Single-item memory, associative memory, and the human hippocampus

We tested recognition memory for items and associations in memory-impaired patients with bilateral lesions thought to be limited to the hippocampal region. In Experiment 1 (Combined memory test), participants studied words and then took a memory test in which studied words, new words, studied word pairs, and recombined word pairs were presented in a mixed order. In Experiment 2 (Separated memory test), participants studied single words and then took a memory test involving studied word and new words. In a separate test, they studied word pairs and then took a memory test involving studied word pairs and recombined word pairs. In both experiments, patients were impaired at memory for single items as well as memory for associations, suggesting that the hippocampus is important for both of these memory functions. In Experiment 1, patients appeared to be more impaired at associative memory than item memory. In Experiment 2, patients were similarly impaired at associative memory and item memory. These different findings are considered, including the fact that in Experiment 1 the results depended on the fact that controls produced unexpectedly low false-alarm rates to recombined pairs. We discuss single-item and associative memory from the perspective that the hippocampus and adjacent cortex work cooperatively to signal recognition and that simple dichotomies do not adequately describe the division of labor within the medial temporal lobe.     

Don’t Shoot the Messnger: Memory for Misspellings in Context

Misspellings in sentences are usually easy to understand by readers due to top-down influences. Although top-down processing allows for fluent reading of misspelled items, the nature of their representations in memory is not known. If representations of misspellings are distinct from representations of correctly spelled words, their influence should be seen in later recognition decisions. In this set of experiments, participants read words and misspellings embedded in sentences and were later given a recognition test. The sentences contained semantically biased or neutral contexts. In Experiment 1, misspellings were created by removing a single letter (e.g., drveway). In Experiment 2, the recognition items probes were presented in uppercase letters (e.g., DRVEWAY) to reduce the visual similarity between study and test items. In Experiment 3, the misspellings were created by substituting visually similar letters (e.g., driweway). In contrast to the previous experiments, in Experiment 4, participants were explicitly told about the memory test to see how response strategies affect performance. Overall, the results indicate that people retain surface feature information about misspellings which seem to inform their memory judgments, and that the processing of this information cannot be strategically controlled.     

Interactive processes in sentence comprehension and recognition

Two experiments examined the roles played by semantic and surface information in reading and recognizing sentences. Subjects read sentences in normal and inverted typography. Their recognition of meaning and other sentence features was tested using sentences whose typography, wording, and/or meaning were either the same as or different from that in the first set of sentences. In Experiment 1, subjects either read aloud or performed a sentence continuation task. For originally inverted sentences, recognition of meaning was high, irrespective of task demands. For originally normal sentences, recognition was low for Read Aloud subjects and high for Sentence Continuation subjects. Sentence recognition was affected by repetition of wording and typography. Experiment 2 replicated the results with the read aloud task and showed the second reading of originally inverted sentences to be equally swift for paraphrase and verbatim test forms. It was concluded that reading and recognition are interactive processes, involving conceptually driven and data driven operations. The interaction of operations may be either automatic or controlled. While processing of normal typography is automatic, inverted typography induces controlled processing, resulting in better retention. Furthermore, semantic and surface information are conceptualized as interacting components of comprehension and memory processes.     

不同注意条件下的知觉启动及其机制

采用快速命名方法探讨不同注意条件下的知觉启动效应及其机制。实验中呈现一系列颜色词,要求被试分别完成集中和分散注意任务,然后进行词命名和再认测验。在词命名任务中．实验1包括旧词、重组颜色词和新词,而在实验2中重组颜色词改为新颜色词。结果表明,在实验1中,只有在集中注意条件下,被试对旧词的命名时间明显短于重组颜色词．即表现出知觉启动效应。而在实验2的两种注意条件下,被试对旧词的命名时间均明显短于新颜色词。这提示,在不同注意条件下的学习会影响其后的颜色知觉启动,并且与词和颜色的联结捆绑有关。     

Age-related associative deficits are absent with nonwords

Words and nonwords were used as stimuli to assess item and associative recognition memory performance in young and older adults. Participants were presented with pairs of items and then tested on both item memory (old/new items) and associative memory (intact/recombined pairs). For words, older participants performed worse than young participants on item and associative tests but to a greater extent on the latter. In contrast, for nonwords, older participants performed equally worse than young participants on item and associative tests. This is the first study to demonstrate that a manipulation of stimulus novelty can alter age-related associative deficits.     

Testing enhances both encoding and retrieval for both tested and untested items

In forward testing effects, taking a test enhances memory for subsequently studied material. These effects have been observed for previously studied and tested items, a potentially item-specific testing effect, and newly studied untested items, a purely generalized testing effect. We directly compared item-specific and generalized forward testing effects using procedures to separate testing benefits due to encoding versus retrieval. Participants studied two lists of Swahili–English word pairs, with the second study list containing “new” pairs intermixed with the previously studied “old” pairs. Participants completed a review phase in which they took a cued-recall test on only the “old” pairs or restudied them. In Experiments 1a, 1b, and 2, the review phase was given either before or after the second study list. Testing benefited memory to the same degree for both “new” and “old” pairs, suggesting that there were no pair-specific benefits of testing. The larger benefit from testing when review was given before rather than after the second study list suggests that the memory enhancement was due to both testing-enhanced encoding and testing-enhanced retrieval. To better equate generalized testing effects for “new” and “old” pairs, Experiment 3 intermixed them in the review phase. A statistically significant pair-specific testing effect for “old” items was now observed. Overall, these results show that forward testing effects are due to both testing-enhanced encoding and retrieval effects and that direct, pair-specific forward testing benefits are considerably smaller than indirect, generalized forward testing benefits.     

Effects of age, speed of processing, and working memory on comprehension of sentences with relative clauses

Two hundred participants, 50 in each of four age ranges (19-29, 30-49, 50-69, 70-90) were tested for working memory, speed of processing, and the processing of sentences with relative clauses. In Experiment 1, participants read four sentence types (cleft subject, cleft object, subject-subject, subject-object) in a word-by-word, non-cumulative, self-paced reading task and made speeded plausibility judgments about them. In Experiment 2, participants read two types of sentences, one of which contained a doubly center embedded relative clause. Older participants' comprehension was less accurate and there was age-related slowing of online processing times in all but the simplest sentences, which increased in syntactically complex sentences in Experiment 1. This pattern suggests an age-related decrease in the efficiency of parsing and interpretation. Slower speed of processing and lower working memory were associated with longer online processing times only in Experiment 2, suggesting that task-related operations are related to general speed of processing and working memory. Lower working memory was not associated with longer reading times in more complex sentences, consistent with the view that general working memory is not critically involved in online syntactic processing. Longer online processing at the most demanding point in the most demanding sentence was associated with better comprehension, indicating that it reflects effective processing under some certain circumstances. However, the poorer comprehension performance of older individuals indicates that their slower online processing reflects inefficient processing even at these points.     

Intact text-specific reading skill in amnesia

Amnesic patients were studied to determine whether the acquisition and retention of item-specific skills can be supported by nondeclarative (implicit) memory. In Experiment 1, subjects read 2 different passages 3 times in succession. Reading speed improved at a similar rate in both amnesic patients and normal subjects and was specific to the text that was read. In Experiment 2, amnesic patients and normal subjects read a passage 3 successive times and then reread the same passage after a 0-s, 10-min, 2-hr, or 1-day delay. In both groups, facilitation persisted for at least 10 min and disappeared within 2 hr. It is suggested that facilitated reading speed depends importantly on both semantic and perceptual information and that such information can be supported by nondeclarative memory.     

Encoding instructions and stimulus presentation in local environmental context-dependent memory studies

Murnane and Phelps (1993) recommend word pair presentations in local environmental context (EC) studies to prevent associations being formed between successively presented items and their ECs and a consequent reduction in the EC effect. Two experiments were conducted to assess the veracity of this assumption. In Experiment 1, participants memorised single words or word pairs, or categorised them as natural or man made. Their free recall protocols were examined to assess any associations established between successively presented items. Fewest associations were observed when the item-specific encoding task (i.e., natural or man made categorisation of word referents) was applied to single words. These findings were examined further in Experiment 2, where the influence of encoding instructions and stimulus presentation on local EC dependent recognition memory was examined. Consistent with recognition dual-process signal detection model predictions and findings (e.g., Macken, 2002; Parks & Yonelinas, 2008), recollection sensitivity, but not familiarity sensitivity, was found to be local EC dependent. However, local EC dependent recognition was observed only after item-specific encoding instructions, irrespective of stimulus presentation. These findings and the existing literature suggest that the use of single word presentations and item-specific encoding enhances local EC dependent recognition.     

内侧颞叶系统在知觉启动中的作用及其机制

以ll例内侧颞叶(MTL)损伤病人为被试,探讨MTL与知觉启动的关系及其内在机制。被试依次完成学习颜色词、快速词命名和再认任务。在实验l的词命名中包括旧词、重组颜色词和新词,结果表明,MTL损伤病人没有表现出旧词的命名时间短于重组颜色词的现象,颜色启动效应受损,其再认成绩也低于正常被试。但是当用新颜色词代替重组颜色词后(实验2),MTL损伤病人读旧词的时间明显短于新颜色词,颜色启动与正常对照组之间没有明显差别,但他们的再认成绩仍比对照组低。这表明,当任务要求被试加工项目与其特性之间的关系时(词与颜色),MTL损伤对启动效应会有影响,提示MTL在一些形式的知觉启动中起重要作用。     

Eye-closure & the retrieval of item-specific information in recognition memory

Two experiments investigated the effect of eye-closure on visual and auditory memory under conditions based on the retrieval of item-specific information. Experiment 1 investigated visual recognition memory for studied, perceptually similar and unrelated items. It was found that intermittent eye-closure increased memory for studied items and decreased memory for related items. This finding was reflected by enhanced item-specific and reduced gist memory. Experiment 2 used the Deese-Roediger-McDermott (DRM) paradigm to assess auditory recognition memory for studied, related and unrelated words that had (vs. had not) been accompanied by pictures during encoding. Pictures but not eye-closure produced a picture superiority effect by enhancing memory for studied items. False memory was reduced by pictures but not eye-closure. Methodological and theoretical considerations are discussed in relation to existing explanations of eye-closure and retrieval strategies.     

PRESERVATION OF IMPLICIT MEMORY FOR NEW ASSOCIATIONS IN GLOBAL AMNESIA

Abstract— This study examined whether amnesic patients have preserved implicit memory for new associations between unrelated words, as measured by repetition priming, despite unpaired explicit memory for such new associations. Prior studies provide conflicting and ambiguous results. Amnesic and control participants read aloud visually presented, unrelated word pairs and then attempted to identify old, recombined, and new word pairs shown at threshold durations. Amnesic and control groups showed equivalent priming for new associations by identifying old pairs better than recombined pairs. Amnesic patients were impaired on a matched explicit test of memory far new associations. The preserved priming in amnesia indicates that implicit memory for new associations need not be, supported by the mnemonic processes and brain structures that mediate explicit memory for new associations.     

The personalisation method applied to a working memory task: Evidence of long-term working memory effects

Ericsson and Kintsch (1995) proposed that, in situations of expertise, individuals can overcome working memory limitations by using long-term working memory. It allows a greater capacity than working memory thanks to long-term memory encoding and retrieving. To test this characteristic, an adaptation of Daneman and Carpenter's (1980) reading span was used. To operationalise expertise, the personalisation method (Guida & Tardieu, 2005) was employed. In Experiment 1, a personalised group, which read reading span sentences that mentioned familiar locations, was compared to a nonpersonalised group, which read sentences with unfamiliar locations. In Experiment 2, a personalised group, which read reading span sentences with neutral locations, was encouraged to mentally personalise these locations by thinking about known locations. This group was compared to a nonpersonalised group, which was encouraged to think about unknown locations. The personalised groups were expected to store and retrieve information in long-term memory via long-term working memory more easily than the nonpersonalised groups, which had to count massively on working memory. The results showed that personalisation enhanced reading span and confirmed one implication of the long-term working memory theory: high- and low-reading-span differences could also be due to long-term memory retrieval. Finally, these results are interpreted in terms of interaction between working memory size and long-term memory knowledge, showing that participants with a lower reading span benefited more from high domain knowledge than participants with a higher reading span.     

Re-exposure to studied items at test does not influence false recognition

In two experiments, we investigated whether re-exposure to previously studied items at test affects false recognition in the DRM paradigm. Furthermore, we examined whether exposure to the critical lure at test influences memory for subsequently presented study items. In Experiment 1, immediately following each studied DRM list, participants were given a recognition test. The tests were constructed such that the number of studied items preceding the critical lure varied from zero to five. Neither false recognition for critical lures nor accurate memory for studied items was affected by this manipulation. In Experiment 2, we replicated this pattern of results under speeded conditions at test. Both experiments confirm that exposure to previously studied items at test does not affect true or false recognition in the DRM paradigm. This pattern strongly suggests that retrieval processes do not influence false recognition in the DRM paradigm.     

额叶参与对新异联系的启动效应——来自脑损伤病人的证据

对新异联系的启动效应是内隐记忆的一种形式,又称联想启动。采用知觉辨认任务,探讨额叶损伤与联想启动的关系。25例额叶损伤病人及18例匹配的正常被试参与实验。结果表明,额叶受损病人辨认旧词对与重组词对的正确率没有明显差别;而且,轻度记忆损伤的额叶病人再认成绩正常,但联想启动值低于对照组,内隐记忆和外显数、坚持性反应数和语词流畅性等有中度相关。这些结果提示,额叶不仅与情节记忆、工作记忆等外显记忆有关,也参与了以非相关词对为材料的联想启动。     

Re-exposure to studied items at test does not influence false recognition

In two experiments, we investigated whether re-exposure to previously studied items at test affects false recognition in the DRM paradigm. Furthermore, we examined whether exposure to the critical lure at test influences memory for subsequently presented study items. In Experiment 1, immediately following each studied DRM list, participants were given a recognition test. The tests were constructed such that the number of studied items preceding the critical lure varied from zero to five. Neither false recognition for critical lures nor accurate memory for studied items was affected by this manipulation. In Experiment 2, we replicated this pattern of results under speeded conditions at test. Both experiments confirm that exposure to previously studied items at test does not affect true or false recognition in the DRM paradigm. This pattern strongly suggests that retrieval processes do not influence false recognition in the DRM paradigm.     

The influence of consistency, frequency, and semantics on learning to read: an artificial orthography paradigm

Two experiments explored learning, generalization, and the influence of semantics on orthographic processing in an artificial language. In Experiment 1, 16 adults learned to read 36 novel words written in novel characters. Posttraining, participants discriminated trained from untrained items and generalized to novel items, demonstrating extraction of individual character sounds. Frequency and consistency effects in learning and generalization showed that participants were sensitive to the statistics of their learning environment. In Experiment 2, 32 participants were preexposed to the sounds of all items (lexical phonology) and to novel definitions for half of these items (semantics). Preexposure to either lexical phonology or semantics boosted the early stages of orthographic learning relative to Experiment 1. By the end of training, facilitation was restricted to the semantic condition and to items containing low-frequency inconsistent vowels. Preexposure reduced generalization, suggesting that enhanced item-specific learning was achieved at the expense of character-sound abstraction. The authors' novel paradigm provides a new tool to explore orthographic learning. Although the present findings support the idea that semantic knowledge supports word reading processes, they also suggest that item-specific phonological knowledge is important in the early stages of learning to read.     

Acquisition-test interactions between

The effects of changes in context on recognition memory were investigated in two experiments. In Experiment 1 target items were embedded in congruous or incongruous sentence frames and then tested in the original, new congruous, or new incongruous contexts. Experiment 2 included a third encoding condition; targets were also embedded in abstract definitional sentences. Both experiments revealed a reliable crossover interaction between the initial encoding condition and the mode of the changed context. Congruous items were recognized better in new congruous contexts, whereas incongruous items were recognized better in new incongruous contexts. Recognition of definitional items was equally impaired by both context changes. The results suggest the importance of the symmetry between acquisition and test encoding dimensions. These experiments also point out the need to distinguish between different ways in which the concept “integration” is used in current research.     

Recognition and frequency judgments in young and elderly adults

Three experiments examined frequency judgments and recognition memory in young and elderly adults. Subjects were presented a long list of words at either a 5-s rate (Experiments 1 & 3) or a 1-s rate (Experiment 2), after which frequency-judgment and recognition memory tasks were administered. Either an absolute (Experiments 1 & 2) or a relative (Experiment 3) frequency-judgment task was used. The recognition test, which involved repeated tests of some items, involved either one incorrect item paired with each correct item (Experiments 1 & 2), or four incorrect items (Experiment 3). Age-related differences in frequency judgments, for the more frequently presented items, were found in all three experiments. For the recognition scores, the predicted interaction between age and successive tests was found only in Experiment 3. The results were interpreted within the framework of age-related differences in elaborative encoding and in distractibility to irrelevant stimuli.     

Retrieval-induced forgetting occurs in tests of item recognition

Using the retrieval-practice paradigm (Anderson, R. A. Bjork, & E. L. Bjork, 1994), we tested whether or not retrieval-induced forgetting could be found in item recognition tests. In Experiment 1, retrieval practice on items from semantic categories depressed recognition of nonpracticed items from the same categories. Similar results were found in Experiment 2 in a more stringent source test for practiced, nonpracticed, and new items. These results conceptually replicate those of previous retrieval-induced forgetting studies done with cued recall (e.g., Anderson et al., 1994). Our findings are inconsistent with the hypothesis that item-specific cues during retrieval will eliminate retrieval interference in the retrieval-practice paradigm (Butler, Williams, Zacks, & Maki, 2001). We discuss our results in relation to other retrieval interference and inhibition effects in recall and recognition.