Specifying theories of developmental dyslexia: a diffusion model analysis of word recognition

The nature of word recognition difficulties in developmental dyslexia is still a topic of controversy. We investigated the contribution of phonological processing deficits and uncertainty to the word recognition difficulties of dyslexic children by mathematical diffusion modeling of visual and auditory lexical decision data. The first study showed that poor visual lexical decision performance of reading disabled children was mainly due to a delay in the evaluation of word characteristics, suggesting impaired phonological processing. The adoption of elevated certainty criteria by the disabled readers suggests that uncertainty contributed to the visual word recognition impairments as well. The second study replicated the outcomes for visual lexical decision with formally diagnosed dyslexic children. In addition, during auditory lexical decision, dyslexics presented with reduced accuracy, which also resulted from delayed evaluation of word characteristics. Since orthographic influences are diminished during auditory lexical decision, this strengthens the phonological processing deficit account. Dyslexic children did not adopt heightened certainty criteria during auditory lexical decision, indicating that uncertainty solely impairs reading and not listening.     

Interaction of stimulus and contextual information during reading: Identifying words within sentences

In general, studies on the effects of a sentence context on word identification have focused on how context affects the efficiency of processing a single target word, presented separately from the context. Such studies probably would be incapable of measuring contextual facilitation resulting from cascaded or parallel processing of neighboring words within a sentence. To measure these and other types of facilitation, we presented entire phrases and sentences for subjects to read as fast as possible and to monitor for nonwords. Subjects read at rates representative of natural reading. Experiment 1 demonstrated a large contextual facilitation effect on decision time. Experiment 2 showed that facilitation is caused by specific semantic information and, perhaps to a greater degree, by nonpredictive syntactic information. Experiment 3 showed that the amount of facilitation is greater than could be accounted for by separate contributions from autonomous word level and sentence level processes. These results present difficulties for an autonomous model of reading, but are consistent with interactive models, in which the results of ongoing sentential analyses are combined with stimulus information to identify words.     

Exploring classical conditioning for strengthening the links between semantic and lexical representations in pure anomia: Preliminary findings from a single case study

The same language symptom might arise at different functional loci in people with aphasia. Therefore, it is plausible that different therapeutic interventions should be adopted to approach the same difficulties in different patients. Although this point of view is still widely accepted, recently the focus has shifted from the functional locus of a rehabilitative intervention to the mechanisms of action underlying the relearning process. We maintain that both aspects should be taken into account when programming a rehabilitative intervention; furthermore, investigating relearning mechanisms might shed new light on the functional architecture of the disrupted processes. Here, we investigated, in a single case study, whether classical conditioning was a suitable relearning paradigm for targeting word‐finding difficulties in pure anomia, that is in a patient with an impairment in accessing intact output lexical representations from a spared semantic system. Using a word‐repetition task on picture presentation, we contrasted a condition in which the stimulus onset asynchrony between word and picture stimuli was well suited to produce classical conditioning with a condition in which repetition training could not benefit from this learning mechanism. Only classical conditioning training exerted a significant, long‐lasting effect on our patient's naming skill. Tentative implications of our results for the functional architecture of single‐word processing are discussed.     

情绪韵律调节情绪词识别的ERP研究

采用韵律/词汇干扰范式和延迟匹配任务, 通过两个ERP实验, 考察了汉语口语中情绪韵律能否、以及如何调节情绪词的识别。实验一中, 不同类型的情绪韵律分组呈现, ERP结果显示, 同与情绪韵律效价一致的情绪词相比, 与情绪韵律效价不一致的情绪词诱发了走向更负的P200、N300和N400成分; 实验二中, 不同类型的情绪韵律随机呈现, 上述效价一致性效应依然存在。实验结果表明, 情绪韵律能够调节情绪词识别, 主要表现在对情绪词的音韵编码和语义加工的双重易化上。     

Evidence for processing of constituent singleand multiletter codes: Support for multilevel coding in word perception

This investigation assessed whether constituent codes are activated during word processing. In two experiments, a priming procedure was used to test whether printed word primes facilitate skilled readers’ identification of subsequently presented letter and letter bigram targets appearing in the primes (present condition), relative to the same targets not appearing in the primes (absent condition). Experiment 1 demonstrated the priming of single-letter targets and indicated that priming effects are facilitative and not inhibitory. In Experiment 2, high- and low-frequency bigram targets appearing in word primes were shown to have a processing advantage over bigram targets not appearing in word primes. Single-letter constituents in low-frequency bigrams also benefited from priming; however, single letters in high-frequency bigrams showed no such benefit. The results in general suggest that both single- and multiletter constituents are available during word processing, and hence support multicomponent models of word perception.     

It's about time: revisiting temporal processing deficits in dyslexia

Temporal processing in French children with dyslexia was evaluated in three tasks: a word identification task requiring implicit temporal processing, and two explicit temporal bisection tasks, one in the auditory and one in the visual modality. Normally developing children matched on chronological age and reading level served as a control group. Children with dyslexia exhibited robust deficits in temporal tasks whether they were explicit or implicit and whether they involved the auditory or the visual modality. First, they presented larger perceptual variability when performing temporal tasks, whereas they showed no such difficulties when performing the same task on a non‐temporal dimension (intensity). This dissociation suggests that their difficulties were specific to temporal processing and could not be attributed to lapses of attention, reduced alertness, faulty anchoring, or overall noisy processing. In the framework of cognitive models of time perception, these data point to a dysfunction of the ‘internal clock’ of dyslexic children. These results are broadly compatible with the recent temporal sampling theory of dyslexia.     

Working memory interference control deficit in children referred by teachers for ADHD symptoms.

It has been hypothesised that children with Attention Deficit/Hyperactivity Disorder (ADHD) present memory problems, including working memory deficits. This research is aimed at finding clearer evidence of a working memory deficit in these children. In the first study 22 children that had been referred by teachers as having ADHD symptoms were compared with a control group. Their performance on a listening span test, drawn up by De Beni, Palladino, Pazzaglia, and Cornoldi (1998), was investigated. In this task the subjects were asked to select the names of animals in word strings and to remember the last word in each string. In a second study, 34 children with ADHD symptoms and 50 control children were presented with a visuospatial working memory task mirroring the verbal task used in Study 1. In both studies, the children with ADHD symptoms had difficulty in remembering the last item in the string and had a higher number of intrusions when memorising items that were not in the final position. The results were interpreted that children with ADHD symptoms have working memory problems because they are not capable of suppressing information that initially has to be processed, and subsequently excluded from memory. This particular difficulty can be interpreted as an inhibitory processing deficit. The implications of the results in understanding learning difficulties in children with ADHD are discussed.     

Syntactic priming effects in aphasia: an investigation of local syntactic dependencies

This study explored on-line processing of local syntactic dependencies in normal subjects and in Broca's and Wernicke's aphasics using a lexical decision paradigm. In addition, subjects performed a grammatically judgement task on the real word pairs used in the lexical decision tasks. Results of two experiments for normal subjects indicated different syntactic priming effects as a function of the type of local syntactic dependency. Word pairs that formed a single constituent phrase, i.e., a verb phrase, showed both facilitory and inhibitory effects, whereas word pairs that reflected local syntactic dependencies across a phrase boundary, i.e., pronoun verb, showed only inhibitory effects. Broca's aphasics failed to show facilitory effects when presented with word pairs forming a single constituent phrase but, similar to normals, did show inhibition when presented with word pairs that reflected local syntactic dependencies across a phrase boundary. In contrast, Wernicke's aphasics failed to show inhibitory effects in both experiments. The implications of these results for theories of language processing deficits in aphasia are considered.     

To What Extent do we Hear Phonemic Contrasts in a Non-native Regional Variety? Tracking the Dynamics of Perceptual Processing with EEG

This combined ERP and behavioral experiment explores the dynamics of processing during the discrimination of vowels in a non-native regional variety. Southern listeners were presented with three word forms, two of which are encountered in both Standard and Southern French ([kot] and [kut]), whereas the third one exists in Standard but not Southern French ([kot]). EEG recordings suggest that all of the word pairs were discriminated by the listeners, although discrimination arose about 100ms later for the pairs which included the non-native word form than for those which contained word forms common to both French varieties. Behavioral data provide evidence that vowel discrimination is sensitive to the influence of the listeners’ native phonemic inventory at a late decisional stage of processing.     

Hemisphere differences in conscious and unconscious word reading

Hemisphere differences in word reading were examined using explicit and implicit processing measures. In an inclusion task, which indexes both conscious (explicit) and unconscious (implicit) word reading processes, participants were briefly presented with a word in either the right or the left visual field and were asked to use this word to complete a three-letter word stem. In an exclusion task, which estimates unconscious word reading, participants completed the word stem with any word other than the prime word. Experiment 1 showed that words presented to either visual field were processed in very similar ways in both tasks, with the exception that words in the right visual field (left hemisphere) were more readily accessible for conscious report. Experiment 2 indicated that unconsciously processed words are shared between the hemispheres, as similar results were obtained when either the same or the opposite visual field received the word stem. Experiment 3 demonstrated that this sharing between hemispheres is cortically mediated by testing a split-brain patient. These results suggest that the left hemisphere advantage for word reading holds only for explicit measures; unconscious word reading is much more balanced between the hemispheres.     

Differential constraints on the working memory and reading abilities of individuals with learning difficulties and typically developing children

This study examined the factors that constrain the working memory span performance and reading ability of individuals with generalized learning difficulties. In the study, 50 individuals with learning difficulties (LD) and 50 typically developing children (TD) matched for reading age completed two working memory span tasks. Participants also completed independent measures of the processing and storage operations involved in each working memory span task and Raven's Coloured Progressive Matrices. The results showed that despite an equivalent level of working memory span, the relative importance of the constraints on working memory differed between the groups. In addition, working memory span was not closely related to word recognition or sentence comprehension performance in the LD group. These results suggest that the working memory span performance of LD and TD individuals may reflect different working memory limitations and that individuals with generalized learning difficulties may approach cognitive tasks in a qualitatively different way from that of typically developing individuals.     

Exploring the contribution of the cerebral hemispheres to language comprehension deficits in adults with developmental language disorder

A divided visual field, priming paradigm was used to observe how adults who have a history of developmental language disorder (DLD) access lexically ambiguous words. The results show that sustained semantic access to subordinate word meanings (such as BANK-RIVER), which is seen in control subjects, is disrupted in the right cerebral hemisphere for this special population of readers. In the left hemisphere, only the most dominant meaning of the ambiguous word shows sustained priming in both controls and DLD participants. Therefore, for the DLD readers the subordinate meanings of words are not primed in either hemisphere and, thus, may not be available during online processing and integration of discourse. This right hemisphere lexical access deficit might contribute to the language comprehension difficulties exhibited by adult readers with a history of DLD.     

Interhemispheric interaction in word‐ and color‐matching of Kanji color words1

Abstract: The aim of the present study was to investigate the possibility that a shift toward a within‐hemisphere advantage would emerge when two stimulus items receive, respectively, different processing (vs. when they receive similar processing). Using right‐handed participants, we briefly presented two Kanji color‐word items as either within‐field or across‐fields. Viewers had to match the two items in terms of ink color (a color‐matching task) or word meaning (a name‐matching task). Each Kanji color word was presented with the same (congruent) or different (incongruent) ink color relative to the word meaning. Our results were twofold. First, a within‐field advantage appeared in the relatively easier color‐matching task, whereas an across‐field advantage tended to occur in the relatively harder name‐matching task. Second, in the word‐matching task an across‐field advantage appeared when both Kanji color words appeared in similar processing manners (both congruent or both incongruent), whereas a within‐field advantage occurred when processing of two Kanji items differed (one congruent and one incongruent). These results suggested that a shift toward a within‐hemisphere advantage occurs when two items are processed in respectively different ways.     

The maze task: Measuring forced incremental sentence processing time

The maze task is an online measure of sentence processing time that provides an alternative to the standard moving window version of self-paced reading. Rather than each word of the sentence being presented in succession, two words are presented at the same time, and the participant must choose which word is a grammatical continuation of the sentence. This procedure forces the reader into an incremental mode of processing in which each word must be fully integrated with the preceding context before the next word can be considered. Previous research with this technique has not considered whether it is sufficiently sensitive to syntactic complexity effects or to garden path effects. Four experiments are reported demonstrating that reliable differences in processing time for subject relatives and object relatives can be obtained, and that this technique generates garden path effects that correspond closely with the data from eyetracking experiments, but without the spillover effects that are sometimes obtained with eyetracking. It is also shown that the task is sensitive to word frequency effects, producing estimates well in excess of those found with eyetracking.     

Developmental dyslexia: Electrophysiological evidence of clinical subgroups

Event-related potentials (ERPs) to word and to musical-chord stimuli were recorded in 13 dyslexic boys and 13 age-matched normal readers. Normal readers and dyslexics whose reading handicaps involved visual-spatial processing deficits had greater word versus musical-chord ERP waveform differences over the left as compared to the right hemisphere. Dyslexics whose reading difficulties were related to auditory-verbal processing deficits did not exhibit this asymmetry. These results are interpreted as supportive of the hypothesis that the latter group of dyslexics has failed to develop normal left hemisphere specialization for processing of auditory-linguistic material.     

Imageability and word recognition in the left and right visual fields: a signal detection analysis

Identifying the information processing constraints that determine whether or not imagery moderates visual field asymmetries is essential for constructing a dynamic model of hemispheric interaction during language processing. In this investigation, we manipulated the global experimental context in which imageable and nonimageable words were presented by contrasting mixed and blocked word lists using a lateralized lexical decision task. Signal detection analyses were employed to assess whether global stimulus context and imageability differentially affect word discriminability (d prime) and response bias (log beta) across visual fields. Both discriminability and response bias varied with imageability and stimulus context, but to a comparable extent across visual fields. This suggests that both hemispheres are sensitive to the global context in which words are presented, and can adjust processing based not only on semantic characteristics of the words themselves, but also on the variability of items in the stimulus environment.     

Emotion words affect eye fixations during reading

Emotion words are generally characterized as possessing high arousal and extreme valence and have typically been investigated in paradigms in which they are presented and measured as single words. This study examined whether a word's emotional qualities influenced the time spent viewing that word in the context of normal reading. Eye movements were monitored as participants read sentences containing an emotionally positive (e.g., lucky), negative (e.g., angry), or neutral (e.g., plain) word. Target word frequency (high or low) was additionally varied to help determine the temporal locus of emotion effects, with interactive results suggesting an early lexical locus of emotion processing. In general, measures of target fixation time demonstrated significant effects of emotion and frequency as well as an interaction. The interaction arose from differential effects with negative words that were dependent on word frequency. Fixation times on emotion words (positive or negative) were consistently faster than those on neutral words with one exception-high-frequency negative words were read no faster than their neutral counterparts. These effects emerged in the earliest eye movement measures, namely, first and single fixation duration, suggesting that emotionality, as defined by arousal and valence, modulates lexical processing. Possible mechanisms involved in processing emotion words are discussed, including automatic vigilance and desensitization, both of which imply a key role for word frequency. Finally, it is important that early lexical effects of emotion processing can be established within the ecologically valid context of fluent reading.     

Semantic facilitation with pictures and words

The present experiments explored the role of processing level and strategic factors in cross-form (word-picture and picture-word) and within-form (picture-picture and word-word) semantic facilitation. Previous studies have produced mixed results. The findings presented in this article indicate that semantic facilitation depends on the task and on the subjects' strategies. When the task required semantic processing of both picture and word targets (e.g., category verification), equivalent facilitation was obtained across all modality combinations. When the task required name processing (e.g., name verification, naming), facilitation was obtained for the picture targets. In contrast, with word targets, facilitation was obtained only when the situation emphasized semantic processing. The results are consistent with models that propose a common semantic representation for both picture and words but that also include assumptions regarding differential order of access to semantic and phonemic features for these stimulus modalities.     

Specifying levels of processing

This study examines the nature of stimulus processing under semantic and nonsemantic orienting instructions. Two experiments are reported in which subjects were presented with a series of trials each beginning with the presentation of a “decision word” about which they made either a semantic or non-semantic orienting decision. This decision was followed by a word in coloured ink whose colour subjects were required to name as quickly as possible. On half the trails the coloured word was the primary associate of the decision word whilst on the other half the two words were normatively unrelated. On completion of the experiments the subjects were given an unexpected free recall test. The semantic orienting condition led to longer colour naming latencies on associate trials whilst no such difference was found in the non-semantic condition. The semantic condition also produced higher levels of incidental recall although paradoxically an analysis of associative clustering in recall failed to show any difference between the two orienting conditions. The results are interpreted as support for the “Levels of Processing” approach to memory since they provide an index of processing depth which is independent of retention performance.     

The role of age of acquisition in memory: effects on judgements of learning and recall

Judgements of learning (JOLs) are self-made predictions of the likelihood that one will later recall information. The influence of stimulus characteristics on JOLs and recall continues to receive attention, yet there are still a number of unexplored lexical word features that may exert an effect on mnemonic processing. Using a standard cue-target paradigm, we focused on the role of word age of acquisition (AoA) and evaluated the role of both cue and target AoA on responses. We replicated the robust delayed-JOL effect and used a novel items analysis approach to examine the relationship between intrinsic word features and accuracy and reaction times for both JOLs and recall. A consistent effect of target AoA was found, even after controlling for a range of covariates previously shown to impact JOLs and recall. These results expand the role of AoA in word processing and suggest that it is a key variable in memory and metacognition; they also support Koriat's (1997) cue utilization framework.