Individual differences in speed of retrieval from semantic memory

In the first of two experiments, the stimulus items consisted of category names followed by a single letter (e.g., fruit-P). The subjects (half introverted, half extraverted) were required to respond as quickly as possible with a member of the specified category starting with the letter. Extraverts responded significantly faster than introverts, and more so when the most likely response was of low frequency than when it was of high frequency. In the second experiment, subjects were assigned to one of four groups representing the four combinations of high and low Extraversion and high and low General Activation. The speed-of-recall task from the first experiment was used on some trials; on the remaining trials, a speed-of-recognition task was used. Extraverts had greater response speed than introverts for recall, but not for recognition. That finding, plus interactions between Extraversion and General Activation, suggested an interpretation of the results in terms of the Yerkes-Dodson Law.     

Individual differences in susceptibility to the effects of speech on reading comprehension

Individuals with high working memory capacity (WMC) are less distracted by task‐irrelevant speech than others. The mechanism behind this relationship, however, is not well understood, and it has only been found in a few paradigms. We used a Number updating task to measure WMC and two suppression mechanisms (immediate and delayed), and tested how they were associated with individual differences in susceptibility to the effects of speech on reading comprehension. The results revealed a negative relationship between WMC and susceptibility to speech distraction. Of the two suppression mechanisms, only immediate suppression was associated with speech distraction, suggesting that susceptibility to distraction is determined by the ability to immediately suppress the irrelevant speech. Furthermore, the relationship between WMC and speech distraction was mediated by the immediate suppression mechanism. The implications of these results and possible explanations of similar results found in other paradigms are discussed. Copyright © 2009 John Wiley & Sons, Ltd.     

Developmental and reading ability differences in accessing information from semantic memory

A categorical judgment task was utilized to investigate the relationships between word recognition skills and reading achievement at several grade levels. In the first experiment skilled and unskilled readers from Grades 2, 4, and 6 made cognitive decisions about pairs of words using either graphemic, lexical, or semantic information. In Experiment 2 skilled, average, and unskilled readers from Grades 1, 3, and 5 made semantic decisions about word or picture pairs. The speed and accuracy of word encoding, lexical access, and semantic memory access processes varied as a function of reading ability. These results suggest that inefficient word recognition skills can contribute to reading deficiencies as can deficiencies in semantic memory organization.     

Individual differences in working memory and comprehension: a test of four hypotheses.

A relationship has consistently been found between measures of working memory and reading comprehension. Four hypotheses for this relationship were tested in 3 experiments. In the first 2 experiments, a moving window procedure was used to present the operation-word and reading span tasks. High- and low-span subjects did not differentially trade off time on the elements of the tasks and the to-be-remembered word. Furthermore, the correlation between span and comprehension was undiminished when the viewing times were partialed out. Experiment 3 compared a traditional experimenter-paced simple word-span and a subject-paced span in their relationship with comprehension. The experimenter-paced word-span correlated with comprehension but the subject-paced span did not. The results of all 3 experiments support a general capacity explanation for the relationship between working memory and comprehension.     

Modification of deficits in reading for comprehension

Subjects were asked to read a passage orally and then to answer questions about the passage. When praise and pennies were given for correct answers, the percentage of correct answers increased in two sixth-grade subjects whose reading for comprehension was tested to be 2 yr below grade level. The behavior of these subjects was compared to that of two subjects whose reading for comprehension was tested to be on grade level. Although no evidence for changes in the accuracy of answering comprehension questions is found in the previous literature, the percentage of correct answers in the children with deficits increased to approximately the same level as the children tested to be on grade level.     

Individual differences in working memory strategies for reading expository text

This study investigated whether individual differences in working memory (WM) span are associated with different WM management strategies during the reading of expository text. In Experiment 1, probe questions were presented on line during reading to determine whether thematic information was maintained in WM throughout comprehension. The data indicated that readers across the range of WM span maintained thematic information in WM throughout the reading of a given passage. In Experiment 2, sentence reading times and accuracy for both topic and detail questions were measured in two conditions: when topic sentences were present and when topic sentences were absent. Subjects performed similarly across the range of WM span in the topic-present condition, but lower span subjects performed more poorly on detail questions in the topic-absent condition. In Experiment 3, the topic-present condition of the second experiment was replicated, except that subjects expected to receive questions about details only. Thematic processing and retention of topic and detail information all increased with span. Taken together, these results suggest that, for more difficult text processing tasks, high- and low-span subjects adopt different WM management strategies and these strategies influence what is learned from reading the text.     

Individual differences in television comprehension

Two experiments explored individual differences in memory and comprehension for adults presented information on television. Experiment 1 tested the correlation between comprehension of television and reading with young adults. The ability to comprehend these two forms of media was significantly correlated (r = .69). This finding is contrary to results from our previous study with third and sixth graders (Pezdek, Lehrer, & Simon, 1984). Experiment 2 probed two specific individual differences factors as predictors of television comprehension. The results were that good television comprehenders (1) had higher visual/spatial ability, as assessed by psychometric test performance, and (2) were more likely to utilize an imagery-based strategy in the sentence-picture verification task of Clark and Chase (1972) (e.g., “STAR IS ABOVE PLUS”). These results suggest differences in the comprehension processes that operate on information presented in different forms of media.     

Bilingualism and reading difficulties: an exploration in episodic and semantic memory

This study was designed to investigate the effect of bilingualism and reading difficulties (RD) on episodic and semantic memory. The subjects included 190 children (aged 9–12 years): 45 Iranian-Swedish bilinguals and 59 Swedish monolinguals with typically developed reading, along with 41 bilinguals and 45 monolinguals with RD. To measure episodic memory, subject-performed and verbal tasks were used for encoding, and both free and cued recall were used for retrieval. Letter and category fluency tasks were used to test semantic memory. In action memory, bilingual children with RD benefited less from enactment encoding form compared to children with typically developed reading. Additionally, bilingual with RD had lower rates of recollection in category fluency compared to their monolingual counterparts. However, in letter fluency, there was not found a difference between performances of bilinguals and monolinguals with RD. We discuss the involvement of long-term memory in both bilingualism and reading.     

Individual differences in cognitive style,working memory,and semantic integration

In two experiments subjects classified as being either high or low in field articulation (FA) performed a semantic integration task with high-information load. In Experiment 1, differences in performance between high- and low-FA subjects on an inference and recognition test were obtained when sentences were presented for 5 sec a piece but not when they were presented for 10 sec a piece. In Experiment 2, performance differences between high and low-FA subjects were eliminated by presenting only a specific subset of the sentences for 10 sec a piece. The implications of these results for explanations of FA effects in semantic integration are discussed.     

Individual differences in children's event memory reports and the narrative elaboration technique

Children between 7 and 8 years old took part in a staged event at school and 1 week later were assessed using a short form of the Wechsler Intelligence scale for children (third edition) and measures of metamemory, narrative ability, and socioeconomic status. Two weeks following the event, children either received narrative elaboration training (NET; K.J. Saywitz & L. Snyder, 1996) and were prompted with the four NET cue cards at interview; received verbal prompts corresponding to the cue card categories, but without prior training; or were presented with the cards at interview without prior training. Children given verbal labels as prompts recalled as much information as children who received NET training and cue cards. Measures of intelligence were predictive of amount recalled for cards-only children but not for the other 2 groups, indicating that differences in recall between low- and high-IQ groups were attenuated when recall was supported by NET training or verbal prompting.     

The relation between children's reading comprehension level and their comprehension of idioms

We report an investigation of 9-year-olds' ability to interpret idioms in relation to their reading comprehension level. We manipulated whether the idioms were transparent or opaque, whether they were real or novel, whether they were presented in isolation or in a supportive narrative context. As predicted, children were better able to explain the meanings of idioms in context than in isolation. The good and poor comprehenders did not differ in their abilities to interpret transparent idioms in context, but the poor comprehenders were significantly worse at using context to work out the meanings of opaque idioms. The explanation task revealed the source of information used by the children to derive nontarget interpretations. We discuss these findings in relation to idiom processing strategies and Levorato and Cacciari's global elaboration model.     

Phonemic effects in reading comprehension and text memory

Two experiments investigated the role of phonemic information in adult reading comprehension and replicated the visual tongue-twister effect in a new paradigm–a modified probe memory task. College students took longer to read sentences that repeated word initial consonants (tongue-twisters) than matched control sentences. Equally important, subjects also took longer to respond to probe words from tongue-twisters. Slower response times in both the sentence reading task and the probe memory task indicate that the tongue-twister effect is indeed phonemic in nature and that phonemic information is used in memory during comprehension.     

Working memory and updating processes in reading comprehension

In this study, we examine the relation between reading comprehension ability and success in working memory updating tasks. Groups of poor and good comprehenders, matched for logical reasoning ability, but different in reading comprehension ability, were administered various updating tasks in a series of experiments. In the first experiment, the participants were presented with lists of words, the length of which (4-10 words) was unknown beforehand, and were required to remember the last 4 words in each series. In this task, we found a decrease in performance that was related to longer series and poor reading ability. In the second experiment, we presented lists of nouns referring to items of different sizes, in a task that simulated the selection and updating of relevant information that occurs in the on-line comprehension process. The participants were required to remember a limited, predefined number of the smallest items presented. We found that poor comprehenders not only had a poorer memory, but also made a greater number of intrusion errors. In the third and fourth experiments, memory load (number of items to be selected) and suppression request (number of potentially relevant items) were manipulated within subjects. Increases in both memory load and suppression requests impaired performance. Furthermore, we found that poor comprehenders produced a greater number of intrusion errors, particularly when the suppression request was increased. Finally, in a fifth experiment, a request to specify the size of presented items was introduced. Poor comprehenders were able to select the appropriate items, although their recall was poorer. Altogether, the data show that working memory abilities, based on selecting and updating relevant information and avoiding intrusion errors, are related to reading comprehension.     

Temporal analyses of children's comprehension during oral reading

Second- and fourth-grade children read aloud one normal story then two stories that contained an anomalous phrase in the third of five sentences. The anomalies were produced by reversing the order of two predicate nouns. The rate of articulation was slower and total pause time was greater when children read the anomalous sentences than when they read the normal sentences. While the anomalous sentences were read literally, all but a few children restored the anomalous phrase to its original meaning or changed some of the words to make the anomalous event more plausible. The results of the study suggest that temporal measures are highly sensitive to comprehension processes and that children comprehend the story as they read and compare what they read with what they know about the world.     

The development of idiom comprehension: an investigation of semantic and contextual processing skills

Two experiments compared 7- and 8-year-olds' and 9- and 10-year-olds' ability to use semantic analysis and inference from context to understand idioms. We used a multiple-choice task and manipulated whether the idioms were transparent or opaque, familiar or novel, and presented with or without a supportive story context. Performance was compared with that of adults (Experiment 1) and 11- and 12-year-olds (Experiment 2). The results broadly support Cacciari and Levorato's global elaboration model of figurative competence with a notable exception: Even the youngest children were able to use semantic analysis to derive the meanings of transparent idioms as well as being sensitive to meaning in context. The findings show that young children process language at both the small-grain phrase level and the discourse level to establish figurative meaning, and they demonstrate that the language processing skills that aid idiom comprehension, as well as idiom knowledge itself, are still not fully developed in 11- and 12-year-olds.     

Electrophysiology reveals semantic memory use in language comprehension

The physical energy that we refer to as a word, whether in isolation or embedded in sentences, takes its meaning from the knowledge stored in our brains through a lifetime of experience. Much empirical evidence indicates that, although this knowledge can be used fairly flexibly, it is functionally organized in ‘semantic memory’ along a number of dimensions, including similarity and association. Here, we review recent findings using an electrophysiological brain component, the N400, that reveal the nature and timing of semantic memory use during language comprehension. These findings show that the organization of semantic memory has an inherent impact on sentence processing. The left hemisphere, in particular, seems to capitalize on the organization of semantic memory to pre-activate the meaning of forthcoming words, even if this strategy fails at times. In addition, these electrophysiological results support a view of memory in which world knowledge is distributed across multiple, plastic-yet-structured, largely modality-specific processing areas, and in which meaning is an emergent, temporally extended process, influenced by experience, context, and the nature of the brain itself.     

Individual differences in working memory during reading with and without parafoveal information: a moving-window study

We examined individual differences in working memory appearing in the effective visual field size while reading Japanese text. Working memory capacity was measured by a Japanese reading span test, and the subjects were divided into high- and low-score groups. Reading performance was measured by reading time, comprehension, and eye movements using a variable moving window through which the subject could read areas of the Japanese text. As the window size decreased, the reading time increased significantly. High-span subjects showed better performance in reading time, comprehension, and fixation duration than low-span subjects even in small visual fields. Interestingly, high-span subjects appear to show better information integration during reading, whereas low-span subjects showed less integration without parafoveal vision. These findings suggest that reading performance was better for subjects with larger working memory resources in a parafoveal restriction condition.     

Individual differences in sentence memory

Results from an experiment with two parts are presented in this paper. In part one, participants listened to sentences containing two, three, four, or five clauses, and were asked questions about the content of the sentences. The results of part one demonstrate that an important unit of representation in sentence memory is the clause, and not some other component of discourse structure. In part two, the same group of participants performed eight different short-term storage/working memory tasks. A composite complex span score was computed for each participant based on three working memory tasks closely based on Daneman & Carpenter's (1980) reading span task. This working memory measure was significantly correlated with the participants' performance on the sentence memory task in part one. A second working memory measure—N-back—was also significantly correlated with the participants' performance on the sentence memory task, and there was no correlation between their performance on the complex span task and the N-back task. It is therefore concluded that (i) working memory consists of a number of dissociable components; and (ii) memory for sentences taps into more than one of these working memory components. Furthermore, the high correlations of sentence memory with the complex span and the N-back tasks (neither of which are language processing tasks) suggests that memory for sentences is not simply a result of linguistic experience; rather, it is likely that an independent working memory component contributes to participants' performance on the sentence memory task.