Environmental context and human memory

Five experiments examined the effects of environmental context on recall and recognition. In Experiment 1, variability of input environments produced higher free recall performance than unchanged input environments. Experiment 2 showed improvements in cued recall when storage and test contexts matched, using a paradigm that unconfounded the variables of context mismatching and context change. In Experiment 3, recall of categories and recall of words within a category were better for same-context than different-context recall. In Experiment 4, subjects given identical input conditions showed strong effects of environmental context when given a free recall test, yet showed no main effects of context on a recognition test. The absence of an environmental context effect on recognition was replicated in Experiment 5, using a cued recognition task to control the semantic encodings of test words. In the discussion of these experiments, environmental context is compared with other types of context, and an attempt is made to identify the memory processes influenced by environmental context.     

Lexical and semantic influences on item and order memory in immediate serial recognition: Evidence from a novel task

Previous studies have reported that, in contrast to the effect on immediate serial recall, lexical/semantic factors have little effect on immediate serial recognition. This has been taken as evidence that linguistic knowledge contributes to verbal short-term memory in a redintegrative process at recall. Contrary to this view, we found that lexicality, frequency, and imageability all influenced matching span. The standard matching span task, requiring changes in item order to be detected, was less susceptible to lexical/semantic factors than was a novel task involving the detection of phoneme order and hence item identity changes. Therefore, in both immediate recognition and immediate serial recall, lexical/semantic knowledge makes a greater contribution to item identity than to item order memory. Task sensitivity, and not the absence of overt recall, may have underpinned previous failures to show effects of these variables in immediate recognition. We also compared matching span for pure and unpredictable mixed lists of words and nonwords. Lexicality had a larger impact on immediate recognition for pure than for mixed lists, in line with findings for immediate serial recall. List composition affected the detection of phoneme but not item order changes in matching span; similarly, in recall, mixed lists produce more frequent word phoneme migrations but not migrations of entire items. These results point to strong similarities between immediate serial recall and recognition. Lexical/semantic knowledge may contribute to phonological stability in both tasks.     

Lexical and semantic influences on item and order memory in immediate serial recognition: evidence from a novel task

Previous studies have reported that, in contrast to the effect on immediate serial recall, lexical/semantic factors have little effect on immediate serial recognition. This has been taken as evidence that linguistic knowledge contributes to verbal short-term memory in a redintegrative process at recall. Contrary to this view, we found that lexicality, frequency, and imageability all influenced matching span. The standard matching span task, requiring changes in item order to be detected, was less susceptible to lexical/semantic factors than was a novel task involving the detection of phoneme order and hence item identity changes. Therefore, in both immediate recognition and immediate serial recall, lexical/semantic knowledge makes a greater contribution to item identity than to item order memory. Task sensitivity, and not the absence of overt recall, may have underpinned previous failures to show effects of these variables in immediate recognition. We also compared matching span for pure and unpredictable mixed lists of words and nonwords. Lexicality had a larger impact on immediate recognition for pure than for mixed lists, in line with findings for immediate serial recall. List composition affected the detection of phoneme but not item order changes in matching span; similarly, in recall, mixed lists produce more frequent word phoneme migrations but not migrations of entire items. These results point to strong similarities between immediate serial recall and recognition. Lexical/semantic knowledge may contribute to phonological stability in both tasks.     

提取方式对相继记忆效应的影响

采用学习－测验（自由回忆和再认）研究范式和事件相关电位方法,研究图形的相继记忆效应（Dm效应）。14名大学生作为研究被试,根据其测验成绩将图片分为记住和未记住两类,对相应编码过程的ERPs进行分析。结果表明：⑴行为上,再认的平均击中率显著高于自由回忆;⑵脑电活动上,在刺激出现后400~700ms编码过程中记住项目的ERPs更正于未记住项目的ERPs;同时两种测验方式Dm效应的脑区分布不同,自由回忆主要分布在额区,再认主要分布在中央区和顶区,且在500~600ms自由回忆有左侧优势。这些结果表明,两种提取方式对Dm效应有不同的影响,这一结果预示自由回忆和再认的编码过程可能有不同的神经生理机制。     

主题关系对无线索回忆再认效应的影响

本研究采用RWCR范式,从无线索回忆再认的视角考察了主题关系对熟悉性的影响。结果发现,主题关系能够引发无线索回忆再认效应。具体表现为,在回忆错误项目中,被试对与学过项目有主题关系线索的熟悉性评分显著高于与学过项目无主题关系线索的熟悉性评分。这一结果表明,个体在信息提取失败时,概念形式的语义信息也能引发基于熟悉性的再认判断。     

Developmental differences in remembering sentences after integrative or selective semantic processing

Fifth graders (age: 10 years) and college undergraduates performed one of four different semantic orienting activities on a series of agent-action-object sentences. Afterwards all subjects received a memory test combining recognition for whole sentences with cued recall for component agents, actions, and objects. Overall levels of both recall and recognition varied with the orienting activities. Relative recallability of agents, actions, and objects varied with orienting activity as well. Recognition performance improved with grade level but recall did not. The interaction between type of memory test and grade level was taken to indicate that organization of material in memory increases during adolescence even when the total amount of material stored does not.     

Acoustic interference in a recognition task

Phonetic or acoustic characteristics of stimuli in recall studies have consistently been shown to generate more interference over short intervals than semantic characteristics. We performed three experiments to determine whether this characteristic also applied to recognition processes over short intervals. Subjects were shown study lists of eight words and were asked to recognize which of those words recurred on subsequent eight-word lists. Delays varied from 0 to 100 s between study and test, with a rehearsal-preventing task inserted during the delays. Phonetic distractors generated greater interference than semantic distractors at all delay levels, and semantic distractors generated greater interference than random distractors. These distractor-type differences were not present in long-term recognition tasks. The deterioration in performance over time was considerably slower in these recognition experiments than in previous recall studies.     

Incidental formation of episodic associations: The importance of sentential context

The influence of relevant semantic context on the incidental formation of episodic associations between words was probed in two experiments. In Experiment 1, we examined the influence of associations formed incidentally between unrelated words presented either in isolation or embedded in a sentential context on subsequent explicit paired-associate leaning tested by cued recall. The results of Experiment 1 showed that the cued-recall rate of words studied in sentential context was higher than that of words co-occurring in isolated pairs. A subsequent single-items recognition test showed equal item memory for words studied in sentences than for words studied in isolated pairs, suggesting that the sentential context effect in cued recall indeed reflected stronger associations between paired words rather than better memory for single words. In Experiment 2, we ruled out memory for the entire sentence as an alternative explanation for the results of Experiment 1. We suggest two possible mechanisms to account for this advantage: First, pairs embedded in a sentence undergo semantic elaboration that might lead to the incidental formation of an association between them. Second, words embedded in a sentence enjoy the conjoint activation of compatible semantic features, a fact that may also facilitate the formation of an episodic association between them. The implications of these results for computational models using word representations based on co-occurrence data are discussed.     

Acoustic Interference in a Recognition Task

Phonetic or acoustic characteristics of stimuli in recall studies have consistently been shown to generate more interference over short intervals than semantic characteristics. We performed three experiments to determine whether this characteristic also applied to recognition processes over short intervals. Subjects were shown study lists of eight words and were asked to recognize which of those words recurred on subsequent eight-word lists. Delays varied from 0 to 100 s between study and test, with a rehearsal-preventing task inserted during the delays. Phonetic distractors generated greater interference than semantic distractors at all delay levels, and semantic distractors generated greater interference than random distractors. These distractor-type differences were not present in long-term recognition tasks. The deterioration in performance over time was considerably slower in these recognition experiments than in previous recall studies.     

The revelation effect: Moderating influences of encoding conditions and type of recognition test

In the revelation effect, slowly revealing a test item immediately prior to a recognition judgment increases the probability of an “old” response. Extant accounts imply that the revelation effect occurs for familiarity-based judgments but not for those involving recall or recollection. To assess this implication, the contribution of recollection was varied by encoding conditions and memory tests. Two manipulations of recollection, semantic encoding and context-item integration, both reduced the revelation effect on a standard recognition test. For the same encoding conditions, a perceptually driven memory test (rhyme recognition) exhibited no revelation effect whatsoever. In a second experiment, the rhyme recognition test exhibited a revelation effect under impoverished encoding conditions. The results document important limits of the revelation effect produced by both encoding and test conditions. Furthermore, the recollection-based limitations of the revelation effect are not restricted to conditions of enhanced semantic encoding.     

Effects of adult aging on utilization of temporal and semantic associations during free and serial recall

Older adults show poorer performance than young adults at word list recall, especially for order information. In contrast with this temporal association deficit, older adults are generally adept at using preexisting semantic associations, when present, to aid recall. We compared the use of temporal and semantic associations in young and older adults' word list recall following both free recall and serial recall instructions. Decomposition of serial position curves confirmed that older adults showed weakened use of temporal context in recall in relation to young adults, a difference that was amplified in serial recall. Older adults' temporal associations were also less effective than young adults' when correlated with serial recall performance. The differential age decrement for serial versus free recall was accompanied by a persistent influence of latent semantic associations in the older adults, even when maladaptive for serial recall.     

In what sense is implicit memory "episodic"? The effect of reinstating environmental context

We consider three aspects of the term episodic. Previous literature shows implicit memory does not make conscious autobiographical reference but does code an item's intrinsic context (e.g., perceptual detail). Here, we consider extrinsic context--namely, that not directly processed as part of item identification and not overtly relevant to the task. Study-test mismatch in environmental context (outdoors vs. indoors) reduced memory in an explicit stem-cued recall task but had no effect on repetition priming in an implicit stem completion task. This was true even for very low frequency words. We support the view that implicit memory reflects traces within perceptual (or semantic) knowledge-based systems that are instance specific but do not code the full spatiotemporal context information necessary to support conscious recollection. We also interpret our results as consistent with differences in environmental context specificity between free recall and recognition.     

Altering memory through recall: The effects of cue-guided retrieval processing

Three experiments were designed to investigate the influence of initial recall on memory by assessing delayed recall after different immediate cued-recall tests. In all experiments, subjects performed semantic and phonemic encoding tasks on a word list. The subjects then received a cued-recall test that cued the target using the same word as the context word in the encoding task, a test that cued the target with a word from the same level at which the target was encoded, a test that cued the target with a cue from a different level at which the target was encoded, or no immediate-recall test. One day later, the subjects performed a final cued-recall test in which the type of cue (semantic or phonemic) was varied. Consistently, delayed recall was facilitated primarily when the cue on the immediate test was from the same level as the cue on the delayed test. This pattern of facilitation suggests that immediate cued-recall produces an elaboration of an existing memory representation that is closely tied to the type of cue used on the immediate test.     

Semantic contribution to verbal short-term memory: Are pleasant words easier to remember than neutral words in serial recall and serial recognition?

In the four experiments reported here, we examined the role of word pleasantness on immediate serial recall and immediate serial recognition. In Experiment 1, we compared verbal serial recall of pleasant and neutral words, using a limited set of items. In Experiment 2, we replicated Experiment 1 with an open set of words (i.e., new items were used on every trial). In Experiments 3 and 4, we assessed immediate serial recognition of pleasant and neutral words, using item sets from Experiments 1 and 2. Pleasantness was found to have a facilitation effect on both immediate serial recall and immediate serial recognition. This study supplies some new supporting arguments in favor of a semantic contribution to verbal short-term memory performance. The pleasantness effect observed in immediate serial recognition showed that, contrary to a number of earlier findings, performance on this task can also turn out to be dependent on semantic factors. The results are discussed in relation to nonlinguistic and psycholinguistic models of short-term memory.     

Test-expectancy and semantic-organization effects in recall and recognition

Two experiments examined whether people expecting recall are, compared with people expecting recognition, more likely to form associations between semantically related words in a list of to-be-remembered words. People were induced to expect either a recall or a recognition test on a critical list that included three conditions of semantic organization. Words in the unrelated (U) condition were semantically unrelated to all other words on the list, whereas words in the two related conditions were semantically related to one other list word. In the related-spaced (R-S) condition, the two related words appeared in input positions separated by 5-11 other items, whereas in the related-massed (R-M) condition, they appeared in adjacent input positions. Different groups received either an expected or unexpected recall (Experiment 1) or recognition (Experiment 2) test on the critical list. In both recall and recognition, (l) people expecting recall did better than those expecting recognition, (2) memory was worst for U words, next best for R-S words, and best for R-M words, and (3) the test-expectancy and semantic-organization effects were additive. A standardizedz-score measure of category dependency in memory indicated that (1) people expecting recall were not more likely than those expecting recognition to form interitem associations between the related words and (2) recognition was category dependent, but less so than recall. Within the framework of Anderson and Bower’s (1972, 1974) theory, these data indicate that, compared with people expecting recognition, those expecting recall are not more likely to form interitem associations by tagging more pathways connecting semantically related nodes but, rather, are more likely to tag the nodes themselves. The implications that semantic-organization effects in recognition have for the Anderson-Bower theory were also discussed.     

Investigating the roles of phonological and semantic memory in sentence recall

The mechanisms underlying short-term sentence recall have been the subject of recent investigations. While both semantic and phonological information have been found to play a role in sentence recall, this has been established using different paradigms in previous research. As a result, it is not clear whether the contributions of semantic and phonological information are equivalent subject only to specific experimental conditions. The present study used a common paradigm with equally plausible lures to systematically compare the roles of semantic and phonological information in short-term sentence recall. The lure intrusion paradigm was used with three different lures that were all equally plausible in the context of the sentence: semantic, onset, and rhyme. Further, no contextual cues were provided in the sentence to bias the participant. The findings indicate that there were significantly more semantic and onset intrusions compared to rhyme intrusions. This is interpreted in light of models incorporating lexical information during sentence production.     

Investigating the roles of phonological and semantic memory in sentence recall

The mechanisms underlying short-term sentence recall have been the subject of recent investigations. While both semantic and phonological information have been found to play a role in sentence recall, this has been established using different paradigms in previous research. As a result, it is not clear whether the contributions of semantic and phonological information are equivalent subject only to specific experimental conditions. The present study used a common paradigm with equally plausible lures to systematically compare the roles of semantic and phonological information in short-term sentence recall. The lure intrusion paradigm was used with three different lures that were all equally plausible in the context of the sentence: semantic, onset, and rhyme. Further, no contextual cues were provided in the sentence to bias the participant. The findings indicate that there were significantly more semantic and onset intrusions compared to rhyme intrusions. This is interpreted in light of models incorporating lexical information during sentence production.     

Primary versus secondary rehearsal in imagined voices: Differential effects on recognition

Subjects were asked to rehearse word trigrams in a particular prefamiliarized male or female voice for 5, 10, or 15 sec. In Experiment 1, recognition performance improved with the amount of primary (maintenance) rehearsal only if the speaker's voice at test matched the rehearsal voice, but recognition performance improved with the amount of secondary (elaborative) rehearsal regardless of the sex of the speaker at test. With a visual testing procedure in Experiments 2 and 3, the amount of primary rehearsal given to a trigram had no effect on recognition performance unless the original voice context was reinstated mentally at test. These results suggest that: (a) Secondary rehearsal builds up semantic associations, whereas primary rehearsal serves to associate items with their physical characteristics at presentation. (b) There is an important memory search component in recognition as well as in recall. (c) Imaginal operations can yield a product in memory that is similar to that left by perceptual operations.     

False recollection in children with reading comprehension difficulties

Children with reading comprehension difficulties display impaired performance on semantic processing tasks. These impairments are assumed to reflect weaker knowledge about abstract semantic associations between words in poor comprehenders [Nation, K., and Snowling, M. (1999). Developmental differences in sensitivity to semantic relations among good and poor comprehenders: evidence from semantic priming. Cognition, 19, B1-B13.]. We examined the performance of poor comprehenders on the Deese/Roediger/McDermott (DRM) paradigm. Children studied spoken words that were semantic associates (e.g., bed, rest, and awake) or phonological associates (e.g., pole, bowl, and hole) followed by free recall and a recognition test containing nonstudied critical words (e.g., sleep and roll). Results showed reduced recall and recognition of critical words in the semantic condition but not in the phonological condition for poor comprehenders. We argue that poor comprehenders are less sensitive to abstract semantic associations between words because of reduced gist memory.     

Older adults show a self-reference effect for narrative information

The self-reference effect (SRE), enhanced memory for information encoded through self-related processing, has been established in younger and older adults using single trait adjective words. We sought to examine the generality of this phenomenon by studying narrative information in these populations. Additionally, we investigated retrieval experience at recognition and whether valence of stimuli influences memory differently in young and older adults. Participants encoded trait adjectives and narratives in self-reference, semantic, or structural processing conditions, followed by tests of recall and recognition. Experiment 1 revealed an SRE for trait adjective recognition and narrative cued recall in both age groups, although the existence of an SRE for narrative recognition was unclear due to ceiling effects. Experiment 2 revealed an SRE on an adapted test of narrative recognition. Self-referential encoding was shown to enhance recollection for both trait adjectives and narrative material in Experiment 1, whereas similar estimates of recollection for self-reference and semantic conditions were found in Experiment 2. Valence effects were inconsistent but generally similar in young and older adults when they were found. Results demonstrate that the self-reference technique extends to narrative information in young and older adults and may provide a valuable intervention tool for those experiencing age-related memory decline.