Neural attenuation: age-related dedifferentiation in the left occipitotemporal cortex for visual word processing.

The present study investigated the age-related neural basis of cognitive decline in the left ventral occipitotemporal cortex (vOT)-a brain area that responds selectively to visual words processing. Functional magnetic resonance imaging was used to estimate neural activity in this area, while young and old adults viewed words and line drawings. Our results demonstrated the existence of neural dedifferentiation of the left vOT in old adults during visual word processing. More specifically, this dedifferentiation was due to neural attenuation that is, decreased response to words rather than increased response to line drawings in old adults compared with young adults. In addition, individuals who showed decreased neural response to words had worse performance in visual word processing. Taken together, our findings support the neural attenuation hypothesis for the cognitive decline in visual word processing in old adults.

A Modified Hybrid Brain-Computer Interface Speller Based on Steady-State Visual Evoked Potentials and Electromyogram.

BACKGROUND: To enhance the information transfer rate (ITR) of a steady-state visual evoked potential (SSVEP)-based speller, more characters with flickering symbols should be used. Increasing the number of symbols might reduce the classification accuracy. A hybrid brain-computer interface (BCI) improves the overall performance of a BCI system by taking advantage of two or more control signals. In a simultaneous hybrid BCI, various modalities work with each other simultaneously, which enhances the ITR. METHODS: In our proposed speller, simultaneous combination of electromyogram (EMG) and SSVEP was applied to increase the ITR. To achieve 36 characters, only nine stimulus symbols were used. Each symbol allowed the selection of four characters based on four states of muscle activity. The SSVEP detected which symbol the subject was focusing on and the EMG determined the target character out of the four characters dedicated to that symbol. The frequency rate for character encoding was applied in the EMG modality and latency was considered in the SSVEP modality. Online experiments were carried out on 10 healthy subjects. RESULTS: The average ITR of this hybrid system was 96.1 bit/min with an accuracy of 91.2%. The speller speed was 20.9 char/min. Different subjects had various latency values. We used an average latency of 0.2 s across all subjects. Evaluation of each modality showed that the SSVEP classification accuracy varied for different subjects, ranging from 80% to 100%, while the EMG classification accuracy was approximately 100% for all subjects. CONCLUSIONS: Our proposed hybrid BCI speller showed improved system speed compared with state-of-the-art systems based on SSVEP or SSVEP-EMG, and can provide a user-friendly, practical system for speller applications.

Sentential Contextual Facilitation of Auditory Word Processing Builds Up during Sentence Tracking.

While listening to meaningful speech, auditory input is processed more rapidly near the end (vs. beginning) of sentences. Although several studies have shown such word-to-word changes in auditory input processing, it is still unclear from which processing level these word-to-word dynamics originate. We investigated whether predictions derived from sentential context can result in auditory word-processing dynamics during sentence tracking. We presented healthy human participants with auditory stimuli consisting of word sequences, arranged into either predictable (coherent sentences) or less predictable (unstructured, random word sequences) 42-Hz amplitude-modulated speech, and a continuous 25-Hz amplitude-modulated distractor tone. We recorded RTs and frequency-tagged neuroelectric responses (auditory steady-state responses) to individual words at multiple temporal positions within the sentences, and quantified sentential context effects at each position while controlling for individual word characteristics (i.e., phonetics, frequency, and familiarity). We found that sentential context increasingly facilitates auditory word processing as evidenced by accelerated RTs and increased auditory steady-state responses to later-occurring words within sentences. These purely top-down contextually driven auditory word-processing dynamics occurred only when listeners focused their attention on the speech and did not transfer to the auditory processing of the concurrent distractor tone. These findings indicate that auditory word-processing dynamics during sentence tracking can originate from sentential predictions. The predictions depend on the listeners' attention to the speech, and affect only the processing of the parsed speech, not that of concurrently presented auditory streams.

When a Sunny Day Gives You Butterflies: An Electrophysiological Investigation of Concreteness and Context Effects in Semantic Word Processing.

Theories on controlled semantic cognition assume that word concreteness and linguistic context interact during semantic word processing. Methodological approaches and findings on how this interaction manifests at the electrophysiological and behavioral levels are heterogeneous. We measured ERPs and RTs applying a validated cueing paradigm with 19 healthy participants, who performed similarity judgments on concrete or abstract words (e.g., "butterfly" or "tolerance") after reading contextual and irrelevant sentential cues. Data-driven analyses showed that concreteness increased and context decreased negative-going deflections in broadly distributed bilateral clusters covering the N400 and N700/late positive component time range, whereas both reduced RTs. Crucially, within a frontotemporal cluster in the N400 time range, contextual (vs. irrelevant) information reduced negative-going amplitudes in response to concrete but not abstract words, whereas a contextual cue reduced RTs only in response to abstract but not concrete words. The N400 amplitudes did not explain additional variance in the RT data, which showed a stronger contextual facilitation for abstract than concrete words. Our results support separate but interacting effects of concreteness and context on automatic and controlled stages of contextual semantic processing and suggest that effects on the electrophysiological versus behavioral level obtained with this paradigm are dissociated.

Form to meaning mapping and the impact of explicit morpheme combination in novel word processing.

In the present study, we leveraged computational methods to explore the extent to which, relative to direct access to semantics from orthographic cues, the additional appreciation of morphological cues is advantageous while inducing the meaning of affixed pseudo-words. We re-analyzed data from a study on a lexical decision task for affixed pseudo-words. We considered a parsimonious model only including semantic variables (namely, semantic neighborhood density, entropy, magnitude, stem proximity) derived through a word-form-to-meaning approach (ngram-based). We then explored the extent to which the addition of equivalent semantic variables derived by combining semantic information from morphemes (combination-based) improved the fit of the statistical model explaining human data. Results suggest that semantic information can be extracted from arbitrary clusters of letters, yet a computational model of semantic access also including a combination-based strategy based on explicit morphological information better captures the cognitive mechanisms underlying human performance. This is particularly evident when participants recognize affixed pseudo-words as meaningful stimuli.

Behavioural and electrophysiological analyses of written word processing in spoken and literary Arabic: New insights into the diglossia question.

Diglossia in Arabic describes the existence and the use of two varieties of the same language: spoken Arabic (SA) and literary Arabic (LA). SA, the dialect first spoken by Arabic native speakers, is used in non-formal situations for everyday conversations, and varies from one region to another in the Arabic world. LA, acquired later in life when the children learn to read and write at school, is used for formal purposes such as media, speeches in public and religious sermons. Previous research showed that, in the auditory modality, SA words are processed faster than LA ones. In the visual modality, written LA words are processed faster than SA ones, the latter comparing with low-frequency words. This study analysed event-related potentials (ERPs) during the processing of high-frequency (LAHF), LA low-frequency (LALF) and SA high-frequency words (SAHF) in a visual lexical decision task. Faster reaction times were observed for LAHF, followed by SAHF and then by LALF. ERPs showed a modulation of the early components starting from the P100 component and of the late P600 component, supposedly related to memory processes. These findings, indicating that processing written SAHF words was largely comparable with processing of LALF, are discussed in the context of Arabic diglossia.

The limits of automatic sensorimotor processing during word processing: investigations with repeated linguistic experience, memory consolidation during sleep, and rich linguistic learning contexts.

While a number of studies have repeatedly demonstrated an automatic activation of sensorimotor experience during language processing in the form of action-congruency effects, as predicted by theories of grounded cognition, more recent research has not found these effects for words that were just learned from linguistic input alone, without sensorimotor experience with their referents. In the present study, we investigate whether this absence of effects can be attributed to a lack of repeated experience and consolidation of the associations between words and sensorimotor experience in memory. To address these issues, we conducted four experiments in which (1 and 2) participants engaged in two separate learning phases in which they learned novel words from language alone, with an intervening period of memory-consolidating sleep, and (3 and 4) we employed familiar words whose referents speakers have no direct experience with (such as plankton). However, we again did not observe action-congruency effects in subsequent test phases in any of the experiments. This indicates that direct sensorimotor experience with word referents is a necessary requirement for automatic sensorimotor activation during word processing.

Partial overlap between holistic processing of words and Gestalt line stimuli at an early perceptual stage.

A dual-route account of holistic processing has been proposed, which includes a stimulus-based and experience-based approach to holistic processing. The bottom-up route was suggested by the observation of holistic processing for novel Gestalt line patterns in the absence of expertise. For words, there is mainly evidence for a late, lexical, experience-based locus of holistic processing with scarce evidence for an early, stimulus-based locus. However, salient early Gestalt information (i.e., connectedness, closure, and continuity between parts) are important for letter and word identification. Thus, there might be an overlap at an early, perceptual processing stage, between Gestalt stimulus-based holistic processing and word holistic processing. In the task we used, words and Gestalt line patterns were superimposed, and we evaluated whether one class of stimuli was processed less holistically when an aligned other class pattern (processed holistically) was superimposed. There was some evidence supporting an early locus for the influence of word processing on Gestalt line patterns, but the interaction between the two stimuli was not reciprocal, which needs further clarification. When an aligned word (processed holistically) was overlaid on a line pattern, the line pattern was processed less holistically. However, when an aligned line pattern (processed holistically) was overlaid on a word, the word was not processed less holistically. This pattern might result from the higher cohesiveness of words and their automaticity and feedback from the lexicon.

Whole-object effects in visual word processing: Parallels with and differences from face recognition.

Visual words and faces differ in their structural properties, but both are objects of high expertise. Holistic processing is said to characterize expert face recognition, but the extent to which whole-word processes contribute to word recognition is unclear, particularly as word recognition is thought to proceed by a component-based process. We review the evidence for experimental effects in word recognition that parallel those used to support holistic face processing, namely inversion effects, the part-whole task, and composite effects, as well as the status of whole-word processing in pure alexia and developmental dyslexia, contrasts between familiar and unfamiliar languages, and the differences between handwriting and typeset font. The observations support some parallels in whole-object influences between face and visual word recognition, but do not necessarily imply similar expert mechanisms. It remains to be determined whether and how the relative balance between part-based and whole-object processing differs for visual words and faces.

Visual Attention and Lexical Involvement in L1 and L2 Word Processing: Emotional Stroop Effect.

Given the fact that the process of engaging and interacting with the text is not only the function of a reader but also the text itself, the current study attempts to examine the role of the type of the word in the attentional engagement. More specifically, the present investigation aims to verify the interplay of sensorimotor information, emotions, and the linguistic information in the word processing. In so doing, for the scale validation, a sample of 220 Iranian English as a Foreign Language (EFL) learners from different language institutes were requested to complete the newly designed Persian and English lexical involvement scales. The results of Structural Equation Modeling (SEM) supported the factor structure and the reliability of the measures. Moreover, using Emotional Stroop task in the experimental set up, the results revealed that there is a strong positive relationship between lexical involvement and visual attentional engagement in L1(Persian). The association was conversely negative in L2 (English). Finally, the statistical analysis indicates that the lexical stimuli differ regarding their magnitude of lexical involvement in L1 and L2.

Two words as one: A multi-naming investigation of the age-of-acquisition effect in compound-word processing.

Previous research has shown that early-acquired words are produced faster than late-acquired words. Juhasz and colleagues (Juhasz, Lai & Woodcock, Behavior Research Methods, 47 (4), 1004-1019, 2015; Juhasz, The Quarterly Journal of Experimental Psychology, 1-10, 2018) argue that the Age-of-Acquisition (AoA) loci for complex words, specifically compound words, are found at the lexical/semantic level. In the current study, two experiments were conducted to evaluate this claim and investigate the influence of AoA in reading compound words aloud. In Experiment 1, 48 participants completed a word naming task. Using general linear mixed modelling, we found that the age at which the compound word was learned significantly affected the naming latencies beyond the other psycholinguistic properties measured. The second experiment required 48 participants to name the compound word when the two morphemes were presented with a space in-between (combinatorial naming, e.g. air plane). We found that the age at which the compound word was learned, as well as the AoA of the individual morphemes that formed the compound word, significantly influenced combinatorial naming latency. These findings are discussed in relation to theories of the AoA in language processing.

Brain regions and functional interactions supporting early word recognition in the face of input variability.

Perception and cognition in infants have been traditionally investigated using habituation paradigms, assuming that babies' memories in laboratory contexts are best constructed after numerous repetitions of the very same stimulus in the absence of interference. A crucial, yet open, question regards how babies deal with stimuli experienced in a fashion similar to everyday learning situations-namely, in the presence of interfering stimuli. To address this question, we used functional near-infrared spectroscopy to test 40 healthy newborns on their ability to encode words presented in concomitance with other words. The results evidenced a habituation-like hemodynamic response during encoding in the left-frontal region, which was associated with a progressive decrement of the functional connections between this region and the left-temporal, right-temporal, and right-parietal regions. In a recognition test phase, a characteristic neural signature of recognition recruited first the right-frontal region and subsequently the right-parietal ones. Connections originating from the right-temporal regions to these areas emerged when newborns listened to the familiar word in the test phase. These findings suggest a neural specialization at birth characterized by the lateralization of memory functions: the interplay between temporal and left-frontal regions during encoding and between temporo-parietal and right-frontal regions during recognition of speech sounds. Most critically, the results show that newborns are capable of retaining the sound of specific words despite hearing other stimuli during encoding. Thus, habituation designs that include various items may be as effective for studying early memory as repeated presentation of a single word.

Tracking Knowledge Evolution in Cloud Health Care Research: Knowledge Map and Common Word Analysis.

BACKGROUND: With the continuous development of the internet and the explosive growth in data, big data technology has emerged. With its ongoing development and application, cloud computing technology provides better data storage and analysis. The development of cloud health care provides a more convenient and effective solution for health. Studying the evolution of knowledge and research hotspots in the field of cloud health care is increasingly important for medical informatics. Scholars in the medical informatics community need to understand the extent of the evolution of and possible trends in cloud health care research to inform their future research. OBJECTIVE: Drawing on the cloud health care literature, this study aimed to describe the development and evolution of research themes in cloud health care through a knowledge map and common word analysis. METHODS: A total of 2878 articles about cloud health care was retrieved from the Web of Science database. We used cybermetrics to analyze and visualize the keywords in these articles. We created a knowledge map to show the evolution of cloud health care research. We used co-word analysis to identify the hotspots and their evolution in cloud health care research. RESULTS: The evolution and development of cloud health care services are described. In 2007-2009 (Phase I), most scholars used cloud computing in the medical field mainly to reduce costs, and grid computing and cloud computing were the primary technologies. In 2010-2012 (Phase II), the security of cloud systems became of interest to scholars. In 2013-2015 (Phase III), medical informatization enabled big data for health services. In 2016-2017 (Phase IV), machine learning and mobile technologies were introduced to the medical field. CONCLUSIONS: Cloud health care research has been rapidly developing worldwide, and technologies used in cloud health research are simultaneously diverging and becoming smarter. Cloud-based mobile health, cloud-based smart health, and the security of cloud health data and systems are three possible trends in the future development of the cloud health care field.

Investigating the functional neuroanatomy of concrete and abstract word processing through direct electric stimulation (DES) during awake surgery.

Neuropsychological, neuroimaging and electrophysiological studies demonstrate that abstract and concrete word processing relies not only on the activity of a common bilateral network but also on dedicated networks. The neuropsychological literature has shown that a selective sparing of abstract relative to concrete words can be documented in lesions of the left anterior temporal regions. We investigated concrete and abstract word processing in 10 patients undergoing direct electrical stimulation (DES) for brain mapping during awake surgery in the left hemisphere. A lexical decision and a concreteness judgment task were added to the neuropsychological assessment during intra-operative monitoring. On the concreteness judgment, DES delivered over the inferior frontal gyrus significantly decreased abstract word accuracy while accuracy for concrete words decreased when the anterior temporal cortex was stimulated. These results are consistent with a lexical-semantic model that distinguishes between concrete and abstract words related to different neural substrates in the left hemisphere.

Synonym-Based Word Frequency Analysis to Support the Development and Presentation of a Public Health Quality Improvement Taxonomy.

CONTEXT: Researchers and analysts have not completely examined word frequency analysis as an approach to creating a public health quality improvement taxonomy. OBJECTIVE: To develop a taxonomy of public health quality improvement concepts for an online exchange of quality improvement work. DESIGN: We analyzed documents, conducted an expert review, and employed a user-centered design along with a faceted search approach to make online entries searchable for users. To provide the most targeted facets to users, we used word frequency to analyze 334 published public health quality improvement documents to find the most common clusters of word meanings. We then reviewed the highest-weighted concepts and categorized their relationships to quality improvement details in our taxonomy. Next, we mapped meanings to items in our taxonomy and presented them in order of their weighted percentages in the data. Using these methods, we developed and sorted concepts in the faceted search presentation so that online exchange users could access relevant search criteria. RESULTS: We reviewed 50 of the top synonym clusters and identified 12 categories for our taxonomy data. The final categories were as follows: Summary; Planning and Execution Details; Health Impact; Training and Preparation; Information About the Community; Information About the Health Department; Results; Quality Improvement (QI) Staff; Information; Accreditation Details; Collaborations; and Contact Information of the Submitter. CONCLUSION: Feedback about the elements in the taxonomy and presentation of elements in our search environment from users has been positive. When relevant data are available, the word frequency analysis method may be useful in other taxonomy development efforts for public health.

The Influence of Sex Information on Gender Word Processing.

Three different tasks (word repetition, lexical decision, and gender decision) were designed to explore the impact of the sex clues (sex of the speaker, sex of the addressee) and the type of gender (semantic, arbitrary) on the processing of isolated Spanish gendered words. The findings showed that the grammatical gender feature was accessed when no mandatory attentional focus was required. In addition, the results indicated that the participants organize information according to their own sex role, which provides more salience to the words that match in grammatical gender with their own sex role representation, even when the gender assignment is arbitrary. Finally, the sex of the speaker biased the lexical access and the grammatical gender selection, serving as a semantic prime when the two dimensions have a congruent relationship. Furthermore, the masculine form serves as the generic gender representing both male and female figures.

Perceived communicative context and emotional content amplify visual word processing in the fusiform gyrus.

The personal significance of a language statement depends on its communicative context. However, this is rarely taken into account in neuroscience studies. Here, we investigate how the implied source of single word statements alters their cortical processing. Participants' brain event-related potentials were recorded in response to identical word streams consisting of positive, negative, and neutral trait adjectives stated to either represent personal trait feedback from a human or to be randomly generated by a computer. Results showed a strong impact of perceived sender. Regardless of content, the notion of receiving feedback from a human enhanced all components, starting with the P2 and encompassing early posterior negativity (EPN), P3, and the late positive potential (LPP). Moreover, negative feedback by the "human sender" elicited a larger EPN, whereas positive feedback generally induced a larger LPP. Source estimations revealed differences between "senders" in visual areas, particularly the bilateral fusiform gyri. Likewise, emotional content enhanced activity in these areas. These results specify how even implied sender identity changes the processing of single words in seemingly realistic communicative settings, amplifying their processing in the visual brain. This suggests that the concept of motivated attention extends from stimulus significance to simultaneous appraisal of contextual relevance. Finally, consistent with distinct stages of emotional processing, at least in contexts perceived as social, humans are initially alerted to negative content, but later process what is perceived as positive feedback more intensely.

Text input speed in persons with cervical spinal cord injury.

STUDY DESIGN: This is a prospective clinical study. OBJECTIVES: The objectives of this study were to determine text input speed (TIS) in persons with cervical spinal cord injury (SCI) and to study the influence of personal characteristics and type of computer access device on TIS. SETTING: This study was conducted in the Rehabilitation Department, Garches, France. METHODS: People with cervical SCI were included if their level of injury was between C4 and C8 Asia A or B, and if they were computer users. In addition, able-bodied people were recruited from the hospital staff. Each participant underwent a single evaluation using their usual computer access devices. TIS was evaluated during a 10- min copying task. The relationship between the characteristics of participants with cervical SCI, type of computer access device and TIS were analyzed using a Scheirer-Ray-Hare test (nonparametric test similar to a two-way analysis of variance). RESULTS: Thirty-five participants with cervical SCI and 21 able-bodied people were included. Median TIS of participants with cervical SCI was 11 (6; 14) words per minute (w.p.m.) and of able-bodied participants was 19 (14; 24) w.p.m. (P=0.001). Median TIS of participants with lesions at or above C5 was 12 (4; 13) w.p.m. and of those with lesions below C5 was 10 (9; 18) w.p.m. (P=0.38) [corrected]. The Scheirer-Ray-Hare test showed that only the type of computer access device significantly influenced TIS. Surprisingly, none of the person's characteristics, including the level of cervical lesion, affected TIS. CONCLUSION: This is the first study to analyze TIS in a group of participants with cervical SCI. The results showed that only the type of computer access device influenced TIS.

A Thousand Words Are Worth a Picture: Snapshots of Printed-Word Processing in an Event-Related Potential Megastudy.

In the experiment reported here, approximately 1,000 words were presented to 75 participants in a go/no-go lexical decision task while event-related potentials (ERPs) were recorded. Partial correlations were computed for variables selected to reflect orthographic, lexical, and semantic processing, as well as for a novel measure of the visual complexity of written words. Correlations were based on the item-level ERPs at each electrode site and time slice while a false-discovery-rate correction was applied. Early effects of visual complexity were seen around 50 ms after word onset, followed by the earliest sustained orthographic effects around 100 to 150 ms, with the bulk of orthographic and lexical influences arising after 200 ms. Effects of a semantic variable (concreteness) emerged later, at around 300 ms. The overall time course of these ERP effects is in line with hierarchical, cascaded, interactive accounts of word recognition, in which fast feed-forward influences are consolidated by top-down feedback via recurrent processing loops.

Automated misspelling detection and correction in clinical free-text records.

Accurate electronic health records are important for clinical care and research as well as ensuring patient safety. It is crucial for misspelled words to be corrected in order to ensure that medical records are interpreted correctly. This paper describes the development of a spelling correction system for medical text. Our spell checker is based on Shannon's noisy channel model, and uses an extensive dictionary compiled from many sources. We also use named entity recognition, so that names are not wrongly corrected as misspellings. We apply our spell checker to three different types of free-text data: clinical notes, allergy entries, and medication orders; and evaluate its performance on both misspelling detection and correction. Our spell checker achieves detection performance of up to 94.4% and correction accuracy of up to 88.2%. We show that high-performance spelling correction is possible on a variety of clinical documents.