Interference in memory for multiple contexts

Remembering that an item occurred in several different lists is formulated here in terms of retrieval of corresponding list tags associated to the item. Therefore, associative interference should operate upon remembering the several list contexts in which an item appeared. Experimental Ss studied four (or five) overlapping lists of 16 words, sampled from a master set of 32 words, with a given word exemplifying one of the 2 4 (or 2s 5 ) possible sequences of appearances and nonappearances over the four (or five) lists. Later Ss rated from memory for each word and for each list whether that word had occurred in that list. After correcting for interlist generalization effects, indices of discriminative memory revealed strong proactive interference and weaker retroactive interference. Discriminative memory that an item occurred in a given list was poorer the more prior or more subsequent lists in which that item had also occurred. Thus, list differentiation appears explicable in terms of item-specific associative interference.     

AN EXTENDED BASIC SIGHT VOCABULARY FOR THE PRIMARY GRADES

Extant word lists are typically based on word frequency counts from various types of literature (e.g., basal readers, content textbooks, trade books, adult reading material). The word list described in this study was constructed by determining what words are commonly known (i.e., recognized in their written form) by beginning readers. Almost 7,000 primary grade children were tested for basic sight recognition of 1,800 high frequency words. Using a 90 percent minimum criterion (i.e., 90 percent or more of the students at each grade level recognized each word), a 1,683‐word list was established that consisted of 587 first‐grade words, 861 second‐grade words, and 235 third‐grade words. Implications and uses of the extended basic sight vocabulary are also discussed.     

Summarizing scrambled stories

Subjects read stories 1,400 words long and wrote 60- to 80-word summaries of these stores. Reading time was either unrestricted or limited, and the stories were either presented in natural order or with their paragraphs scrambled. Reading times were longer for the scrambled stories, but the same kind of summaries were produced whether stories were presented in natural or scrambled order. When a well-structured story was used, judges were unable to distinguish the two types of summaries and rated the adequacy of summaries based upon the scrambled version about as high as that of summaries based upon normal stories. For a less well-structured story, judges could differentiate between the summaries from natural and scrambled stories. These results demonstrate the effectiveness of the story schema which permits subjects to comprehend scrambled stories by reorganizing them.     

A comparison of the effects of formal similarity among trigrams and among word triads

The central question of this report concerned the role of formal similarity in free recall of lists of trigrams and lists of three-letter word triads. Similarity was manipulated among trigrams by duplicating letters and among triads by duplicating words. An initial study showed that lists of 16 letters were learned more rapidly than a list of 16 three-letter words. Therefore, in the major experiment, the Ss were given all appropriate elements on test trials so that only associative learning was required. Increases in formal similarity caused decreases in rate of learning for both types of lists, and the mechanisms of the interference seemed to be the same for both types of lists, However, the learning of the trigram lists was more rapid than the learning of the triad lists, the difference being maximal with low similarity.     

The neural basis of the right visual field advantage in reading: an MEG analysis using virtual electrodes

Right-handed participants respond more quickly and more accurately to written words presented in the right visual field (RVF) than in the left visual field (LVF). Previous attempts to identify the neural basis of the RVF advantage have had limited success. Experiment 1 was a behavioral study of lateralized word naming which established that the words later used in Experiment 2 showed a reliable RVF advantage which persisted over multiple repetitions. In Experiment 2, the same words were interleaved with scrambled words and presented in the LVF and RVF to right-handed participants seated in an MEG scanner. Participants read the real words silently and responded "pattern" covertly to the scrambled words. A beamformer analysis created statistical maps of changes in oscillatory power within the brain. Those whole-brain maps revealed activation of the reading network by both LVF and RVF words. Virtual electrode analyses used the same beamforming method to reconstruct the responses to real and scrambled words in three regions of interest in both hemispheres. The middle occipital gyri showed faster and stronger responses to contralateral than to ipsilateral stimuli, with evidence of asymmetric channeling of information into the left hemisphere. The left mid fusiform gyrus at the site of the 'visual word form area' responded more strongly to RVF than to LVF words. Activity in speech-motor cortex was lateralized to the left hemisphere, and stronger to RVF than LVF words, which is interpreted as representing the proximal cause of the RVF advantage for naming written words.     

Short-term memory for intonation.

Ss were presented with lists of 16 words, each word spoken in one of four intonations. The final word was a repetition of one of the first 15 words, 40 Ss having to judge whether it was spoken in the same intonation as its earlier occurrence. A control group of 40 Ss did a similar task, ignoring intonation. Retention of intonation was significantly poorer, indicating that intonation is an additional load not normally retained. This argues against acoustic or articulatory encoding in short-term memory and in favor of an abstract-verbal encoding mode. Results are also interpreted as supporting the position that verbal and motor short-term membory obey similar laws.     

Reading deficits in learning disabled children

The purpose of this study was to determine whether LD children exhibited problems in the processes of attention, memory, or syntactical awareness when decoding written prose. Eighteen LD children and 18 normal controls were matched for initial word recognition skills. Subjects were then trained to read a list of individual words to criterion. Subsequently, they were tested on their ability to decode the same words in paragraph form, presented both immediately after training, and then again one week later. Half the children read paragraphs following standard English syntax, while the other half read a syntactically scrambled version of the same paragraph. The results indicated that a major contributing factor in the reading (decoding) difficulties demonstrated by the LD children derived from problems of acquisition and retrieval from long-term memory storage. The results were discussed in terms of their implications for the developmental lag theory of learning disabilities.     

Detection of intraword and interword letter repetition: A test of the word unitization hypothesis

Do words, as familiar units or gestalts, tend to swallow up and conceal their letter components (Pillsbury, 1897)? Letters typically are detected faster and more accurately in words than in nonwords (i.e., scrambled collections of letters), and in more frequent words than in less frequent words. However, a word advantage at encoding, where the representation of the string is formed, might compensate for, and thus mask, a word disadvantage at decoding and comparison, where the component letters of the representation are accessed and compared with the target letter. To better reveal any such word disadvantage, a task was used in this study that increased the amount of letter processing. Subjects judged whether a letter was repeated within a six-letter word or a nonword (Experiment 1; intraword letter repetition) or was repeated between two adjacent unrelated six-letter words or nonwords (Experiment 2; interword letter repetition). Contrary to Pillsbury's word unitization hypothesis, both types of letter repetition (intraword and interword) were detected faster and just as accurately with words as with nonwords. In Experiment 2, however, interword letter repetition was detected less accurately on common words (but not on rare words or third-order pseudowords) than on the corresponding nonwords. Thus, although the familiar word does not deny access to its own component letters, it does make their comparison with letters from other words more difficult.     

Norms for word lists that create false memories

Roediger and McDermott (1995) induced false recall and false recognition for words that were not presented in lists. They had subjects study 24 lists of 15 words that were associates of a common word (called the critical target or critical lure) that was not presented in the list. False recall and false recognition of the critical target occurred frequently in response to these lists. The purpose of the current work was to provide a set of normative data for the lists Roediger and McDermott used and for 12 others developed more recently. We tested false recall and false recognition for critical targets from 36 lists. Despite the fact that all lists were constructed to produce false remembering, the diversity in their effectiveness was large--60% or more of subjects falsely recalled window and sleep following the appropriate lists, and false recognition for these items was greater than 80%. However, the list generated from king led to 10% false recall and 27% false recognition. Possible reasons for these wide differences in effectiveness of the lists are discussed. These norms serve as a useful benchmark for designing experiments about false recall and false recognition in this paradigm.     

99 MULTIPLE MEANING WORDS FOR PRIMARY STUDENTS AND WAYS TO TEACH THEM

The cumulative first grade word lists from three widely‐used basal series were combined and alphabetized through the use of a computer program. Of the 255 words common to all three lists, 228 (almost 90%) had multiple meanings. From these a basic list of 99 multiple meaning words was selected by applying three criteria: (a) all or most definitions of the word could be related to primary grade children's experiences; (b) the word was used as more than one part of speech; and (c) the word had four or more different definitions. Activities to develop children's knowledge of the multiple meanings of words are suggested through the use of pictures and objects, picture dictionaires and concept books, semantic mapping, and sentence context.     

The role of vowels and context in the reading of highly skilled native Arabic readers

The role of context and vowels among highly skilled native Arabic readers was investigated in this study. Sixty-eight high school participants were selected after reading a list of isolated words. Only the highly skilled students participated in this study. Each participant individually had to read aloud vowelized and unvowelized paragraphs, and vowelized and unvowelized lists of words. The results showed that vowels and context were significant facilitators of word recognition in Arabic orthography.     

Detection of missing words in spoken text

Two tests were conducted to examine listeners' detection of missing words in spoken paragraph contexts. Detection was assessed by presenting listeners with normal paragraphs and with paragraphs each containing a single occurrence of a missed word, an inappropriate pause, or a mispronounced word. In the first test, listeners were simply asked whether they detected any abnormalities and to describe them. The results indicated that listeners reported missed words in only 34 to 49% of the paragraphs containing such words. In the second test, a separate group of listeners was given more specific instructions beforehand, indicating the three possible types of abnormality. In this task, the correct detection of missed words rose to 96%. Taken together, the results indicate that listeners do not readily detect occasional missing words under ordinary circumstances but are capable of such detection in a task specifically focused on message abnormalities.This work was supported by NIH Grant NS 20071. We thank Stephen Eady for serving as the speaker for the test recordings and Pamela Mueller for writing paragraphs.     

Growth functions for rapid remembering

Children between ages 9 and 13 were tested for recognizing and remembering words from 6- and 12-word lists. Opportunities for using deliberate mnemonics were severely restricted. Developmental functions showed different growth patterns for remembering the items in a short list than for remembering order, and different patterns for storing items from a long list than for retrieving them. However, none of these functions was parallel to the growth function of rapid word recognition. This absence of parallel growth contradicted a hypothesis that memory develops when item recognition develops. The data suggested, instead, that modest but reliable gains in rapid processes of storage and retrieval contribute to memory development during middle childhood.     

On the nature of talker variability effects on recall of spoken word lists.

In a recent study, Martin, Mullennix, Pisoni, and Summers (1989) reported that subjects' accuracy in recalling lists of spoken words was better for words in early list positions when the words were spoken by a single talker than when they were spoken by multiple talkers. The present study was conducted to examine the nature of these effects in further detail. Accuracy of serial-ordered recall was examined for lists of words spoken by either a single talker or by multiple talkers. Half the lists contained easily recognizable words, and half contained more difficult words, according to a combined metric of word frequency, lexical neighborhood density, and neighborhood frequency. Rate of presentation was manipulated to assess the effects of both variables on rehearsal and perceptual encoding. A strong interaction was obtained between talker variability and rate of presentation. Recall of multiple-talker lists was affected much more than single-talker lists by changes in presentation rate. At slow presentation rates, words in early serial positions produced by multiple talkers were actually recalled more accurately than words produced by a single talker. No interaction was observed for word confusability and rate of presentation. The data provide support for the proposal that talker variability affects the accuracy of recall of spoken words not only by increasing the processing demands for early perceptual encoding of the words, but also by affecting the efficiency of the rehearsal process itself.     

Investigating the influence of continuous babble on auditory short-term memory performance

A number of factors could explain the adverse effect that babble noise has on memory for spoken words (Murphy, Craik, Li, & Schneider, 2000). Babble could degrade the perceptual representation of words to such an extent that it compromises their subsequent processing, or the presence of speech noise in the period between word presentations could interfere with rehearsal. Thirdly, the top-down processes needed to extract the words from the babble could draw on resources that otherwise would be used for encoding. We tested all these hypotheses by presenting babble either only during word presentation or rehearsal, or by gating the babble on and off 500 ms before and after each word pair. Only the last condition led to a decline in memory. We propose that this decline in memory occurred because participants were focusing their attention on the auditory stream (to enable them to better segregate the words from the noise background) rather than on remembering the words they had heard. To further support our claim we show that a similar memory deficit results when participants perform the same memory task in quiet together with a nonauditory attention-demanding secondary task.     

Context effects in visual word recognition: Lexical relatedness and syntactic context

In three experiments, we investigated how associative word-word priming effects in German depend on different types of syntactic context in which the related words are embedded. The associative relation always concerned a verb as prime and a noun as target. Prime word and target word were embedded in visually presented strings of words that formed either a correct sentence, a scrambled list of words, or a sentence in which the target noun and the preceding definite article disagreed in syntactic gender. In contrast to previous studies (O’Seaghdha, 1989; Simpson, Peterson, Casteel, & Burgess, 1989), associative priming effects were not only obtained in correct sentences but also in scrambled word lists. Associative priming, however, was not obtained when the definite article and the target noun disagreed in syntactic gender. The latter finding suggests that a rather local violation of syntactic coherence reduces or eliminates word-word priming effects. The results are discussed in the context of related work on the effect of gender dis-/agreement between a syntactic context and a target noun.     

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.     

Sequential letter and word recognition in deaf and hearing subjects

To examine the processing of sequentially presented letters of familiar and nonsense words, especially among Ss of vastly differing experience on sequential tasks, three groups of Ss were tested on letters of words spelled sequentially on an alphanumeric display and on letters of words fingerspelled. These were a deaf group (N=33) with little or no hearing and who varied in their fingerspelling ability; a staff group (N=12) who taught fingerspelling and were highly proficient; and a hearing group (N=19). Of principal interest was the finding that the hearing Ss did better on nonsense letter recognition, while the deaf group did better on word recognition. Word length was important except to the staff Ss on fingerspelled words, which also suggests that concentration on fingerspelling proficiency forces attention to the whole word and not its component letters. Hearing Ss, who are the group faced with an unfamiliar task, seemed to attend to each letter and hence had more difficulty with recognition of the longer unit.     

The Effects of Two Different Reading Acceleration Training Programs on Improving Reading Skills of Second Graders

It has been well established that poor reading skills in the first grades of primary school can lead to poor reading skills in all coming years. A reading acceleration program (RAP) known to improve reading skills in adults and children with and without reading difficulties (RD) was tested for its effect on children in second grade with standard reading skills. The influence of the RAP on improving all reading skills—decoding, fluency, and reading comprehension—was examined. Seventy-nine children in second grade were divided into two study groups and one control group. Each study group received a training program that emphasizes reading skills: decoding, fluency, and comprehension were trained at the levels of words and sentences in Version A and at the levels of words and paragraphs in Version B. Both programs significantly improved reading skills compared with the control group that was not trained: Group A improved word fluency whereas Group B improved accuracy measures (word, pseudo-word, and text). Both training groups showed significantly greater improvement over time than the control group on reading comprehension. We conclude that a RAP training that combines words, sentences, and paragraphs is the most effective for improving reading skills.     

Two studies of visual search for word targets with controlled rates of presentation*

The two studies reported involve the visual search of word lists for a target item when the rate of presentation is controlled and the words are presented tachistoscopically. In the first study, the target is differentiated physically from the filler items by being capitalized. When the target is the last item in a list, it is readily identified at all presentation rates, but when it is the first word or is embedded in a list, recognition accuracy is inversely related to presentation rate. In the second study, the differentiation between target and filler items is in terms of the presence or absence of category membership. All Ss at all presentation rates do significantly better on lists with an animal word as a target and a set of unrelated words as filler items than on the converse arrangement.