List context manipulation reveals orthographic deficits in Italian readers with developmental dyslexia

We tested the influence of list context on word frequency and length effects on the reading aloud of Italian developmental dyslexics and skilled peers. The stimuli were presented either in mixed blocks (alternating words and nonwords) or in pure blocks. The analyses based on the rate-and-amount model (Faust et al., 1999) indicated that group differences in reaction times between dyslexic and skilled readers (a) were well accounted for in terms of global components and (b) were modulated by context in the case of words but not in the case of nonwords. ANOVAs on z-transformed reaction time data further indicated the influence of stimulus length. Importantly, the frequency effect interacted with context: Controls showed a list context effect for high- and low-frequency words, while dyslexics showed a list context effect only for high-frequency words. The effect of length on reading times remained unaffected by context manipulation. It is proposed that this pattern of results may be accounted for by hypothesizing two separate deficits: An early graphemic impairment affecting performance independently of context and a later inefficiency in activating entries in the orthographic lexicon as a function of context demands.

from Child Neuropsychology

Remembering ‘zeal’ but not ‘thing’: Reverse frequency effects as a consequence of deregulated semantic processing

More efficient processing of high frequency (HF) words is a ubiquitous finding in healthy individuals, yet frequency effects are often small or absent in stroke aphasia. We propose that some patients fail to show the expected frequency effect because processing of HF words places strong demands on semantic control and regulation processes, counteracting the usual effect. This may occur because HF words appear in a wide range of linguistic contexts, each associated with distinct semantic information. This theory predicts that in extreme circumstances, patients with impaired semantic control should show an outright reversal of the normal frequency effect. To test this prediction, we tested two patients with impaired semantic control with a delayed repetition task that emphasised activation of semantic representations. By alternating HF and low frequency (LF) trials, we demonstrated a significant repetition advantage for LF words, principally because of perseverative errors in which patients produced the previous LF response in place of the HF target. These errors indicated that HF words were more weakly activated than LF words. We suggest that when presented with no contextual information, patients generate a weak and unstable pattern of semantic activation for HF words because information relating to many possible contexts and interpretations is activated. In contrast, LF words tend to associate with more stable patterns of activation because similar semantic information is activated whenever they are encountered.

from Neuropsychologia

Beyond Capacity Limitations II: Effects of Lexical Processes on Word Recall in Verbal Working Memory Tasks in Children With and Without Specific Language Impairment

Conclusions: Performance on verbal working memory span tasks for both SLI and CA children is influenced by word frequency, lexical cohorts, and semantic representations. Future studies need to examine the extent to which verbal working memory capacity is a cognitive construct independent of extant language knowledge representations.

from the Journal of Speech, Language, and Hearing Research

Explaining Lexical–Semantic Deficits in Specific Language Impairment: The Role of Phonological Similarity, Phonological Working Memory, and Lexical Competition

Conclusions: Individual differences in richness of lexical semantic representations as well as differences between children with SLI and typically developing peers may—at least, in part—be explained by processes of competition. However, difficulty with auditory perception or phonological working memory does not fully explain difficulties in lexical semantics.

from the Journal of Speech, Language, and Hearing Research

The effects of word frequency and context variability in cued recall

Normative word frequency and context variability affect memory in a range of episodic memory tasks and place constraints on theoretical development. In four experiments, we independently manipulated the word frequency and context variability of the targets (to-be-generated items) and cues in a cued recall paradigm. We found that high frequency targets were better recalled in both pure and mixed lists, even when context variability was held constant. High frequency cues were slightly more effective, but this benefit was eliminated when context variability was held constant. Low context variability cues were most effective while the context variability of the target had little effect on performance. The data suggest that words with fewer pre-experimental connections are better able to isolate the list and that generation of an item from memory benefits from frequency, perhaps due to the ease of generating common orthographic and phonological features. Implications for current models of memory and the prospects of future models are discussed.

from the Journal of Memory and Language

Naming and repetition in aphasia: Steps, routes, and frequency effects

This paper investigates the cognitive processes underlying picture naming and auditory word repetition. In the two-step model of lexical access, both the semantic and phonological steps are involved in naming, but the former has no role in repetition. Assuming recognition of the to-be-repeated word, repetition could consist of retrieving the word’s output phonemes from the lexicon (the lexical-route model), retrieving the output phonology directly from input phonology (the nonlexical-route model) or employing both routes together (the summation dual-route model). We tested these accounts by comparing the size of the word frequency effect (an index of lexical retrieval) in naming and repetition data from 59 aphasic patients with simulations of naming and repetition models. The magnitude of the frequency effect (and the influence of other lexical variables) was found to be comparable in naming and repetition, and equally large for both the lexical and summation dual-route models. However, only the dual-route model was fully consistent with data from patients, suggesting that nonlexical input is added on top of a fully-utilized lexical route.

from the Journal of Memory and Language

Neighborhood Density and Word Frequency Predict Vocabulary Size in Toddlers

Conclusion: Children at the lowest points of a continuum of vocabulary size may be extracting statistical properties of the input language in a manner quite different from their more able age peers.

from the Journal of Speech, Language, and Hearing Research

Lexical effects on spoken word recognition performance among Mandarin-speaking children with normal hearing and cochlear implants

Lexical effects on Mandarin word recognition were only demonstrated among disyllabic words by NH and the CI children, while Mandarin homophones appearing in monosyllabic words were suggested. Lexical effects on spoken word recognition in Mandarin are not substantially demonstrated as in English, but the Mandarin LNT and MLNT provided reliable information on the spoken word recognition of pediatric CI users in the initial stage after implantation as well as in the rehabilitation progress.

from the International Journal of Pediatric Otorhinolaryngology

The Development of Polysemy and Frequency Use in English Second Language Speakers

Spoken language data were collected from six adult second language (L2) English learners over a year-long period in order to explore the development of word polysemy and frequency use. The data were analyzed both quantitatively and qualitatively. In the first analysis, the growth of WordNet polysemy values and CELEX word frequency values were examined. For both indexes, significant growth was demonstrated from the 2nd to the 16th week of observation, after which values remained stable. Growth in word polysemy values also correlated with changes in word frequency, supporting the notion that frequency and polysemy effects in word use are related. A second analysis used the WordNet dictionary to explore qualitative changes in word sense use concerning six frequent lexical items in the learner corpus (think, know, place, work, play, and name). A qualitative analysis compared normalized frequencies for each word sense in the first trimester of the study to the later trimesters. Differences in the number of word senses used across trimesters were found for all six words. Analyses 1 and 2, taken together, support the notion that L2 learners begin to use words that have the potential for more senses during the first 4 months; learners then begin to extend the core meanings of these polysemous words. These findings provide further insights into the development of lexical proficiency in L2 learners and the growth of lexical networks.

from Language Learning

Improving children’s formal word definitions: A feasibility study

The ability to define a word with accuracy and precision is an important skill that has been associated with academic achievement. This study investigated the feasibility of conducting a lesson on formal word definitions to improve children’s definitional production. The participants were 18 children in grade 4 (mean age: 9 years; 8 months) who were delayed readers by one grade level. Initially, the children wrote definitions for high- and lower-frequency nouns and verbs. Subsequently, a definitional lesson was delivered, which focused on the formal structure of noun and verb definitions and accuracy/precision of meaning. Lastly, the children were given a written post-test, which also contained high- and lower-frequency nouns and verbs. Words were controlled for frequency, imageability, difficulty, and familiarity. Noun and verb definitions were coded and scored for level of structure (form). Nouns were coded and scored for content (expressed meaning). Results indicated that post-test scores were significantly higher for form for nouns and verbs. For content, noun scores were significantly higher in post-test. Findings indicated that a one-time lesson on formal definitional production can positively influence children’s definitions. Limitations of the study and future research ideas are discussed.

from Child Language Teaching and Therapy

Word frequency as a cue for identifying function words in infancy

While content words (e.g., ‘dog’) tend to carry meaning, function words (e.g., ‘the’) mainly serve syntactic purposes. Here, we ask whether 17-month old infants can use one language–universal cue to identify function word candidates: their high frequency of occurrence. In Experiment 1, infants listened to a series of short, naturally recorded sentences in a foreign language (i.e., in French). In these sentences, two determiners appeared much more frequently than any content word. Following this, infants were presented with a visual object, and simultaneously with a word pair composed of a determiner and a noun. Results showed that infants associated the object more strongly with the infrequent noun than with the frequent determiner. That is, when presented with both the old object and a novel object, infants were more likely to orient towards the old object when hearing a label with a new determiner and the old noun compared to a label with a new noun and the old determiner. In Experiment 2, infants were tested using the same procedure as in Experiment 1, but without the initial exposure to French sentences. Under these conditions, infants did not preferentially associate the object with nouns, suggesting that the preferential association between nouns and objects does not result from specific acoustic or phonological properties. In line with various biases and heuristics involved in acquiring content words, we provide the first direct evidence that infants can use distributional cues, especially the high frequency of occurrence, to identify potential function words.

from Cognition

Frequency of Use Leads to Automaticity of Production: Evidence from Repair in Conversation

In spontaneous speech, speakers sometimes replace a word they have just produced or started producing by another word. The present study reports that in these replacement repairs, low-frequency replaced words are more likely to be interrupted prior to completion than high-frequency words, providing support to the hypothesis that the production of high-frequency words is more automatic than the production of low-frequency words (Bybee, 2002; Logan, 1982). Frequency appears to have an effect on interruptibility even when word duration is statistically controlled. In addition, the frequency of the replaced word is positively correlated with the frequency of the word it is replaced by, supporting the hypothesis that high-frequency words are easier to access in production (Kittredge, Dell, Verkuilen, & Schwartz, 2008): vkapatsi@uoregon.edu the more frequent the target, the more frequent an inappropriate word needs to be to overcome the target and be uttered, only to be replaced.

from Language and Speech

Effects of word frequency on semantic memory in schizophrenia: Electrophysiological evidence for a deficit in linguistic access

Background
Abnormal storage and/or access are among the hypothesized causes of semantic memory deficit in schizophrenia. Neuropsychological and connectionist models have emphasized functional systems that serve the processing of word meaning and frequency: semantic storage disturbance is presumed to result from weak representations of word meaning; defective access is assumed to result from compromises to pathways that activate word frequency knowledge. Candidate biological systems include neuromodulatory pathways that normally function to enhance neural signals (e.g., cholinergic system). Electrophysiological responding may be informative regarding the storage-access distinction for schizophrenia.

Methods
Visual event-related potentials were recorded for 14 schizophrenia outpatients receiving atypical antipsychotics, and 14 healthy controls group-matched to patients on age, gender, and demographics. N400 was elicited using an incidental semantic priming paradigm, in which semantic relatedness and word frequency were varied, and a letter probe task.

Results
Compared to controls, patients showed reduced N400 (µV) discrimination of semantic relatedness. Groups also showed different patterns of N400 to word frequency. Controls’ N400 increased in negativity as words decreased in frequency of occurrence, while patients did not show a linear relationship between N400 and word frequency. Groups also differed for N400 to frequently occurring words. Patients exhibited increased negativity to high and very high frequency words, compared to controls. A subgroup of patients receiving antipsychotics with known affinity binding for muscarinic receptors (clozapine, olanzapine) showed significant albeit limited N400 priming, but their N400 to word frequency remained nonsignificant.

Conclusions
Results suggest a deficit in semantic access for schizophrenia, as well as an influence of neuromodulators on the activation of connections among semantic representations. Cumulative findings indicating only limited N400 priming for patients receiving either typical or atypical antipsychotics support the hypothesis that semantic memory deficit represents a trait marker for schizophrenia.

from

Word-superiority effect as a function of semantic transparency of Chinese bimorphemic compound words

Abstract
The word-superiority effect (WSE) describes the superior recognition of word constituents in a word, as opposed to a non-word, context. In this study, the WSE was used as a diagnostic tool to examine the modulatory effect of word semantic transparency on the degree to which Chinese bimorphemic compound words are lexically represented as unitised wholes. Word semantic transparency refers to the degree to which word constituents are semantically transparent/opaque to whole-word meaning. A modified Reicher-Wheeler paradigm and a character identification task were employed. Compounds with at least one opaque constituent (fully and partially opaque) patterned together and displayed a larger WSE (more word-like) than fully transparent compounds. A space occurs naturally between constituents of Chinese compounds. Present results corroborated with recent results on English compound processing in which a space was artificially inserted between constituents of naturally concatenated compounds. Independently, the WSE was larger for high-frequency than low-frequency Chinese compounds.

from Language and Cognitive Processes

Reading aloud: Qualitative differences in the relation between stimulus quality and word frequency as a function of context

Virtually all theories of visual word recognition assume (typically implicitly) that when a pathway is used, processing within that pathway always unfolds in the same way. This view is challenged by the observation that simple variations in list composition are associated with qualitative changes in performance. The present experiments demonstrate that when reading aloud, the joint effects of stimulus quality and word frequency on response time are driven by the presence/absence of nonwords in the list. Interacting effects of these factors are seen when only words appear in the experiment, whereas additive effects are seen when words and nonwords are randomly intermixed. One way to explain these and other data appeals to the distinction between cascaded processing (or interactive activation) on the one hand versus a thresholded mode of processing on the other, with contextual factors determining which mode of processing dominates. (PsycINFO Database Record (c) 2008 APA, all rights reserved)

from the Journal of Experimental Psychology: Learning, Memory, and Cognition