7 国際: 2013年9月アーカイブ
Authors:
Osaka,M. Yaoi,K., Minamoto,T.,& Osaka,N.
Title:
When do negative and positive emotions modulate working memory performance?
Journal:
Scientific Reports
doi:
10.1038/srep01375
論文URL:
http://www.nature.com/srep/index.html
Abstract:
The present study investigated when emotion modulates working memory
from the perspective of neural activation. Using fMRI, we measured brain
activity during the encoding and retrieval phases of a reading span test
(RST) that used emotional contexts. The emotional RST required
participants to read sentences that elicited negative, neural or
positive emotional states while they were memorizing target words from
the sentences. Compared with the neutral RST, the negative RST activated
the right amygdala during the reading phase. Significant activation was
also found in the parahippocampal gyrus, albeit only after activation of
the amygdala became comparable to that in the neutral RST. In contrast,
the positive RST activated the substantia nigra during the reading phase
relative to the neutral RST. These findings suggest that negative and
positive emotions modulate working memory through distinctive neural
circuits. We also discuss possible relationships between emotional
modulation and working memory capacity.
著者Contact先の email:
mosaka@hus.osaka-u.ac.jp
Osaka,M. Yaoi,K., Minamoto,T.,& Osaka,N.
Title:
When do negative and positive emotions modulate working memory performance?
Journal:
Scientific Reports
doi:
10.1038/srep01375
論文URL:
http://www.nature.com/srep/index.html
Abstract:
The present study investigated when emotion modulates working memory
from the perspective of neural activation. Using fMRI, we measured brain
activity during the encoding and retrieval phases of a reading span test
(RST) that used emotional contexts. The emotional RST required
participants to read sentences that elicited negative, neural or
positive emotional states while they were memorizing target words from
the sentences. Compared with the neutral RST, the negative RST activated
the right amygdala during the reading phase. Significant activation was
also found in the parahippocampal gyrus, albeit only after activation of
the amygdala became comparable to that in the neutral RST. In contrast,
the positive RST activated the substantia nigra during the reading phase
relative to the neutral RST. These findings suggest that negative and
positive emotions modulate working memory through distinctive neural
circuits. We also discuss possible relationships between emotional
modulation and working memory capacity.
著者Contact先の email:
mosaka@hus.osaka-u.ac.jp
Authors:
Osaka, N.,Ikeda, T.,& Osaka, M.
Title:
Effect of intentional bias on agency attribution of animated motion: An
event-related fMRI study
Journal:
PLoS One
doi:
10.1371/journal.pone.0049053
論文URL:
http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0049053
Abstract:
Animated movements of simple geometric shapes can readily be interpreted
as depicting social events in which animate agents are engaged in
intentional activity. However, the brain regions associated with such
intention have not been clearly elucidated. In this study, intentional
bias was manipulated using shape and pattern animations while measuring
associated brain activity using event-related functional magnetic
resonance imaging (fMRI). Twenty-five higher-intention involved and
twenty-five lower-intention involved animations were presented to
participants. Behavioral results showed that the degree of agency
attribution of the mental state increased as intentional involvement
increased. fMRI results revealed that the posterior superior temporal
sulcus (STS), inferior temporal gyrus (ITG), inferior frontal gyrus
(IFG), premotor, temporal pole, supramarginal gyrus, and superior
parietal lobule (SPL) were activated while participants viewed the
high-intention animations. In contrast, occipital, lingual, and middle
frontal gyri were activated while the participants viewed the
low-intention animations. These findings suggest that as agent
attribution increases, the visual brain changes its functional role to
the intentional brain and becomes a flexible network for processing
information about social interaction.
著者Contact先の email:
nosaka@bun.kyoto-u.ac.jp
Osaka, N.,Ikeda, T.,& Osaka, M.
Title:
Effect of intentional bias on agency attribution of animated motion: An
event-related fMRI study
Journal:
PLoS One
doi:
10.1371/journal.pone.0049053
論文URL:
http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0049053
Abstract:
Animated movements of simple geometric shapes can readily be interpreted
as depicting social events in which animate agents are engaged in
intentional activity. However, the brain regions associated with such
intention have not been clearly elucidated. In this study, intentional
bias was manipulated using shape and pattern animations while measuring
associated brain activity using event-related functional magnetic
resonance imaging (fMRI). Twenty-five higher-intention involved and
twenty-five lower-intention involved animations were presented to
participants. Behavioral results showed that the degree of agency
attribution of the mental state increased as intentional involvement
increased. fMRI results revealed that the posterior superior temporal
sulcus (STS), inferior temporal gyrus (ITG), inferior frontal gyrus
(IFG), premotor, temporal pole, supramarginal gyrus, and superior
parietal lobule (SPL) were activated while participants viewed the
high-intention animations. In contrast, occipital, lingual, and middle
frontal gyri were activated while the participants viewed the
low-intention animations. These findings suggest that as agent
attribution increases, the visual brain changes its functional role to
the intentional brain and becomes a flexible network for processing
information about social interaction.
著者Contact先の email:
nosaka@bun.kyoto-u.ac.jp
Authors:
Tsubomi,H., Ikeda, T., & Osaka, N.
Title:
Primary visual cortex scales individual's perceived brightness with
power function: Inner psychophysics with fMRI.
Journal:
Journal of Experimental Psychology: Human Perception & Performance
doi:
10.1037/a0030025
論文URL:
http://www.apa.org/pubs/journals/xhp/index.aspx
Abstract:
Perceived brightness is well described by Stevens' power function (S. S.
Stevens, 1957, On the psychophysical law, Psychological Review, Vol. 64,
pp. 153-181), with a power exponent of .33 (the cubic-root function of
luminance). The power exponent actually varies across individuals, yet
little is known about neural substrates underlying this individual
difference. The present functional MRI study investigated how neural
activation levels in the visual cortex serve to scale individual's
subjective brightness. Participants rated brightness of a disk ranging
from 1- to 100-cd/m(2) luminance. Subjective brightness ratings showed
an almost perfect log-linear dependence on luminance intensity, with the
power exponent averaging .32. The fMRI results showed that activity in
the bilateral primary visual cortex along with the calcarine sulcus
(also known as Brodmann's area 17 and VI) increased log-linearly with
physical luminance, showing average power exponents of .32 and .27 in
the left and right hemispheres, respectively. There were substantial
individual variations in the power function exponents for both
subjective brightness ratings (.14 to .46) and primary visual cortex
activation (.12 to .55). An important finding was that 2 power exponents
were closely correlated (r = .62). Subjective brightness ratings and
primary visual cortex activation were both better correlated with
stimulus luminance than stimulus contrast (at the border of the
stimulus). These results suggest that primary visual cortex activation
can scale individual's subjective brightness in accordance with Stevens'
power law.
著者Contact先の email:
htsubomi@fennel.rcast.u-tokyo.ac.jp
Tsubomi,H., Ikeda, T., & Osaka, N.
Title:
Primary visual cortex scales individual's perceived brightness with
power function: Inner psychophysics with fMRI.
Journal:
Journal of Experimental Psychology: Human Perception & Performance
doi:
10.1037/a0030025
論文URL:
http://www.apa.org/pubs/journals/xhp/index.aspx
Abstract:
Perceived brightness is well described by Stevens' power function (S. S.
Stevens, 1957, On the psychophysical law, Psychological Review, Vol. 64,
pp. 153-181), with a power exponent of .33 (the cubic-root function of
luminance). The power exponent actually varies across individuals, yet
little is known about neural substrates underlying this individual
difference. The present functional MRI study investigated how neural
activation levels in the visual cortex serve to scale individual's
subjective brightness. Participants rated brightness of a disk ranging
from 1- to 100-cd/m(2) luminance. Subjective brightness ratings showed
an almost perfect log-linear dependence on luminance intensity, with the
power exponent averaging .32. The fMRI results showed that activity in
the bilateral primary visual cortex along with the calcarine sulcus
(also known as Brodmann's area 17 and VI) increased log-linearly with
physical luminance, showing average power exponents of .32 and .27 in
the left and right hemispheres, respectively. There were substantial
individual variations in the power function exponents for both
subjective brightness ratings (.14 to .46) and primary visual cortex
activation (.12 to .55). An important finding was that 2 power exponents
were closely correlated (r = .62). Subjective brightness ratings and
primary visual cortex activation were both better correlated with
stimulus luminance than stimulus contrast (at the border of the
stimulus). These results suggest that primary visual cortex activation
can scale individual's subjective brightness in accordance with Stevens'
power law.
著者Contact先の email:
htsubomi@fennel.rcast.u-tokyo.ac.jp
Authors:
Matsuyoshi, D., Ikeda, T., Sawamoto, N., Kakigi, R., Fukuyama, H., &
Osaka, N.
Title:
Differential roles for parietal and occipital cortices in visual working
memory.
Journal:
PLoS ONE
doi:
10.1371/journal.pone.0038623
論文URL:
http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0038623
Abstract:
Visual working memory (VWM) is known as a highly capacity-limited
cognitive system that can hold 3-4 items. Recent studies have
demonstrated that activity in the intraparietal sulcus (IPS) and
occipital cortices correlates with the number of representations held in
VWM. However, differences among those regions are poorly understood,
particularly when task-irrelevant items are to be ignored. The present
fMRI-based study investigated whether memory load-sensitive regions such
as the IPS and occipital cortices respond differently to task-relevant
information. Using a change detection task in which participants are
required to remember pre-specified targets, here we show that while the
IPS exhibited comparable responses to both targets and distractors, the
dorsal occipital cortex manifested significantly weaker responses to an
array containing distractors than to an array containing only targets,
despite that the number of objects presented was the same for the two
arrays. These results suggest that parietal and occipital cortices
engage differently in distractor processing and that the dorsal
occipital, rather than parietal, activity appears to reflect output of
stimulus filtering and selection based on behavioral relevance.
著者Contact先の email:
nosaka@bun.kyoto-u.ac.jp
Matsuyoshi, D., Ikeda, T., Sawamoto, N., Kakigi, R., Fukuyama, H., &
Osaka, N.
Title:
Differential roles for parietal and occipital cortices in visual working
memory.
Journal:
PLoS ONE
doi:
10.1371/journal.pone.0038623
論文URL:
http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0038623
Abstract:
Visual working memory (VWM) is known as a highly capacity-limited
cognitive system that can hold 3-4 items. Recent studies have
demonstrated that activity in the intraparietal sulcus (IPS) and
occipital cortices correlates with the number of representations held in
VWM. However, differences among those regions are poorly understood,
particularly when task-irrelevant items are to be ignored. The present
fMRI-based study investigated whether memory load-sensitive regions such
as the IPS and occipital cortices respond differently to task-relevant
information. Using a change detection task in which participants are
required to remember pre-specified targets, here we show that while the
IPS exhibited comparable responses to both targets and distractors, the
dorsal occipital cortex manifested significantly weaker responses to an
array containing distractors than to an array containing only targets,
despite that the number of objects presented was the same for the two
arrays. These results suggest that parietal and occipital cortices
engage differently in distractor processing and that the dorsal
occipital, rather than parietal, activity appears to reflect output of
stimulus filtering and selection based on behavioral relevance.
著者Contact先の email:
nosaka@bun.kyoto-u.ac.jp
Authors:
Azuma, M., Ikeda, T., Minamoto, T., Osaka, M., Osaka, N.
Title:
High working memory performers have efficient eye movement control
systems under Reading Span Test
Journal:
Journal of Eye Movement Research
doi:
なし
論文URL:
www.jemr.org/online 5/3/1
Abstract:
Controlled eye movements are critical in performing highly goal oriented
behavior such as text reading. Previous studies have examined the
relationship between working memory capacity and eye movement control
during working memory task. However, the results were inconsistent, due
to a methodological issue including the predictability of target
location. In the present study, we used Japanese version of reading span
test, where the position of to-be-remembered word is not predictable so
that more efficient attentional control is required, and investigated
how working memory capacity contributes to eye movement control during
reading span test. Results based on total fixation time revealed that
highworking memory performers efficiently control or shift their
attention under high memory load.
著者Contact先の email:
azuma.miyuki.8v@kyoto-u.ac.jp
Azuma, M., Ikeda, T., Minamoto, T., Osaka, M., Osaka, N.
Title:
High working memory performers have efficient eye movement control
systems under Reading Span Test
Journal:
Journal of Eye Movement Research
doi:
なし
論文URL:
www.jemr.org/online 5/3/1
Abstract:
Controlled eye movements are critical in performing highly goal oriented
behavior such as text reading. Previous studies have examined the
relationship between working memory capacity and eye movement control
during working memory task. However, the results were inconsistent, due
to a methodological issue including the predictability of target
location. In the present study, we used Japanese version of reading span
test, where the position of to-be-remembered word is not predictable so
that more efficient attentional control is required, and investigated
how working memory capacity contributes to eye movement control during
reading span test. Results based on total fixation time revealed that
highworking memory performers efficiently control or shift their
attention under high memory load.
著者Contact先の email:
azuma.miyuki.8v@kyoto-u.ac.jp
Authors:
Osaka,M.,Yaoi,K., Otsuka, Y., Katsuhara, M., & Osaka, N
Title:
Practice on conflict tasks promotes executive function of working memory
in the elderly.
Journal:
Behavioural Brain Research
doi:
10.1016/j.bbr.2012.04.044
論文URL:
http://www.journals.elsevier.com/behavioural-brain-research/
Abstract:
Effects of practice on a conflict task in elderly individuals are
examined with a focus on its impact on executive function in working
memory. During a short-term practice period, healthy elderly
participants practiced switching attention using a Stroop task that
involved a conflict between a task relevant stimulus and an irrelevant
stimulus. To explore neural substrates underlying practice effects, two
working memory tasks were used: a focus reading span test (F-RST) and a
non-focus reading span test (NF-RST); the NF-RST test demanded greater
switching attention due to a conflict between the relevant task stimulus
and an irrelevant task stimulus, thus requiring an attention switch from
the latter to the former. Following the Stroop task practice, fMRI data
showed that participants who had engaged in practice had significant
increases in activation in the anterior cingulate cortex (ACC), the left
inferior parietal lobule (IPL), the left dorsolateral prefrontal cortex
(DLPFC) and the precuneus regions during the NF-RST. By contrast, a
control group, which did not practice, showed no significant increases
in these regions. Results suggest that practice on conflict tasks in
elderly individuals activated regions related to conflict perceiving and
attention switching regions as well as attention-maintenance regions
thereby improving performance on tasks requiring a high degree of
attention control of working memory.
著者Contact先の email:
mosaka@hus.osaka-u.ac.jp
Osaka,M.,Yaoi,K., Otsuka, Y., Katsuhara, M., & Osaka, N
Title:
Practice on conflict tasks promotes executive function of working memory
in the elderly.
Journal:
Behavioural Brain Research
doi:
10.1016/j.bbr.2012.04.044
論文URL:
http://www.journals.elsevier.com/behavioural-brain-research/
Abstract:
Effects of practice on a conflict task in elderly individuals are
examined with a focus on its impact on executive function in working
memory. During a short-term practice period, healthy elderly
participants practiced switching attention using a Stroop task that
involved a conflict between a task relevant stimulus and an irrelevant
stimulus. To explore neural substrates underlying practice effects, two
working memory tasks were used: a focus reading span test (F-RST) and a
non-focus reading span test (NF-RST); the NF-RST test demanded greater
switching attention due to a conflict between the relevant task stimulus
and an irrelevant task stimulus, thus requiring an attention switch from
the latter to the former. Following the Stroop task practice, fMRI data
showed that participants who had engaged in practice had significant
increases in activation in the anterior cingulate cortex (ACC), the left
inferior parietal lobule (IPL), the left dorsolateral prefrontal cortex
(DLPFC) and the precuneus regions during the NF-RST. By contrast, a
control group, which did not practice, showed no significant increases
in these regions. Results suggest that practice on conflict tasks in
elderly individuals activated regions related to conflict perceiving and
attention switching regions as well as attention-maintenance regions
thereby improving performance on tasks requiring a high degree of
attention control of working memory.
著者Contact先の email:
mosaka@hus.osaka-u.ac.jp
Authors:
Osaka, M., Otsuka, Y., & Osaka, N.
Title:
Verbal to visual code switching improves working memory in the elderly:
An fMRI study.
Journal:
Frontiers of Human Neuroscience
doi:
10.3389/fnhum.2012.00024
論文URL:
http://www.frontiersin.org/Journal/FullText.aspx?s=537&name=Human_Neuroscience&ART_DOI=10.3389/fnhum.2012.00024
Abstract:
The effect of verbal to visual code switching training on working memory
performance was investigated in individuals aged 63 and older. During
verbal working memory task performance, the training group (n = 25) was
introduced to a verbal to visual code switching strategy while the
control group (n = 25) was not exposed to such a strategy. Working
memory recognition accuracy was enhanced only in the training group. To
explore the neural substrates underlying these strategy effects, fMRI
was used to measure brain activity in both groups during working memory
task performance before and after an attention training period. In a
comparison between pre- and post-training sessions, results showed
increased activation in the anterior cingulate cortex (ACC). Relative to
the control group, the post-training group exhibited increased
activation in the left and right inferior parietal lobules (IPLs) and
right superior parietal lobule (SPL). These findings suggest that use of
a verbal to visual code switching strategy may assist older individuals
in the maintenance of information in working memory.
著者Contact先の email:
mosaka@hus.osaka-u.ac.jp
Osaka, M., Otsuka, Y., & Osaka, N.
Title:
Verbal to visual code switching improves working memory in the elderly:
An fMRI study.
Journal:
Frontiers of Human Neuroscience
doi:
10.3389/fnhum.2012.00024
論文URL:
http://www.frontiersin.org/Journal/FullText.aspx?s=537&name=Human_Neuroscience&ART_DOI=10.3389/fnhum.2012.00024
Abstract:
The effect of verbal to visual code switching training on working memory
performance was investigated in individuals aged 63 and older. During
verbal working memory task performance, the training group (n = 25) was
introduced to a verbal to visual code switching strategy while the
control group (n = 25) was not exposed to such a strategy. Working
memory recognition accuracy was enhanced only in the training group. To
explore the neural substrates underlying these strategy effects, fMRI
was used to measure brain activity in both groups during working memory
task performance before and after an attention training period. In a
comparison between pre- and post-training sessions, results showed
increased activation in the anterior cingulate cortex (ACC). Relative to
the control group, the post-training group exhibited increased
activation in the left and right inferior parietal lobules (IPLs) and
right superior parietal lobule (SPL). These findings suggest that use of
a verbal to visual code switching strategy may assist older individuals
in the maintenance of information in working memory.
著者Contact先の email:
mosaka@hus.osaka-u.ac.jp
Authors:
Minamoto, T., Osaka, M., Engle, R. W., & Osaka, N.
Title:
Incidental encoding of goal-irrelevant information is associated with
insufficient engagement of the dorsal frontal cortex and the inferior
parietal cortex.
Journal:
Brain Research
doi:
10.1016/j.brainres.2011.10.034
論文URL:
http://www.journals.elsevier.com/brain-research/
Abstract:
Previous studies have shown that goal-irrelevant distractors are
incidentally encoded into long-term memory. Neuroimaging studies have
suggested that the medial temporal and visual association regions are
involved in incidental encoding of goal-irrelevant information. However,
few studies have investigated prefrontal/parietal influence during the
incidental encoding. The present study performed whole brain analysis to
identify the brain regions involved in the incidental encoding of
goal-irrelevant information. A face working memory (WM) task was
administered with insertion of face distractors during the delay period.
Following the WM task, a surprise recognition task was given in an MRI
scanner. Recognition rate of distractors was higher than that of novel
fillers. Recognition time was also faster in distractors than in novel
fillers. Neuroimaging results showed less activation to distractors
subsequently remembered than those forgotten in the middle and superior
frontal regions and the lateral inferior parietal lobe including the
angular gyrus and the temporoparietal regions. However, the left
anterior hippocampus and the right fusiform gyrus showed greater
activation to distractors subsequently remembered. Those findings
suggest that insufficient engagement of the dorsal frontal cortex which
regulates attentional control and the inferior parietal lobe which
functions to reorient attention may allow goal-irrelevant information
access to working memory and to be encoded into long-term memory.
著者Contact先の email:
nosaka@bun.kyoto-u.ac.jp
Minamoto, T., Osaka, M., Engle, R. W., & Osaka, N.
Title:
Incidental encoding of goal-irrelevant information is associated with
insufficient engagement of the dorsal frontal cortex and the inferior
parietal cortex.
Journal:
Brain Research
doi:
10.1016/j.brainres.2011.10.034
論文URL:
http://www.journals.elsevier.com/brain-research/
Abstract:
Previous studies have shown that goal-irrelevant distractors are
incidentally encoded into long-term memory. Neuroimaging studies have
suggested that the medial temporal and visual association regions are
involved in incidental encoding of goal-irrelevant information. However,
few studies have investigated prefrontal/parietal influence during the
incidental encoding. The present study performed whole brain analysis to
identify the brain regions involved in the incidental encoding of
goal-irrelevant information. A face working memory (WM) task was
administered with insertion of face distractors during the delay period.
Following the WM task, a surprise recognition task was given in an MRI
scanner. Recognition rate of distractors was higher than that of novel
fillers. Recognition time was also faster in distractors than in novel
fillers. Neuroimaging results showed less activation to distractors
subsequently remembered than those forgotten in the middle and superior
frontal regions and the lateral inferior parietal lobe including the
angular gyrus and the temporoparietal regions. However, the left
anterior hippocampus and the right fusiform gyrus showed greater
activation to distractors subsequently remembered. Those findings
suggest that insufficient engagement of the dorsal frontal cortex which
regulates attentional control and the inferior parietal lobe which
functions to reorient attention may allow goal-irrelevant information
access to working memory and to be encoded into long-term memory.
著者Contact先の email:
nosaka@bun.kyoto-u.ac.jp
Authors:
Osaka, N., Minamoto, T., Yaoi, K., & Osaka, M.
Title:
Neural correlates of delicate sadness: An fMRI study based on the
neuroaesthetics of Noh-masks
Journal:
Neuroreport
doi:
10.1097/WNR.0b013e32834dccda
論文URL:
http://journals.lww.com/neuroreport/toc/2012/01040
Abstract:
Although the role of the amygdala in processing facial expressions of
fear is well established, its role in the processing of other emotions,
such as sadness, remains unclear. We hypothesized that the amygdala
would respond to a negative emotion such as sadness, when sadness was
represented by a theatrical mask. In the traditional Japanese Noh
theater, performers use masks to indicate many of the mental states of
the characters they portray. Here, we report a functional MRI study, in
which participants' brains were scanned while viewing Noh masks, whose
faces appeared delicately sad. Among seventy standard Noh masks
previously rated by the individual participants, we chose six top-rated
sad masks and six neutral masks to study the neural correlates of such
delicate sadness. Results based on a region of interest analysis
indicated the activation of the right amygdala while viewing sad masks.
We suggest the fact that such delicate sad masks could activate the
amygdala, and it could possibly be because of an underlying similarity
to emotions such as fear and disgust.
著者Contact先の email:
nosaka@bun.kyoto-u.ac.jp
Osaka, N., Minamoto, T., Yaoi, K., & Osaka, M.
Title:
Neural correlates of delicate sadness: An fMRI study based on the
neuroaesthetics of Noh-masks
Journal:
Neuroreport
doi:
10.1097/WNR.0b013e32834dccda
論文URL:
http://journals.lww.com/neuroreport/toc/2012/01040
Abstract:
Although the role of the amygdala in processing facial expressions of
fear is well established, its role in the processing of other emotions,
such as sadness, remains unclear. We hypothesized that the amygdala
would respond to a negative emotion such as sadness, when sadness was
represented by a theatrical mask. In the traditional Japanese Noh
theater, performers use masks to indicate many of the mental states of
the characters they portray. Here, we report a functional MRI study, in
which participants' brains were scanned while viewing Noh masks, whose
faces appeared delicately sad. Among seventy standard Noh masks
previously rated by the individual participants, we chose six top-rated
sad masks and six neutral masks to study the neural correlates of such
delicate sadness. Results based on a region of interest analysis
indicated the activation of the right amygdala while viewing sad masks.
We suggest the fact that such delicate sad masks could activate the
amygdala, and it could possibly be because of an underlying similarity
to emotions such as fear and disgust.
著者Contact先の email:
nosaka@bun.kyoto-u.ac.jp
Authors:
Tsubomi, H., Ikeda, T., Hanakawa, T., Hirose, N., Fukuyama, H., & Osaka, N.
Title:
Dissociable neural activations of conscious visibility and attention
Journal:
Journal of Cognitive Neuroscience
doi:
なし
論文URL:
http://www.mitpressjournals.org/loi/jocn
Abstract:
Recent neuroimaging evidence indicates that visual consciousness of
objects is reflected by the activation in the lateral occipital cortex
as well as in the frontal and parietal cortex. However, most previous
studies used behavioral paradigms in which attention raised or enhanced
visual consciousness (visibility or recognition performance). This
co-occurrence made it difficult to reveal whether an observed cortical
activation is related to visual consciousness or attention. The present
fMRI study investigated the dissociability of neural activations
underlying these two cognitive phenomena. Toward this aim, we used a
visual backward masking paradigm in which directing attention could
either enhance or reduce the object visibility. The participantsʼ task
was to report the level of subjective visibility for a briefly presented
target object. The target was presented in the center with four
flankers, which was followed by the same number of masks. Behavioral
results showed that attention to the flankers enhanced the target
visibility, whereas attention to the masks attenuated it. The fMRI
results showed that the occipito-temporal sulcus increased activation in
the attend flankers condition compared with the attend masks condition,
and occipito-temporal sulcus activation levels positively correlated
with the target visibility in both attentional conditions. On the other
hand, the inferior frontal gyrus and the intraparietal sulcus increased
activation in both the attend flankers and attend masks compared with an
attend neither condition, and these activation levels were independent
of target visibility. Taken together, present results showed a clear
dissociation in neural activities between conscious visibility and
attention.
著者Contact先の email:
htsubomi@fennel.rcast.u-tokyo.ac.jp
Tsubomi, H., Ikeda, T., Hanakawa, T., Hirose, N., Fukuyama, H., & Osaka, N.
Title:
Dissociable neural activations of conscious visibility and attention
Journal:
Journal of Cognitive Neuroscience
doi:
なし
論文URL:
http://www.mitpressjournals.org/loi/jocn
Abstract:
Recent neuroimaging evidence indicates that visual consciousness of
objects is reflected by the activation in the lateral occipital cortex
as well as in the frontal and parietal cortex. However, most previous
studies used behavioral paradigms in which attention raised or enhanced
visual consciousness (visibility or recognition performance). This
co-occurrence made it difficult to reveal whether an observed cortical
activation is related to visual consciousness or attention. The present
fMRI study investigated the dissociability of neural activations
underlying these two cognitive phenomena. Toward this aim, we used a
visual backward masking paradigm in which directing attention could
either enhance or reduce the object visibility. The participantsʼ task
was to report the level of subjective visibility for a briefly presented
target object. The target was presented in the center with four
flankers, which was followed by the same number of masks. Behavioral
results showed that attention to the flankers enhanced the target
visibility, whereas attention to the masks attenuated it. The fMRI
results showed that the occipito-temporal sulcus increased activation in
the attend flankers condition compared with the attend masks condition,
and occipito-temporal sulcus activation levels positively correlated
with the target visibility in both attentional conditions. On the other
hand, the inferior frontal gyrus and the intraparietal sulcus increased
activation in both the attend flankers and attend masks compared with an
attend neither condition, and these activation levels were independent
of target visibility. Taken together, present results showed a clear
dissociation in neural activities between conscious visibility and
attention.
著者Contact先の email:
htsubomi@fennel.rcast.u-tokyo.ac.jp
Authors:Shibata, Hiroshi; Inui, Toshio; Ogawa, Kenji Title:Role of the dorsolateral prefrontal cortex in recognizing hand actions performed in social contexts: a functional MRI study Journal(書誌情報）:Neuroreport. 24(14):803-807, 2013 doi:10.1097/WNR.0b013e3283646287 論文URL:http://journals.lww.com/neuroreport/Abstract/2013/10020 /Role_of_the_dorsolateral_prefrontal_cortex_in.8.aspx Abstract:We investigated the role of the prefrontal areas in recognizing hand actions performed in social contexts. We used video clips depicting the interaction between two individuals: one person (requester) requested the other person to pass one of two objects. The other person (responder) then passed the object that was congruent to the request in the congruent condition or incongruent in the incongruent condition. Both requester and responder appeared on screen in the two-person condition and only the responder appeared in the one-person condition. Participants were required to observe the clips and to judge whether the responder's actions were congruent or incongruent. Functional MRI showed the incongruency effect in the prefrontal cortex. In particular, the brain areas including the bilateral dorsolateral prefrontal cortex showed the interaction effect; the magnitude of activation in the incongruent condition was significantly higher than that in the congruent ! condition, but this difference was found only in the two-person condition. These results suggest that the dorsolateral prefrontal cortex play an important role in the detection of incongruency between the requester's request and the responder's action depending on social contexts. 著者Contact先の email:hshibata@rehab.tbgu.ac.jp
