The Experts below are selected from a list of 25269144 Experts worldwide ranked by ideXlab platform
Kara D. Federmeier - One of the best experts on this subject based on the ideXlab platform.
-
hemispheric differences in orthographic and semantic processing as revealed by event related potentials
Neuropsychologia, 2014Co-Authors: Danielle S Dickson, Kara D. FedermeierAbstract:Differences in how the right and left hemispheres (RH, LH) apprehend visual words were examined using event-related potentials (ERPs) in a repetition paradigm with visual half-field (VF) presentation. In both hemispheres (RH/LVF, LH/RVF), initial presentation of items elicited similar and typical effects of orthographic neighborhood size, with larger N400s for orthographically regular items (words and pseudowords) than for irregular items (acronyms and meaningless illegal strings). However, hemispheric differences emerged on repetition effects. When items were repeated in the LH/RVF, orthographically regular items, relative to irregular items, elicited larger repetition effects on both the N250, a component reflecting processing at the level of visual form (orthography), and on the N400, which has been linked to semantic access. In contrast, in the RH/LVF, repetition effects were biased toward irregular items on the N250 and were similar in size across item types for the N400. The results suggest that processing in the LH is more strongly affected by wordform regularity than in the RH, either due to enhanced processing of familiar orthographic patterns or due to the fact that regular forms can be more readily mapped onto phonology.
-
fN400 potentials are functionally identical to N400 potentials and reflect semantic processing during recognition testing
Psychophysiology, 2011Co-Authors: Joel L Voss, Kara D. FedermeierAbstract:The "F" in FN400 denotes a more frontal scalp distribution relative to the morphologically similar N400 component-a distinction consistent with the hypothesized distinct roles of FN400 in familiarity memory versus N400 in language. However, no direct comparisons have substantiated these assumed dissimilarities. To this end, we manipulated short-term semantic priming during a recognition test. Semantic priming effects on N400 were indistinguishable from memory effects at the same latency, and semantic priming strongly modulated the "FN400," despite having no influence on familiarity memory. Thus, no evidence suggested either electrophysiological or functional differences between the N400 and FN400, and findings were contrary to the linking of the "FN400" to familiarity. Instead, it appears that semantic/conceptual priming (reflected in the N400) occurs during recognition tests and is frequently (mis)labeled as FN400 and attributed to familiarity.
-
fN400 potentials are functionally identical to N400 potentials and reflect semantic processing during recognition testing
Psychophysiology, 2011Co-Authors: Joel L Voss, Kara D. FedermeierAbstract:AbstractThe ‘‘F’’ in FN400 denotes a more frontal scalp distribution relative to the morphologically similar N400 compo-nentFa distinction consistent with the hypothesized distinct roles of FN400 in familiarity memory versus N400 inlanguage. However, no direct comparisons have substantiated these assumed dissimilarities. To this end, we manip-ulatedshort-termsemanticprimingduringarecognitiontest.SemanticprimingeffectsonN400wereindistinguishablefrom memory effects at the same latency, and semantic priming strongly modulated the ‘‘FN400,’’ despite having noinfluence on familiarity memory. Thus, no evidence suggested either electrophysiological or functional differencesbetween the N400 and FN400, and findings were contrary to the linking of the ‘‘FN400’’ to familiarity. Instead, itappears that semantic/conceptual priming (reflected in the N400) occurs during recognition tests and is frequently(mis)labeled as FN400 and attributed to familiarity.Descriptors: Learning/memory, Language/speech, Normal volunteers, EEG/ERPFamiliarity and recollection are two hypothesized processes thatcontributetoperformanceintestsofrecognitionmemory(Man-dler, 1980; Yonelinas, 2002). Many investigators interpret twodistinct ERP effects obtained during recognition tests as uniqueneural correlates of familiarity and recollection: FN400 old/neweffects and late-parietal old/new effects, respectively (Mecklin-ger, 2000; Paller, Voss, & Boehm, 2007; Rugg & Curran, 2007).The validity of these hypothesized associations is of substantialtheoretical importance. For instance, the dissociation betweenthe FN400 and late-parietal ERPs has been widely taken as re-ification of the constructs of familiarity and recollection and,thus, as justification for launching more detailed neuroanatom-ical studies of these hypothesized processes (e.g., Eichenbaum,Yonelinas, & Ranganath, 2007). Moreover, investigators in-creasingly cite the strength of associations between the FN400and familiarity and late-parietal potentials and recollectionas justification to infer the involvement of familiarity and/orrecollection whenever these potentials are identified, that is,make reverse inferences of familiarity and recollection based onFN400 and late-parietal potentials (e.g., Czernochowski, Meck-linger,JEcker,Arend,Bergstrom,Z Klonek, Tamm, Hofmann, & Jacobs, 2009; Mecklinger,Brunnemann, & Kipp, 2010; Nyhus & Curran, 2009; Opitz C Speer & Curran, 2007).However, as we review below, recent work has called intoquestion the mapping between the FN400 and familiarity andhas suggested that the FN400 may not be different from theN400 component. The N400 has been characterized primarilywithin the domain of language comprehension, but also morebroadly, and has been linked to implicit semantic access pro-cesses. The FN400 bears striking similarity to the N400 in mor-phology, timing, and response pattern; indeed, effects that arenow referred to as FN400s were originally characterized asN400s in the early literature looking at cognitive electrophysi-ologicalresponsesinmemoryparadigms.Yet,toourknowledge,no empirical work has attempted to elicit both responses in tan-dem to directly compare them. We therefore set out to answerfundamental and yet untested questions regarding FN400potentials: Are they in fact N400 potentials present during rec-ognitiontests, andare they related tosemanticprocessing ratherthan to familiarity?The N400 component was first characterized by Kutas andHillyard (1980), who found larger negative ERP amplitudes tounexpected relative to expected words completing sentences.
-
thirty years and counting finding meaning in the N400 component of the event related brain potential erp
Annual Review of Psychology, 2011Co-Authors: Marta Kutas, Kara D. FedermeierAbstract:We review the discovery, characterization, and evolving use of the N400, an event-related brain potential response linked to meaning processing. We describe the elicitation of N400s by an impressive range of stimulus types—including written, spoken, and signed words or pseudowords; drawings, photos, and videos of faces, objects, and actions; sounds; and mathematical symbols—and outline the sensitivity of N400 amplitude (as its latency is remarkably constant) to linguistic and nonlinguistic manipulations. We emphasize the effectiveness of the N400 as a dependent variable for examining almost every aspect of language processing and highlight its expanding use to probe semantic memory and to determine how the neurocognitive system dynamically and flexibly uses bottom-up and top-down information to make sense of the world. We conclude with different theories of the N400’s functional significance and offer an N400-inspired reconceptualization of how meaning processing might unfold.
-
The impact of semantic memory organization and sentence context information on spoken language processing by younger and older adults: An ERP study
Psychophysiology, 2002Co-Authors: Kara D. Federmeier, Devon B. Mclennan, Esmeralda De Ochoa, Marta KutasAbstract:To examine changes in semantic memory organization and use during aging, we recorded event-related potentials as younger and older adults listened to sentences ending with the expected word, an unexpected word from the same semantic category, or an unexpected word from a different category. Half of the contexts were highly constraining. In both groups, expected words elicited less negativity 300–500 ms ~N400! than unexpected ones, and unexpected words elicited smaller N400s when these were categorically related. Whereas younger adults showed the greatest N400 reduction to unexpected but related words in high constraint contexts, older adults showed the opposite tendency. Thus, unlike younger adults, older adults as a group do not seem to be using context predictively. Older adults with higher verbal fluency and larger vocabularies, however, showed the younger response pattern, suggesting resource availability may offset certain age-related changes.
Phillip J. Holcomb - One of the best experts on this subject based on the ideXlab platform.
-
phonological and semantic priming in american sign language n300 and N400 effects
Language cognition and neuroscience, 2018Co-Authors: Gabriela Meade, Phillip J. Holcomb, Brittany Lee, Katherine J Midgley, Karen EmmoreyAbstract:This study investigated the electrophysiological signatures of phonological and semantic priming in American Sign Language (ASL). Deaf signers made semantic relatedness judgments to pairs of ASL si...
-
phonological and semantic priming in american sign language n300 and N400 effects
Language cognition and neuroscience, 2018Co-Authors: Gabriela Meade, Phillip J. Holcomb, Brittany Lee, Katherine J Midgley, Karen EmmoreyAbstract:This study investigated the electrophysiological signatures of phonological and semantic priming in American Sign Language (ASL). Deaf signers made semantic relatedness judgments to pairs of ASL signs separated by a 1300 ms prime-target SOA. Phonologically related sign pairs shared two of three phonological parameters (handshape, location, and movement). Target signs preceded by phonologically related and semantically related prime signs elicited smaller negativities within the N300 and N400 windows than those preceded by unrelated primes. N300 effects, typically reported in studies of picture processing, are interpreted to reflect the mapping from the visual features of the signs to more abstract linguistic representations. N400 effects, consistent with rhyme priming effects in the spoken language literature, are taken to index lexico-semantic processes that appear to be largely modality independent. Together, these results highlight both the unique visual-manual nature of sign languages and the linguistic processing characteristics they share with spoken languages.
-
pea nuts and bolts of visual narrative structure and meaning in sequential image comprehension
Cognitive Psychology, 2012Co-Authors: Neil Cohn, Phillip J. Holcomb, Martin Paczynski, Ray Jackendoff, Gina R KuperbergAbstract:Just as syntax differentiates coherent sentences from scrambled word strings, the comprehension of sequential images must also use a cognitive system to distinguish coherent narrative sequences from random strings of images. We conducted experiments analogous to two classic studies of language processing to examine the contributions of narrative structure and semantic relatedness to processing sequential images. We compared four types of comic strips: (1) Normal sequences with both structure and meaning, (2) Semantic Only sequences (in which the panels were related to a common semantic theme, but had no narrative structure), (3) Structural Only sequences (narrative structure but no semantic relatedness), and (4) Scrambled sequences of randomly-ordered panels. In Experiment 1, participants monitored for target panels in sequences presented panel-by-panel. Reaction times were slowest to panels in Scrambled sequences, intermediate in both Structural Only and Semantic Only sequences, and fastest in Normal sequences. This suggests that both semantic relatedness and narrative structure offer advantages to processing. Experiment 2 measured ERPs to all panels across the whole sequence. The N300/N400 was largest to panels in both the Scrambled and Structural Only sequences, intermediate in Semantic Only sequences and smallest in the Normal sequences. This implies that a combination of narrative structure and semantic relatedness can facilitate semantic processing of upcoming panels (as reflected by the N300/N400). Also, panels in the Scrambled sequences evoked a larger left-lateralized anterior negativity than panels in the Structural Only sequences. This localized effect was distinct from the N300/N400, and appeared despite the fact that these two sequence types were matched on local semantic relatedness between individual panels. These findings suggest that sequential image comprehension uses a narrative structure that may be independent of semantic relatedness. Altogether, we argue that the comprehension of visual narrative is guided by an interaction between structure and meaning.
-
invariance to rotation in depth measured by masked repetition priming is dependent on prime duration
Brain Research, 2011Co-Authors: Marianna D Eddy, Phillip J. HolcombAbstract:Abstract The current experiment examined invariance to pictures of objects rotated in depth using event-related potentials (ERPs) and masked repetition priming. Specifically we rotated objects 30°, 60° or 150° from their canonical view and, across two experiments, varied the prime duration (50 or 90 ms). We examined three ERP components, the P/N190, N300 and N400. In Experiment 1, only the 30° rotation condition produced repetition priming effects on the N/P190, N300 and N400. The other rotation conditions only showed repetition priming effects on the early perceptual component, the N/P190. Experiment 2 extended the prime duration to 90 ms to determine whether additional exposure to the prime may produce invariance on the N300 and N400 for the 60° and 150° rotation conditions. Repetition priming effects were found for all rotation conditions across the N/P190, N300 and N400 components. We interpret these results to suggest that whether or not view invariant priming effects are found depends partly on the extent to which representation of an object has been activated.
-
masked repetition priming and event related brain potentials a new approach for tracking the time course of object perception
Psychophysiology, 2006Co-Authors: Marianna D Eddy, Annette Schmid, Phillip J. HolcombAbstract:This study reports a new approach to studying the time-course of the perceptual processing of objects by combining for the first time the masked repetition priming technique with the recording of event-related potentials (ERPs). In a semantic categorization task ERPs were recorded to repeated and unrelated target pictures of common objects that were immediately preceded by briefly presented pattern masked prime objects. Three sequential ERP effects were found between 100 and 650 ms post-target onset. These effects included an early posterior positivity/anterior negativity (N/P190) that was suggested to reflect early feature processing in visual cortex. This early effect was followed by an anterior negativity (N300) that was suggested to reflect processing of object-specific representations and finally by a widely distributed negativity (N400) that was argued to reflect more domain general semantic processing.
Tim Curran - One of the best experts on this subject based on the ideXlab platform.
-
separating the fN400 and N400 potentials across recognition memory experiments
Brain Research, 2016Co-Authors: Pawel Strozak, Delora Abedzadeh, Tim CurranAbstract:There is a growing debate as to whether frontally distributed FN400 potentials reflect familiarity-based recognition or are functionally identical to centro-parietal N400 reflecting semantic processing. We conducted two experiments in which event-related potentials (ERPs) associated with semantic priming and recognition were recorded, either when priming was embedded within a recognition test (Experiment 1), or when these two phases were separated (Experiment 2). In Experiment 1, we observed 300-500 ms differences between primed and unprimed old words as well as differences between old and new primed words, but these two effects did not differ topographically and both showed midline central maxima. In Experiment 2, the N400 for priming was recorded exclusively during encoding and again showed a midline central distribution. The ERP component of recognition was only found for unrelated words (not primed previously during encoding), and also showed a midline central maximum, but, in addition, was present in the left frontal area of the scalp. Conversely, the priming effect was absent in the left frontal cluster. This pattern of results indicate that FN400 and N400 potentials share similar neural generators; but when priming and recognition are not confounded, these potentials do not entirely overlap in terms of topographical distribution and presumably reflect functionally distinct processes.
-
the electrophysiology of incidental and intentional retrieval erp old new effects in lexical decision and recognition memory
Neuropsychologia, 1999Co-Authors: Tim CurranAbstract:Abstract Event-related brain potentials (ERPs), recorded from a 128-sensor array were used todifferentiate brain processes associated with intentional vs incidental memory retrieval. Twoexperiments examined ERP differences between old (studied) and new (non-studied) words andpseudowords while subjects performed either a recognition memory task or lexical decision task.Previous research has related a P600 old⧸new effect to the recollection of details, and the presentexperiments show that this effect was not amplified by intentional retrieval. The P600 effect waslarger for words than pseudowords. An earlier (300 to 500 ms), frontally maximal, N400-likeold⧸new effect (FN400) was similar for words and pseudowords. A third, previously unidentified,mid-frontal, old⧸new effect was associated with only pseudoword recognition from 300 to 500ms. Results are discussed with respect to dual-process theories of recognition memory.
Marta Kutas - One of the best experts on this subject based on the ideXlab platform.
-
patients with mci and N400 or p600 abnormalities are at very high risk for conversion to dementia
Neurology, 2008Co-Authors: John M Olichney, Marta Kutas, Jason R Taylor, James Gatherwright, David P Salmon, A J Bressler, V J IraguimadozAbstract:Mild cognitive impairment (MCI), as originally proposed,1 is considered a transitional stage between normal aging and Alzheimer disease (AD). This is supported by the high rate of conversion1,2 and high prevalence of AD neuropathology.3–5 The criteria1 require history and objective evidence of memory difficulties, relative sparing of general cognition, and intact activities of daily living. Cognitive ERPs, comprised of summated EPSPs and IPSPs,6 provide an excellent tool for measuring the timing of synaptic processing. A late positive component (LPC), a.k.a. the P600, has been implicated in both memory encoding and retrieval processes.7,8 In word list recognition experiments, a consistent finding has been larger late positivities (with left parietal maxima) for recognized words.9 In contrast, when semantically predictable words are repeated, P600 amplitudes are generally smaller (relative to initial).10,11 P600 generators have been identified in several regions important for episodic/declarative memory (i.e., hippocampus, entorhinal, cingulate, and ventral prefrontal cortex).12–14 We have previously reported severely reduced P600 word repetition effects in circumscribed amnesia10 and mild AD.15 The N400 component may also be related to verbal learning/memory.16 N400 amplitude is proportional to semantic processing load and inversely proportional to semantic expectancy.17,18 Invasive electrophysiology (and magnetoencephalography) reveal N400 generators in the anterior fusiform,19 lateral parahippocampal gyri,19 and the superior temporal sulcus.14,20,21 Our studies of circumscribed amnesia10 showed relatively normal N400 effects (e.g., larger N400s to new than old incongruous words). In contrast, patients with mild AD generally have absent N400 word repetition effects.15 To seek biomarkers/predictors of subsequent conversion to AD, we conducted annual longitudinal ERP assessments in MCI. We hypothesized that 1) patients with MCI with poorer memory or subsequent conversion would show reduced P600 word repetition effects, and 2) MCI converters will exhibit pronounced N400 abnormalities (decreased repetition and congruity effects) as they develop incipient dementia and subtle impairments in semantic/linguistic processing.
-
The impact of semantic memory organization and sentence context information on spoken language processing by younger and older adults: An ERP study
Psychophysiology, 2002Co-Authors: Kara D. Federmeier, Devon B. Mclennan, Esmeralda De Ochoa, Marta KutasAbstract:To examine changes in semantic memory organization and use during aging, we recorded event-related potentials as younger and older adults listened to sentences ending with the expected word, an unexpected word from the same semantic category, or an unexpected word from a different category. Half of the contexts were highly constraining. In both groups, expected words elicited less negativity 300–500 ms ~N400! than unexpected ones, and unexpected words elicited smaller N400s when these were categorically related. Whereas younger adults showed the greatest N400 reduction to unexpected but related words in high constraint contexts, older adults showed the opposite tendency. Thus, unlike younger adults, older adults as a group do not seem to be using context predictively. Older adults with higher verbal fluency and larger vocabularies, however, showed the younger response pattern, suggesting resource availability may offset certain age-related changes.
-
a rose by any other name long term memory structure and sentence processing
Journal of Memory and Language, 1999Co-Authors: Kara D. Federmeier, Marta KutasAbstract:Abstract The effects of sentential context and semantic memory structure during on-line sentence processing were examined by recording event-related brain potentials as individuals read pairs of sentences for comprehension. The first sentence established an expectation for a particular exemplar of a semantic category, while the second ended with (1) that expected exemplar, (2) an unexpected exemplar from the same (expected) category, or (3) an unexpected item from a different (unexpected) category. Expected endings elicited a positivity between 250 and 550 ms while all unexpected endings elicited an N400, which was significantly smaller to items from the expected category. This N400 reduction varied with the strength of the contextually induced expectation: unexpected, categorically related endings elicited smaller N400s in more constraining contexts, despite their poorer fit to context (lower plausibility). This pattern of effects is best explained as reflecting the impact of context-independent long-term memory structure on sentence processing. The results thus suggest that physical and functional similarities that hold between objects in the world—i.e., category structure—influence neural organization and, in turn, routine language comprehension processes.
-
the N400 in a semantic categorization task across 6 decades
Electroencephalography and Clinical Neurophysiology, 1998Co-Authors: Marta Kutas, Vicente J IraguiAbstract:Abstract Objectives : To characterize the effects of normal aging on the amplitude, latency and scalp distribution of the N400 congruity effect. Methods : Event-related brain potentials (ERPs) were recorded from 72 adults (half of them men) between the ages of 20 and 80 years (12/decade) as they performed a semantic categorization task. Participants listened to spoken phrases (e.g. `a type of fruit' or `the opposite of black') followed about 1 s later by a visually-presented word that either did or did not fit with the sense of the preceding phrase; they reported the word read and whether or not it was appropriate. ERP measurements (mean amplitudes, peak amplitudes, peak latencies) were subjected to analysis of variance and linear regression analyses. Results : All participants, regardless of age, produced larger N400s to words that did not fit than to those that did. The N400 congruity effect (no-fit ERPs−fit ERPs) showed a reliable linear decrease in the amplitude (0.05–0.09 μ V per year, r =0.40) and a reliable linear increase peak latency (1.5–2.1 ms/year, r =0.60) with age. Conclusions : In sum, the N400 semantic congruity effect at the scalp gets smaller, slower and more variable with age, consistent with a quantitative rather than qualitative change in semantic processing (integration) with normal aging.
-
human temporal lobe potentials in verbal learning and memory processes
Neuropsychologia, 1997Co-Authors: Christian E Elger, Marta Kutas, Christoph Helmstaedter, Thomas Grunwald, Klaus Lehnertz, Anke Brockhaus, Dirk Van Roost, H J HeinzeAbstract:Animal experiments and lesion studies have shown the importance of temporal lobe structures for language and memory. We recorded intracranial cognitive potentials from the human lateral and medial temporal lobe in 26 patients with temporal lobe epilepsy undergoing presurgical evaluation, using a word- and a picture-recognition paradigm. Neuropsychological testing included word fluency, verbal reasoning, sustained attention and a verbal learning memory test (VLMT), which was an adapted version of the Rey auditory verbal learning test. Word-specific N400-potentials elicited in the middle temporal gyrus of the dominant left hemisphere (LTL-N400) predicted immediate recall performance after learning, whereas N400s, elicited by words but not pictures in the left anterior medial temporal lobe (AMTL-N400), predicted delayed recall. The number of words that were learned but forgotten after a 30-min delay correlated only with N400s elicited by words in the left anterior medial temporal lobe. Thus, intracranial recordings indicated that different electrophysiological responses in different temporal lobe structures were linked to memory scores from specific neuropsychological tests.
Michael S Franklin - One of the best experts on this subject based on the ideXlab platform.
-
separating the visual sentence N400 effect from the p400 sequential expectancy effect cognitive and neuroanatomical implications
Brain Research, 2010Co-Authors: Joseph Dien, Michael S Franklin, Charles A MichelsonAbstract:The N400 is an event-related potential (ERP) component that is elicited by semantically meaningful stimuli; one of its defining characteristics is that it is amplified for sentence completions that are semantically unexpected or incongruous with the preceding context. Some prior reports using visual sentence reading paradigms have suggested that there may also be a Cz-centered P400 (a P400cz) that is also responding to semantic congruity manipulations, distinct from the classic Pz-centered N400 (the N400pz). In the present experiment, sentences were presented visually one word at a time, and half of the sentences ended with a semantically incongruent ending. High-density 129-channel event-related potential data were recorded from 26 participants. A combination of temporo-spatial principal components analysis (PCA) and item averaging was applied to decompose the waveforms. The presence of the P400cz was confirmed. The P400cz was much more sensitive to congruity and somewhat more sensitive to cloze probability than the N400pz. The separation of the N400 semantic effect into these two portions is consistent with both MEG studies and intracranial studies. The data suggest that the N400pz has its major source in the bilateral anterior medial temporal lobe (AMTL) whereas it is suggested that the P400cz has its major source in the medial parietal region. It is further suggested that whereas the N400pz process appears to be semantic in nature, some prior reports suggest that the P400cz reflects a general sequential expectancy system.
-
semantic priming modulates the N400 n300 and N400rp
Clinical Neurophysiology, 2007Co-Authors: Michael S Franklin, Joseph Dien, James H Neely, Elizabeth Huber, Lauren D WatersonAbstract:Objective: To determine whether ERP components can differentiate between the semantic priming mechanisms of automatic spreading activation, expectancy, and semantic matching. Methods: The present study manipulated two factors known to differentiate semantic priming mechanisms: associations between words (forward, backward, and symmetrical) and prime-target stimulus onset asynchrony (SOA). Twenty-six participants were tested in each SOA condition while high-density 128-channel data were collected. Principal components analysis was applied to separate the ERP components. Results: Priming was observed for all conditions. Three semantic components were present: (1) the standard N400 effect for symmetric and forward priming pairs at both short and long SOAs, (2) an N300 for the long SOA symmetric priming pairs, and (3) a right-lateralized posterior N400RP for long SOA backward priming pairs. Conclusions: Results suggest that the N300 reflects expectancy, but only for categorical and/or semantic similarity priming. Results further suggest that the N400RP is a replicable ERP component that responds to semantic matching. There is also some evidence that the N400 indirectly responds to both ASA and expectancy, perhaps as part of a post-lexical updating process and that backward priming at short SOAs is different from that at long SOAs. Significance: Improved understanding of the semantic properties of the N400 and related ERP components may increase their utility for understanding language processes and for diagnostic purposes. � 2007 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.
