DEA.ppt

A direct comparison of Geodesic Sensor Net (128-channel) and A direct comparison of Geodesic Sensor Net (128-channel) and conventional (30-channel) ERPs in tonal and phonetic oddball tasksconventional (30-channel) ERPs in tonal and phonetic oddball tasks

Jürgen Kayser, Craig E. Tenke, Jürgen Kayser, Craig E. Tenke, Nilabja Bhattacharya, Nilabja Bhattacharya, Barbara K. Stuart, Jeffrey Hudson, Barbara K. Stuart, Jeffrey Hudson, Gerard E. BruderGerard E. Bruder

New York State Psychiatric Institute, Department of BiopsychologyNew York State Psychiatric Institute, Department of Biopsychology

http://psychophysiology.cpmc.columbia.eduhttp://psychophysiology.cpmc.columbia.edu

Society for Psychophysiological Research (SPR), 40th annual meeting, San Diego, CA, October 18-22, 2000Society for Psychophysiological Research (SPR), 40th annual meeting, San Diego, CA, October 18-22, 2000Symposium 14: Symposium 14: Dense electrode array ERPs: Methodological developments, challenges and benefitsDense electrode array ERPs: Methodological developments, challenges and benefits

These task-specific ERP asymmetries interact with response hand in an unbalanced fashion

Background

Tonal Phonetic Tonal - Phonetic

N2/P3 Amplitude

pitch discrimination (right frontotemporal)

phoneme discrimination (left parietotemporal)

• enhanced N2/P3 amplitude over the right lateral-temporal region for complex tones

• enhanced N2/P3 amplitude over the left parietal region for syllables

ERPs of right-handed adults during auditory oddball tasks are characterized by stimulus-dependent N2/P3 asymmetries

• Kayser, Tenke, & Bruder (1998). Psychophysiology, 35(5), 576-590.• Tenke, Kayser, Fong, Leite, Towey, & Bruder (1998). Brain Topography, 10(3), 201-210.

Complex TonesComplex Tones

-square wavessquare waves [444 Hz, 485 Hz][444 Hz, 485 Hz] of major notesof major notes

SyllablesSyllables

-consonant-vowelsconsonant-vowels [/da/, /ka/] matched[/da/, /ka/] matched for discriminabilityfor discriminability

Oddball TasksOddball Tasks: Tonal and Phonetic Stimuli: Tonal and Phonetic Stimuli

...

B

20% targets20% targets80% nontargets80% nontargets

binauralbinaural

...

/da/

/ka/

binauralbinaural

AB

BB

Left Pressor

Right Pressor

Silent Count

Left Pressor

Right Pressor

Silent Count

A

/da//da/

/da/

/ka/

960 trials total960 trials total 12 blocks (80 trials)12 blocks (80 trials)

32 targets/condition32 targets/condition128 nontargets/condtion 128 nontargets/condtion

ElectroCapElectroCap(30-channel)(30-channel)

Geodesic Sensor NetGeodesic Sensor Net(128-channel)(128-channel)

DesignDesign

Minimum 14 trials/conditionElectroCapElectroCap 2424GSNGSN 1717

GenderGender

AgeAge (21 – 41 yrs)(21 – 41 yrs)

HandednessHandedness(Oldfield, 1971)(Oldfield, 1971)

ParticipantsParticipants

27.8 ±6.527.8 ±6.5

10 female10 female14 male14 male

79.7 ±22.679.7 ±22.6

N = 24N = 24

26.5 ±6.326.5 ±6.3

6 female6 female11 male11 male

77.5 ±24.977.5 ±24.9

N = 17N = 17

Data Recording and ProcessingData Recording and ProcessingGeodesic Sensor NetGeodesic Sensor NetElectroCapElectroCap

Reference nose tip vertex#17 moved to nose tip

Bipolar EOG EOG leads from facial EEG leads

Storage format NeuroScan NeuroScanEGI

Initial artifacting clipped epoch/trial clipped epoch/trial/site

Interactive blink correction(linear regression)

Off-line filtering20 Hz / 24 dB low pass

Re-reference nose tip

Artifacting ±100 µV1. flag artifacts (100 µV threshold)2. interactive editing of EEG epoch/trial/site (reject or

replace after visual analysis of complete EEG montage)

ERP averaging

• 100 µV step response

External calibration• 400 µV 20 Hz sine wave

Behavioral DataBehavioral Data: Correct button presses: Correct button presses

TaskTask pp = .0002 = .0002TaskTask pp = .0002 = .0002

ERP WaveformsERP Waveforms: Complex Tones: Complex Tones ElectroCapElectroCap

------- Nontargets------- Targets

ElectroCapElectroCap


ERP WaveformsERP Waveforms: CV Syllables: CV Syllables

ERP WaveformsERP Waveforms: Complex Tones: Complex Tones Geodesic Sensor NetGeodesic Sensor Net


ERP WaveformsERP Waveforms: CV Syllables: CV Syllables


Geodesic Sensor NetGeodesic Sensor Net

ERP WaveformsERP Waveforms: Vertex: Vertex

CV SyllablesCV SyllablesComplex TonesComplex Tones

Targets

NontargetsNontargets

------- Geodesic Sensor NetGeodesic Sensor Net------- ElectroCapElectroCap

ERP TopographiesERP Topographies: Surface Potentials (: Surface Potentials (Targets)) Time interval: 0 - 700 msTime interval: 0 - 700 ms


Tonal Tonal PhoneticPhonetic

Geodesic Geodesic Sensor NetSensor Net


ElectroCap (30-channel)ElectroCap (30-channel)

S890S890

P380P380P300P300

N200N200

N110N110

Temporal PCATemporal PCA: Factor Loadings: Factor Loadings

• covariance matrix• unscaled Varimax rotation

GSN (30-channel)GSN (30-channel)

GSN (128-channel)GSN (128-channel)

P380 36.7%P380 36.7%S890 26.1%S890 26.1%P300 15.2%P300 15.2%N200 6.1%N200 6.1%N110 3.0%N110 3.0%

Explained VarianceExplained Variance

87.1%87.1%__________

S890S890

P380P380P300P300

N200N200N110N110

ElectroCapElectroCap (30-channel)(30-channel)GSNGSN (30-channel)(30-channel)

N110N110

ERP TopographiesERP Topographies: N110 (: N110 (Targets))





N200N200

ERP TopographiesERP Topographies: N200 (: N200 (Targets))





Syst x Task x HemiSyst x Task x Hemi pp = .04 = .04

ECap ECap Task x HemiTask x Hemi pp = .0001 = .0001

GSN GSN Task x HemiTask x Hemi pp = .03 = .03

P300P300

ERP TopographiesERP Topographies: P300 (: P300 (Targets))





SystemSystem pp = .006 = .006

Syst x SiteSyst x Site pp = .03 = .03

ERP TopographiesERP Topographies: P380 (: P380 (Targets))





P380P380

Syst x SiteSyst x Site pp = .02 = .02

PzPz Syst x Task Syst x Task pp = .0001 = .0001

(P380+P300) – (N200)(P380+P300) – (N200)

ERP TopographiesERP Topographies: N2/P3 Amplitude (: N2/P3 Amplitude (Targets))






Syst x TaskSyst x Task pp = .03 = .03

Syst x Task x SiteSyst x Task x Site pp = .007 = .007

ECap ECap Task x HemiTask x Hemi pp = .002 = .002

GSN GSN Task x HemiTask x Hemi pp = .004 = .004ECap ECap Task x Hemi x SiteTask x Hemi x Site pp = .0008 = .0008

GSN GSN Task x Hemi x SiteTask x Hemi x Site pp = .0009 = .0009

Left Press Left Press Right PressRight Press


Silent Count Silent Count

Tonal Tonal

PhoneticPhonetic

ERP TopographiesERP Topographies: N2/P3 Amplitude (: N2/P3 Amplitude (Targets))

(P380+P300) – (N200)(P380+P300) – (N200)

ERP Noise EstimatesERP Noise Estimates: Vertex referenced to nose tip: Vertex referenced to nose tip

SystemSystem pp = .0003 = .0003 SystemSystem pp = .0006 = .0006

ConditionCondition

Syst x CondSyst x Cond pp = .02 = .02pp < .0001 < .0001


ConditionCondition pp < .0001 < .0001

Conclusions

ERPs were remarkably similar across the two systems for corresponding recording sites using the same reference

improved spatial resolution of the DEA montage increases confidence in the topographical findings

advantages come at a significant cost

requirements for maintaining conventional standards with DEA recordings

• component structure• peak latencies• topographies

• labor/time intensive data processing (an order of magnitude!)• loss of subjects and/or data

• decrease in effect size

• reduced S/N ratio and late ERP amplitudes (e.g., P3)

• large number of trials and/or subjects

• need for new tools for data processing (including EOG correction, artifacting, replacing missing channels)

• sufficient manpower

ERP TopographiesERP Topographies: Surface Potentials (: Surface Potentials (Targets)) Time interval: 0 - 700 msTime interval: 0 - 700 ms




Tonal Tonal

PhoneticPhonetic

ERP TopographiesERP Topographies: Local Hjorth (: Local Hjorth (Targets)) Time interval: 0 - 695 msTime interval: 0 - 695 ms




Tonal Tonal

PhoneticPhonetic

sink

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DEA.ppt