EEG Beta Range Dynamics and Emotional Judgments
of Face and Voices
K. Hiyoshi-Taniguchi
1,2
, M. Kawasaki
3
, T. Yokota
1
, H. Bakardjian
4,1
, H. Fukuyama
2
,
F. B. Vialatte
5,1
and A. Cichocki
1
1
Laboratory for Advanced Brain Signal Processing, RIKEN Brain Science Institute, Wakō, Japan
2
Human Brain Research Centres, Kyoto University Graduate of Medicine, Kyoto, Japan
3
RIKEN BSI-TOYOTA Collaboration Center, RIKEN, Wakō, Japan
4
IM2A, Groupe Hospitalier Pitié-Salpétrière, Paris, France
5
Laboratoire SIGMA, ESPCI ParisTech, Paris, France
Keywords: Emotion, Multi-modal, EEG.
Abstract: The purpose of this study is to clarify multi-modal brain processing related to human emotional judgment.
This study aimed to induce a controlled perturbation in the emotional system of the brain by multi-modal
stimuli, and to investigate whether such emotional stimuli could induce reproducible and consistent changes
in the brain dynamics. As we were especially interested in the temporal dynamics of the brain responses, we
studied EEG signals. We exposed twelve subjects to auditory, visual, or combined audio-visual stimuli.
Audio stimuli consisted of voice recordings of the Japanese word ‘arigato’ (thank you) pronounced with
three different intonations (Angry - A, Happy - H or Neutral - N). Visual stimuli consisted of faces of
women expressing the same emotional valences (A, H or N). Audio-visual stimuli were composed using
either congruent combinations of faces and voices (e.g. H x H) or non-congruent (e.g. A x H). The data was
collected with a 32-channel Biosemi EEG system. We report here significant changes in EEG power and
topographies between those conditions. The obtained results demonstrate that EEG could be used as a tool
to investigate emotional valence and discriminate various emotions.
1 INTRODUCTION
Judgment is the operation of the mind by which
knowledge of the values and relations of things is
obtained. Judgment is important for decision
making, and involves both cognitive and infra-
cognitive processes. In social cognition, judging the
emotion of another human being is important to
interpret communications. For instance, patients
with emotional judgment disorders, such as patients
suffering from major depression (Griamm et al.,
2008), can have serious social impairments. Our
purpose is to investigate the neurodynamics of
human emotional judgments.
Human communication is based both on face and
voice perception, therefore facial expression and
tone of voice is important to understand emotions.
Such multi-modal brain processes are difficult to
investigate. Anatomically, a huge literature
emphasizes the role of sub-cortical areas in emotion
processing (see e.g. Ledoux, 2000). This explains
the preponderance of fMRI studies in brain science
literature, as this imaging technique provides
information about sub-cortical activities. However,
these sub-cortical areas do not work independently
one from another, and consequently emotion
processing necessarily involves large-scale networks
of neural assemblies, in cortico-subcortical transient
interactions, where the time evolution of the network
is a key factor (Tsuchiya and Adolfs, 2007).
Therefore, EEG could provide crucial information
about emotional processes. For this reason, in a
previous pilot study, we investigated the effects of
voice and face emotional judgments on EEG signals,
on two subjects (Hiyoshi-Taniguchi, et al., 2011).
Here we extend those results with 12 subjects.
The purpose of our study was to induce a
controlled perturbation in the emotional system of
the brain by multi-modal stimuli, and to control if
such stimuli could induce reproducible changes in
EEG signal. We used a combination of photos and
voices with congruent or non congruent emotional
738
Hiyoshi-Taniguchi K., Kawasaki M., Yokota T., Bakardjian H., Fukuyama H., B. Vialatte F. and Cichocki A..
EEG Beta Range Dynamics and Emotional Judgments of Face and Voices.
DOI: 10.5220/0004184307380740
In Proceedings of the 4th International Joint Conference on Computational Intelligence (SSCN-2012), pages 738-740
ISBN: 978-989-8565-33-4
Copyright
c
2012 SCITEPRESS (Science and Technology Publications, Lda.)
valence. Through the investigation of this
‘abnormal’ perceptual condition, we intend to reveal
the mechanisms of normal emotional judgment (how
one can distinguish the valence of emotions in a
given stimulus). The use of three different valence
stimuli (neutral, angry, happy) will be compared.
2 METHOD
We recruited 12 subjects for this study. All subjects
were young (age =21.9 ± 0.31) healthy adults,
without prior history of any neurological or
psychiatric disorders. All subjects were screened to
be right handed using the Edinburgh handedness
test. 10 subjects were female, 2 were male.
We exposed these subjects to auditory, visual, or
combined audio-visual stimuli. Stimuli were
presented for 2 sec, the subjects was asked to answer
afterwards within a 3 sec window, and then had 5
sec of rest (one trial = 10 sec). Audio stimuli
consisted of voice recordings of the word ‘arigato
(thank you) pronounced with three different
intonations (Angry - A, Happy - H or Neutral - N).
Visual stimuli consisted of faces of women
expressing the same emotional valences (A, H or N).
Audio-visual stimuli were composed using either
congruent combinations of faces and voices (e.g.
HxH) or non-congruent (e.g. AxH):
3 RESULT
For multimodal stimuli, the common pattern
between emotional conditions (both in HxH vs. NxN
and in AxA vs. NxN) is observed, with a general
increase of the EEG power in peripheral areas, for
beta range.
In the non-congruent condition, specific effects are
observed (Figure 1):
- when comparing a congruent stimulus with a
non-congruent stimulus with a visual difference
(HxH vs. AxH), one can observe a distinct pattern: a
longitudinal shift of power in the alpha range
(increased in the frontal area, decreased in the
occipital area). The same shift is obtained in the beta
range, but only for the HxH vs. AxH condition.
- when comparing a congruent stimulus with a
non-congruent stimulus with an auditory difference
(HxH vs. HxA), another distinct pattern is visible: a
longitudinal shift of power in the beta range
(increased in the frontal area, decreased in the
occipital area).
Finally, in all the non-congruent conditions, an
increase of activity is observed in the theta range, in
a right centro-temporal location (C
4
, CP
4
).
Figure 1: Illustration of the difference between HxH and
AxH and HxA conditions in the beta (12-25 ) ranges.
4 DISCUSSION
We first off all analyzed congruent emotional
judgment. Emotional judgment is known to be
associated with neural correlates in the left and right
dorso-lateral prefrontal cortex (Nakamura, et al.,
1999; Ochsner, et al., 2002; Lange, et al., 2003;
Keightley, et al., 2003; Northoff, et al., 2004;
Grimm, et al., 2006). We indeed observed in the
congruent condition strong activations in the
prefrontal channels, especially in the alpha and beta
EEGBetaRangeDynamicsandEmotionalJudgmentsofFaceandVoices
739
ranges. From our result, we observe an angry-visual
and happy-auditory preferential association. This
effect might be due to a well-known reaction of
preparation to danger (the Colavita visual
dominance effect, see e.g. van Damme, et al., 2009):
perception of angry emotion means a potential
danger, which would place the subject in a
preferential visual dominance mode. Threatening
facial expression also induces avoidance behaviour,
visible in eye-tracking (Rigoulot and Pell, 2012).
These effects might be correlates of the EEG
occipital area alpha range increase.
REFERENCES
Grimm, S., Schmidt, C. F., Bermpohl, F., Heinzel, A.,
Dahlem, Y., Wyss M., 2006, Segregated neural
representation of distinct emotion dimensions in the
prefrontal cortex—an fMRI study. NeuroImage
30:325–340.
Hiyoshi-Taniguchi, K., Vialatte, F. B., Kawasaki, M.,
Fukuyama, H., Cichocki, A., 2011, Neurodynamics of
Emotional Judgments in the Human Brain. 4th
Internationcal Conference on Neural Computation
Theory and Applications (NCTA 2011), Barcelona,
Spain.
Keightley, M. L., Winocur, G., Graham, S. J., Mayberg,
H. S., Hevenor, S. J., Grady C. L., 2003, An fMRI
study investigating cognitive modulation of brain
regions associated with emotional processing of visual
stimuli. Neuropsychologia 41:585–596.
Lange, K., Williams, L. M., Young, A. W., Bullmore, E.
T., Brammer, M. J., Williams, S. C. R., 2003, Task
instructions modulate neural responses to fearful facial
expressions. Biol Psychiatry 53:226 –232.
Ledoux, J. E., 2000, Emotion circuits in the brain. Annu.
Rev. Neurosci., 23:155-184.
McGurk, H., MacDonald, J., 1976, Hearing lips and
seeing voices. Nature, 264(5588):746–748.
Nakamura, K., Kawashima, R., Ito, K., Sugiura, M., Kato,
T., Nakamura, A. 1999, Activation of the right inferior
frontal cortex during assessment of facial emotion. J
Neurophysiol 82:1610 –1614.
Northoff, G., Heinzel, A., Bermpohl, F., Niese, R.,
Pfennig, A., Pascual-Leone, A., Schlaug G., 2004,
Reciprocal modulation and attenuation in the
prefrontal cortex: An fMRI study on emotional–
cognitive interaction. Hum. Brain Mapp. 21:202–212.
Ochsner, K. N., Bunge, S. A., Gross, J. J., Gabrieli J D
(2002): Rethinking feelings: An FMRI study of the
cognitive regulation of emotion. J Cogn Neurosci
14:1215–1229.
Rigoulot S., Pell M. D., 2012, Seeing emotion with your
ears: emotional prosody implicitly guides visual
attention to faces. PLoS One, 7(1):e30740.
Tsuchiya, N, Adolphs, R., 2007, Emotion and
consciousness. Trends Cogn Sci. 11(4):158-67
Van den Stock J., Grèzes, J., de, Geldera, B., 2008,
Human and animal sounds influence recognition of
body language. Brain Research, 1242(25):185-190.
Van Damme, S., Crombez, G., Spence, C. 2009, Is visual
dominance modulated by the threat value of visual and
auditory stimuli? Exp. Brain Res., 193(2):197-204.
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