Orthographic recognition in late adolescents: An assessment through event-related brain potentials

Reading speed and efficiency are achieved through the automatic recognition of written words. Difficulties in learning and recognizing the orthography of words can arise despite reiterative exposure to texts. This study aimed to investigate, in native Spanish-speaking late adolescents, how different levels of orthographic knowledge might result in behavioral and event-related brain potential differences during the recognition of orthographic errors. Forty-five healthy high school students were selected and divided into 3 equal groups (High, Medium, Low) according to their performance on a 5-test battery of orthographic knowledge. All participants performed an orthographic recognition task consisting of the sequential presentation of a picture (object, fruit, or animal) followed by a correctly, or incorrectly, written word (orthographic mismatch) that named the picture just shown. Electroencephalogram (EEG) recording took place simultaneously. Behavioral results showed that the Low group had a significantly lower number of correct responses and increased reaction times while processing orthographical errors. Tests showed significant positive correlations between higher performance on the experimental task and faster and more accurate reading. The P150 and P450 components showed higher voltages in the High group when processing orthographic errors, whereas N170 seemed less lateralized to the left hemisphere in the lower orthographic performers. Also, trials with orthographic errors elicited a frontal P450 component that was only evident in the High group. The present results show that higher levels of orthographic knowledge correlate with high reading performance, likely because of faster and more accurate perceptual processing, better visual orthographic representations, and top-down supervision, as the event-related brain potential findings seem to suggest. © EEG and Clinical Neuroscience Society (ECNS) 2013

Oscillations in controlled processes: Two experimental study cases

Reading speed and efficiency are achieved through the automatic recognition of written words. Difficulties in learning and recognizing the orthography of words can arise despite reiterative exposure to texts. This study aimed to investigate, in native Spanish-speaking late adolescents, how different levels of orthographic knowledge might result in behavioral and event-related brain potential differences during the recognition of orthographic errors. Forty-five healthy high school students were selected and divided into 3 equal groups (High, Medium, Low) according to their performance on a 5-test battery of orthographic knowledge. All participants performed an orthographic recognition task consisting of the sequential presentation of a picture (object, fruit, or animal) followed by a correctly, or incorrectly, written word (orthographic mismatch) that named the picture just shown. Electroencephalogram (EEG) recording took place simultaneously. Behavioral results showed that the Low group had a significantly lower number of correct responses and increased reaction times while processing orthographical errors. Tests showed significant positive correlations between higher performance on the experimental task and faster and more accurate reading. The P150 and P450 components showed higher voltages in the High group when processing orthographic errors, whereas N170 seemed less lateralized to the left hemisphere in the lower orthographic performers. Also, trials with orthographic errors elicited a frontal P450 component that was only evident in the High group. The present results show that higher levels of orthographic knowledge correlate with high reading performance, likely because of faster and more accurate perceptual processing, better visual orthographic representations, and top-down supervision, as the event-related brain potential findings seem to suggest. " EEG and Clinical Neuroscience Society (ECNS) 2013.",,,,,,"10.1177/1550059413489975",,,"http://hdl.handle.net/20.500.12104/43431","http://www.scopus.com/inward/record.url?eid=2-s2.0-84899031481&partnerID=40&md5=aa569abc0bb64f1a92dccef59efff58

Evaluation of chemical parameters in soft mold-ripened cheese during ripening by mid-infrared spectroscopy

Three inverse serial digit detection tasks were evaluated with event-related brain potentials (ERPs) in 15 II-year-old children to determine how the increase of perceptual or memory demands could modify detection processing. Reaction times were significantly longer for the task that used visual blurring, compared to that with a greater memory demand. Difference-ERPs (target minus non-target conditions) showed three significant parietal components; one earlier positive peak at 162 ms interpreted as an index of working memory load; a same polarity 295 ms peak which probably represents a P3 analogous and a subsequent negative polarity component (520ms) possibly involved with motor preparation. A fourth difference-component was a frontal positive peak at 680 ms, interpreted as related to task difficulty. "2001 Lippincott Williams & Wilkins.",,,,,,,,,"http://hdl.handle.net/20.500.12104/41357","http://www.scopus.com/inward/record.url?eid=2-s2.0-0035800229&partnerID=40&md5=bf9d473a31cedb62081fc46b39ddfd3f",,,,,,"9",,"NeuroReport",,"199

Event-related brain potentials in normal children during detection of inverse serial digits

Three inverse serial digit detection tasks were evaluated with event-related brain potentials (ERPs) in 15 II-year-old children to determine how the increase of perceptual or memory demands could modify detection processing. Reaction times were significantly longer for the task that used visual blurring, compared to that with a greater memory demand. Difference-ERPs (target minus non-target conditions) showed three significant parietal components; one earlier positive peak at 162 ms interpreted as an index of working memory load; a same polarity 295 ms peak which probably represents a P3 analogous and a subsequent negative polarity component (520ms) possibly involved with motor preparation. A fourth difference-component was a frontal positive peak at 680 ms, interpreted as related to task difficulty. ©2001 Lippincott Williams & Wilkins

Visual processing in a facial emotional context: An ERP study

Facial emotional processing can be bypassed when faces are task-irrelevant and attention is diverted, although this effect has not been examined when cognitive task occurs within a facial background. Event-related potential (ERP) measures were obtained to evaluate the influence of different irrelevant facial emotional contexts on a simultaneous "ear-size" detection task performance in five processing contexts: (1) neutral face, (2) happy face, (3) fearful face, (4) facial contour, and (5) non-facial context. Reaction times were longer when visual processing occurred in a facial context, regardless of its emotional content. The context of neutral faces also demonstrated a lower number of correct responses, with fewer incorrect responses found during the presentation of fearful faces compared to the neutral facial context. ERP morphology was similar across all conditions, but ERP amplitude from components for the non-facial context was larger than that of the alternative conditions from 100 to 300\ua0ms, with a similar N170-like potential also observed. The findings suggest that simultaneous irrelevant emotional facial stimuli may affect cognitive processing by altering two temporarily overlapped neural mechanisms: one responsible for earlier face detection, and the other involved in emotional recognition. The first might delay simultaneous cognitive actions by diverting attention, whereas while the latter may enhance the availability of processing resources through the participation of a subcortical pathway. © 2008 Elsevier B.V. All rights reserved

Event-related brain potentials in reading disabled children during an inverse serial digit detection task

It has been reported that limitations in different components of working memory could underlie reading disabilities. In addition, reading-disabled (RD) children seem to perform worse when digit name processing is required. With the purpose to explore further these assumptions one inverse serial digit detection task was evaluated using event-related brain potentials in fifteen 8-year-old RD children and a control group (CG). CG obtained significantly more correct responses than RD, but had similar reaction times. The experimental task performance significantly correlated with the performance on reading tests. Difference event-related potentials showed a voltage component peaking at 160 ms over frontocentral leads (P160d) that reached significantly higher amplitude in RD group, and was interpreted as an index of the amount of neural resources involved in visual working memory load. The amplitude of P160d significantly correlated with reading speed, the backward digit span and with the experimental task performance. Present results point out that highly demanding working memory tasks reveal behavioral and electrophysiological differences in RD children with respect to healthy controls

Vegetative, reproductive, and physiological Adaptations to aridity of pitayo (Stenocereus queretaroensis, Cactaceae)

Facial emotional processing can be bypassed when faces are task-irrelevant and attention is diverted, although this effect has not been examined when cognitive task occurs within a facial background. Event-related potential (ERP) measures were obtained to evaluate the influence of different irrelevant facial emotional contexts on a simultaneous "ear-size" detection task performance in five processing contexts: (1) neutral face, (2) happy face, (3) fearful face, (4) facial contour, and (5) non-facial context. Reaction times were longer when visual processing occurred in a facial context, regardless of its emotional content. The context of neutral faces also demonstrated a lower number of correct responses, with fewer incorrect responses found during the presentation of fearful faces compared to the neutral facial context. ERP morphology was similar across all conditions, but ERP amplitude from components for the non-facial context was larger than that of the alternative conditions from 100 to 300 ms, with a similar N170-like potential also observed. The findings suggest that simultaneous irrelevant emotional facial stimuli may affect cognitive processing by altering two temporarily overlapped neural mechanisms: one responsible for earlier face detection, and the other involved in emotional recognition. The first might delay simultaneous cognitive actions by diverting attention, whereas while the latter may enhance the availability of processing resources through the participation of a subcortical pathway. " 2008 Elsevier B.V. All rights reserved.",,,,,,"10.1016/j.ijpsycho.2008.07.017",,,"http://hdl.handle.net/20.500.12104/45694","http://www.scopus.com/inward/record.url?eid=2-s2.0-58149288258&partnerID=40&md5=b1419f8ab38aa0fa7fbb300e1ea3d30

Quantitative electroencephalogram analysis confirms the presence of frontal lobe deficit among children with attention deficit hyperactivity disorder [Análisis cuantitativo del electroencefalograma para confirmar trastorno funcional frontal en niños con trastorno por déficit de atención con hiperactividad]

Backgroud: The Attention Deficit Disorder with Hyperactivity (ADDH) Barkley model predicts concomitant deficits in working memory and in the development of a sense of time as a consequence of poor behavioral inhibition. Objective: To evaluate electrophysiologically Barkley's theory (1997). Subjects and methods: We studied the electroencephalogram (EEG) of fifteen right-handed, normal limit IQ ADDH children (inattentive subtype), aged 7-11 years, and a control group. Subjects were studied at rest, with the eyes open (RO) while performing a time estimation task (ET). Forty-two data matrices were analyzed in three conditions: RO, ET and ET-RO, to assess broad-band spectral parameters; the anteriority, temporal-referenced and laterality quotients (Aq, Aqt and Lq, respectively); and the theta/alpha and theta/beta ratios. Results: Analyses of variance revealed significant differences for ES-RA, in absolute (Aq & Aqt) and relative powers (Aq). Discriminant function analysis was able to predict group membership with an accuracy over 80%, but it decreased slightly when the leave-oneout method was applied. Linear discrimination based on right hemisphere Aqt values showed the highest discrimination accuracy. Conclusions: These results support Barkley's theory, suggesting further evaluation of the temporal-referenced anteriority quotient as a promising electrophysiological tool for the diagnosis and follow up of ADDH children

Quantitative electroencephalogram analysis confirms the presence of frontal lobe deficit among children with attention deficit hyperactivity disorder [Análisis cuantitativo del electroencefalograma para confirmar trastorno funcional frontal en niños con trastorno por déficit de atención con hiperactividad]

Backgroud: The Attention Deficit Disorder with Hyperactivity (ADDH) Barkley model predicts concomitant deficits in working memory and in the development of a sense of time as a consequence of poor behavioral inhibition. Objective: To evaluate electrophysiologically Barkley's theory (1997). Subjects and methods: We studied the electroencephalogram (EEG) of fifteen right-handed, normal limit IQ ADDH children (inattentive subtype), aged 7-11 years, and a control group. Subjects were studied at rest, with the eyes open (RO) while performing a time estimation task (ET). Forty-two data matrices were analyzed in three conditions: RO, ET and ET-RO, to assess broad-band spectral parameters; the anteriority, temporal-referenced and laterality quotients (Aq, Aqt and Lq, respectively); and the theta/alpha and theta/beta ratios. Results: Analyses of variance revealed significant differences for ES-RA, in absolute (Aq & Aqt) and relative powers (Aq). Discriminant function analysis was able to predict group membership with an accuracy over 80%, but it decreased slightly when the leave-oneout method was applied. Linear discrimination based on right hemisphere Aqt values showed the highest discrimination accuracy. Conclusions: These results support Barkley's theory, suggesting further evaluation of the temporal-referenced anteriority quotient as a promising electrophysiological tool for the diagnosis and follow up of ADDH children

Emotional content of stimuli improves visuospatial working memory

Processing and storage in visuospatial working memory (VSWM) seem to depend on attention-based mechanisms. In order to explore the effect of attention-attractive stimuli, such as emotional faces on VSWM performance, ERPs were obtained from 20 young adults while reproducing spatial sequences of six facial (happy and neutral) and non-facial control stimuli in inverse order. Behavioral performances revealed that trials with happy facial expressions resulted in a significantly higher amount of correct responses. For positive emotional facial stimuli, N170 amplitude was higher over right temporo-parietal regions, while P2 amplitude was higher over frontal and lower over parietal regions. In addition, LPP amplitude was also significantly higher for this type of stimuli. Both behavioral and electrophysiological results support the notion of the domain-general attention-based mechanism of VSWM maintenance, in which spatial to-be-remembered locations might be influenced by the emotional content of the stimuli. © 2014 Elsevier Ireland Ltd