Source localization of the N400 response in a sentence-reading paradigm using evoked magnetic fields and magnetic resonance imaging

Panagiotis G. Simos, Luis F.H. Basile, Andrew Papanicolaou

Research output: Contribution to journalArticle

126 Citations (Scopus)

Abstract

The aim of the present investigation was to localize the sources of the N400 response elicited in a sentence-reading paradigm. Eight neurologically healthy adults viewed sentences that were presented one word at a time in the center of a computer screen. Half of the sentences ended with a semantically inappropriate word, while the other half had appropriate endings. Event- related potentials recorded at Fz and Pz showed a negative-going deflection, the amplitude of which was strongly affected by semantic congruity (N400). Evoked magnetic fields that were simultaneously recorded over the left hemisphere showed clear magnetic field extrema in seven subjects during the time course of the N400. Underlying sources were successfully modeled as single equivalent current dipoles. Anatomical regions that contained the dipoles were localized by superimposing dipole coordinates onto magnetic resonance scans. Dipole regions were found in temporal lobe structures, in the vicinity of the hippocampus and the parahippocampal gyms (in two subjects) and in posterior temporal neocortical regions (in the vicinity of the middle temporal gyms; in five subjects). These findings are consistent with the view that posterior association cortices in the left hemisphere are involved in word recognition and semantic comprehension during reading.

Original languageEnglish (US)
Pages (from-to)29-39
Number of pages11
JournalBrain Research
Volume762
Issue number1-2
DOIs
StatePublished - Jul 11 1997

Fingerprint

Magnetic Fields
Reading
Magnetic Resonance Imaging
Temporal Lobe
Semantics
Evoked Potentials
Hippocampus
Magnetic Resonance Spectroscopy

All Science Journal Classification (ASJC) codes

  • Neuroscience(all)
  • Molecular Biology
  • Developmental Biology
  • Clinical Neurology

Cite this

Source localization of the N400 response in a sentence-reading paradigm using evoked magnetic fields and magnetic resonance imaging. / Simos, Panagiotis G.; Basile, Luis F.H.; Papanicolaou, Andrew.

In: Brain Research, Vol. 762, No. 1-2, 11.07.1997, p. 29-39.

Research output: Contribution to journalArticle

Simos, Panagiotis G. ; Basile, Luis F.H. ; Papanicolaou, Andrew. / Source localization of the N400 response in a sentence-reading paradigm using evoked magnetic fields and magnetic resonance imaging. In: Brain Research. 1997 ; Vol. 762, No. 1-2. pp. 29-39.
@article{e8965551571c4bd2bde7ef2277c5a985,
title = "Source localization of the N400 response in a sentence-reading paradigm using evoked magnetic fields and magnetic resonance imaging",
abstract = "The aim of the present investigation was to localize the sources of the N400 response elicited in a sentence-reading paradigm. Eight neurologically healthy adults viewed sentences that were presented one word at a time in the center of a computer screen. Half of the sentences ended with a semantically inappropriate word, while the other half had appropriate endings. Event- related potentials recorded at Fz and Pz showed a negative-going deflection, the amplitude of which was strongly affected by semantic congruity (N400). Evoked magnetic fields that were simultaneously recorded over the left hemisphere showed clear magnetic field extrema in seven subjects during the time course of the N400. Underlying sources were successfully modeled as single equivalent current dipoles. Anatomical regions that contained the dipoles were localized by superimposing dipole coordinates onto magnetic resonance scans. Dipole regions were found in temporal lobe structures, in the vicinity of the hippocampus and the parahippocampal gyms (in two subjects) and in posterior temporal neocortical regions (in the vicinity of the middle temporal gyms; in five subjects). These findings are consistent with the view that posterior association cortices in the left hemisphere are involved in word recognition and semantic comprehension during reading.",
author = "Simos, {Panagiotis G.} and Basile, {Luis F.H.} and Andrew Papanicolaou",
year = "1997",
month = "7",
day = "11",
doi = "10.1016/S0006-8993(97)00349-1",
language = "English (US)",
volume = "762",
pages = "29--39",
journal = "Brain Research",
issn = "0006-8993",
publisher = "Elsevier",
number = "1-2",

}

TY - JOUR

T1 - Source localization of the N400 response in a sentence-reading paradigm using evoked magnetic fields and magnetic resonance imaging

AU - Simos, Panagiotis G.

AU - Basile, Luis F.H.

AU - Papanicolaou, Andrew

PY - 1997/7/11

Y1 - 1997/7/11

N2 - The aim of the present investigation was to localize the sources of the N400 response elicited in a sentence-reading paradigm. Eight neurologically healthy adults viewed sentences that were presented one word at a time in the center of a computer screen. Half of the sentences ended with a semantically inappropriate word, while the other half had appropriate endings. Event- related potentials recorded at Fz and Pz showed a negative-going deflection, the amplitude of which was strongly affected by semantic congruity (N400). Evoked magnetic fields that were simultaneously recorded over the left hemisphere showed clear magnetic field extrema in seven subjects during the time course of the N400. Underlying sources were successfully modeled as single equivalent current dipoles. Anatomical regions that contained the dipoles were localized by superimposing dipole coordinates onto magnetic resonance scans. Dipole regions were found in temporal lobe structures, in the vicinity of the hippocampus and the parahippocampal gyms (in two subjects) and in posterior temporal neocortical regions (in the vicinity of the middle temporal gyms; in five subjects). These findings are consistent with the view that posterior association cortices in the left hemisphere are involved in word recognition and semantic comprehension during reading.

AB - The aim of the present investigation was to localize the sources of the N400 response elicited in a sentence-reading paradigm. Eight neurologically healthy adults viewed sentences that were presented one word at a time in the center of a computer screen. Half of the sentences ended with a semantically inappropriate word, while the other half had appropriate endings. Event- related potentials recorded at Fz and Pz showed a negative-going deflection, the amplitude of which was strongly affected by semantic congruity (N400). Evoked magnetic fields that were simultaneously recorded over the left hemisphere showed clear magnetic field extrema in seven subjects during the time course of the N400. Underlying sources were successfully modeled as single equivalent current dipoles. Anatomical regions that contained the dipoles were localized by superimposing dipole coordinates onto magnetic resonance scans. Dipole regions were found in temporal lobe structures, in the vicinity of the hippocampus and the parahippocampal gyms (in two subjects) and in posterior temporal neocortical regions (in the vicinity of the middle temporal gyms; in five subjects). These findings are consistent with the view that posterior association cortices in the left hemisphere are involved in word recognition and semantic comprehension during reading.

UR - http://www.scopus.com/inward/record.url?scp=0030871921&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0030871921&partnerID=8YFLogxK

U2 - 10.1016/S0006-8993(97)00349-1

DO - 10.1016/S0006-8993(97)00349-1

M3 - Article

VL - 762

SP - 29

EP - 39

JO - Brain Research

JF - Brain Research

SN - 0006-8993

IS - 1-2

ER -