Valida ion o a Low-Cos EEG De ice o
Mood Induc ion S udies
Alejand o RODRÍGUEZa,1 Bea iz REYa,b and Ma iano ALCAÑIZ a,b
a
Ins i u o In e uni e si a io de In es igación en Bioingenie ía y Tecnología O ien ada
al Se Humano, Uni e si a Poli ècnica de València, I3BH/LabHuman,
Camino de Ve a s/n, 46022 Valencia, España
b
Cibe , Fisiopa ología de Obesidad y Nu ición, CB06/03
Ins i u o de Salud Ca los III, Spain
Abs ac . New elec oencephalog aphy (EEG) de ices, mo e po able and cheape ,
a e appea ing on he ma ke . S udying he eliabili y o hese EEG de ices o
emo ional s udies would be in e es ing, as hese de ices could be mo e economical
and compa ible wi h Vi ual Reali y (VR) se ings. The e o e, he aim in his wo k
was o alida e a low-cos EEG de ice (Emo i Epoc) o moni o b ain ac i i y
du ing a posi i e emo ional induc ion p ocedu e. Emo ional pic u es (IAPS) we e
used o induce a posi i e mood in six een pa icipan s. Changes in he b ain
ac i i y o subjec s we e compa ed be ween posi i e induc ion and neu al
condi ions. Ob ained esul s we e in acco dance wi h p e ious scien i ic li e a u e
ega ding on al EEG asymme y, which suppo s he possibili y o using his
low-cos EEG de ice in u u e mood induc ion s udies combined wi h VR.
Keywo ds. EEG, Emo i Epoc, Mood Induc ion, EEGLAB, IAPS
In oduc ion
In emo ional s udies, he on al elec oencephalog aphic (EEG) asymme y model
s a es ha each hemisphe e is specialized in p ocessing di e en emo ions [1]. This
model decla es ha he e exis s an asymme y in he ac i i y o he on al lobe o he
b ain, and by means o his asymme ic ac i i y i is possible o mode a e and p ocess
di e en emo ional esponses. Consequen ly, on al EEG asymme y can be e alua ed
and applied o dis inguish he a ec i e alence o an emo ion el .
Findings om nume ous s udies show an e iden consensus ha an inc ease o le
on al ac i i y and a dec ease o igh on al ac i i y a e associa ed wi h posi i e
emo ions, and ha an inc ease o igh on al ac i i y and a dec ease o le on al
ac i i y a e associa ed wi h nega i e emo ions. This has o igina ed he
app oach/wi hd awal model o Da idson [2-3] and is consis en wi h b ain inju y
s udies.
The esul s o p e ious s udies we e ob ained h ough EEG signal measu emen s,
whe e he pa icipan s we e in a es momen . O he s s udies ha e complemen ed his
in e p e a ion abou on al EEG asymme y du ing a mood induc ion p ocedu e. They
ha e conside ed in e es ing o measu e he on al EEG signal in speci ic emo ional
1 Co esponding Au ho .
Annual Re iew o Cybe he apy and Telemedicine 2013
B.K. Wiede hold and G. Ri a (Eds.)
© 2013 In e ac i e Media Ins i u e
43
con ex s wi h he aim o analyzing he abili y o each indi idual o espond emo ionally
[2-3]. I was obse ed ha on al EEG asymme y, du ing a ea induc ion, was a
be e nega i e a ec p edic o han an analysis o EEG in a es condi ion. Howe e ,
he posi i e a ec could be p edic ed by EEG analysis bo h du ing a es condi ion and
a posi i e induc ion momen .
Clinical EEG de ices ha e been used in mos o hese s udies. The majo i y o
hese sys ems a e e y p ecise bu hey ha e as disad an ages ha hey a e expensi e,
in usi e and di icul o use by he he apis .
Recen ly, he new low-cos EEG de ices, which a e appea ing on he ma ke ,
p o ide g ea po abili y and a good quali y b ain signal. Mo eo e , hese EEG de ices
ha e a g ea compa ibili y wi h o he echnologies, such as Vi ual Reali y. Low-cos
EEG de ices could be used in a Vi ual Reali y s udy wi hou in luencing he p og ess
o his s udy.
In he p esen wo k, he possibili ies o EEG moni o ing h ough a po able de ice
o e alua e mood induc ion o pa icipan s we e analyzed. The e o e, he goal o his
s udy was o analyze i a low-cos EEG de ice (speci ically, he Emo i EPOC) was
able o measu e changes in b ain ac i a ion in he on al EEG while a posi i e mood
was induc ed o he subjec s.
1. Ma e ials and Me hods
Six een heal hy pa icipan s, 8 men and 8 women, we e e alua ed in his s udy, all o
hem igh -handed and wi h ages be ween 23-30 yea s old wi h no mal o co ec ed- o-
no mal ision. The subjec s we e uni e si y s uden s wi hou any psychological
diso de and none o hem was an expe in he use o he echnologies applied in his
s udy. They signed an in o med consen o allowing hei da a o be used in his s udy.
I was no necessa y o exclude any pa icipan due o w ong egis a ion o he EEG
signal.
The EEG signal was moni o ed by means o an EEG po able de ice, Emo i
EPOC [4] which had 14 EEG channels using he s anda d 10/20 layou and 2 e e ence
channels (CMS/DRL), Fig 1.
Figu e 1. Emo i EPOC de ice and Emo i EPOC elec odes posi ioning on s anda d 10/20 layou .
A. Rod íguez e al. / Valida ion o a Low-Cos EEG De ice o Mood Induc ion S udies44
EEG eco dings we e analyzed o -line using cus om so wa e w i en in
MATLAB. This cus om so wa e was based on EEGLAB [5] ools. Many EEG
unc ions we e used o clean he EEG-da a and analyze changes in alpha-spec al powe .
In he s udy, he pa icipan s had o wa ch posi i e and neu al pic u es o IAPS [6],
which we e used as mood induc ion s imulus, in a desk op sc een.
The expe imen al session was di ided in o ou s eps o wo minu es each. In he
i s s ep, he pa icipan s had o wa ch a black sc een ( es s age). In he second s ep,
he emo ional pic u es we e p esen ed (15 neu al pic u es). In he hi d s ep, ano he
es s age was p esen ed. And in he las s ep, he o he emo ional pic u es we e
p esen ed (15 posi i e pic u es). S eps numbe wo and ou we e coun e balanced.
A wo way epea ed measu ed ANOVA was applied, being he independen ac o s
he expe imen al momen , Neu al Condi ion e sus Posi i e Induc ion, and b ain
hemisphe e ( igh /le ). Alpha-ERD (1) alues, calcula ed o F3 (le hemisphe e) and
F4 ( igh hemisphe e) [2, 7, 8] senso s, we e used as dependen a iables. F3 and F4
we e used because hey a e he senso s mo e used in he scien i ic li e a u e o analyze
he alence o he pa icipan s as hey a e loca ed abo e he do sola e al p e on al
co ex [9].
(1)
2. Resul s
Resul s showed signi ican di e ences be ween neu al and posi i e momen s
(F(1,15)=5.859; p=0.029) and a signi ican in luence o he in e sec ion ac o be ween
hemisphe e and momen (F(1,15)=9.594; p=0.007).
Pai -wise compa isons only showed signi ican di e ences be ween hemisphe es
du ing he posi i e induc ion (p=0.010).
Table 1. Mean and s anda d de ia ion Alpha-ERD alues o he F3 and F4 senso s.
Senso Neu al Condi ion Posi i e Induc ion
Mean S d. Mean S d.
F3 1.094 5.074 1.600 5.803
F4 0.386 4.545 -3.649 1.026
A dec ease was obse ed in he Alpha-ERD in he igh hemisphe e and an
inc ease in he le hemisphe e when he posi i e emo ion was induc ed. Mean alues
and s anda d de ia ion alues o each senso can be seen in he Table 1.
Figu e 2 shows h ee opog aphic scalp maps, which gi e a isual ep esen a ion
abou he dis ibu ion o a e age alpha ERD alues a ound scalp in he posi i e
momen , he neu al momen and he di e ence be ween posi i e and neu al momen s,
espec i ely.
A. Rod íguez e al. / Valida ion o a Low-Cos EEG De ice o Mood Induc ion S udies 45
Figu e 2. Topog aphic scalp map o a e age alpha ERD alues.
3. Discussion
The goal o his s udy was o analyze i a low-cos EEG de ice would be able o
measu e changes in b ain ac i a ion in he on al EEG while a posi i e mood was
induc ed o he subjec s h ough emo ional pic u es.
S a is ical esul s show ac i a ion in he le hemisphe e signi ican ly g ea e han
in he igh hemisphe e du ing he posi i e images isualiza ion. This ac i a ion was
g ea e du ing posi i e induc ion han du ing neu al induc ion.
In he igu e 2, he di e ence be ween alpha ERD alues o each momen can be
seen. I shows ha he e is a igh hemisphe e deac i a ion and an inc ease in he le
hemisphe e du ing he posi i e induc ion, in compa ison wi h he neu al induc ion
momen .
These esul s show e idence o a on al asymme y in he EEG o he pa icipan s
du ing a posi i e induc ion, which is in acco dance wi h science li e a u e [1, 2, 8], ha
a i ms ha ac i a ion o le hemisphe e is linked wi h posi i e emo ion induc ion [1, 2,
7, 8, 9].
This esul s suppo he possibili y o using he low-cos EEG de ices, in pa icula
Emo i Epoc, as an emo ional measu ing ool in u u e s udies.
Acknowledgmen s
This s udy was unded by Vice ec o ado de In es igación de la Uni e si a Poli ècnica
de València, Spain, PAID-06-2011, R.N. 1984; by Minis e io de Educación y Ciencia,
Spain, P ojec Game Teen (TIN2010-20187) and pa ially by p ojec s Consolide -C
(SEJ2006-14301/PSIC), “CIBER o Physiopa hology o Obesi y and Nu i ion, an
ini ia i e o ISCIII” and Excellence Resea ch P og am PROMETEO (Gene ali a
Valenciana. Conselle ía de Educación, 2008-157).
The wo k o Alejand o Rod íguez was suppo ed by he Spanish MEC unde an FPI
G an BES-2011-043316.
Re e ences
[1] Allen JJ, Coan JA, Naza ian M. Issues and assump ions on he oad om aw signals o me ics o on al
EEG asymme y in emo ion. Biol Psychol 2004;67(1–2):183–218.
[2] Coan, J. A., & Allen, J. J. (2004). F on al EEG asymme y as a mode a o and media o o emo ion.
Biological psychology, 67(1), 7-50.
A. Rod íguez e al. / Valida ion o a Low-Cos EEG De ice o Mood Induc ion S udies46
[3] Da idson, R.J., Ekman, P., Sa on, C.D., Senulis, J.A., F iesen, W.V. (1990). App oach-wi hd awal and
ce eb al asymme y: emo ional exp ession and b ain physiology. In e na ional Jou nal o Pe sonali y
and Social Psychology 58(2), 330-341.
[4] Zhang, B., Wang, J., Fuhlb igge, T. (2010). A Re iew o he Comme cial B ain-Compu e In e ace
Technology om Pe spec i e o Indus ial Robo ics. P oceedings o he 2010 IEEE In e na ional
Con e ence on Au oma ion and Logis ics.
[5] Delo me A & Makeig S (2004) EEGLAB: an open sou ce oolbox o analysis o single- ial EEG
dynamics. Jou nal o Neu oscience Me hods 134:9-21.
[6] P.J.Lang, M.M. B adley, B.N.Cu hbe , In e na ional A ec i e Pic u e Sys em (IAPS): A ec i e Ra ings
o Pic u es and Ins uc ion Manual, Technical Repo A-8 (2008).
[7] Bos, Danny Oude. EEG-Based Emo ion Recogni ion. Emo ion, 57:1798-1806, 2006.
[8] Richa d S. Lewis, Nicole Y. Weekes, and T acy H. Wang. The e ec o a na u alis ic s esso on on al
eeg asymme y, s ess, and heal h. Biological Psychology, 75(3): 239 - 247, 2007. ISSN 0301-0511.
[9] Niemic, C.P. S udies o emo ion: A heo e ical and empi ical e iew o psychophysiological s udies o
emo ion. Jou nal o Unde g adua e Resea ch, 1:15-18, 2002.
A. Rod íguez e al. / Valida ion o a Low-Cos EEG De ice o Mood Induc ion S udies 47