scholarly journals Dissociating N400 Effects of Prediction from Association in Single-word Contexts

2013 ◽  
Vol 25 (3) ◽  
pp. 484-502 ◽  
Author(s):  
Ellen F. Lau ◽  
Phillip J. Holcomb ◽  
Gina R. Kuperberg
Keyword(s):  
Semantic Processing ◽  
Semantic Category ◽  
Semantic Content ◽  
Substantial Contribution ◽  
N400 Effect ◽  
Relatedness Proportion ◽  
Memory Representations ◽  
N400 Component ◽  
Associated Prime

When a word is preceded by a supportive context such as a semantically associated word or a strongly constraining sentence frame, the N400 component of the ERP is reduced in amplitude. An ongoing debate is the degree to which this reduction reflects a passive spread of activation across long-term semantic memory representations as opposed to specific predictions about upcoming input. We addressed this question by embedding semantically associated prime–target pairs within an experimental context that encouraged prediction to a greater or lesser degree. The proportion of related items was used to manipulate the predictive validity of the prime for the target while holding semantic association constant. A semantic category probe detection task was used to encourage semantic processing and to preclude the need for a motor response on the trials of interest. A larger N400 reduction to associated targets was observed in the high than the low relatedness proportion condition, consistent with the hypothesis that predictions about upcoming stimuli make a substantial contribution to the N400 effect. We also observed an earlier priming effect (205–240 msec) in the high-proportion condition, which may reflect facilitation because of form-based prediction. In summary, the results suggest that predictability modulates N400 amplitude to a greater degree than the semantic content of the context.

scholarly journals No fruits without color: Cross-modal priming and EEG reveal different roles for different features across semantic categories

PLoS ONE ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. e0234219
Author(s):  
Georgette Argiris ◽  
Raffaella I. Rumiati ◽  
Davide Crepaldi
Keyword(s):  
Semantic Processing ◽  
Fruits And Vegetables ◽  
Event Related Potentials ◽  
Semantic Category ◽  
N400 Effect ◽  
Semantic Categories ◽  
Natural Entities ◽  
Significant Difference ◽  
Related Potentials ◽  
Orientation Feature

Category-specific impairments witnessed in patients with semantic deficits have broadly dissociated into natural and artificial kinds. However, how the category of food (more specifically, fruits and vegetables) fits into this distinction has been difficult to interpret, given a pattern of deficit that has inconsistently mapped onto either kind, despite its intuitive membership to the natural domain. The present study explores the effects of a manipulation of a visual sensory (i.e., color) or functional (i.e., orientation) feature on the consequential semantic processing of fruits and vegetables (and tools, by comparison), first at the behavioral and then at the neural level. The categorization of natural (i.e., fruits/vegetables) and artificial (i.e., utensils) entities was investigated via cross–modal priming. Reaction time analysis indicated a reduction in priming for color-modified natural entities and orientation-modified artificial entities. Standard event-related potentials (ERP) analysis was performed, in addition to linear classification. For natural entities, a N400 effect at central channel sites was observed for the color-modified condition compared relative to normal and orientation conditions, with this difference confirmed by classification analysis. Conversely, there was no significant difference between conditions for the artificial category in either analysis. These findings provide strong evidence that color is an integral property to the categorization of fruits/vegetables, thus substantiating the claim that feature-based processing guides as a function of semantic category.

scholarly journals Characteristics of N400 component elicited in patients who have migraine with aura

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Igor Petrusic ◽  
Vojislav Jovanovic ◽  
Vanja Kovic ◽  
Andrej Savic
Keyword(s):  
Migraine With Aura ◽  
Semantic Processing ◽  
Event Related Potentials ◽  
New Method ◽  
Healthy Controls ◽  
N400 Effect ◽  
Related Potentials ◽  
N400 Component ◽  
The Difference

Abstract Background This study aimed to examine the N400 effect and event-related potentials (ERPs) elicited from congruent and incongruent stimuli in patients who have migraines with aura (MwA). Methods A total of 33 MwA patients and 20 healthy controls (HCs) were studied. They were balanced in age (35.12 ± 8.94 vs 34.70 ± 9.59 years, p = 0.872) and sex (69.7 vs 75.0% females, p = 0.761). ERPs were measured in response to both stimuli, where pictures were preceded with an object name that either matched or mismatched with the object. Averaged amplitudes, peaks, peak latencies, difference waves and topography were compared between MwA and HCs. Results MwA patients had significantly lower averaged amplitudes at the Fz and F4 sites during incongruent stimuli, as well as reduced peaks at the C3 and Pz sites. Topography showed a more widespread N400 effect over scalp relative to HCs. The difference ERP waveforms did not differ in the N400 effect between groups, but the P600 effect was significantly stronger in the HCs group relative to the MwA group at the Pz (6.52 ± 2.57 vs. 3.50 ± 3.15, p = 0.001) and P4 (5.86 ± 2.79 vs. 3.95 ± 3.64, p = 0.040) sites. Conclusions Picture-word matching tasks could serve as a potential new method for the investigation of semantic processing in MwA patients.

Proactive inhibition and semantic organization Relationship with verbal memory in patients with schizophrenia

1996 ◽  
Vol 2 (6) ◽  
pp. 486-493 ◽  
Author(s):  
David A. Kareken ◽  
Paul J. Moberg ◽  
Ruben C. Gur
Keyword(s):  
Verbal Memory ◽  
Semantic Processing ◽  
Verbal Learning ◽  
Semantic Category ◽  
Semantic Content ◽  
Proactive Inhibition ◽  
California Verbal Learning Test ◽  
Retroactive Inhibition ◽  
Intrusion Errors ◽  
Learning Test

AbstractCompared to other cognitive functions in schizophrenia, evidence suggests that verbal memory is particularly impaired. This study used the California Verbal Learning Test (CVLT) to examine proactive inhibition (PI) and semantic processing in verbal memory in 29 patients with schizophrenia and 29 healthy controls. Patients showed significantly less PI, but also did not organize (cluster) their recall according to semantic category. Controls and patients demonstrated small retroactive inhibition (RI) effects regardless of semantic content. Although both groups made similar types and numbers of free recall intrusion errors, patients committed more phonemic and nonshared recognition errors. Results suggest that reduced semantic processing prevented build of PI, and contributes to defective memory in schizophrenia. The anatomic-physiologic abnormalities that underlie these findings may be particularly pronounced in prefrontal and temporal-parietal cortical areas. (JINS, 1996, 2, 486–493.)

Conceptual Processing in Music as Revealed by N400 Effects on Words and Musical Targets

2009 ◽  
Vol 21 (10) ◽  
pp. 1882-1892 ◽  
Author(s):  
Jérôme Daltrozzo ◽  
Daniele Schön
Keyword(s):  
Cognitive Processing ◽  
Semantic Processing ◽  
Linguistic Context ◽  
N400 Effect ◽  
Brain Potentials ◽  
Conceptual Processing ◽  
Electrophysiological Responses ◽  
Musical Excerpts ◽  
N400 Component ◽  
Nature Neuroscience

The cognitive processing of concepts, that is, abstract general ideas, has been mostly studied with language. However, other domains, such as music, can also convey concepts. Koelsch et al. [Koelsch, S., Kasper, E., Sammler, D., Schulze, K., Gunter, T., & Friederici, A. D. Music, language and meaning: Brain signatures of semantic processing. Nature Neuroscience, 7, 302–307, 2004] showed that 10 sec of music can influence the semantic processing of words. However, the length of the musical excerpts did not allow the authors to study the effect of words on musical targets. In this study, we decided to replicate Koelsch et al. findings using 1-sec musical excerpts (Experiment 1). This allowed us to study the reverse influence, namely, of a linguistic context on conceptual processing of musical excerpts (Experiment 2). In both experiments, we recorded behavioral and electrophysiological responses while participants were presented 50 related and 50 unrelated pairs (context/target). Experiments 1 and 2 showed a larger N400 component of the event-related brain potentials to targets following a conceptually unrelated compared to a related context. The presence of an N400 effect with musical targets suggests that music may convey concepts. The relevance of these results for the comprehension of music as a structured set of conceptual units and for the domain specificity of the mechanisms underlying N400 effects are discussed.

scholarly journals No fruits without color: Cross-modal priming and EEG reveal different roles for different features across semantic categories

2020 ◽  
Author(s):  
Georgette Argiris ◽  
Raffaella I. Rumiati ◽  
Davide Crepaldi
Keyword(s):  
Semantic Processing ◽  
Fruits And Vegetables ◽  
Event Related Potentials ◽  
Semantic Category ◽  
N400 Effect ◽  
Semantic Categories ◽  
Natural Entities ◽  
Significant Difference ◽  
Related Potentials ◽  
Orientation Feature

AbstractCategory-specific impairments witnessed in patients with semantic deficits have broadly dissociated into natural and artificial kinds. However, how the category of food (more specifically, fruits and vegetables) fits into this distinction has been difficult to interpret, given a pattern of deficit that has inconsistently mapped onto either kind, despite its intuitive membership to the natural domain. The present study explores the effects of a manipulation of a visual sensory (i.e., color) or functional (i.e., orientation) feature on the consequential semantic processing of fruits and vegetables (and tools, by comparison), first at the behavioral and then at the neural level. The categorization of natural (i.e., fruits/vegetables) and artificial (i.e., utensils) entities was investigated via cross–modal priming. Reaction time analysis indicated a reduction in priming for color-modified natural entities and orientation-modified artificial entities. Standard event-related potentials (ERP) analysis was performed, in addition to linear classification. For natural entities, a N400 effect at central channel sites was observed for the color-modified condition compared relative to normal and orientation conditions, with this difference confirmed by classification analysis. Conversely, there was no significant difference between conditions for the artificial category in either analysis. These findings provide strong evidence that color is an integral property to the categorization of fruits/vegetables, thus substantiating the claim that feature-based processing guides as a function of semantic category.

scholarly journals Semantic Processing Impairment in Patients with Temporal Lobe Epilepsy

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Amanda G. Jaimes-Bautista ◽  
Mario Rodríguez-Camacho ◽  
Iris E. Martínez-Juárez ◽  
Yaneth Rodríguez-Agudelo
Keyword(s):  
Episodic Memory ◽  
Temporal Lobe Epilepsy ◽  
Temporal Lobe ◽  
Semantic Processing ◽  
Functional Neuroimaging ◽  
Declarative Memory ◽  
Semantic Networks ◽  
N400 Effect ◽  
Functional Reorganization ◽  
Electrophysiological Studies

The impairment in episodic memory system is the best-known cognitive deficit in patients with temporal lobe epilepsy (TLE). Recent studies have shown evidence of semantic disorders, but they have been less studied than episodic memory. The semantic dysfunction in TLE has various cognitive manifestations, such as the presence of language disorders characterized by defects in naming, verbal fluency, or remote semantic information retrieval, which affects the ability of patients to interact with their surroundings. This paper is a review of recent research about the consequences of TLE on semantic processing, considering neuropsychological, electrophysiological, and neuroimaging findings, as well as the functional role of the hippocampus in semantic processing. The evidence from these studies shows disturbance of semantic memory in patients with TLE and supports the theory of declarative memory of the hippocampus. Functional neuroimaging studies show an inefficient compensatory functional reorganization of semantic networks and electrophysiological studies show a lack of N400 effect that could indicate that the deficit in semantic processing in patients with TLE could be due to a failure in the mechanisms of automatic access to lexicon.

scholarly journals Are all code-switches processed the same? Examining semantic v. language unexpectancy

2020 ◽  
Author(s):  
Jorge Valdés Kroff ◽  
Patricia Roman ◽  
Paola E. Dussias
Keyword(s):  
Semantic Processing ◽  
Time Window ◽  
Time Windows ◽  
Target Population ◽  
Code Switching ◽  
Event Related Potential ◽  
N400 Effect ◽  
Online Processing ◽  
Sentence Level ◽  
Main Effect

Prior studies using the event-related potential (ERP) technique show that integrating sentential code-switches in online processing lead to a broadly distributed late positivity component while processing semantically unexpected continuations instead lead to the emergence of an N400 effect. While the N400 is generally assumed to index lexico-semantic processing, the LPC has two different interpretations. One account suggests that it reflects the processing of an improbable or unexpected event while an alternative account proposes sentence-level reanalysis. To investigate the relative costs of semantic to language-based unexpectancies (i.e., code-switches), the current study tests 24 Spanish-English bilinguals in an ERP reading study. Semantically constrained Spanish frames either varied in their semantic expectancy (high vs low expectancy) and/or their language continuation (same language vs code-switch) while participants’ electrophysiological responses were recorded. The Spanish-to-English switch direction provides a more naturalistic test for integration costs to code-switching as it better approximates the code-switching practices of the target population. Analyses across three time windows show a main effect for semantic expectancy in the N400 time window and a main effect for code-switching in the LPC time window. Additional analyses based on the self-reported code-switching experience of the participants suggested an early positivity linked to less experience with code-switching. The results suggest that not all code-switches lead to similar integration costs and that prior experience with code-switching is an important additional factor that modulates online processing.

Lipolysis and glycerol gluconeogenesis in simultaneously fasting and lactating northern elephant seals

2007 ◽  
Vol 293 (6) ◽  
pp. R2376-R2381 ◽  
Author(s):  
Dorian S. Houser ◽  
Cory D. Champagne ◽  
Daniel E. Crocker
Keyword(s):  
Adult Female ◽  
Glucose Production ◽  
Endogenous Glucose Production ◽  
High Rate ◽  
Constant Infusion ◽  
Substantial Contribution ◽  
Fasting Period ◽  
Elephant Seals ◽  
Glucoregulatory Hormones

Adult female elephant seals ( Mirounga angustirostris) combine long-term fasting with lactation and molting. Glycerol gluconeogenesis has been hypothesized as potentially meeting all of the glucose requirements of the seals during these fasts. To test this hypothesis, a primed constant infusion of [2-14C]glycerol was administered to 10 ten adult female elephant seals at 5 and 21–22 days postpartum and to 10 additional adult females immediately after the molt. Glycerol kinetics, rates of lipolysis, and the contribution of glycerol to glucose production were determined for each period. Plasma metabolite levels as well as insulin, glucagon, and cortisol were also measured. Glycerol rate of appearance was not significantly correlated with mass ( P = 0.14, r2 = 0.33) but was significantly related to the percentage of glucose derived from glycerol ( P < 0.01, r2 = 0.81) during late lactation. The contribution of glycerol to glucose production was <3% during each fasting period, suggesting a lower contribution to gluconeogenesis than is observed in other long-term fasting mammals. Because of a high rate of endogenous glucose production in fasting elephant seals, it is likely that glycerol gluconeogenesis still makes a substantial contribution to the substrate needs of glucose-dependent tissues. The lack of a relationship between glucoregulatory hormones and glycerol kinetics, glycerol gluconeogenesis, and metabolites supports the proposition that fasting elephant seals do not conform to the traditional insulin-glucagon model of substrate metabolism.

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