Contextual cuing and memory performance in brain-damaged amnesics and old people

In Experiment 1, groups of Korsakoff amnesics and alcoholic controls learned a list of paired-associate words in a standard testing room or in a room with distinctive contextual features. Recall was tested 48 hr later in the same or other context. This procedure was repeated in Experiment 2 with old people living in institutions or in the community, but matched for age, health, education, and socioeconomic background. The amnesic patients and institutionalized old people, relative to their comparison groups, were more impaired in recalling the lists under standard conditions and were more responsive to contextual cuing, especially when the distinctive cues were provided during original learning. The results highlight the susceptibility to interference of Korsakoff amnesics and institutionalized old people and offer further evidence that both groups are more responsive to salient contextual cues than either young people or old people living in the community.     

Revisiting an old issue: Retroactive interference as a function of the degree of original and interpolated learning

Prior research has generally shown that the greater the degree of original learning of a list, the greater the amount of retroactive interference that list suffers. In addition, greater learning of interpolated lists produces more retroactive interference. However, in prior research, the degree of learning has typically been confounded with the amount of retrieval practice on the list. Two free-recall experiments are reported in which subjects studied one original list and then 0, 1, 2, 3, or 4 interpolated lists. The degree of original and of interpolated learning was manipulated by varying exposure time. In Experiment 1, where the typical confounding of retrieval practice and degree of interpolated learning was present, greater interpolated learning induced greater retroactive interference, which is consistent with prior research. However, in Experiment 2, where the degree of interpolated learning was manipulated without concomitant variation in retrieval practice, retroactive interference was the same, whether the interpolated lists had been learned well or poorly. Therefore, greater interpolated learning does not increase the amount of retroactive interference. The results also show that the amount of retroactive interference does not depend on the degree of original learning, in agreement with other work on normal forgetting.     

Representation of serial order in pigeons (Columba livia)

In Experiment 1, 2 groups of pigeons were trained to respond to either a 4-item (A→B→C→D) or 5-item (A→B→C→D→E) list. After learning their respective list, half of the subjects were trained on a positive pair with reinforcement provided when pairs were responded to in the order true to that of the original sequence (4-item: B→C; 5-item: B→D). The remaining subjects were trained on a negative pair with reinforcement provided for responding to the pairs in the order opposite to that learned in the original sequence (4-item: C→B; 5-item: D→B). Subjects in the positive pair condition learned their respective pair faster than did subjects in the negative pair condition. In Experiment 2, after reaching criterion on a 4-item list, subjects received 16 BC probe trials spread across 4 sessions of training. Subjects performed significantly above chance on the probe trials. The performance of our subjects in Experiments 1 and 2 demonstrates that, similar to monkeys, pigeons form a representation of the lists that they learn.     

Retention beyond the threshold: Test-enhanced relearning of forgotten information

The effect of repeated testing on delayed relearning of paired associates was investigated. Participants learned two lists of Lithuanian-Dutch word pairs until reaching the criterion of one correct recall from long-term memory. In one condition, items subsequently received three post-retrieval study trials and in the other condition items received three post-retrieval test trials. Participants returned one week later for delayed recall and relearning. Post-retrieval test trials resulted in better delayed recall performance than post-retrieval study trials. Moreover, we found that the items that were repeatedly studied or tested one week prior to relearning were relearned faster than a new set of similar (not previously presented) items. Most importantly, items were relearned faster when they had previously been learned under conditions of post-retrieval testing than items learned under conditions of post-retrieval study. Taken together, the results indicate that the benefits of repeated testing are not just limited to conscious recall on a delayed test. Repeated testing during initial learning is also a very effective strategy to enhance delayed relearning.     

Memory, acquisition, and category clustering in learning-disabled children.

In Experiment 1, single trial, immediate-free recall of learning disabled and nondisabled children was compared. The primacy effect in learning-disabled children was lower, suggesting that rehearsal or other types of elaborative encoding may be deficient in these children. In Experiment 2, acquisition of randomly presented categorical lists in a multitrial-free recall task was compared in learning disabled and nondisabled children. One-half of each group was required to learn the same number of words (34 per list), whereas list length for the other half exceeded the primacy effect of each child in immediate-free recall to the same degree. When the same number of items was learned, acquisition was slower in learning disabled than nondisabled children. When the number of items varied according to the primacy effect of each child, acquisition of both groups was similar. Clustering was lower in learning disabled than nondisabled children. In Experiment 3, multitrial-free recall acquisition of categorical lists was examined in a subject-paced task. When the number of words learned exceeded the primacy effect of each child to the same degree, trials to criterion were similar in both groups but, when the children learned the same number of items, learning-disabled children required more trials to criterion. Presentation rates were faster in learning-disabled children. Presentation rates were negatively correlated with trials to criterion and positively correlated with clustering and primacy in immediate-free recall, suggesting that study time may be taken up by clustering, rehearsal, and/or other encoding strategies. Deficient elaborative encoding may be responsible for the slower acquisition of learning-disabled children.     

Retroactive interference as a function of degree of interpolated study without overt retrieval practice

In two experiments, retroactive interference (RI) was examined under conditions designed to minimize retrieval-induced inhibition and output interference. In Experiment 1, the participants first learned a list of 10 person-location pairs, after which they viewed an interpolated list with the same person terms and different locations for one, four, or eight cycles. Learning was via a study-only method, so that the experimental participants did not perform instructed retrieval of the second list before a cued recall test that asked for List 1 locations only. The experimental participants in Experiment 2 received incidental learning instructions and then viewed a list of 20 unrelated words followed by another list presented either one or four times; the first two letters of each List 1 word were provided on the critical recall test. In both experiments, RI occurred and increased with degree of interpolation. The results suggest that RI does not require retrieval-induced inhibition.     

Serial list combination by monkeys (Macaca mulatta): test cues and linking

This investigation assessed prospective bases of non-human primate cognitive operations that support serial list memory. Four macaques learned 3-, 5-item ordered lists of objects (as two-choice problems) and then either did or did not (in a within-subject design) receive training on pairs that linked the three original lists into a 15-item serial order. Next, subjects experienced selective exposure trials on object pairs that either maintained or contrasted to the serial position relationships seen during original learning. Subsequent comprehensive tests assessed the interactive effects of linking and exposure conditions on choosing in accord with a combined 15-item serial order. Linking readily induced monkeys to merge lists into a 15-item order, but restricting early exposure to pairs with the same positional relationships as original training slowed, but did not prevent, list combination. Exposure to positional relationships congruent with the combined (15-item) list and different from those of original 5-item training aided both expression of the linking effect and acquisition after no link training. Thus, list linking facilitated serial reorganization by inducing release from error derived from memory for prior learned positional relationships. The task was recommended as a prospective evaluator of continuity of cognitive processes among species.     

The simultaneous acquisition effect: simultaneous task learning inhibits memory for order

Delayed recall of a list of words learned simultaneously with other lists is superior to that of a list of words learned singly. A Brown-Peterson-like task was used to investigate this simultaneous acquisition effect from the perspective of the item-order distinction. It was hypothesized that simultaneous task learning would impede the encoding of order information but promote the encoding of item-specific information relative to single-task learning. The results of the first four experiments strongly supported the hypothesis that simultaneous task learning decreases the encoding of order information but provided no evidence that it facilitated the encoding of item-specific information. Additionally, Experiment 5 showed that the simultaneous acquisition effect did not occur in a mixed-list design, demonstrating an important boundary condition of the effect.     

Testing effects in mixed- versus pure-list designs

In the present study, we investigated the role of list composition in the testing effect. Across three experiments, participants learned items through study and initial testing or study and restudy. List composition was manipulated, such that tested and restudied items appeared either intermixed in the same lists (mixed lists) or in separate lists (pure lists). In Experiment 1, half of the participants received mixed lists and half received pure lists. In Experiment 2, all participants were given both mixed and pure lists. Experiment 3 followed Erlebacher’s (Psychological Bulletin, 84, 212–219, 1977) method, such that mixed lists, pure tested lists, and pure restudied lists were given to independent groups. Across all three experiments, the final recall results revealed significant testing effects for both mixed and pure lists, with no reliable difference in the magnitude of the testing advantage across list designs. This finding suggests that the testing effect is not subject to a key boundary condition—list design—that impacts other memory phenomena, including the generation effect.     

Working memory load in the initial learning phase facilitates relearning: a study of vocabulary learning

In this study, the effect of working memory load in the initial learning phase on the relearning phase was examined. Exp. 1 examined the effect of articulatory suppression in paired associative learning with a relearning method. In the learning phase, 28 participants (M age=21.8 yr., SD=2.1) learned all word-nonword associations under conditions of articulatory suppression or simple tapping. After a delay, they answered a cued recall task in a nonsuppressed condition and a relearning task in a simple tapping condition. The subjects who learned under the simple tapping condition in the learning phase required significantly more trials in the relearning phase. In Exp. 2, 28 participants (M age=20.8 yr., SD=1.5) participated, and the result was replicated. These results suggested that working memory load facilitates relearning. Results are best explained by contextual interference (Battig) rather than by the less-is-more hypothesis of Newport.     

The influence of acoustic and semantic similarity on long-term memory for word sequences

It has been shown that short-term memory (STM) for word sequences is grossly impaired when acoustically similar words are used, but is relatively unaffected by semantic similarity. This study tests the hypothesis that long-term memory (LTM) will be similarly affected. In Experiment I subjects attempted to learn one of four lists of 10 words. The lists comprised either acoustically or semantically similar words (A and C) or control words of equal frequency (B and D). Lists were learned for four trials, after which subjects spent 20 min. on a task involving immediate memory for digits. They were then asked to recall the word list. The acoustically similar list was learned relatively slowly, but unlike the other three lists showed no forgetting. Experiment II showed that this latter paradox can be explained by assuming the learning score to depend on both LTM and STM, whereas the subsequent retest depends only on LTM. Experiment III repeats Experiment I but attempts to minimize the effects of STM during learning by interposing a task to prevent rehearsal between the presentation and testing of the word sequences. Unlike STM, LTM proved to be impaired by semantic similarity but not by acoustic similarity. It is concluded that STM and LTM employ different coding systems.     

Influences of environmental context on the recency effect in free recall

A total of 208 undergraduate participants incidentally encoded a list of seven pairs of familiar words in two experiments. A 30-sec calculation task was imposed before and after each pair was encoded. Participants received a free recall test 24 h (Experiment 1) or 10 min (Experiment 2) after the encoding session, under conditions in which the original environmental context was reinstated or not. The environmental context was manipulated in terms of the combination of the physical features of the room, the subsidiary task conducted, the experimenter (Experiment 1), or background music (Experiment 2). A recency effect appeared when the original environmental context was reinstated in both experiments, even though the IPI/RI ratio was too small to produce recency effects according to the ratio rule. The results imply that the environmental context should be taken into account for the recency effect.     

项目特异性加工和关系加工对非熟练中-英双语者跨语言错误记忆的影响

采用DRM范式进行跨语言错误记忆的研究较为鲜见, 而且得出了许多不同的结果, 关于错误记忆跨语言产生的理论解释也是各执己见。研究以非熟练中-英双语大学生为被试, 采用DRM范式对非熟练中-英双语者的跨语言错误记忆进行了研究。在2个实验中, 分别探讨了项目特异性加工和关系加工条件下, 语义激活的不同水平对跨语言错误记忆的影响。结果发现：1)非熟练中-英双语者也存在跨语言的错误记忆; 2)在项目特异性加工和关系加工条件下, 相同语言内与不同语言间发生关键诱词的错误再认的结果是不同的; 3)只在项目特异性加工条件下, 长词表比短词表会诱发更多的对关键诱词的错误再认。研究结果支持了激活-监测理论。     

Enhancement of recall using multiple environmental contexts during learning

Distributing the presentation of sublists of words into multiple learning rooms produced better free recall scores than a single learning room condition for subjects who were given a comprehensive recall test in a new environment. No such effects occurred on recognition or list differentiation tests in Experiment 2, implying a retrieval explanation rather than one relying upon learning or list differentiation effects. Experiment 3 found that the contextual dependence of recall li.e., recall tested in a learning context is better than recall tested in a new context was nullified by using multiple learning rooms, rather than a single room for input. The data are consistent with an explanation that states that the multiple learning rooms become associated with the different sublists during learning and subsequently act as memory landmarks that guide the course of retrieval.     

A primacy effect in monkeys when list position is relevant

In Experiment 1 (1a and 1b), Rhesus monkeys (Macaca mulatta) learned lists of two-choice visual discriminations in which list position was relevant to discrimination performance. For example, Stimulus A was the rewarded stimulus if it was presented at List Position 1, but was not rewarded if it was presented at any other position in the list; similarly, Stimulus B was rewarded only at List Position 2, and so on. In learning these lists, all animals showed a marked primacy effect. In Experiment 2 (2a and 2b), Rhesus monkeys and Cynomolgus monkeys (M. fascicularis) learned lists of visual discriminations in which each visual stimulus occupied a fixed position in a list, but list position was not relevant to discrimination performance. For example, Stimulus E was always rewarded, and was always presented at List Position 1. To increase the salience of list beginning as a distinctive event, successive presentations of the list were separated by 24-hr intervals. In Experiment 2 there was no primacy effect, however. These results show for the first time that a primacy effect can be obtained in visual discrimination learning by monkeys. Furthermore, they suggest that it is obtained only when list position is relevant to the discrimination learning task.     

记忆的前向测试效应对老年人学习新事物的作用

为检验前置测试是否可以有效地提升老年人学习新事物的能力,参与实验的老年人被随机分为有前置测试的实验组和无前置测试的对照组,在实验1中学习了5列单词,在实验2中记忆了5列日用品,在实验3中学习了4段讲座视频。结果表明,实验组老年人对新事物的记忆成绩均高于对照组的老年人。结论认为,前置测试能够显著提升老年人学习新事物的能力,干扰降低与学习参与相结合的“加减”理论能更好地解释提升老年人记忆的前向测试效应。     

Effects of Word Processing and Short-term Memory Deficits on Verbal Learning: Evidence from Aphasia

We report two experiments that investigate the abilities of aphasic subjects with lexical and short-term memory impairments to learn supraspan lists of 10 words. We examined effects of stimulus factors (characteristics of words and lists to be learned) and subject factors (verbal and nonverbal STM span, nature of language impairment). Learning ability was influenced by the imageability and frequency of the words to be learned (Experiment 1) and by the linguistic relationship among words in a list (Experiment 2). Additionally, learning ability was affected by the nature of a subject's word processing deficit (whether it involved semantic and/or phonological processes). Phonological ability was positively associated with learning in both experiments, and semantic ability was associated with learning when words in a list were high in both frequency and imageability (Experiment 1) or were contextually related to one another (Experiment 2). Finally, verbal STM span was positively related to learning performance, but the effect was more pronounced for word span than digit span. These relationships among word processing ability, verbal STM span, and learning ability are discussed with reference to learning in aphasia and to models of learning more generally.     

Can false memories spontaneously recover?

Can false memories that were suppressed at one time spontaneously recover at a later time? Fuzzy trace theory and activation-monitoring theory predict that false memories in the Deese, Roediger, and McDermott (DRM) procedure become substantially reduced as list learning progresses because participants employ a memory-editing process. It follows that if the editing process is rendered less effective, false memories should spontaneously recover. We found that after DRM lists were well learned and false recognition to critical words was substantially reduced by multiple study–test trials, those false memories spontaneously recovered when participants were either rushed or delayed on a retest. We attributed the reduction in false recognition over trials to a memory-editing process that suppresses false recognition as participants gradually learn which words were in the lists and which words, though similar, were not. Rushing or delaying the participants on a retest made it more difficult for them to edit their memory, and false memories spontaneously returned.     

The simultaneous learning effect: why does simultaneous task learning improve retention?

Despite the prevalence of encoding variables that have been shown to influence the rate of learning, very few affect the rate of forgetting of verbal material. However, when a list of words is learned simultaneously with other lists, the rate of forgetting is markedly lower than that of single-task learning. Although the magnitude of this simultaneous learning effect is large compared with typical list learning effects, it has received little empirical attention. Experiments 1 and 2 tested the hypothesis that the simultaneous learning effect is the result of a differential contribution of short-term memory during encoding. The results showed that the advantage for simultaneous task learning was obtained even under conditions that minimized the potential effects of short-term memory. Experiment 3 revealed that the simultaneous learning effect was larger when the specific items learned simultaneously were the same on each learning trial than when they were different. This finding supported a cuing explanation of the effect: the items from the other lists act as retrieval cues during delayed recall.     

Can false memories spontaneously recover?

Can false memories that were suppressed at one time spontaneously recover at a later time? Fuzzy trace theory and activation-monitoring theory predict that false memories in the Deese, Roediger, and McDermott (DRM) procedure become substantially reduced as list learning progresses because participants employ a memory-editing process. It follows that if the editing process is rendered less effective, false memories should spontaneously recover. We found that after DRM lists were well learned and false recognition to critical words was substantially reduced by multiple study-test trials, those false memories spontaneously recovered when participants were either rushed or delayed on a retest. We attributed the reduction in false recognition over trials to a memory-editing process that suppresses false recognition as participants gradually learn which words were in the lists and which words, though similar, were not. Rushing or delaying the participants on a retest made it more difficult for them to edit their memory, and false memories spontaneously returned.