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Eklund R, Gerdfeldter B, Wiens S. The early but not the late neural correlate of auditory awareness reflects lateralized experiences. Neuropsychologia 2021; 158:107910. [PMID: 34090867 DOI: 10.1016/j.neuropsychologia.2021.107910] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Revised: 05/31/2021] [Accepted: 06/01/2021] [Indexed: 01/08/2023]
Abstract
Theories disagree as to whether it is the early or the late neural correlate of awareness that plays a critical role in phenomenal awareness. According to recurrent processing theory, early activity in primary sensory areas corresponds closely to phenomenal awareness. In support, research with electroencephalography found that in the visual and somatosensory modality, an early neural correlate of awareness is contralateral to the perceived side of stimulation. Thus, early activity is sensitive to the perceived side of visual and somatosensory stimulation. Critically, it is unresolved whether this is true also for hearing. In the present study (N = 26 students), Bayesian analyses showed that the early neural correlate of awareness (auditory awareness negativity, AAN) was stronger for contralateral than ipsilateral electrodes whereas the late correlate of auditory awareness (late positivity, LP) was not lateralized. These findings demonstrate that the early but not the late neural correlate of auditory awareness reflects lateralized experiences. Thus, these findings imply that AAN is a more suitable NCC than LP because it correlates more closely with lateralized experiences.
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Affiliation(s)
- Rasmus Eklund
- Gösta Ekmans Laboratorium, Stockholm University, Sweden.
| | | | - Stefan Wiens
- Gösta Ekmans Laboratorium, Stockholm University, Sweden
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Saito H, Yazawa S, Shinozaki J, Murahara T, Shiraishi H, Matsuhashi M, Nagamine T. Appraisal of definition of baseline length for somatosensory evoked magnetic fields. J Neurosci Methods 2021; 359:109213. [PMID: 33951455 DOI: 10.1016/j.jneumeth.2021.109213] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2021] [Revised: 04/16/2021] [Accepted: 04/29/2021] [Indexed: 11/17/2022]
Abstract
BACKGROUND The baseline (BL) segment in the prestimulus period is generally assigned as a reference of evoked activities. However, an experimenter empirically defines its length in each condition. So far, the criterion for the length of a BL segment has not been established. NEW METHOD We evaluated the effect of the length of the BL segment by recording somatosensory evoked magnetic fields (SEFs) under fixed stimulus onset asynchrony (SOA). For the evaluation of the length of the BL segment in the prestimulus period, five proportions in relation to SOA were used as the BL segment. In addition, we adopted other two types of BL segment which were the single data point measured from the value of stimulus onset (BL0) and the mean value of the whole raw data throughout the recording (DC mean). We investigated the influence of the BL segments on SEFs by utilizing two indicators: normalized N20 m amplitudes and estimated locations of corresponding equivalent current dipoles (ECDs). RESULTS Both indicators did not show any significant differences, based on the factor of BL segments, in any SOA conditions. COMPARISON WITH EXISTING METHOD The BL0 had by far the largest variation in the ECD locations.Therefore, utilizing stimulus onset as the BL segment should be avoided. In addition, considering that other BL segments provided comparable values by the two indicators, the DC mean can reasonably be adopted. CONCLUSIONS We suggest that utilizing the DC mean could be employed as the BL segment.
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Affiliation(s)
- Hidekazu Saito
- Department of Systems Neuroscience, School of Medicine, Sapporo Medical University, South 1, West 17, Chuo-ku, Sapporo, 060-8556, Japan; Department of Occupational Therapy, School of Health Sciences, Sapporo Medical University, South 1, West 17, Chuo-ku, Sapporo, 060-8556, Japan.
| | - Shogo Yazawa
- Department of Systems Neuroscience, School of Medicine, Sapporo Medical University, South 1, West 17, Chuo-ku, Sapporo, 060-8556, Japan.
| | - Jun Shinozaki
- Department of Systems Neuroscience, School of Medicine, Sapporo Medical University, South 1, West 17, Chuo-ku, Sapporo, 060-8556, Japan.
| | - Takashi Murahara
- Department of Systems Neuroscience, School of Medicine, Sapporo Medical University, South 1, West 17, Chuo-ku, Sapporo, 060-8556, Japan.
| | - Hideaki Shiraishi
- Department of Pediatrics, Hokkaido University School of Medicine, North 15, West 7, Kita-ku, Sapporo, 060-8638, Japan.
| | - Masao Matsuhashi
- Department of Epilepsy, Movement Disorders and Physiology, Kyoto University School of Medicine, Shogoin, Sakyo-ku, Kyoto, 606-8507, Japan.
| | - Takashi Nagamine
- Department of Systems Neuroscience, School of Medicine, Sapporo Medical University, South 1, West 17, Chuo-ku, Sapporo, 060-8556, Japan.
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Auditory Mapping With MEG: An Update on the Current State of Clinical Research and Practice With Considerations for Clinical Practice Guidelines. J Clin Neurophysiol 2020; 37:574-584. [DOI: 10.1097/wnp.0000000000000518] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
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4
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Naganuma R, Yabe I, Takeuchi M, Morishita K, Nakane S, Takase R, Takahashi-Iwata I, Matsushima M, Otsuki M, Shiraishi H, Sasaki H. Clinical factors affecting evoked magnetic fields in patients with Parkinson's disease. PLoS One 2020; 15:e0232808. [PMID: 32941428 PMCID: PMC7498017 DOI: 10.1371/journal.pone.0232808] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2020] [Accepted: 08/31/2020] [Indexed: 11/19/2022] Open
Abstract
Studies on evoked responses in Parkinson's disease (PD) may be useful for elucidating the etiology and quantitative evaluation of PD. However, in previous studies, the association between evoked responses and detailed motor symptoms or cognitive functions has not been clear. This study investigated the characteristics of the visual (VEF), auditory (AEF), and somatosensory (SEF) evoked magnetic fields in patients with Parkinson’s disease (PD), and the correlations between evoked fields and the patient’s clinical characteristics, motor symptoms, and cognitive functions. Twenty patients with PD and 10 healthy controls (HCs) were recruited as participants. We recorded VEF, AEF, and SEF, collected clinical characteristics, performed physical examinations, and administered 10 cognitive tests. We investigated differences in the latencies of the evoked fields between patients with PD and HCs. We also evaluated the correlation of the latencies with motor symptoms and cognitive functioning. There were significant differences between the two groups in 6 of the cognitive tests, all of which suggested mild cognitive impairment in patients with PD. The latencies of the VEF N75m, P100m, N145m, AEF P50m, P100m, and SEF P60m components were greater in the patients with PD than in the HCs. The latencies mainly correlated with medication and motor symptoms, less so with cognitive tests, with some elements of the correlations remaining significant after Bonferroni correction. In conclusion, the latencies of the VEF, AEF, and SEF were greater in PD patients than in HCs and were mainly correlated with medication and motor symptoms rather than cognitive functioning. Findings from this study suggest that evoked fields may reflect basal ganglia functioning and are candidates for assessing motor symptoms or the therapeutic effects of medication in patients with PD.
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Affiliation(s)
- Ryoji Naganuma
- Department of Neurology, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Sapporo, Hokkaido, Japan
| | - Ichiro Yabe
- Department of Neurology, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Sapporo, Hokkaido, Japan
- * E-mail:
| | - Megumi Takeuchi
- Department of Neurology, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Sapporo, Hokkaido, Japan
| | - Kirari Morishita
- Division of Laboratory and Transfusion Medicine, Hokkaido University Hospital, Sapporo, Hokkaido, Japan
| | - Shingo Nakane
- Division of Magnetoencephalography, Hokkaido University Hospital, Sapporo, Hokkaido, Japan
| | - Ryoken Takase
- Faculty of Health Sciences/Graduate School of Health Sciences/Department of Health Sciences, School of Medicine, Hokkaido University, Sapporo, Hokkaido, Japan
- Department of Radiation Technology, Sapporo City General Hospital, Sapporo, Hokkaido, Japan
| | - Ikuko Takahashi-Iwata
- Department of Neurology, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Sapporo, Hokkaido, Japan
| | - Masaaki Matsushima
- Department of Neurology, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Sapporo, Hokkaido, Japan
| | - Mika Otsuki
- Faculty of Health Sciences/Graduate School of Health Sciences/Department of Health Sciences, School of Medicine, Hokkaido University, Sapporo, Hokkaido, Japan
| | - Hideaki Shiraishi
- Department of Pediatrics, Hokkaido University Hospital, Sapporo, Hokkaido, Japan
| | - Hidenao Sasaki
- Department of Neurology, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Sapporo, Hokkaido, Japan
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Pike M, Biagio-de Jager L, le Roux T, Hofmeyr LM. Short-Term Test-Retest Reliability of Electrically Evoked Cortical Auditory Potentials in Adult Cochlear Implant Recipients. Front Neurol 2020; 11:305. [PMID: 32411080 PMCID: PMC7198904 DOI: 10.3389/fneur.2020.00305] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Accepted: 03/30/2020] [Indexed: 11/13/2022] Open
Abstract
Background: Late latency auditory evoked potentials (LLAEPs) provide objective evidence of an individual's central auditory processing abilities. Electrically evoked cortical auditory evoked potentials (eCAEPs) are a type of LLAEP that provides an objective measure of aided speech perception and auditory processing abilities in cochlear implant (CI) recipients. Aim: To determine the short-term test-retest reliability of eCAEPs in adult CI recipients. Design: An explorative, within-subject repeated measures research design was employed. Study Sample: The study sample included 12 post-lingually deafened, unilaterally implanted adult CI recipients with at least 9 months of CI experience. Method: eCAEPs representing basal, medial and apical cochlear regions were recorded in the implanted ears of each participant. Measurements were repeated 7 days after the initial assessment. Results: No significant differences between either median latencies or amplitudes at test and retest sessions (p > 0.05) were found when results for apical, medial and basal electrodes were averaged together. Mean intraclass correlation coefficient (ICC) scores averaged across basal, medial and apical cochlear stimulus regions indicated that both consistency and agreement were statistically significant and ranged from moderate to good (ICC = 0.58-0.86, p < 0.05). ICC confidence intervals did demonstrate considerable individual variability in both latency and amplitudes. Conclusion: eCAEP latencies and amplitudes demonstrated moderate to good short-term test-retest reliability. However, confidence intervals indicated individual variability in measurement consistency which is likely linked to attention and listening effort required from the CI recipients.
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Affiliation(s)
- Meghan Pike
- Department of Speech Language Pathology and Audiology, University of Pretoria, Pretoria, South Africa
| | - Leigh Biagio-de Jager
- Department of Speech Language Pathology and Audiology, University of Pretoria, Pretoria, South Africa
| | - Talita le Roux
- Department of Speech Language Pathology and Audiology, University of Pretoria, Pretoria, South Africa
| | - Louis M Hofmeyr
- Department of Speech Language Pathology and Audiology, University of Pretoria, Pretoria, South Africa
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Jack BN, Le Pelley ME, Han N, Harris AW, Spencer KM, Whitford TJ. Inner speech is accompanied by a temporally-precise and content-specific corollary discharge. Neuroimage 2019; 198:170-180. [DOI: 10.1016/j.neuroimage.2019.04.038] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Accepted: 04/11/2019] [Indexed: 11/29/2022] Open
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7
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Altered neocortical tactile but preserved auditory early change detection responses in Friedreich ataxia. Clin Neurophysiol 2019; 130:1299-1310. [PMID: 31176929 DOI: 10.1016/j.clinph.2019.05.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Revised: 04/16/2019] [Accepted: 05/01/2019] [Indexed: 12/17/2022]
Abstract
OBJECTIVE To study using magnetoencephalography (MEG) the spatio-temporal dynamics of neocortical responses involved in sensory processing and early change detection in Friedreich ataxia (FRDA). METHODS Tactile (TERs) and auditory (AERs) evoked responses, and early neocortical change detection responses indexed by the mismatch negativity (MMN) were recorded using tactile and auditory oddballs in sixteen FRDA patients and matched healthy subjects. Correlations between the maximal amplitude of each response, genotype and clinical parameters were investigated. RESULTS Evoked responses were detectable in all FRDA patients but one. In patients, TERs were delayed and reduced in amplitude, while AERs were only delayed. Only tactile MMN responses at the contralateral secondary somatosensory cortex were altered in FRDA patients. Maximal amplitudes of TERs, AERs and tactile MMN correlated with genotype, but did not correlate with clinical parameters. CONCLUSIONS In FRDA, theamplitude of tactile MMN responses at SII cortex are reduced and correlate with the genotype, whileauditory MMN responses are not altered. SIGNIFICANCE Somatosensory pathways and tactile early change detection are selectively impaired in FRDA.
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Shen G, Meltzoff AN, Marshall PJ. Touching lips and hearing fingers: effector-specific congruency between tactile and auditory stimulation modulates N1 amplitude and alpha desynchronization. Exp Brain Res 2018; 236:13-29. [PMID: 29038847 PMCID: PMC5976883 DOI: 10.1007/s00221-017-5104-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Accepted: 10/05/2017] [Indexed: 10/18/2022]
Abstract
Understanding the interactions between audition and sensorimotor processes is of theoretical importance, particularly in relation to speech processing. Although one current focus in this area is on interactions between auditory perception and the motor system, there has been less research on connections between the auditory and somatosensory modalities. The current study takes a novel approach to this omission by examining specific auditory-tactile interactions in the context of speech and non-speech sound production. Electroencephalography was used to examine brain responses when participants were presented with speech syllables (a bilabial sound /pa/ and a non-labial sound /ka/) or finger-snapping sounds that were simultaneously paired with tactile stimulation of either the lower lip or the right middle finger. Analyses focused on the sensory-evoked N1 in the event-related potential and the extent of alpha band desynchronization elicited by the stimuli. N1 amplitude over fronto-central sites was significantly enhanced when the bilabial /pa/ sound was paired with tactile lip stimulation and when the finger-snapping sound was paired with tactile stimulation of the finger. Post-stimulus alpha desynchronization at central sites was also enhanced when the /pa/ sound was accompanied by tactile stimulation of the lip. These novel findings indicate that neural aspects of somatosensory-auditory interactions are influenced by the congruency between the location of the bodily touch and the bodily origin of a perceived sound.
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Affiliation(s)
- Guannan Shen
- Department of Psychology, 1701 N 13th Street, Philadelphia, PA, 19122, USA.
| | - Andrew N Meltzoff
- Department of Psychology, 1701 N 13th Street, Philadelphia, PA, 19122, USA
- Institute for Learning and Brian Sciences, University of Washington, Seattle, USA
| | - Peter J Marshall
- Department of Psychology, 1701 N 13th Street, Philadelphia, PA, 19122, USA
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9
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Borna A, Carter TR, Goldberg JD, Colombo AP, Jau YY, Berry C, McKay J, Stephen J, Weisend M, Schwindt PDD. A 20-channel magnetoencephalography system based on optically pumped magnetometers. Phys Med Biol 2017; 62:8909-8923. [PMID: 29035875 DOI: 10.1088/1361-6560/aa93d1] [Citation(s) in RCA: 68] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
We describe a multichannel magnetoencephalography (MEG) system that uses optically pumped magnetometers (OPMs) to sense the magnetic fields of the human brain. The system consists of an array of 20 OPM channels conforming to the human subject's head, a person-sized magnetic shield containing the array and the human subject, a laser system to drive the OPM array, and various control and data acquisition systems. We conducted two MEG experiments: auditory evoked magnetic field and somatosensory evoked magnetic field, on three healthy male subjects, using both our OPM array and a 306-channel Elekta-Neuromag superconducting quantum interference device (SQUID) MEG system. The described OPM array measures the tangential components of the magnetic field as opposed to the radial component measured by most SQUID-based MEG systems. Herein, we compare the results of the OPM- and SQUID-based MEG systems on the auditory and somatosensory data recorded in the same individuals on both systems.
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Affiliation(s)
- Amir Borna
- Sandia National Laboratories, PO Box 5800, Albuquerque, NM 87185-1082, United States of America
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Perceptual Temporal Asymmetry Associated with Distinct ON and OFF Responses to Time-Varying Sounds with Rising versus Falling Intensity: A Magnetoencephalography Study. Brain Sci 2016; 6:brainsci6030027. [PMID: 27527227 PMCID: PMC5039456 DOI: 10.3390/brainsci6030027] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2016] [Revised: 07/26/2016] [Accepted: 07/29/2016] [Indexed: 11/29/2022] Open
Abstract
This magnetoencephalography (MEG) study investigated evoked ON and OFF responses to ramped and damped sounds in normal-hearing human adults. Two pairs of stimuli that differed in spectral complexity were used in a passive listening task; each pair contained identical acoustical properties except for the intensity envelope. Behavioral duration judgment was conducted in separate sessions, which replicated the perceptual bias in favour of the ramped sounds and the effect of spectral complexity on perceived duration asymmetry. MEG results showed similar cortical sites for the ON and OFF responses. There was a dominant ON response with stronger phase-locking factor (PLF) in the alpha (8–14 Hz) and theta (4–8 Hz) bands for the damped sounds. In contrast, the OFF response for sounds with rising intensity was associated with stronger PLF in the gamma band (30–70 Hz). Exploratory correlation analysis showed that the OFF response in the left auditory cortex was a good predictor of the perceived temporal asymmetry for the spectrally simpler pair. The results indicate distinct asymmetry in ON and OFF responses and neural oscillation patterns associated with the dynamic intensity changes, which provides important preliminary data for future studies to examine how the auditory system develops such an asymmetry as a function of age and learning experience and whether the absence of asymmetry or abnormal ON and OFF responses can be taken as a biomarker for certain neurological conditions associated with auditory processing deficits.
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Salmela E, Renvall H, Kujala J, Hakosalo O, Illman M, Vihla M, Leinonen E, Salmelin R, Kere J. Evidence for genetic regulation of the human parieto-occipital 10-Hz rhythmic activity. Eur J Neurosci 2016; 44:1963-71. [PMID: 27306141 PMCID: PMC5113795 DOI: 10.1111/ejn.13300] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2016] [Revised: 06/10/2016] [Accepted: 06/14/2016] [Indexed: 01/23/2023]
Abstract
Several functional and morphological brain measures are partly under genetic control. The identification of direct links between neuroimaging signals and corresponding genetic factors can reveal cellular-level mechanisms behind the measured macroscopic signals and contribute to the use of imaging signals as probes of genetic function. To uncover possible genetic determinants of the most prominent brain signal oscillation, the parieto-occipital 10-Hz alpha rhythm, we measured spontaneous brain activity with magnetoencephalography in 210 healthy siblings while the subjects were resting, with eyes closed and open. The reactivity of the alpha rhythm was quantified from the difference spectra between the two conditions. We focused on three measures: peak frequency, peak amplitude and the width of the main spectral peak. In accordance with earlier electroencephalography studies, spectral peak amplitude was highly heritable (h(2) > 0.75). Variance component-based analysis of 28 000 single-nucleotide polymorphism markers revealed linkage for both the width and the amplitude of the spectral peak. The strongest linkage was detected for the width of the spectral peak over the left parieto-occipital cortex on chromosome 10 (LOD = 2.814, nominal P < 0.03). This genomic region contains several functionally plausible genes, including GRID1 and ATAD1 that regulate glutamate receptor channels mediating synaptic transmission, NRG3 with functions in brain development and HRT7 involved in the serotonergic system and circadian rhythm. Our data suggest that the alpha oscillation is in part genetically regulated, and that it may be possible to identify its regulators by genetic analyses on a realistically modest number of samples.
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Affiliation(s)
- Elina Salmela
- Molecular Neurology Research ProgramResearch Programs UnitUniversity of HelsinkiPO Box 63FI‐00014HelsinkiFinland
- Folkhälsan Institute of GeneticsBiomedicum HelsinkiHelsinkiFinland
| | - Hanna Renvall
- Department of Neuroscience and Biomedical EngineeringAalto University School of ScienceEspooFinland
- Aalto NeuroimagingMEG CoreAalto UniversityEspooFinland
- Clinical Neurosciences, NeurologyUniversity of Helsinki and Department of NeurologyHelsinki University HospitalHelsinkiFinland
| | - Jan Kujala
- Department of Neuroscience and Biomedical EngineeringAalto University School of ScienceEspooFinland
- Aalto NeuroimagingMEG CoreAalto UniversityEspooFinland
| | - Osmo Hakosalo
- Molecular Neurology Research ProgramResearch Programs UnitUniversity of HelsinkiPO Box 63FI‐00014HelsinkiFinland
| | - Mia Illman
- Department of Neuroscience and Biomedical EngineeringAalto University School of ScienceEspooFinland
- Aalto NeuroimagingMEG CoreAalto UniversityEspooFinland
| | - Minna Vihla
- Department of Neuroscience and Biomedical EngineeringAalto University School of ScienceEspooFinland
- Aalto NeuroimagingMEG CoreAalto UniversityEspooFinland
- City of Helsinki Health CentreHelsinkiFinland
| | - Eira Leinonen
- Molecular Neurology Research ProgramResearch Programs UnitUniversity of HelsinkiPO Box 63FI‐00014HelsinkiFinland
- Folkhälsan Institute of GeneticsBiomedicum HelsinkiHelsinkiFinland
| | - Riitta Salmelin
- Department of Neuroscience and Biomedical EngineeringAalto University School of ScienceEspooFinland
- Aalto NeuroimagingMEG CoreAalto UniversityEspooFinland
| | - Juha Kere
- Molecular Neurology Research ProgramResearch Programs UnitUniversity of HelsinkiPO Box 63FI‐00014HelsinkiFinland
- Folkhälsan Institute of GeneticsBiomedicum HelsinkiHelsinkiFinland
- Science for Life LaboratoryKarolinska InstitutetSolnaSweden
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Ahonen L, Huotilainen M, Brattico E. Within- and between-session replicability of cognitive brain processes: An MEG study with an N-back task. Physiol Behav 2016; 158:43-53. [PMID: 26855266 DOI: 10.1016/j.physbeh.2016.02.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2015] [Revised: 12/17/2015] [Accepted: 02/03/2016] [Indexed: 11/25/2022]
Abstract
In the vast majority of electrophysiological studies on cognition, participants are only measured once during a single experimental session. The dearth of studies on test-retest reliability in magnetoencephalography (MEG) within and across experimental sessions is a preventing factor for longitudinal designs, imaging genetics studies, and clinical applications. From the recorded signals, it is not straightforward to draw robust and steady indices of brain activity that could directly be used in exploring behavioral effects or genetic associations. To study the variations in markers associated with cognitive functions, we extracted three event-related field (ERF) features from time-locked global field power (GFP) epochs using MEG while participants were performing a numerical N-back task in four consecutive measurements conducted during two different days separated by two weeks. We demonstrate that the latency of the M170, a neural correlate associated with cognitive functions such as working memory, was a stable parameter and did not show significant variations over time. In addition, the M170 peak amplitude and the mean amplitude of late positive component (LPP) also expressed moderate-to-strong reliability across multiple measures over time over many sensor spaces and between participants. The M170 amplitude varied more significantly between the measurements in some conditions but showed consistency over the participants over time. In addition we demonstrated significant correlation with the M170 and LPP parameters and cognitive load. The results are in line with the literature showing less within-subject fluctuation for the latency parameters and more consistency in between-subject comparisons for amplitude based features. The within-subject consistency was apparent also with longer delays between the measurements. We suggest that with a few limitations the ERF features show sufficient reliability and stability for longitudinal research designs and clinical applications for cognitive functions in single as well as cross-subject designs.
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Affiliation(s)
- L Ahonen
- Brain Work Research Centre, Finnish Institute of Occupational Health, Finland.
| | - M Huotilainen
- Brain Work Research Centre, Finnish Institute of Occupational Health, Finland; BioMag Laboratory, HUS Medical Imaging Center, Helsinki University Central Hospital, Finland
| | - E Brattico
- Center for Music in the Brain (MIB), Department of Clinical Medicine, Aarhus University, Denmark; Cognitive Brain Research Unit, Institute of Behavioural Sciences, University of Helsinki, Finland
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Campbell TA. A theory of attentional modulations of the supratemporal generation of the auditory mismatch negativity (MMN). Front Hum Neurosci 2015; 8:1065. [PMID: 25688198 PMCID: PMC4310267 DOI: 10.3389/fnhum.2014.01065] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2014] [Accepted: 12/22/2014] [Indexed: 11/13/2022] Open
Affiliation(s)
- Tom A Campbell
- Neuroscience Center, University of Helsinki Helsinki, Finland
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14
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Overlapping auditory M100 and M200 abnormalities in schizophrenia and bipolar disorder: a MEG study. Schizophr Res 2014; 160:201-7. [PMID: 25468188 DOI: 10.1016/j.schres.2014.10.042] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/24/2013] [Revised: 09/25/2014] [Accepted: 10/19/2014] [Indexed: 11/22/2022]
Abstract
OBJECTIVES Schizophrenia and bipolar disorder share common etiological factors and pathophysiological pathways and have overlapping clinical features. Only few studies have directly compared early auditory information processing in the two disorders. The objective of this study was to investigate the M100 and M200 auditory responses in patients with schizophrenia and bipolar disorder and compare them with healthy controls using magnetoencephalography (MEG). METHODS Whole-head MEG data were acquired during an auditory oddball paradigm in 24 schizophrenia patients, 26 bipolar I disorder patients, and 31 healthy controls. The strengths and latencies of M100 and M200 in both hemispheres and the dipole source localizations were investigated from the standard stimuli. RESULTS The M100 and M200 dipolar sources were localized to the left and right posterior portion of the superior temporal gyrus (STG) in all the subjects. An asymmetric pattern of M100 and M200 auditory response with more anterior sources in the right STG was observed in the healthy controls. However, both the schizophrenia and bipolar disorder patients showed a symmetric M100 and M200 source pattern. When compared with the healthy control group, both patient groups showed significantly reduced M100 and M200 source strength in both hemispheres. CONCLUSIONS Our study suggests that early auditory information processing deficits may be similar in schizophrenia and bipolar disorder and may be related to abnormalities of the STG.
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Huang S, Chang WT, Belliveau JW, Hämäläinen M, Ahveninen J. Lateralized parietotemporal oscillatory phase synchronization during auditory selective attention. Neuroimage 2013; 86:461-9. [PMID: 24185023 DOI: 10.1016/j.neuroimage.2013.10.043] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2013] [Revised: 09/24/2013] [Accepted: 10/18/2013] [Indexed: 10/26/2022] Open
Abstract
Based on the infamous left-lateralized neglect syndrome, one might hypothesize that the dominating right parietal cortex has a bilateral representation of space, whereas the left parietal cortex represents only the contralateral right hemispace. Whether this principle applies to human auditory attention is not yet fully clear. Here, we explicitly tested the differences in cross-hemispheric functional coupling between the intraparietal sulcus (IPS) and auditory cortex (AC) using combined magnetoencephalography (MEG), EEG, and functional MRI (fMRI). Inter-regional pairwise phase consistency (PPC) was analyzed from data obtained during dichotic auditory selective attention task, where subjects were in 10-s trials cued to attend to sounds presented to one ear and to ignore sounds presented in the opposite ear. Using MEG/EEG/fMRI source modeling, parietotemporal PPC patterns were (a) mapped between all AC locations vs. IPS seeds and (b) analyzed between four anatomically defined AC regions-of-interest (ROI) vs. IPS seeds. Consistent with our hypothesis, stronger cross-hemispheric PPC was observed between the right IPS and left AC for attended right-ear sounds, as compared to PPC between the left IPS and right AC for attended left-ear sounds. In the mapping analyses, these differences emerged at 7-13Hz, i.e., at the theta to alpha frequency bands, and peaked in Heschl's gyrus and lateral posterior non-primary ACs. The ROI analysis revealed similarly lateralized differences also in the beta and lower theta bands. Taken together, our results support the view that the right parietal cortex dominates auditory spatial attention.
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Affiliation(s)
- Samantha Huang
- Harvard Medical School, Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, MA, USA
| | - Wei-Tang Chang
- Harvard Medical School, Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, MA, USA
| | - John W Belliveau
- Harvard Medical School, Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, MA, USA; Harvard-MIT Division of Health Sciences and Technology, Cambridge, MA, USA
| | - Matti Hämäläinen
- Harvard Medical School, Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, MA, USA; Harvard-MIT Division of Health Sciences and Technology, Cambridge, MA, USA
| | - Jyrki Ahveninen
- Harvard Medical School, Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, MA, USA.
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Ahveninen J, Huang S, Belliveau JW, Chang WT, Hämäläinen M. Dynamic oscillatory processes governing cued orienting and allocation of auditory attention. J Cogn Neurosci 2013; 25:1926-43. [PMID: 23915050 DOI: 10.1162/jocn_a_00452] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
In everyday listening situations, we need to constantly switch between alternative sound sources and engage attention according to cues that match our goals and expectations. The exact neuronal bases of these processes are poorly understood. We investigated oscillatory brain networks controlling auditory attention using cortically constrained fMRI-weighted magnetoencephalography/EEG source estimates. During consecutive trials, participants were instructed to shift attention based on a cue, presented in the ear where a target was likely to follow. To promote audiospatial attention effects, the targets were embedded in streams of dichotically presented standard tones. Occasionally, an unexpected novel sound occurred opposite to the cued ear to trigger involuntary orienting. According to our cortical power correlation analyses, increased frontoparietal/temporal 30-100 Hz gamma activity at 200-1400 msec after cued orienting predicted fast and accurate discrimination of subsequent targets. This sustained correlation effect, possibly reflecting voluntary engagement of attention after the initial cue-driven orienting, spread from the TPJ, anterior insula, and inferior frontal cortices to the right FEFs. Engagement of attention to one ear resulted in a significantly stronger increase of 7.5-15 Hz alpha in the ipsilateral than contralateral parieto-occipital cortices 200-600 msec after the cue onset, possibly reflecting cross-modal modulation of the dorsal visual pathway during audiospatial attention. Comparisons of cortical power patterns also revealed significant increases of sustained right medial frontal cortex theta power, right dorsolateral pFC and anterior insula/inferior frontal cortex beta power, and medial parietal cortex and posterior cingulate cortex gamma activity after cued versus novelty-triggered orienting (600-1400 msec). Our results reveal sustained oscillatory patterns associated with voluntary engagement of auditory spatial attention, with the frontoparietal and temporal gamma increases being best predictors of subsequent behavioral performance.
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Affiliation(s)
- Jyrki Ahveninen
- Harvard Medical School-Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, MA
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Ahveninen J, Kopčo N, Jääskeläinen IP. Psychophysics and neuronal bases of sound localization in humans. Hear Res 2013; 307:86-97. [PMID: 23886698 DOI: 10.1016/j.heares.2013.07.008] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/15/2013] [Revised: 07/02/2013] [Accepted: 07/10/2013] [Indexed: 10/26/2022]
Abstract
Localization of sound sources is a considerable computational challenge for the human brain. Whereas the visual system can process basic spatial information in parallel, the auditory system lacks a straightforward correspondence between external spatial locations and sensory receptive fields. Consequently, the question how different acoustic features supporting spatial hearing are represented in the central nervous system is still open. Functional neuroimaging studies in humans have provided evidence for a posterior auditory "where" pathway that encompasses non-primary auditory cortex areas, including the planum temporale (PT) and posterior superior temporal gyrus (STG), which are strongly activated by horizontal sound direction changes, distance changes, and movement. However, these areas are also activated by a wide variety of other stimulus features, posing a challenge for the interpretation that the underlying areas are purely spatial. This review discusses behavioral and neuroimaging studies on sound localization, and some of the competing models of representation of auditory space in humans. This article is part of a Special Issue entitled Human Auditory Neuroimaging.
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Affiliation(s)
- Jyrki Ahveninen
- Harvard Medical School - Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, MA, USA.
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Cervenka MC, Franaszczuk PJ, Crone NE, Hong B, Caffo BS, Bhatt P, Lenz FA, Boatman-Reich D. Reliability of early cortical auditory gamma-band responses. Clin Neurophysiol 2013; 124:70-82. [PMID: 22771035 PMCID: PMC3468656 DOI: 10.1016/j.clinph.2012.06.003] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2011] [Revised: 05/10/2012] [Accepted: 06/14/2012] [Indexed: 11/15/2022]
Abstract
OBJECTIVE To evaluate the test-retest reliability of event-related power changes in the 30-150 Hz gamma frequency range occurring in the first 150 ms after presentation of an auditory stimulus. METHODS Repeat intracranial electrocorticographic (ECoG) recordings were performed with 12 epilepsy patients, at ≥1-day intervals, using a passive odd-ball paradigm with steady-state tones. Time-frequency matching pursuit analysis was used to quantify changes in gamma-band power relative to pre-stimulus baseline. Test-retest reliability was estimated based on within-subject comparisons (paired t-test, McNemar's test) and correlations (Spearman rank correlations, intra-class correlations) across sessions, adjusting for within-session variability. Reliability estimates of gamma-band response robustness, spatial concordance, and reproducibility were compared with corresponding measurements from concurrent auditory evoked N1 responses. RESULTS All patients showed increases in gamma-band power, 50-120 ms post-stimulus onset, that were highly robust across recordings, comparable to the evoked N1 responses. Gamma-band responses occurred regardless of patients' performance on behavioral tests of auditory processing, medication changes, seizure focus, or duration of test-retest interval. Test-retest reproducibility was greatest for the timing of peak power changes in the high-gamma range (65-150 Hz). Reliability of low-gamma responses and evoked N1 responses improved at higher signal-to-noise levels. CONCLUSIONS Early cortical auditory gamma-band responses are robust, spatially concordant, and reproducible over time. SIGNIFICANCE These test-retest ECoG results confirm the reliability of auditory gamma-band responses, supporting their utility as objective measures of cortical processing in clinical and research studies.
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Affiliation(s)
- Mackenzie C. Cervenka
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Piotr J. Franaszczuk
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Human Research and Engineering Directorate, U.S. Army Research Laboratory, Aberdeen Proving Ground, MD, USA
| | - Nathan E. Crone
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Bo Hong
- Department of Biomedical Engineering, Tsinghua University School of Medicine, Beijing, China
| | - Brian S. Caffo
- Department of Biostatistics, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - Paras Bhatt
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Frederick A. Lenz
- Department of Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Dana Boatman-Reich
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
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Validation of head movement correction and spatiotemporal signal space separation in magnetoencephalography. Clin Neurophysiol 2012; 123:2180-91. [DOI: 10.1016/j.clinph.2012.03.080] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2011] [Revised: 03/19/2012] [Accepted: 03/21/2012] [Indexed: 11/23/2022]
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Sörös P, Stanton SG. On Variability and Genes: Inter-individual Differences in Auditory Brain Function. Front Hum Neurosci 2012; 6:150. [PMID: 22675294 PMCID: PMC3365443 DOI: 10.3389/fnhum.2012.00150] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2011] [Accepted: 05/14/2012] [Indexed: 02/01/2023] Open
Affiliation(s)
- Peter Sörös
- Department of Clinical Neurological Sciences, London Health Sciences Centre, Western University London, ON, Canada
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Park YS, Kim BS, Lee DK, Lee SK, Kwon HC, Kim K, Lee YH, Chang JW. Assessment of non-motor hearing symptoms in hemifacial spasm using magnetoencephalography. Acta Neurochir (Wien) 2012; 154:509-15. [PMID: 22116454 DOI: 10.1007/s00701-011-1231-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2011] [Accepted: 11/09/2011] [Indexed: 11/26/2022]
Abstract
BACKGROUND Hemifacial spasm patients often suffer from non-motor symptoms such as tinnitus. These non-motor symptoms are known to be associated with changes in cortical activity. Magnetoencephalography (MEG) is a technique that can record brain activity noninvasively. To determine the usefulness of MEG in assessing changes in cortical activity associated with non-motor hearing symptoms in hemifacial spasm patients. METHODS We used MEG to evaluate the reactivity of the auditory cortex in 26 hemifacial spasm patients. We divided patients into a subjective tinnitus group (n = 10) and a non-tinnitus group (n = 16). The latency and amplitude of the most prominent deflection, N100m, was compared between the two groups. RESULTS There was a significant difference in the pure tone audiogram on the spasm side compared with the non-spasm side. After stimulation on the spasm side, the amplitude of the N100m peak in the contralateral hemisphere was lower in the subjective tinnitus group than in the non-tinnitus group. CONCLUSIONS Our results indicate that MEG can detect differences in cortical activity between hemifacial spasm patients with and without tinnitus. This suggests that MEG can identify changes in cortical activity associated with non-motor symptoms.
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Affiliation(s)
- Young Seok Park
- Department of Neurosurgery, Yonsei University College of Medicine, 134 Shinchon-Dong, Seodaemoon-Gu, Seoul, Korea
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Monahan PJ, Idsardi WJ. Auditory Sensitivity to Formant Ratios:Toward an Account of Vowel Normalization. LANGUAGE AND COGNITIVE PROCESSES 2010; 25:808-839. [PMID: 20606713 PMCID: PMC2893733 DOI: 10.1080/01690965.2010.490047] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
A long-standing question in speech perception research is how do listeners extract linguistic content from a highly variable acoustic input. In the domain of vowel perception, formant ratios, or the calculation of relative bark differences between vowel formants, have been a sporadically proposed solution. We propose a novel formant ratio algorithm in which the first (F1) and second (F2) formants are compared against the third formant (F3). Results from two magnetoencephelographic (MEG) experiments are presented that suggest auditory cortex is sensitive to formant ratios. Our findings also demonstrate that the perceptual system shows heightened sensitivity to formant ratios for tokens located in more crowded regions of the vowel space. Additionally, we present statistical evidence that this algorithm eliminates speaker-dependent variation based on age and gender from vowel productions. We conclude that these results present an impetus to reconsider formant ratios as a legitimate mechanistic component in the solution to the problem of speaker normalization.
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Affiliation(s)
- Philip J. Monahan
- Basque Center on Cognition, Brain and Language, Donostia-San Sebastián, Spain
| | - William J. Idsardi
- Department of Linguistics, University of Maryland, USA
- Neuroscience and Cognitive Science Program University of Maryland, USA
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23
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May PJC, Tiitinen H. Mismatch negativity (MMN), the deviance-elicited auditory deflection, explained. Psychophysiology 2010; 47:66-122. [DOI: 10.1111/j.1469-8986.2009.00856.x] [Citation(s) in RCA: 374] [Impact Index Per Article: 26.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Gilmore CS, Clementz BA, Berg P. Hemispheric differences in auditory oddball responses during monaural versus binaural stimulation. Int J Psychophysiol 2009; 73:326-33. [PMID: 19463866 PMCID: PMC2756307 DOI: 10.1016/j.ijpsycho.2009.05.005] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2008] [Revised: 03/24/2009] [Accepted: 05/09/2009] [Indexed: 11/17/2022]
Abstract
Hemispheric lateralization of early event-related potentials (ERPs; e.g. N1) is largely based on anatomy of the afferent pathway; lateralization of later auditory ERPs (P2/N2, P250, P3b) is less clear. Using 257-channel EEG, the present study examined hemispheric laterality of auditory ERPs by comparing binaural and monaural versions of an auditory oddball task. N1 showed a contralateral bias over auditory cortex in both hemispheres as a function of ear of stimulation, although right hemisphere sources were activated regardless of which ear received input. Beginning around N1 and continuing through the time of P3b, right hemisphere temporal-parietal and frontal areas were more activated than their left hemisphere counterparts for stimulus evaluation/comparison and target detection. P250 and P3b component amplitudes, topographies, and source estimations were significantly influenced by ear of stimulation, with right hemisphere activity being stronger. This was particularly true for anterior temporal and inferior frontal sources which were more strongly associated with the later, more cognitive components (P250, P3b). Results are consistent with theories of a right hemisphere network that is prominently involved in sustained attention, stimulus evaluation, target detection, and working memory/context updating.
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Affiliation(s)
- Casey S Gilmore
- Department of Psychology, University of Minnesota, Elliott Hall, 75 East River Road, Minneapolis, MN 55455, USA.
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25
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Dikker S, Rabagliati H, Pylkkänen L. Sensitivity to syntax in visual cortex. Cognition 2009; 110:293-321. [PMID: 19121826 DOI: 10.1016/j.cognition.2008.09.008] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2007] [Revised: 09/17/2008] [Accepted: 09/19/2008] [Indexed: 11/15/2022]
Abstract
One of the most intriguing findings on language comprehension is that violations of syntactic predictions can affect event-related potentials as early as 120 ms, in the same time-window as early sensory processing. This effect, the so-called early left-anterior negativity (ELAN), has been argued to reflect word category access and initial syntactic structure building (Friederici, 2002). In two experiments, we used magnetoencephalography to investigate whether (a) rapid word category identification relies on overt category-marking closed-class morphemes and (b) whether violations of word category predictions affect modality-specific sensory responses. Participants read sentences containing violations of word category predictions. Unexpected items varied in whether or not their word category was marked by an overt function morpheme. In Experiment 1, the amplitude of the visual evoked M100 component was increased for unexpected items, but only when word category was overtly marked by a function morpheme. Dipole modeling localized the generator of this effect to the occipital cortex. Experiment 2 replicated the main results of Experiment 1 and eliminated two non-morphology-related explanations of the M100 contrast we observed between targets containing overt category-marking and targets that lacked such morphology. Our results show that during reading, syntactically relevant cues in the input can affect activity in occipital regions at around 125 ms, a finding that may shed new light on the remarkable rapidity of language processing.
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Affiliation(s)
- Suzanne Dikker
- Department of Linguistics, New York University, New York, NY 10003, USA
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Campbell T, Winkler I, Kujala T. N1 and the mismatch negativity are spatiotemporally distinct ERP components: Disruption of immediate memory by auditory distraction can be related to N1. Psychophysiology 2007; 44:530-40. [PMID: 17532805 DOI: 10.1111/j.1469-8986.2007.00529.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Event-related potentials (ERPs) were recorded for ignored tones presented during the retention interval of a delayed serial recall task. The mismatch negativity (MMN) and N1 ERP components were measured to discern spatiotemporal and functional properties of their generation. A nine-token sequence with nine different tone pitches was more disruptive than an oddball (two-token) sequence, yet this oddball sequence was no more disruptive than a single repeating tone (one-token). Tones of the nine-token sequence elicited augmented N1 amplitudes compared to identical tones delivered in the one-token sequence, yet deviants elicited an additional component (MMN) with distinct temporal properties and topography. These results suggested that MMN and N1 are separate, functionally distinct components. Implications are discussed for the N1 hypothesis and the changing-state hypothesis of the disruption of serial recall performance by auditory distraction.
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Affiliation(s)
- Tom Campbell
- Helsinki Collegium for Advanced Studies, University of Helsinki, Helsinki, Finland.
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27
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Boeijinga PH, Soufflet L, Santoro F, Luthringer R. Ketamine effects on CNS responses assessed with MEG/EEG in a passive auditory sensory-gating paradigm: an attempt for modelling some symptoms of psychosis in man. J Psychopharmacol 2007; 21:321-37. [PMID: 17591659 DOI: 10.1177/0269881107077768] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Disturbances in integrative function have been consistentLy described in psychotic disorder; for instance, prepulse inhibition of the startle reflex (startle-PPI) which is a marker of sensory gating, is deficient in persons with schizophrenia. The N-methyl-D-aspartate antagonist ketamine produces in control subjects a spectrum of neurobehavioural symptoms like encountered in schizophrenia, and disrupts startle-PPI in animals. In the present study, we investigated in 12 healthy subjects whether ketamine would reduce sensory-gating in auditory responses at doses which produce psychotic symptoms. In a double-blind, crossover design loading doses of 0.024, 0.081 and 0.27 mg/kg or saline were employed, followed by maintenance infusion for 120 min. A passive paradigm has been developed which consisted in tone bursts, preceded or not by a (near-threshold) click at intervals of 100 ms or 500 ms. Brain electromagnetic activity imaging of the responses to sound stimuli has been carried out by way of a 148-channel magnetoencephalography-system. Actual evoked response amplitudes and underlying equivalent current dipole strengths have been compared to multi-electrode evoked potentials from the scalp. A click stimulus is capable to inhibit test responses under placebo at the 100 ms interval. During maintenance infusion of ketamine at steady-state (for >30 min) after 0.27 mg/kg, no such amplitude changes were observed anymore (p <0.05) and under these circumstances significant increases in Brief Psychiatric Rating scale and Scale for the Assessment of Negative Symptoms scores were evidenced (p < 0.001). Intermediate effects have been observed when the dose was lowered to 0.081 mg/kg. The present results have shown that ketamine may induce a psychotic-like clinical state associated with gating deficits in healthy subjects.
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Affiliation(s)
- Peter H Boeijinga
- FORENAP - FRP - Institute for Research in Neuroscience, Neuropharmacology and Psychiatry, Rouffach, France. [corrected]
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28
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Korvenoja A, Kirveskari E, Aronen HJ, Avikainen S, Brander A, Huttunen J, Ilmoniemi RJ, Jääskeläinen JE, Kovala T, Mäkelä JP, Salli E, Seppä M. Sensorimotor Cortex Localization: Comparison of Magnetoencephalography, Functional MR Imaging, and Intraoperative Cortical Mapping. Radiology 2006; 241:213-22. [PMID: 16908676 DOI: 10.1148/radiol.2411050796] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PURPOSE To prospectively evaluate magnetoencephalography (MEG) and functional magnetic resonance (MR) imaging, as compared with intraoperative cortical mapping, for identification of the central sulcus. MATERIALS AND METHODS Fifteen patients (six men, nine women; age range, 25-58 years) with a lesion near the primary sensorimotor cortex (13 gliomas, one cavernous hemangioma, and one meningioma) were examined after institutional review board approval and written informed consent from each patient were obtained. At MEG, evoked magnetic fields to median nerve stimulation were recorded; at functional MR imaging, hemodynamic responses to self-paced palmar flexion of the wrist were imaged. General linear model analysis with contextual clustering (P < .01) was used to analyze functional MR imaging data, and dipole modeling was used to analyze MEG data. MEG and functional MR localizations were compared with intraoperative cortical mappings. The distance from the area of functional MR imaging activation to the tumor margin was compared between the patients with discordant and those with concordant intraoperative mapping findings by using unpaired t testing. RESULTS MEG depicted the central sulcus correctly in all 15 patients, as verified at intraoperative mapping. The functional MR imaging localization results agreed with the intraoperative mappings in 11 patients. In all four patients with a false localization, the primary activation was in the postcentral sulcus region, but it did not differ significantly from the primary activation in the patients with correct localization with respect to proximity to the tumor (P = .38). Furthermore, at functional MR imaging, multiple nonprimary areas were activated, with considerable interindividual variation. CONCLUSION Although both MEG and functional MR imaging can provide useful information for neurosurgical planning, in the present study, MEG proved to be superior for locating the central sulcus. Activation of multiple nonprimary cerebral areas may confound the interpretation of functional MR imaging results.
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Affiliation(s)
- Antti Korvenoja
- Functional Brain Imaging Unit, Helsinki Brain Research Center, Medical Imaging Center, University of Helsinki, Helsinki, Finland.
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Sörös P, Michael N, Tollkötter M, Pfleiderer B. The neurochemical basis of human cortical auditory processing: combining proton magnetic resonance spectroscopy and magnetoencephalography. BMC Biol 2006; 4:25. [PMID: 16884545 PMCID: PMC1553472 DOI: 10.1186/1741-7007-4-25] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2006] [Accepted: 08/03/2006] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND A combination of magnetoencephalography and proton magnetic resonance spectroscopy was used to correlate the electrophysiology of rapid auditory processing and the neurochemistry of the auditory cortex in 15 healthy adults. To assess rapid auditory processing in the left auditory cortex, the amplitude and decrement of the N1m peak, the major component of the late auditory evoked response, were measured during rapidly successive presentation of acoustic stimuli. We tested the hypothesis that: (i) the amplitude of the N1m response and (ii) its decrement during rapid stimulation are associated with the cortical neurochemistry as determined by proton magnetic resonance spectroscopy. RESULTS Our results demonstrated a significant association between the concentrations of N-acetylaspartate, a marker of neuronal integrity, and the amplitudes of individual N1m responses. In addition, the concentrations of choline-containing compounds, representing the functional integrity of membranes, were significantly associated with N1m amplitudes. No significant association was found between the concentrations of the glutamate/glutamine pool and the amplitudes of the first N1m. No significant associations were seen between the decrement of the N1m (the relative amplitude of the second N1m peak) and the concentrations of N-acetylaspartate, choline-containing compounds, or the glutamate/glutamine pool. However, there was a trend for higher glutamate/glutamine concentrations in individuals with higher relative N1m amplitude. CONCLUSION These results suggest that neuronal and membrane functions are important for rapid auditory processing. This investigation provides a first link between the electrophysiology, as recorded by magnetoencephalography, and the neurochemistry, as assessed by proton magnetic resonance spectroscopy, of the auditory cortex.
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Affiliation(s)
- Peter Sörös
- Department of Imaging Research, Sunnybrook Health Sciences Centre, Toronto, ON, Canada
| | - Nikolaus Michael
- Department of Psychiatry, University Hospital Münster, Münster, Germany
| | - Melanie Tollkötter
- Department of Clinical Radiology, University Hospital Münster, Münster, Germany
| | - Bettina Pfleiderer
- Department of Clinical Radiology, University Hospital Münster, Münster, Germany
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Boonstra TW, Daffertshofer A, Peper CE, Beek PJ. Amplitude and phase dynamics associated with acoustically paced finger tapping. Brain Res 2006; 1109:60-9. [PMID: 16860292 DOI: 10.1016/j.brainres.2006.06.039] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2006] [Revised: 06/12/2006] [Accepted: 06/13/2006] [Indexed: 11/17/2022]
Abstract
To gain insight into the brain activity associated with the performance of an acoustically paced synchronization task, we analyzed the amplitude and phase dynamics inherent in magnetoencephalographic (MEG) signals across frequency bands in order to discriminate between evoked and induced responses. MEG signals were averaged with respect to motor and auditory events (tap and tone onsets). Principal component analysis was used to compare amplitude and phase changes during listening and during paced and unpaced tapping, allowing a separation of brain activity related to motor and auditory processes, respectively. Motor performance was accompanied by phasic amplitude changes and increased phase locking in the beta band. Auditory processing of acoustic stimuli resulted in a simultaneous increase of amplitude and phase locking in the theta and alpha band. The temporal overlap of auditory-related amplitude changes and phase locking indicated an evoked response, in accordance with previous studies on auditory perception. The temporal difference of movement-related amplitude and phase dynamics in the beta band, on the other hand, suggested a change in ongoing brain activity, i.e., an induced response supporting previous results on motor-related brain dynamics in the beta band.
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Affiliation(s)
- T W Boonstra
- Institute for Fundamental and Clinical Human Movement Sciences, Faculty of Human Movement Sciences, Vrije Universiteit, Van der Boechorststraat 9, 1081 BT Amsterdam, The Netherlands.
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Abstract
OBJECTIVE To determine if (1) evoked potentials elicited by amplified speech sounds (/si/ and /[symbol: see text]/) can be recorded reliably in individuals, (2) amplification alters neural response patterns, and (3) different amplified speech sounds evoke different neural patterns. DESIGN Cortical evoked potentials were recorded in sound field from seven normal-hearing young adults in response to naturally produced speech tokens /si/ and /[symbol: see text]/ from the Nonsense Syllable Test. With the use of a repeated-measures design, subjects were tested and then retested within an 8-day period in both aided and unaided conditions. RESULTS (1) Speech-evoked cortical potentials can be recorded reliably in individuals in both aided and unaided conditions. (2) Hearing aids that provide a mild high-frequency gain only subtly enhance peak amplitudes relative to unaided cortical recordings. (3) If the consonant-vowel boundary is preserved by the hearing aid, it can also be detected neurally, resulting in different neural response patterns for /si/ and /[symbol: see text]/. CONCLUSIONS Speech-evoked cortical potentials can be recorded reliably in individuals during hearing aid use. A better understanding of how amplification (and device settings) affects neural response patterns is still needed.
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Affiliation(s)
- Kelly L Tremblay
- Department of Speech and Hearing Sciences, University of Washington, Seattle, Washington 98105, USA.
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Darvas F, Rautiainen M, Pantazis D, Baillet S, Benali H, Mosher JC, Garnero L, Leahy RM. Investigations of dipole localization accuracy in MEG using the bootstrap. Neuroimage 2005; 25:355-68. [PMID: 15784414 DOI: 10.1016/j.neuroimage.2004.09.045] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2004] [Revised: 07/30/2004] [Accepted: 09/28/2004] [Indexed: 10/25/2022] Open
Abstract
We describe the use of the nonparametric bootstrap to investigate the accuracy of current dipole localization from magnetoencephalography (MEG) studies of event-related neural activity. The bootstrap is well suited to the analysis of event-related MEG data since the experiments are repeated tens or even hundreds of times and averaged to achieve acceptable signal-to-noise ratios (SNRs). The set of repetitions or epochs can be viewed as a set of independent realizations of the brain's response to the experiment. Bootstrap resamples can be generated by sampling with replacement from these epochs and averaging. In this study, we applied the bootstrap resampling technique to MEG data from somatotopic experimental and simulated data. Four fingers of the right and left hand of a healthy subject were electrically stimulated, and about 400 trials per stimulation were recorded and averaged in order to measure the somatotopic mapping of the fingers in the S1 area of the brain. Based on single-trial recordings for each finger we performed 5000 bootstrap resamples. We reconstructed dipoles from these resampled averages using the Recursively Applied and Projected (RAP)-MUSIC source localization algorithm. We also performed a simulation for two dipolar sources with overlapping time courses embedded in realistic background brain activity generated using the prestimulus segments of the somatotopic data. To find correspondences between multiple sources in each bootstrap, sample dipoles with similar time series and forward fields were assumed to represent the same source. These dipoles were then clustered by a Gaussian Mixture Model (GMM) clustering algorithm using their combined normalized time series and topographies as feature vectors. The mean and standard deviation of the dipole position and the dipole time series in each cluster were computed to provide estimates of the accuracy of the reconstructed source locations and time series.
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Affiliation(s)
- F Darvas
- Signal and Image Processing Institute, USC, Los Angeles, CA 90089, USA
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Simos PG, Sarkari S, Castillo EM, Billingsley-Marshall RL, Pataraia E, Clear T, Papanicolaou AC. Reproducibility of measures of neurophysiological activity in Wernicke's area: a magnetic source imaging study. Clin Neurophysiol 2005; 116:2381-91. [PMID: 16099211 DOI: 10.1016/j.clinph.2005.06.019] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2004] [Revised: 05/23/2005] [Accepted: 06/08/2005] [Indexed: 10/25/2022]
Abstract
OBJECTIVE The purpose of this study was to evaluate the reproducibility of estimates of neurophysiological activity obtained with Magnetic Source Imaging. METHODS Split-half data sets were obtained from 14 healthy volunteers during performance of a continuous recognition task for spoken words. The concurrent validity of spatiotemporal activation maps obtained with this task has been previously verified through comparisons with the Wada test and electrocortical stimulation mapping. Consecutive late activity sources (> 200 ms after stimulus onset) were modeled independently as equivalent current dipoles (ECDs) and used to identify the location of language-specific cortex in the left hemisphere (Wernicke's area). RESULTS Linear displacement of the geometric center of the cluster of ECDs in this region ranged between 2 and 8 mm across subjects. Intraparticipant variability (range) in the onset latency of activity was +/-50 ms, while the range of change in global field power for the entire set of ECDs in Wernicke's area was less than 17% in all cases. CONCLUSIONS The results indicate that despite its many conceptual limitations the ECD model can provide reliable estimates of regional cortical activity associated with the engagement of linguistic processes. SIGNIFICANCE The results highlight the need for reproducibility studies when research questions pose particular requirements for precision of estimates of regional neurophysiological activity.
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Affiliation(s)
- Panagiotis G Simos
- Department of Psychology, University of Crete, Rethymno, Crete 74100, Greece.
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Tervaniemi M, Sinkkonen J, Virtanen J, Kallio J, Ilmoniemi RJ, Salonen O, Näätänen R. Test–retest stability of the magnetic mismatch response (MMNm). Clin Neurophysiol 2005; 116:1897-905. [PMID: 15990358 DOI: 10.1016/j.clinph.2005.03.025] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2003] [Revised: 02/18/2005] [Accepted: 03/12/2005] [Indexed: 11/25/2022]
Abstract
OBJECTIVE We investigated the replicability of the magnetically measured mismatch negativity (MMNm). METHODS The MMNm was recorded twice by using a 122-channel whole-head magnetometer in 15 healthy young adults. The MMNm responses for duration, intensity and frequency deviants were analyzed separately in left and right hemispheres for the response strength, latency, dipole moment, and generator loci. RESULTS In the right hemisphere, the test-retest correlations were statistically significant for all MMNm parameters (r = 0.49-0.89). In the left hemisphere, the majority of the MMNm parameters also demonstrated statistically significant test-retest correlations (r = 0.61-0.82). In addition, the MMNm generator loci were stable for all deviants. CONCLUSIONS AND SIGNIFICANCE The present results are encouraging in terms of both research and clinical use of MMNm in studying human auditory discrimination in its normal and deteriorated states.
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Affiliation(s)
- Mari Tervaniemi
- Cognitive Brain Research Unit, Department of Psychology, University of Helsinki, P.O. Box 9, Finland.
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Campbell T, Winkler I, Kujala T. Disruption of immediate memory and brain processes: an auditory ERP protocol. ACTA ACUST UNITED AC 2005; 14:77-86. [PMID: 15721813 DOI: 10.1016/j.brainresprot.2004.11.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/01/2004] [Indexed: 10/26/2022]
Abstract
An event-related potential (ERP) protocol is described that can be used to investigate those sound-evoked neural processes that may be implicated in disrupting immediate memory. Conventional electroencephalogram (EEG) is recorded during the performance of a task that involves ignoring irrelevant sounds while trying to hold in memory lists of numbers. Specific bioelectric measures are made to prevent the contamination of recordings by the movements of articulators. An approach is also outlined which controls the timing of ERP components to sounds with different envelopes. Using this approach, it has been shown that the neural processes involved in the elicitation of the auditory N1 ERP response may be involved in the disruption of memory for serial order produced by irrelevant sound.
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Affiliation(s)
- Tom Campbell
- Helsinki Collegium for Advanced Studies, University of Helsinki, Finland.
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36
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Kähkönen S, Marttinen Rossi E, Yamashita H. Alcohol impairs auditory processing of frequency changes and novel sounds: a combined MEG and EEG study. Psychopharmacology (Berl) 2005; 177:366-72. [PMID: 15290001 DOI: 10.1007/s00213-004-1960-1] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/12/2003] [Accepted: 06/03/2004] [Indexed: 10/26/2022]
Abstract
RATIONALE Alcohol has been shown to impair involuntary attention studied by event-related potentials using mismatch negativity (MMN) and P3a. OBJECTIVES However, no studies have investigated whether alcohol affects the magnetic counterparts of N1 (N1m), MMN (MMNm) and P3a (P3am). METHODS Auditory evoked potentials and magnetic fields elicited by infrequent deviant tones differing in frequency (5% and 20% change) and novel sounds were recorded with whole-head magnetoencephalography (MEG) and electroencephalography (EEG). Stimuli were presented separately to the left and right ear. Eleven right-handed subjects were studied in a double-blind, placebo-controlled (0.8 g/kg ethanol or juice), cross-over design. N1m, MMNm, and P3am were calculated from the channel pair at the temporal cortex showing the strongest responses in the hemisphere contralateral to the stimulation. N1, MMN and P3a were analyzed from 12 electrodes at the midline frontocentral area. RESULTS Alcohol reduced bilaterally N1, N1m, MMN and MMNm amplitudes. P3a amplitudes, but not P3am amplitudes were also significantly decreased. No effects of alcohol on the latencies of N1, MMN and P3a or their magnetic counterparts were observed. CONCLUSIONS Alcohol impairs the processing of tones, frequency change and novel sounds at different phases of auditory processing similarly in both hemispheres. MEG provides us with additional information unobtainable with EEG about the effects of alcohol on the neural correlates of cognition.
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Affiliation(s)
- Seppo Kähkönen
- BioMag Laboratory, Helsinki University Central Hospital, PO Box 340, 00290, Helsinki, Finland.
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37
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Campbell T, Winkler I, Kujala T, Näätänen R. The N1 hypothesis and irrelevant sound: evidence from token set size effects. ACTA ACUST UNITED AC 2004; 18:39-47. [PMID: 14659495 DOI: 10.1016/j.cogbrainres.2003.09.001] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
This study investigated how increases in the number of different types of sound (token set size) within a heard but ignored sequence influence brain activity and performance in a serial recall task (the irrelevant sound effect). We tested the hypothesis that brain processes affected by the refractory state of the neuronal populations involved in generating the auditory N1 play a role in the memory disruption produced by irrelevant sound. Auditory event-related potentials (ERPs) were recorded when volunteers performed a serial recall task that required remembering lists of visually presented numbers that were followed by a distractor-filled retention interval. The results showed that both increments in set size from 1 to 2 and from 2 to 5 elicited an increase of the N1 amplitude. Furthermore, increases in set size from 2 to 5, but not from 1 to 2, caused a significant decrease of the serial recall performance. This result suggested that, if N1 were to play a role in the disruption produced by irrelevant sound, the processes underlying the N1 wave may only serve as a necessary rather than a sufficient condition for disruption.
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Affiliation(s)
- Tom Campbell
- Cognitive Brain Research Unit, University of Helsinki, Helsinki, Finland
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38
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Crowley KE, Colrain IM. A review of the evidence for P2 being an independent component process: age, sleep and modality. Clin Neurophysiol 2004; 115:732-44. [PMID: 15003751 DOI: 10.1016/j.clinph.2003.11.021] [Citation(s) in RCA: 573] [Impact Index Per Article: 28.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/17/2003] [Indexed: 11/21/2022]
Abstract
This article reviews the event-related potential (ERP) literature in relation to the P2 waveform of the human auditory evoked potential. Within the auditory evoked potential, a positive deflection at approximately 150-250 ms is a ubiquitous feature. Unlike other cognitive components such as N1 or the P300, remarkably little has been done to investigate the underlying neurological correlates or significance of this waveform. Indeed until recently, many researchers considered it to be an intrinsic part of the 'vertex potential' complex, involving it and the earlier N1. This review seeks to describe the evidence supportive of P2 being the result of independent processes and highlights several features, such as its persistence from wakefulness into sleep, the general consensus that unlike most other EEG phenomena it increases with age, and the fact that it can be generated using respiratory stimuli.
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Affiliation(s)
- Kate E Crowley
- Human Sleep Research Program, SRI International, 333 Ravenswood Avenue, Menlo Park, CA 94025, USA.
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Eulitz C, Obleser J, Lahiri A. Intra-subject replication of brain magnetic activity during the processing of speech sounds. ACTA ACUST UNITED AC 2004; 19:82-91. [PMID: 14972361 DOI: 10.1016/j.cogbrainres.2003.11.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/18/2003] [Indexed: 11/20/2022]
Abstract
The present study examined the cortical activity during processing of vocalic segments by means of whole-head magnetoencephalography (MEG) to see whether respective cortical maps are stable across repeated measurements. We investigated the spatial configuration and temporal characteristics of the N100m generators of the auditory-evoked field during the processing of the synthetic German vowels [a], [e] and [i] across 10 repeated measurements in a single subject. Between vowels, N100m latency as well as source location differences were found with the latency differences being in accordance with tonochronic principles. The spatial configuration of the different vowel sources was related to differences in acoustic/phonological features. Vowels differing maximally in those features, i.e., [a] and [i], showed larger Euclidean distances between N100m vowel sources than [e] and [i]. This pattern was repeatable across sessions and independent of the source modeling strategy for left-hemispheric data. Compared to a pure tone control condition, the N100m generators of vowels were localized in more anterior, superior and lateral parts of the temporal lobe and showed longer latencies. Being aware of the limited significance of conclusions drawn from a single case study, the study yielded a repeatable spatial and temporal pattern of vowel source activity in the auditory cortex which was determined by the distinctiveness of the formant frequencies corresponding to abstract phonological features.
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Affiliation(s)
- Carsten Eulitz
- Department of Clinical Psychology, University of Konstanz, Giessberg 10, P.O. Box D25, 78457 Konstanz, Germany.
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40
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Pang EW, Gaetz W, Otsubo H, Chuang S, Cheyne D. Localization of auditory N1 in children using MEG: source modeling issues. Int J Psychophysiol 2003; 51:27-35. [PMID: 14629920 DOI: 10.1016/s0167-8760(03)00150-8] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Techniques for localizing auditory (AEF) sources are a topic of on-going discussion and this is particularly pertinent in pediatric research. Smaller head sizes are: (1) subject to bilateral temporal lobe source interference from both temporal lobes; and (2) further from MEG sensors resulting in poorer signal-to-noise ratios. An additional consideration in children is that the components of the AEF have distinct contributions along the development spectrum resulting in an ever-changing morphology for the pediatric AEF. These factors present a complicated picture for dipole fitting and raise the question of the most effective fitting strategy. We examined the AEF localizations in five children from 151, 70 and 47 MEG channels of data. We found evidence that bilateral source interaction could result in localization errors along the medial-lateral axis of up to 1 cm. We suggest that any modeling strategy needs to sufficiently account for this interaction and more precise models allowing for multiple sources need to be developed.
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Affiliation(s)
- Elizabeth W Pang
- Division of Neurology, Hospital for Sick Children, Toronto, ONT, Canada M5G 1X8.
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41
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Tremblay KL, Friesen L, Martin BA, Wright R. Test-retest reliability of cortical evoked potentials using naturally produced speech sounds. Ear Hear 2003; 24:225-32. [PMID: 12799544 DOI: 10.1097/01.aud.0000069229.84883.03] [Citation(s) in RCA: 104] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
OBJECTIVE To determine if naturally produced speech stimuli evoke distinct neural response patterns that can be reliably recorded in individuals. DESIGN Auditory cortical evoked potentials were obtained from seven normal-hearing young adults in response to four naturally produced speech tokens (/bi/, /pi/, /[U0283]i/, and /si/). Stimuli were tokens from the standardized UCLA version of the Nonsense Syllable Test (NST) ( Dubno & Schaefer, 1992). Using a repeated measures design, subjects were tested and then retested within an 8-day period. RESULTS Auditory cortical evoked potentials elicited by naturally produced speech sounds were reliably recorded in individuals. Also, naturally produced speech tokens, representing different acoustic cues, evoked distinct neural response patterns. CONCLUSIONS 1) Cortical evoked potentials elicited by naturally produced speech sounds can be reliably recorded in individuals. 2) Naturally produced speech tokens, representing different acoustic cues, evoke distinct neural response patterns. 3) Given the reliability of the response, this work has potential application to the study of neural processing of speech in individuals with communication disorders as well as changes over time after various types of auditory rehabilitation.
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Affiliation(s)
- K L Tremblay
- Department of Speech and Hearing Sciences, University of Washington, 1417 NE 42nd St., Seattle, WA 98105, USA.
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42
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Kwon H, Lee YH, Kim JM, Park YK, Kuriki S. Localization accuracy of single current dipoles from tangential components of auditory evoked fields. Phys Med Biol 2002; 47:4145-54. [PMID: 12502039 DOI: 10.1088/0031-9155/47/23/302] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
We investigated the localization accuracy of single current dipoles from the tangential components of auditory evoked fields. The tangential fields were measured using planar gradiometers arranged in a way so as to detect two orthogonal field components parallel to a flat plane. Field responses to 1 kHz pure tones were recorded and equivalent current dipoles (ECDs) of N1m peak were estimated based on a locally fitted spherical conductor model. As a measure of localization accuracy, the standard deviation of the coordinates of the ECDs of N1m was obtained from repeated measurements for one subject. The estimated ECDs had a standard deviation of 5.5 mm and their mean location was at the supratemporal plane in the sylvian fissure on the MR image of the subject. In order to investigate the contribution of various errors to the localization accuracy, simulations using a sphere model and experiments using a realistically shaped skull phantom were performed. It was found that the background noise, which consisted of instrumental noise and spontaneous brain fields, was the main source of the errors that could explain the observed standard deviation. Further, the amount of systematic error was much less than the standard deviation due to the background noise. These results suggest that the volume currents in a non-spherical conductor shape such as the temporal region do not produce substantial errors in the localization of current dipoles from tangential components of auditory evoked fields.
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Affiliation(s)
- H Kwon
- Korea Research Institute of Standards and Science, PO Box 102, Yuseong, Daejeon, 305-600 Korea.
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43
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Herrmann CS, Knight RT. Mechanisms of human attention: event-related potentials and oscillations. Neurosci Biobehav Rev 2001; 25:465-76. [PMID: 11595268 DOI: 10.1016/s0149-7634(01)00027-6] [Citation(s) in RCA: 421] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Electrophysiological and hemodynamical responses of the brain allow investigation of the neural origins of human attention. We review attention-related brain responses from auditory and visual tasks employing oddball and novelty paradigms. Dipole localization and intracranial recordings as well as functional magnetic resonance imaging reveal multiple areas involved in generating and modulating attentional brain responses. In addition, the influence of brain lesions of circumscribed areas of the human cortex onto attentional mechanisms are reviewed. While it is obvious that damaged brain tissue no longer functions properly, it has also been shown that functions of non-lesioned brain areas are impaired due to loss of modulatory influence of the lesioned area. Both early (P1 and N1) and late (P3) event-related potentials are modulated by excitatatory and inhibitory mechanisms. Oscillatory EEG-correlates of attention in the alpha and gamma frequency range also show attentional modulation.
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Affiliation(s)
- C S Herrmann
- Max Planck Institute of Cognitive Neuroscience, D-04303, Leipzig, Germany
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44
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Vasama JP, Marttila T, Lahin T, Mäkelä JP. Auditory pathway function after vestibular schwannoma surgery. Acta Otolaryngol 2001; 121:378-83. [PMID: 11425204 DOI: 10.1080/000164801300102833] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
We studied seven patients before and after vestibular schwannoma surgery. Four patients became unilaterally profoundly deaf and three patients preserved their hearing. Cortical responses were recorded with a 122-channel whole-scalp SQUID neuromagnetometer using tone-burst stimuli to the healthy ear. Brainstem auditory evoked potentials (BAEPs) were measured using alternating clicks. Ten healthy volunteers served as a control group. In patients, preoperative cortical response latencies and strengths did not differ significantly from those of controls. However, 6 months after the operation the latency was, on average, 7 ms longer than preoperatively over both hemispheres. BAEPs were in the normal range both before and after the operation. These results suggest that unilateral lesion in peripheral auditory pathways also affects cortical reactivity to stimuli presented to the non-affected ear, possibly reflecting altered binaural interaction in the auditory pathways.
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Affiliation(s)
- J P Vasama
- Department of Otolaryngology, Medical Engineering Centre, Helsinki University Central Hospital, Finland.
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45
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Albrecht R, Suchodoletz W, Uwer R. The development of auditory evoked dipole source activity from childhood to adulthood. Clin Neurophysiol 2000; 111:2268-76. [PMID: 11090781 DOI: 10.1016/s1388-2457(00)00464-8] [Citation(s) in RCA: 115] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
OBJECTIVE Multi-channel recordings show that observed developmental changes of late auditory evoked potentials (LAEP) depend on the location of the scalp electrode. These findings suggest that different LAEP generators have a distinct developmental course. The goal of this study was to investigate the maturational process of cortical LAEP generators. METHODS Eighty-seven healthy children and adolescents with normal hearing, ages 5-16 years, and 21 adults, ages 20-30 years, participated in the study. Pure tone LAEP were recorded from 21 derivations. Dipole source analysis was performed by means of brain electric source analysis (BESA). Peak latencies and amplitudes of dipole source activity were estimated. RESULTS While the number, location, and direction of dipole sources were similar in children and adults, the course of their activity differed greatly. The latencies shortened and the amplitudes decreased during development. In adolescence a new component appeared in the activity of the tangential dipole, which reflects the generators in the supra-temporal plane. The variability of parameters was greater in children than in adults. CONCLUSIONS Since the dipole source activity of LAEP in childhood differs considerably from that in adulthood, dipole source analysis could be a useful tool for studying both normal and disturbed maturation of the auditory perceptual function.
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Affiliation(s)
- R Albrecht
- Department of Child and Adolescent Psychiatry, University of Munich, Nussbaumstrasse 7, D-80336, Munich, Germany
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46
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Ahveninen J, Jääskeläinen IP, Pekkonen E, Hallberg A, Hietanen M, Näätänen R, Sillanaukee P. Global field power of auditory N1 correlates with impaired verbal-memory performance in human alcoholics. Neurosci Lett 2000; 285:131-4. [PMID: 10793244 DOI: 10.1016/s0304-3940(00)01041-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
First weeks after alcohol withdrawal, associated with profound changes in neural transmission, constitute the critical period for relapse prevention and pharmacological intervention in alcoholism. Here, 20 male alcoholics with 1-6 weeks of abstinence and 20 age-matched healthy controls were studied using auditory event-related potentials (ERP), measured with a 32-channel electroencephalogram, and neuropsychological tests of auditory-verbal memory. Global field power maximum of ERP during 80-150 ms period after presentation of unattended tones (binaural 700 Hz pure tones, inter-stimulus interval 2.5 s) was significantly (P<0.01) larger in the alcoholics than controls. This effect, reflecting augmented N1 generation, significantly correlated (r=0.5) with impaired memory performance in the alcoholics. The profound change in pre-attentive auditory processing, predicting impaired memory performance, might reflect impaired cerebral inhibitory transmission in alcoholics.
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Affiliation(s)
- J Ahveninen
- Cognitive Brain Research Unit, Department of Psychology, P.O. Box 13, FIN-00014 University of, Helsinki, Finland.
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47
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Roberts TP, Ferrari P, Stufflebeam SM, Poeppel D. Latency of the auditory evoked neuromagnetic field components: stimulus dependence and insights toward perception. J Clin Neurophysiol 2000; 17:114-29. [PMID: 10831104 DOI: 10.1097/00004691-200003000-00002] [Citation(s) in RCA: 126] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
This review will focus on investigations of the auditory evoked neuromagnetic field component, the M100, detectable in the magnetoencephalogram recorded during presentation of auditory stimuli, approximately 100 milliseconds after stimulus onset. In particular, the dependence of M100 latency on attributes of the stimulus, such as intensity, pitch and timbre will be discussed, along with evidence relating M100 latency observations to perceptual features of the stimuli. Comparison with investigation of the analogous electrical potential component, the N1, will be made. Parametric development of stimuli from pure tones through complex tones to speech elements will be made, allowing the influence of spectral pitch, virtual pitch and perceptual categorization to be delineated and suggesting implications for the role of such latency observations in the study of speech processing. The final section will deal with potential clinical applications offered by M100 latency measurements, as objective indices of normal and abnormal cortical processing.
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Affiliation(s)
- T P Roberts
- Department of Radiology, University of California, San Francisco 94143, USA
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48
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Central auditory processing. Curr Opin Otolaryngol Head Neck Surg 1999. [DOI: 10.1097/00020840-199910000-00011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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