scholarly journals Emerging Neurophysiological Specialization for Letter Strings

2005 ◽  
Vol 17 (10) ◽  
pp. 1532-1552 ◽  
Author(s):  
Urs Maurer ◽  
Silvia Brem ◽  
Kerstin Bucher ◽  
Daniel Brandeis

In adult readers, printed words and other letter strings activate specialized visual functions within 200 msec, as evident from neurophysiological recordings of brain activity. These fast, specialized responses to letter strings are thought to develop through plastic changes in the visual system. However, it is unknown whether this specialization emerges only with the onset of word reading, or represents a precursor of literacy. We compared 6-year-old kindergarten children who could not yet read words to adult readers. Both age groups detected immediate repetitions of visually presented words, pseudo-words, symbol strings, and pictures during event-related potential (ERP) mapping. Maps from seven corresponding ERP segments in children and adults were analyzed regarding fast (<250 msec) and slow (>300 msec) specialization for letter strings. Adults reliably differentiated words through increased fast (<150 msec) occipito-temporal N1 activity from symbols. Children showed a later, more mid-occipital N1 with marginal word-symbol differences, which were absent in those children with low letter knowledge. Children with high letter knowledge showed some fast sensitivity to letter strings, which was confined to right occipito-temporal sites, unlike the stronger adult N1 specialization. This suggests that a critical degree of early literacy induces some immature, but fast, specialization for letter strings before word reading becomes possible. Children also differentiated words from symbols in later segments through increased right occipito-temporal negativity for words. This slow specialization for letter strings was not modulated by letter knowledge and was absent in adults, possibly reflecting a visual precursor of literacy due to visual familiarity with letter strings.

2021 ◽  
Author(s):  
Rohan Saha ◽  
Jennifer Campbell ◽  
Janet F. Werker ◽  
Alona Fyshe

Infants start developing rudimentary language skills and can start understanding simple words well before their first birthday. This development has also been shown primarily using Event Related Potential (ERP) techniques to find evidence of word comprehension in the infant brain. While these works validate the presence of semantic representations of words (word meaning) in infants, they do not tell us about the mental processes involved in the manifestation of these semantic representations or the content of the representations. To this end, we use a decoding approach where we employ machine learning techniques on Electroencephalography (EEG) data to predict the semantic representations of words found in the brain activity of infants. We perform multiple analyses to explore word semantic representations in two groups of infants (9-month-old and 12-month-old). Our analyses show significantly above chance decodability of overall word semantics, word animacy, and word phonetics. As we analyze brain activity, we observe that participants in both age groups show signs of word comprehension immediately after word onset, marked by our model's significantly above chance word prediction accuracy. We also observed strong neural representations of word phonetics in the brain data for both age groups, some likely correlated to word decoding accuracy and others not. Lastly, we discover that the neural representations of word semantics are similar in both infant age groups. Our results on word semantics, phonetics, and animacy decodability, give us insights into the evolution of neural representation of word meaning in infants.


2011 ◽  
Vol 44 (6) ◽  
pp. 543-555 ◽  
Author(s):  
Julie A. Wolter ◽  
Trisha Self ◽  
Kenn Apel

The purpose of this study was to examine the relation between the ability to quickly acquire initial mental graphemic representations (MGRs) in kindergarten and fourth grade literacy skills in children with typical language (TL) and children with language impairment (LI). The study is a longitudinal extension of a study conducted by Wolter and Apel in which kindergarten children with LI and TL were administered early literacy measures as well as a novel written pseudoword task of MGR learning (spelling and identification of target pseudowords). In the current study (4 years later), the authors administered reading and spelling measures to 37 of the original 45 children (18 children with LI, 19 children with TL). The children with LI performed significantly lower than their peers with TL on all fourth grade literacy measures. For both groups, kindergarten initial MGR acquisition ability significantly related to fourth grade real-word reading and spelling. For the children with LI, kindergarten initial MGR acquisition ability also related to fourth grade pseudoword decoding and reading comprehension. Collectively, the findings suggest that initial MGR learning in kindergarten is an essential skill that may uniquely relate to later literacy abilities.


Author(s):  
Yu. E. Moskalenko ◽  
T. I. Kravchenko ◽  
Yu. V. Novozhilova

Introduction. Slow fl uctuations in the volume and pressure of liquids in the cranial cavity have been known for a long time and have been studied for more than 100 years. However, their quantitative indicators and their practical signifi cance remain unclear until now due to the diffi culties of research. Nevertheless, it was found that they were connected with the brain activity, which made it possible to use them as one of the physiological indicators in studying the problems of manned space fl ights. Goal of research — to study the possibility of using spectral analysis of slow fl uctuations of the volume of liquids inside the cranium in order to realize the quantitative assessment of their indicators with the use of modern microelectronics and computer technology.Materials and methods. In order to solve this problem we created a complex, in which rheoencephalograph-RG-01 («Mizar») was used as a converter-modulator of physiological signals into electrical oscillations. The device was connected with the ADC (Firm «ADIstrument»), Its software allows to calculate the spectrogram with a sampling rate of 128 kHz. Studies were conducted on volunteers of younger, middle and older age groups. The respiratory rate and the electrocardiography were registered together with the rheoencephalography. Electrodes were fi xed on the volonteers′ fronto-mastoid area.Results. Slow fl uctuations the cranium representan independent physiological phenomenon. The most considerable and valuable were fl uctuations in 0,1–0,3 Hz. It was found that current frequency of 100 or 200 kHz and frequency for quantization of 80–100 kHz was optimal for performing their spectrograms. The structure of such diagram consists of 4–7 peaks with amplitude of 0,4–0,7 units compared with REG pulse amplitude. They depend on age and are characterized by hemispheric asymmetry. Spectral diagrams of slow fl ucation inside cranium are representing inpendent physiological phenomenon. These fl uctuations are not connected by common origin, with heart activity and respiration. They are connected by nature with brain activity and PRM.Conclusion. Can be an informative method for diagnostic and assessment of general status of osteopathic patients well as for the assessment of mechanisms of action of some osteopathic techniques.


2000 ◽  
Vol 12 (4) ◽  
pp. 622-634 ◽  
Author(s):  
Matti Laine ◽  
Riitta Salmelin ◽  
Päivi Helenius ◽  
Reijo Marttila

Magnetoencephalographic (MEG) changes in cortical activity were studied in a chronic Finnish-speaking deep dyslexic patient during single-word and sentence reading. It has been hypothesized that in deep dyslexia, written word recognition and its lexical-semantic analysis are subserved by the intact right hemisphere. However, in our patient, as well as in most nonimpaired readers, lexical-semantic processing as measured by sentence-final semantic-incongruency detection was related to the left superior-temporal cortex activation. Activations around this same cortical area could be identified in single-word reading as well. Another factor relevant to deep dyslexic reading, the morphological complexity of the presented words, was also studied. The effect of morphology was observed only during the preparation for oral output. By performing repeated recordings 1 year apart, we were able to document significant variability in both the spontaneous activity and the evoked responses in the lesioned left hemisphere even though at the behavioural level, the patient's performance was stable. The observed variability emphasizes the importance of estimating consistency of brain activity both within and between measurements in brain-damaged individuals.


2008 ◽  
Vol 01 (02) ◽  
pp. 195-206 ◽  
Author(s):  
TING LI ◽  
LI LI ◽  
PENG DU ◽  
QINGMING LUO ◽  
HUI GONG

Compared with event-related potential (ERP) which is widely used in psychology research, functional near-infrared imaging (fNIRI) is a new technique providing hemodynamic information related to brain activity, except for electrophysiological signals. Here, we use both these techniques to study ocular attention. We conducted a series of experiments with a classic paradigm of ocular nonselective attention, and monitored responses with fNIRI and ERP respectively. The results showed that fNIRI measured brain activations in the left prefrontal lobe, while ERPs showed activation in frontal lobe. More importantly, only with the combination measurements of fNIRI and ERP, we were then able to find the pinpoint source of ocular nonselective attention, which is in the left and upper corner in Brodmann area 10. These results demonstrated that fNIRI is a reliable technique in psychology, and the combination of fNIRI and ERP can be promising to reveal more information in the research of brain mechanism.


1984 ◽  
Vol 54 (3) ◽  
pp. 795-801 ◽  
Author(s):  
David M. Blaske

Sex-typing of occupations and its antecedent elements have been investigated using different methods across a variety of age groups. Exp. 1 utilized a memory test as its principal criterion, along with a job-preference question to investigate sex-typing in fourth-grade children. On the memory test the mean numbers of sex-typing errors were significantly different; the subjects presenting traditional sex-typed pairings committed far fewer sex-typing errors. The job-preference question also disclosed sex-typed beliefs pertaining to occupational aspirations. The method in Exp. 2 required 66 kindergarten children to supply names to stick figures performing traditional male and female occupations in each of 10 picture cards. A significant number of sex-typed responses were given. Girls were more sex-typed than boys, traditional male occupations were more sex-typed than traditional female occupations, and boys were less sex-typed when their mothers were employed.


1999 ◽  
Vol 20 (2) ◽  
pp. 167-190 ◽  
Author(s):  
DEBORAH L. SPEECE ◽  
FROMA P. ROTH ◽  
DAVID H. COOPER ◽  
SUSAN DE LA PAZ

This study examined relationships between oral language and literacy in a two-year, multivariate design. Through empirical cluster analysis of a sample of 88 kindergarten children, four oral language subtypes were identified based on measures of semantics, syntax, metalinguistics, and oral narration. Validation efforts included (a) concurrent and predictive analyses of subtype differences on reading, spelling, and listening comprehension measures based on a priori hypotheses and (b) a comparison of the teacher classification of the children with the empirical classification. The subtypes represented high average, low average, high narrative, and low overall patterns of oral language skill. The high average subtype received the most consistent evidence for validation. The pattern of validation results indicates that the relationship between oral language and literacy is not uniform and suggests a modification of the assumption that oral language skills have a direct role in reading acquisition.


2020 ◽  
Author(s):  
Emily S. Kappenman ◽  
Jaclyn Farrens ◽  
Wendy Zhang ◽  
Andrew X Stewart ◽  
Steven J Luck

Event-related potentials (ERPs) are noninvasive measures of human brain activity that index a range of sensory, cognitive, affective, and motor processes. Despite their broad application across basic and clinical research, there is little standardization of ERP paradigms and analysis protocols across studies. To address this, we created ERP CORE (Compendium of Open Resources and Experiments), a set of optimized paradigms, experiment control scripts, data processing pipelines, and sample data (N = 40 neurotypical young adults) for seven widely used ERP components: N170, mismatch negativity (MMN), N2pc, N400, P3, lateralized readiness potential (LRP), and error-related negativity (ERN). This resource makes it possible for researchers to 1) employ standardized ERP paradigms in their research, 2) apply carefully designed analysis pipelines and use a priori selected parameters for data processing, 3) rigorously assess the quality of their data, and 4) test new analytic techniques with standardized data from a wide range of paradigms.


2020 ◽  
Author(s):  
Robin Hellerstedt ◽  
Arianna Moccia ◽  
Chloe M. Brunskill ◽  
Howard Bowman ◽  
Zara M. Bergström

AbstractERP-based forensic memory detection is based on the logic that guilty suspects will hold incriminating knowledge about crimes they have committed, and therefore should show parietal ERP positivities related to recognition when presented with reminders of their crimes. We predicted that such forensic memory detection might however be inaccurate in older adults, because of changes to recognition-related brain activity that occurs with aging. We measured both ERPs and EEG oscillations associated with episodic old/new recognition and forensic memory detection in 30 younger (age < 30) and 30 older (age > 65) adults. EEG oscillations were included as a complementary measure which is less sensitive to temporal variability and component overlap than ERPs. In line with predictions, recognition-related parietal ERP positivities were significantly reduced in the older compared to younger group in both tasks, despite highly similar behavioural performance. We also observed ageing-related reductions in oscillatory markers of recognition in the forensic memory detection test, while the oscillatory effects associated with episodic recognition were similar across age groups. This pattern of results suggests that while both forensic memory detection and episodic recognition are accompanied by ageing-induced reductions in parietal ERP positivities, these reductions may be caused by non-overlapping mechanisms across the two tasks. Our findings suggest that EEG-based forensic memory detection tests are invalid in older populations, limiting their practical applications.


Sign in / Sign up

Export Citation Format

Share Document