Search results for "Semantic"
showing 10 items of 941 documents
Parafoveal versus foveal N400s dissociate spreading activation from contextual fit.
2009
Using concurrent electroencephalogram and eye movement measures to track natural reading, this study shows that N400 effects reflecting predictability are dissociable from those owing to spreading activation. In comparing predicted sentence endings with related and unrelated unpredicted endings in antonym constructions ('the opposite of black is white/yellow/nice'), fixation-related potentials at the critical word revealed a predictability-based N400 effect (unpredicted vs. predicted words). By contrast, event-related potentials time locked to the last fixation before the critical word showed an N400 only for the nonrelated unpredicted condition (nice). This effect is attributed to a parafo…
Pitch accent type affects the N400 during referential processing
2010
Discourse processing depends on semantic memory as well as maintaining and updating of a mental model. Using event-related potentials, we investigated how a referent's information status (new, accessible, given) is processed in combination with three different prosodic realizations (an appropriate accent and two inappropriate accents). The data reveal a biphasic N400-late positivity pattern, indicating that prosodic information affects an early discourse linking stage, during which prominence information reflecting a referent's accessibility is computed (N400), and a later discourse updating stage, during which conflicts between prosodic information and a referent's actual information statu…
Unconscious processing of Arabic numerals in unilateral neglect
2005
This study explores the processing of Arabic numerals in three patients with dense left unilateral neglect. Three tasks have been used: a test of visual awareness (is the stimulus on the left, on the right or on both sides?), a number comparison task (is the number larger or smaller than 5?), a number parity judgment task (is the number odd or even?). The test of visual awareness indicated that all three patients were completely unaware of the stimuli presented in the left hemifield. Despite this, the number comparison and number parity judgment tasks clearly indicated that Arabic numerals were unconsciously processed at semantic level (i.e. quantity). These results show that patients with …
Examining task-dependencies of different attentional processes as reflected in the P3a and reorienting negativity components of the human event-relat…
2005
Abstract Unexpected changes in task-irrelevant auditory stimuli are capable to distract processing of task-relevant visual information. This effect is accompanied by the elicitation of event-related potential (ERP) components associated with attentional orientation, i.e. P3a and reorienting negativity (RON). In the present study we varied the demands of a visual task in order to test whether the RON component – as an index of attentional reorientation after distraction – is confined to a semantic task requiring working memory. In two ERP experiments we applied an auditory-visual distraction paradigm in which subjects were instructed to discriminate visual stimuli preceded by a task-irreleva…
Exploring the relationship between semantics and space
2009
The asymmetric distribution of human spatial attention has been repeatedly documented in both patients and healthy controls. Biases in the distribution of attention and/or in the mental representation of space may also affect some aspects of language processing. We investigated whether biases in attention and/or mental representation of space affect semantic representations. In particular, we investigated whether semantic judgments could be modulated by the location in space where the semantic information was presented and the role of the left and right parietal cortices in this task. Healthy subjects were presented with three pictures arranged horizontally (one middle and two outer picture…
The effects of length and transposed-letter similarity in lexical decision: evidence with beginning, intermediate, and adult readers.
2007
Do length and transposed-letter effects reflect developmental changes on reading acquisition in a transparent orthography? Can computational models of visual word recognition accommodate these changes? To answer these questions, we carried out a masked priming lexical decision experiment with Spanish beginning, intermediate, and adult readers (N=36, 44, and 39; average age: 7, 11, and 22 years, respectively). Target words were either short or long (6.5 vs. 8.5 letters), and transposed-letter primes were formed by the transposition of two letters (e.g. aminal-ANIMAL) or by the substitution of two letters (orthographic control: arisal-ANIMAL). Children showed a robust length effect (i.e. long…
Picture naming yields highly consistent cortical activation patterns: Test–retest reliability of magnetoencephalography recordings
2020
Reliable paradigms and imaging measures of individual-level brain activity are paramount when reaching from group-level research studies to clinical assessment of individual patients. Magnetoencephalography (MEG) provides a direct, non-invasive measure of cortical processing with high spatiotemporal accuracy, and is thus well suited for assessment of functional brain damage in patients with language difficulties. This MEG study aimed to identify, in a delayed picture naming paradigm, source-localized evoked activity and modulations of cortical oscillations that show high test–retest reliability across measurement days in healthy individuals, demonstrating their applicability in clinical set…
Intellectual functioning and memory deficits in schizophrenia
2007
Background: There is converging evidence about the existence of different subgroups of patients with schizophrenia in relation to intellectual ability (intelligence quotient [IQ]). Studying cognitive deficits in such patients in relation to IQ, and more specifically to memory, could help determine the patterns of preserved and impaired functioning in cognitive abilities in association with patterns of preserved and compromised intellect. This information could serve to delimit the possibilities of treatment and rehabilitation in those patients. Methods: A total of 44 patients with schizophrenia completed a cognitive battery that included executive functioning, attention, speed of informatio…
Gesture's body orientation modulates the N400 for visual sentences primed by gestures
2020
Abstract Body orientation of gesture entails social‐communicative intention, and may thus influence how gestures are perceived and comprehended together with auditory speech during face‐to‐face communication. To date, despite the emergence of neuroscientific literature on the role of body orientation on hand action perception, limited studies have directly investigated the role of body orientation in the interaction between gesture and language. To address this research question, we carried out an electroencephalography (EEG) experiment presenting to participants (n = 21) videos of frontal and lateral communicative hand gestures of 5 s (e.g., raising a hand), followed by visually presented …
Blocking by word frequency and neighborhood density in visual word recognition: A task-specific response criteria account
2004
International audience; Effects of blocking words by frequency class (high vs. low) and neighborhood density (high vs. low) were examined in two experiments using progressive demasking and lexical decision tasks. The aim was to examine the predictions of a task-specific response criteria account of list-blocking effects. Distinct patterns of blocking effects were obtained in the two tasks. In the progressive demasking task, a pure-list disadvantage was obtained to low frequency-high density words, whereas high frequency-low density produced a trend toward a pure-list advantage. In lexical decision, high-frequency words showed a pure-list advantage that was strongest in high-density words, w…