultaneously. Exp VII explored the latency effect with a semantic memory paradigm, and Exp VIII required Ss to make semantic category judgments while retaining sequences of 6 digits. Exp IX examined the effect of concurrent digital load on the rate of generating items from semantic categories. Overall findings reveal that a demanding concurrent task did not reduce the probability of retrieving an item from semantic or episodic memory. However, concurrent load during learning substantially effected recall performance. A concurrent task during retrieval did not have a clear effect on latency. The contrast between the pattern shown by errors and by that shown by latencies suggests that attempts to estimate the attentional demands of any task should be interpreted with considerable caution when based on a single measure, such as performance errors, performance latency, or a response to a probe RT signal. (38 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Adult age differences in short-term memory and subsequent long-term memory for actions.

Short-term memory for actions was investigated for young adult and elderly adult Ss with the Brown-Peterson procedure at retention intervals of 0 and 15 sec. The short-term memory trials were followed by the long-term recall of the prior to-be-remembered actions. The 15-sec retention interval was filled either with no activity or with 1 of 3 different interfering activities. Verbal interference had little effect on short-term memory at either age level. Actions performed in the interval either by the Ss or by the experimenter produced significantly lower recall scores at each age level, with the decrement being more pronounced for the elderly than for the young Ss. The long-term memory results indicated that successful short-term recall enhanced later long-term recall, regardless of age level. (PsycINFO Database Record (c) 2010 APA, all rights reserved)