Minamoto,T., Shipstead,Z., Osaka, N.,Engle, R.

Low Cognitive Load Strengthens Distractor Interference while High Load
Attenuates when Cognitive Load and Distractor Possess Similar Visual

Attention, Perception & Psychophysics, 77, 1659-1673

doi 10.3758/s13414-015-0866-9


Studies on visual cognitive load have reported inconsistent effects of
distractor interference when distracters have visual characteristic that
are similar to the cognitive load.Some studies have shown that the
cognitive load enhances distractor interference, while others reported
an attenuating effect. We attribute these inconsistencies to the amount
of cognitive load that a person is required to maintain. Lower amounts
of cognitive load increase distractor interference by orienting
attention toward visually similar distractors. Higher amounts of
cognitive load attenuate distractor interference by depleting
attentional resources needed to process distractors.In the present
study, cognitive load consisted of faces (Experiments 1-3) or scenes
(Experiment 2). Participants performed a selective attention task in
which they ignored face distractors while judging a color of a target
dot presented nearby, under differing amounts of load. Across these
experiments distractor interference was greater in the low-load
condition and smaller in the high-load condition when the content of
the cognitive load had similar visual characteristic to the
distractors. We also found that when a series of judgments needed to be
made, the effect was apparent for the first trial but not for the
second. We further tested an involvement of working memory capacity
(WMC) in the load effect (Experiment 3). Interestingly, both high and
low WMC groups received an equivalent effect of the cognitive load in
the first distractor, suggesting these effects are fairly automatic.

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Minamoto,T., Azuma,M., Yaoi, K., Ashizuka, A., Mima, T., Osaka, M.,
Fukuyama, H., Osaka, N.

Title: The anodal tDCS over the left posterior parietal cortex enhances
attention toward a focus word in a sentence,

Frontiers of Human Neuroscience, 8, 992

doi: 10.3389/fnhum.2014.00992

http:// www.frontiersin.org

The posterior parietal cortex (PPC) has two attentional functions:
top-down attentional control and stimulus-driven attentional
processing.Using the focused version of the reading span test(RST),in
which the target word to be remembered is the critical word for
comprehending a sentence(focusedword) or a non-focused word, we examined
the effect of tDCS on resolution of distractor interference by the
focused word in the non-focus condition (top-dow nattentiona lcontrol)
and on augmented/shrunk attentional capture by the focused word in both
the focus and non-focus conditions(stimulus-driven attentional
processing). Participants were divided into two groups: anodal
tDCS(atDCS) and cathodal tDCS(ctDCS). Online stimulation was given while
participants performed the RST. A post-hoc recognition task was also
administered in which three kinds of words were presented: target words
in the RST,distractor words in the RST, and novel words. A tDCS
augmented the effect of the focused word by increasing differences in
performance between the focus and non-focus conditions. Such an effect
was not observed in the ctDCS group. As for the recognition task, a tDCS
again produced the augmented effect of the focused words in the
distractor recognition. On the otherhand, ctDCS brought less recognition
of non-focused target words in comparison to sham. The results indicate
that atDCS promotes stimulus-driven attentional processing, possibly by
affecting neural firing in the inferior parietal regions. Incontrast,
ctDCS appears to prevent retrieval of less important information from
episodic memory,which may require top-down attentional processing

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Minamoto, T., Yaoi, K., Osaka, M., Osaka, N.

Title: The rostral prefrontal cortex underlies individual differences in
working memory capacity: An approach from the hierarchical model of the
cognitive control.

Cortex, 71, 277-290.2015

doi: org/10.1016/j.cortex.2015.07.025

http:// www.elsevier.com/locate/cortex

Neuroimaging and behavioral evidence has suggested that the lateral
prefrontal cortex is involved in individual differences in working
memory capacity (WMC). However, few studies have localized the neural
structures that differentiate high and low WMC individuals, considering
the functional architecture of the prefrontal cortex. The present study
aimed to identify a frontal region that underlies individual differences
from the perspective of the hierarchical architecture of the frontal
cortex. By manipulating an episodic factor of cognitive control (control
in selecting an appropriate task set according to a temporal context)
and using a parametric modulation analysis, we found that both highand
low- WMC individuals have similar activation patterns in the premotor
cortex (BA6, 8), caudal prefrontal cortex (BA44, 45), and frontopolar
cortex (BA10, 11), but differed in the rostral part of the prefrontal
cortex (BA46/47); high WMC individuals showed greater activation in the
higher episodic control condition, whereas low WMC individuals showed
reduced activation when episodic control was required. Similar patterns
of activation were found in the right inferior parietal and
middle/inferior temporal cortices. These results indicate that the
rostral prefrontal cortex, which supports episodic cognitive control,
possibly by sending a weighting signal toward the inferior parietal and
middle/inferior temporal cortices that modulate saliency and sensory
processing, underlies individual differences in WMC. Episodic control
account, which considers the organization of the prefrontal cortex, fits
well with previous findings of individual differences in WMC.

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Ikeda, T., Matsuyoshi, D., Sawamoto, N., Fukuyama, H.,Osaka, N.

Title: Color harmony represented by activity in the medial orbitofrontal
cortex and amygdale.

Frontiers in Human Neuroscience, 9, 382

doi: org/10.3389/fnhum.2015.00382

http:// www.frontiersin.org

Observing paired colors with a different hue (in terms of chroma and
lightness) engenders pleasantness from such harmonious combinations;
however, negative reactions can emerge from disharmonious combinations.
Currently, neural mechanisms underlying the esthetic and emotional
aspects of color perception remain unknown. The current study reports
evidence regarding the neural correlates of color harmony and
disharmony. Functional magnetic resonance imaging was used to assess
brain regions activated by harmonious or disharmonious color
combinations in comparison to other stimuli. Results showed that the
left medial orbitofrontal cortex (mOFC) and left amygdale were activated
when participants observed harmonious and disharmonious stimuli,
respectively. Taken together, these findings suggest that color
disharmony may depend on stimulus properties and more automatic neural
processes mediated by the amygdala,whereas color harmony is harder to
discriminate based on color characteristics and is reflected by the
esthetic value represented in the mOFC. This study has a limitation that
we could not exclude the effect of preference for color combination,
which has a strong positive correlation with color harmony.

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Osaka, N.,Minamoto, T., Yaoi, K., Azuma, M., Minamoto-Shimada, Y. Osaka, M.

Title: How two brains make one synchronized mind in the inferior frontal
cortex: fNIRS-based hyperscanning during cooperative singing,

Frontiers of Psychology, 6:1811


http:// www.frontiersin.org

One form of communication that is common in all cultures is people
singing together. Singing together reflects an index of cognitive
synchronization and cooperation of human brains. Little is known about
the neural synchronization mechanism, however. Here, we examined how two
brains make one synchronized behavior using cooperated singing/humming
between two people and hyperscanning, a new brain scanning technique.
Hyperscanning allowed us to observe dynamic cooperation between
interacting participants. We used functional near-infrared spectroscopy
(fNIRS) to simultaneously record the brain activity of two people while
they cooperatively sang or hummed a song in face-to-face (FtF) or
face-to-wall (FtW) conditions. By calculating the inter-brain wavelet
transform coherence between two interacting brains, we found a
significant increase in the neural synchronization of the left inferior
frontal cortex (IFC) for cooperative singing or humming regardless of
FtF or FtW compared with singing or humming alone. On the other hand,
the right IFC showed an increase in neural synchronization for humming
only, possibly due to more dependence on musical processing.

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