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Yuko Akitsuki

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University of Chicago

Robert Lickliter

Florida International University

University of Chicago

Kalina Michalska

University of California, Riverside

Kansas State University

FILIPPOS VLACHOS

UNIVERSITY OF THESSALY, GREECE

Vincent D . Costa

Emory University

Marco Tullio Liuzza

University of Padova

Stefka G Eriksen

University of Oslo

Dragos Simandan

Brock University

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Papers by Yuko Akitsuki

Processing of Anomalous Sentences in Japanese : An fMRI Study

Journal of Cognitive Science, 2007

Encouraging Mother-Child Play Improves Maternal and Child Mental Health as Well as Child Cognitive Development: A Randomized-Controlled Trial

An fMRI study of scrambling effects on sentence comprehension

Human Brain Mapping

The present study aims to confirm the cortical correlates of scrambling effects, a free word orde... more The present study aims to confirm the cortical correlates of scrambling effects, a free word order phenomenon that has been observed in a variety of cross-linguistic investigations but whose mechanism still remains unclarified. Many syntax-oriented hypotheses on scrambling have been provided to develop the structural basis of the free word order permutation in Japanese, leading to the most recent phrasal architecture, in which the object noun phrase of a transitive sentence ''moves'' to a higher position than the subject to form an asymmetric structure including antecedentegap relationships. Such a configurational structure formed by scrambling operation predicts that the scrambled sentences have a more complex structure than canonical sentences, and that the former requires a greater burden on cognitive processes in related areas within the brain. Based on this general assumption, we employed an experimental method of whole-sentence presentation of Japanese transitive sentences, for both canonical transitive sentences (SubjecteObjecteVerb) and their scrambled counterparts (ObjecteSubjecteVerb). The result showed more activation at the left inferior frontal gyrus (IFG) and the left dorsal prefrontal cortex (DPFC) during the comprehension of scrambled sentences than that of canonical sentences. This indicates, in accordance with previous findings on scrambling from neurolinguistic perspectives, that the scrambling in Japanese is indeed one of the grammatical operations and that the parsing strategy for the asymmetric antecedentegap relationship demands an additional cognitive activation in the brain.

Neural network involved in the lexical and morphological processing: An fMRI study

Neuroscience Research

Nutritional Quality of Breakfast Affects Cognitive Function: An fMRI Study

Neuroscience & Medicine, 2011

To investigate the neural underpinnings of the effect of nutrition, brain activity of six young h... more To investigate the neural underpinnings of the effect of nutrition, brain activity of six young healthy volunteers who had a breakfast including various nutrients was compared to when they skipped breakfast or had only sugar for breakfast by functional magnetic resonance imaging. A repeated measure counterbalanced crossover design was employed. We demonstrated that significantly higher brain activation was observed in the medial aspect of the prefrontal cortex when the subjects had a nutritionally balanced breakfast while the subjects were conducting N-back tasks. This preliminary report was the first to demonstrate by means of brain imaging techniques that taking various nutrients as breakfast as well sugar has relevant impacts on underlying physiological events or cognition.

Cortical activation during reading aloud of long sentences: fMRI study

Neuroreport, Jan 26, 2003

The purpose of this study was to investigate human brain activity during the reading aloud of Jap... more The purpose of this study was to investigate human brain activity during the reading aloud of Japanese sentences using fMRI. Twenty-three right-handed normal Japanese subjects performed three reading tasks: covert reading of meaningful or meaningless sentences, and reading aloud of meaningful sentences. Areas in the bilateral frontal and temporal cortices were activated during the reading-aloud task compared with the covert reading task. In addition, activation of these brain areas showed significant positive correlation with the reading speed during the reading-aloud task. Our results indicate that bilateral frontal-temporal networks are involved in phonological processing during reading aloud.

Compensatory Effort Parallels Midbrain Deactivation during Mental Fatigue: An fMRI Study

PLoS ONE, 2013

Fatigue reflects the functioning of our physiological negative feedback system, which prevents us... more Fatigue reflects the functioning of our physiological negative feedback system, which prevents us from overworking. When fatigued, however, we often try to suppress this system in an effort to compensate for the resulting deterioration in performance. Previous studies have suggested that the effect of fatigue on neurovascular demand may be influenced by this compensatory effort. The primary goal of the present study was to isolate the effect of compensatory effort on neurovascular demand. Healthy male volunteers participated in a series of visual and auditory divided attention tasks that steadily increased fatigue levels for 2 hours. Functional magnetic resonance imaging scans were performed during the first and last quarter of the study (Pre and Post sessions, respectively). Tasks with low and high attentional load (Low and High conditions, respectively) were administrated in alternating blocks. We assumed that compensatory effort would be greater under the High-attentional-load condition compared with the Low-load condition. The difference was assessed during the two sessions. The effect of compensatory effort on neurovascular demand was evaluated by examining the interaction between load (High vs. Low) and time (Pre vs. Post). Significant fatigue-induced deactivation (i.e., Pre.Post) was observed in the frontal, temporal, occipital, and parietal cortices, in the cerebellum, and in the midbrain in both the High and Low conditions. The interaction was significantly greater in the High than in the Low condition in the midbrain. Neither significant fatigue-induced activation (i.e., Pre,Post), nor its interaction with factor Load, was identified. The observed midbrain deactivation ([PreH -PostH]. [PreE-PostE]) may reflect suppression of the negative feedback system that normally triggers recuperative rest to maintain homeostasis.

Social interaction and concern for others in episodic memory: an fMRI study

Neuroscience Research, 2009

Family structure around a child is one of the strongest environmental factors for his/her social ... more Family structure around a child is one of the strongest environmental factors for his/her social and mental development. To investigate how the behavioral traits of juvenile primate represent human development, we prepared three groups of subjects different in their family structure, that is, bred without other siblings, either by human (H1) or by its own parents (P1), and with another sibling by its own parents (P2). We evaluated their behavioral development in our original meeting test between two or four peers. The multivariate analysis of the test result expressed the different behavioral patterns more distinctly at the contexts in 4 peers than 2. Interestingly, P1's pattern showed the least change from 2-to 4-peer-context, comparing to H1's or P2's. These results suggest that social brain function was sculpted through social interaction between parent-child and peers during development.

Cortical mechanisms of person representation: Recognition of famous and personally familiar names

NeuroImage, 2006

Personally familiar people are likely to be represented more richly in episodic, emotional, and b... more Personally familiar people are likely to be represented more richly in episodic, emotional, and behavioral contexts than famous people, who are usually represented predominantly in semantic context. To reveal cortical mechanisms supporting this differential person representation, we compared cortical activation during name recognition tasks between personally familiar and famous names, using an event-related functional magnetic resonance imaging (fMRI). Normal subjects performed familiar-or unfamiliar-name detection tasks during visual presentation of personally familiar (Personal), famous (Famous), and unfamiliar (Unfamiliar) names. The bilateral temporal poles and anterolateral temporal cortices, as well as the left temporoparietal junction, were activated in the contrasts Personal -Unfamiliar and Famous -Unfamiliar to a similar extent. The bilateral occipitotemporoparietal junctions, precuneus, and posterior cingulate cortex showed activation in the contrasts Personal -Unfamiliar and Personal -Famous. Together with previous findings, differential activation in the occipitotemporoparietal junction, precuneus, and posterior cingulate cortex between personally familiar and famous names is considered to reflect differential person representation. The similar extent of activation for personally familiar and famous names in the temporal pole and anterolateral temporal cortex is consistent with the associative role of the anterior temporal cortex in person identification, which has been conceptualized as a person identity node in many models of person identification. The left temporoparietal junction was considered to process familiar written names. The results illustrated the neural correlates of the person representation as a network of discrete regions in the bilateral posterior cortices, with the anterior temporal cortices having a unique associative role. D

Multiple brain networks for visual self-recognition with different sensitivity for motion and body part

by Yuko Akitsuki and Hyeonjeong Jeong

Neuroimage, Jan 1, 2006

Multiple brain networks may support visual self-recognition. It has been hypothesized that the le... more Multiple brain networks may support visual self-recognition. It has been hypothesized that the left ventral occipito-temporal cortex processes one's own face as a symbol, and the right parieto-frontal network processes self-image in association with motion -action contingency. Using functional magnetic resonance imaging, we first tested these hypotheses based on the prediction that these networks preferentially respond to a static self-face and to moving one's whole body, respectively. Brain activation specifically related to self-image during familiarity judgment was compared across four stimulus conditions comprising a two factorial design: factor Motion contrasted picture (Picture) and movie (Movie), and factor Body part a face (Face) and whole body (Body). Second, we attempted to segregate self-specific networks using a principal component analysis (PCA), assuming an independent pattern of inter-subject variability in activation over the four stimulus conditions in each network. The bilateral ventral occipito-temporal and the right parietal and frontal cortices exhibited self-specific activation. The left ventral occipitotemporal cortex exhibited greater self-specific activation for Face than for Body, in Picture, consistent with the prediction for this region. The activation profiles of the right parietal and frontal cortices did not show preference for Movie Body predicted by the assumed roles of these regions. The PCA extracted two cortical networks, one with its peaks in the right posterior, and another in frontal cortices; their possible roles in visuo-spatial and conceptual self-representations, respectively, were suggested by previous findings. The results thus supported and provided evidence of multiple brain networks for visual self-recognition. D

Context-dependent cortical activation in response to financial reward and penalty: an event-related fMRI study

NeuroImage, 2003

An event-related fMRI technique was used to assess neural responses to financial reward and penal... more An event-related fMRI technique was used to assess neural responses to financial reward and penalty during a simple gambling task. We attempted to determine whether brain activities are dependent on the unique context of an event sequence. Thirty-six healthy volunteers participated in the study. The task was to guess the color of the suit of a card on each trial and to respond by pressing a button. Every correct response ("win") and incorrect response ("loss") was associated with financial reward and penalty, respectively. The magnitude of reward or penalty in each trial did not change; however, the subjects' self-reported emotional arousal was significantly higher for the events of "the fourth win of four wins in a row" and "the fourth loss of four losses in a row." We also found that the bilateral anterior cingulate and medial prefrontal cortices were specifically activated when the subjects experienced "the fourth win of four wins in a row" and "the fourth loss of four losses in a row. "When the subjects experienced "a win following four losses in a row" or "a loss following four wins in a row, "the right dorsolateral prefrontal cortex was specifically activated. Our data indicate that there exist brain activities associated with the event-sequence context in which abstract reward or penalty is received. These context-dependent activities appear to be crucial for adapting oneself to new circumstances and may account for clinical symptoms of various mental illnesses in which dysfunction of these regions has been reported.

Age-related differences in brain activity during extended continuous word recognition in children

NeuroImage, 2009

a b s t r a c t Old/new effect N1 P2 N400 Late positive complex (LPC) Memory Child development Ex... more

Effects of Aging on Hippocampal and Anterior Temporal Activations during Successful Retrieval of Memory for Face–Name Associations

Journal of Cognitive Neuroscience, 2011

Memory for face-name associations is an important type of memory in our daily lives, and often de... more Memory for face-name associations is an important type of memory in our daily lives, and often deteriorates in older adults. Although difficulty retrieving face-name associations is often apparent in the elderly, there is little neuroscientific evidence of age-related decline in this memory. The current fMRI study investigated differences in brain activations between healthy young and older adults during the successful retrieval of people&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s names (N) and job titles (J) associated with faces. During encoding, participants viewed unfamiliar faces, each paired with a job title and name. During retrieval, each learned face was presented with two job titles or two names, and participants were required to choose the correct job title or name. Retrieval success activity (RSA) was identified by comparing retrieval-phase activity for hits versus misses in N and J, and the RSAs in each task were compared between young and older adults. The study yielded three main findings. First, the hippocampus showed significant RSA in both tasks of N and J, and the activity was greater for young compared to older subjects. Second, the left anterior temporal lobe (ATL) showed greater RSA in N than in J, but there was no age difference in the activity in this region. Third, functional connectivity between hippocampal and ATL activities in both retrieval tasks was higher for young than for older adults. Taken together, age-related differences in hippocampal activities and hippocampus-ATL connectivity could contribute to age-related decline in relational memory and to complaints of poor retrieval of people&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s names by older adults.

Anatomical Segregation of Representations of Personally Familiar and Famous People in the Temporal and Parietal Cortices

by Yuko Akitsuki and Yuko Sassa

Journal of Cognitive Neuroscience, 2009

Person recognition has been assumed to entail many types of person-specific cognitive responses, ... more Person recognition has been assumed to entail many types of person-specific cognitive responses, including retrieval of knowledge, episodic recollection, and emotional responses. To demonstrate the cortical correlates of this modular structure of multimodal person representation, we investigated neural responses preferential to personally familiar people and responses dependent on familiarity with famous people in the temporal and parietal cortices. During functional magnetic resonance imaging (fMRI) measurements, normal subjects recognized personally familiar names (personal) or famous names with high or low degrees of familiarity (high or low, respectively). Effects of familiarity with famous people (i.e., high-low) were identified in the bilateral angular gyri, the left supramarginal gyrus, the middle part of the bilateral posterior cingulate cortices, and the left precuneus. Activation preferentially relevant to personally familiar people (i.e., personal-high) was identified in the bilateral temporo-parietal junctions, the right anterolateral temporal cortices, posterior middle temporal gyrus, posterior cingulate cortex (with a peak in the posterodorsal part), and the left precuneus; these activation foci exhibited varying degrees of activation for high and low names. An equivalent extent of activation was observed for all familiar names in the bilateral temporal poles, the left orbito-insular junction, the middle temporal gyrus, and the anterior part of the posterior cingulate cortex. The results demonstrated that distinct cortical areas supported different types of cognitive responses, induced to different degrees during recognition of famous and personally familiar people, providing neuroscientific evidence for the modularity of multimodal person representation.

Cortical Mechanisms Involved in the Processing of Verbs: An fMRI Study

Journal of Cognitive Neuroscience, 2006

In this study, we investigated two aspects of verb processing: first, whether verbs are processed... more In this study, we investigated two aspects of verb processing: first, whether verbs are processed differently from nouns; and second, how verbal morphology is processed. For this purpose, we used functional magnetic resonance imaging to compare three types of lexical processing in Japanese: the processing of nouns, unmarked active verbs, and inflected passive verbs. Twenty-eight healthy subjects were shown a lexical item and asked to judge whether the presented item was a legal word. Although all three conditions activated the bilateral inferior frontal, occipital, the left middle, and inferior temporal cortices, we found differences in the degree of activation for each condition. Verbs elicited greater activation in the left middle temporal gyrus than nouns, and inflected verbs showed greater activation in the left inferior frontal gyrus than unmarked verbs. This study demonstrates that although verbs are basically processed in the same cortical network as nouns, nouns and verbs elicit different degrees of activation due to the cognitive demands involved in lexical semantic processing. Furthermore, this study also shows that the left inferior frontal cortex is related to the processing of verbal inflectional morphology.

Brain training game improves executive functions and processing speed in the elderly: a randomized controlled trial

PloS one, 2012

The beneficial effects of brain training games are expected to transfer to other cognitive functi... more

Mental Visual Synthesis is Originated in the Fronto-temporal Network of the Left Hemisphere

Cerebral Cortex, 2004

Mental visual synthesis is the capacity for experiencing, constructing, or manipulating 'mental i... more Mental visual synthesis is the capacity for experiencing, constructing, or manipulating 'mental imagery'. To investigate brain networks involved in mental visual synthesis, brain activity was measured in right-handed healthy volunteers during mental imagery tasks, in which the subjects were instructed to imagine a novel object, that does not exist in the real world, by composing it from two visually presented words associated with a real object or two achromatic line drawings of a real object, using functional magnetic resonance imaging (fMRI). Both tasks activated the same areas in the inferior frontal and inferior temporal cortices of the left hemisphere. Our results indicate that the source of mental visual synthesis may be formed by activity of a brain network consisting of these areas, which are also involved in semantic operations and visual imagery.

Brain activation during the course of sentence comprehension

Brain and Language, 2006

The purpose of this study is to determine, by functional magnetic resonance imaging, how the acti... more The purpose of this study is to determine, by functional magnetic resonance imaging, how the activated regions of the brain change as a Japanese sentence is presented in a grammatically correct order. In this study, we presented constituents of a sentence to Japanese participants one by one at regular intervals. The results showed that the left lingual gyrus was signiWcantly activated at the beginning of the sentence, then the left inferior frontal gyrus and left supplementary motor area, in the middle of the sentence, and the left inferior temporal gyrus, at the end of the sentence. We suggest that these brain areas are involved in sentence comprehension in this temporal order.

Activity in the primary somatosensory cortex induced by reflexological stimulation is unaffected by pseudo-information: a functional magnetic resonance imaging study

BMC Complementary and Alternative Medicine, 2013

Background: Reflexology is an alternative medical practice that produces beneficial effects by ap... more Background: Reflexology is an alternative medical practice that produces beneficial effects by applying pressure to specific reflex areas. Our previous study suggested that reflexological stimulation induced cortical activation in somatosensory cortex corresponding to the stimulated reflex area; however, we could not rule out the possibility of a placebo effect resulting from instructions given during the experimental task. We used functional magnetic resonance imaging (fMRI) to investigate how reflexological stimulation of the reflex area is processed in the primary somatosensory cortex when correct and pseudo-information about the reflex area is provided. Furthermore, the laterality of activation to the reflexological stimulation was investigated. Methods: Thirty-two healthy Japanese volunteers participated. The experiment followed a double-blind design. Half of the subjects received correct information, that the base of the second toe was the eye reflex area, and pseudoinformation, that the base of the third toe was the shoulder reflex area. The other half of the subjects received the opposite information. fMRI time series data were acquired during reflexological stimulation to both feet. The experimenter stimulated each reflex area in accordance with an auditory cue. The fMRI data were analyzed using a conventional two-stage approach. The hemodynamic responses produced by the stimulation of each reflex area were assessed using a general linear model on an intra-subject basis, and a two-way repeated-measures analysis of variance was performed on an intersubject basis to determine the effect of reflex area laterality and information accuracy. Results: Our results indicated that stimulation of the eye reflex area in either foot induced activity in the left middle postcentral gyrus, the area to which tactile sensation to the face projects, as well as in the postcentral gyrus contralateral foot representation area. This activity was not affected by pseudo information. The results also indicate that the relationship between the reflex area and the projection to the primary somatosensory cortex has a lateral pattern that differs from that of the actual somatotopical representation of the body.

Atypical empathic responses in adolescents with aggressive conduct disorder: a functional MRI investigation.

by Jean Decety, Kalina Michalska, and Yuko Akitsuki

Because youth with aggressive conduct disorder (CD) often inflict pain on others, it is important... more Because youth with aggressive conduct disorder (CD) often inflict pain on others, it is important to determine if they exhibit atypical empathic responses to viewing others in pain. In this initial functional magnetic resonance imaging (fMRI) study, 8 adolescents with aggressive CD and 8 matched controls were scanned while watching animated visual stimuli depicting other people experiencing pain or not experiencing pain. Furthermore, these situations involved either an individual whose pain was caused by accident or an individual whose pain was inflicted on purpose by another person. After scanning, participants rated how painful the situations were. In both groups the perception of others in pain was associated with activation of the pain matrix, including the ACC, insula, somatosensory cortex, supplementary motor area and periaqueductal gray. The pain matrix was activated to a significantly greater extent in participants with CD, who also showed strong amygdala, ventral striatum, and temporal pole activation. When watching situations in which pain was intentionally inflicted, control youth also exhibited signal increase in the medial prefrontal frontal cortex, lateral obitofrontal cortex, and temporoparietal junction, whereas youth with CD only exhibited activation in the insula. Furthermore, connectivity analyses demonstrated that youth with CD exhibited less amygdala/prefrontal coupling when watching pain inflicted by another than did control youth. These preliminary findings suggest that youth with aggressive CD exhibit an atypical pattern of neural response to viewing others in pain that should be explored in further studies.

Processing of Anomalous Sentences in Japanese : An fMRI Study

Journal of Cognitive Science, 2007

Encouraging Mother-Child Play Improves Maternal and Child Mental Health as Well as Child Cognitive Development: A Randomized-Controlled Trial

An fMRI study of scrambling effects on sentence comprehension

Human Brain Mapping

The present study aims to confirm the cortical correlates of scrambling effects, a free word orde... more The present study aims to confirm the cortical correlates of scrambling effects, a free word order phenomenon that has been observed in a variety of cross-linguistic investigations but whose mechanism still remains unclarified. Many syntax-oriented hypotheses on scrambling have been provided to develop the structural basis of the free word order permutation in Japanese, leading to the most recent phrasal architecture, in which the object noun phrase of a transitive sentence ''moves'' to a higher position than the subject to form an asymmetric structure including antecedentegap relationships. Such a configurational structure formed by scrambling operation predicts that the scrambled sentences have a more complex structure than canonical sentences, and that the former requires a greater burden on cognitive processes in related areas within the brain. Based on this general assumption, we employed an experimental method of whole-sentence presentation of Japanese transitive sentences, for both canonical transitive sentences (SubjecteObjecteVerb) and their scrambled counterparts (ObjecteSubjecteVerb). The result showed more activation at the left inferior frontal gyrus (IFG) and the left dorsal prefrontal cortex (DPFC) during the comprehension of scrambled sentences than that of canonical sentences. This indicates, in accordance with previous findings on scrambling from neurolinguistic perspectives, that the scrambling in Japanese is indeed one of the grammatical operations and that the parsing strategy for the asymmetric antecedentegap relationship demands an additional cognitive activation in the brain.

Neural network involved in the lexical and morphological processing: An fMRI study

Neuroscience Research

Nutritional Quality of Breakfast Affects Cognitive Function: An fMRI Study

Neuroscience & Medicine, 2011

To investigate the neural underpinnings of the effect of nutrition, brain activity of six young h... more To investigate the neural underpinnings of the effect of nutrition, brain activity of six young healthy volunteers who had a breakfast including various nutrients was compared to when they skipped breakfast or had only sugar for breakfast by functional magnetic resonance imaging. A repeated measure counterbalanced crossover design was employed. We demonstrated that significantly higher brain activation was observed in the medial aspect of the prefrontal cortex when the subjects had a nutritionally balanced breakfast while the subjects were conducting N-back tasks. This preliminary report was the first to demonstrate by means of brain imaging techniques that taking various nutrients as breakfast as well sugar has relevant impacts on underlying physiological events or cognition.

Cortical activation during reading aloud of long sentences: fMRI study

Neuroreport, Jan 26, 2003

The purpose of this study was to investigate human brain activity during the reading aloud of Jap... more The purpose of this study was to investigate human brain activity during the reading aloud of Japanese sentences using fMRI. Twenty-three right-handed normal Japanese subjects performed three reading tasks: covert reading of meaningful or meaningless sentences, and reading aloud of meaningful sentences. Areas in the bilateral frontal and temporal cortices were activated during the reading-aloud task compared with the covert reading task. In addition, activation of these brain areas showed significant positive correlation with the reading speed during the reading-aloud task. Our results indicate that bilateral frontal-temporal networks are involved in phonological processing during reading aloud.

Compensatory Effort Parallels Midbrain Deactivation during Mental Fatigue: An fMRI Study

PLoS ONE, 2013

Fatigue reflects the functioning of our physiological negative feedback system, which prevents us... more Fatigue reflects the functioning of our physiological negative feedback system, which prevents us from overworking. When fatigued, however, we often try to suppress this system in an effort to compensate for the resulting deterioration in performance. Previous studies have suggested that the effect of fatigue on neurovascular demand may be influenced by this compensatory effort. The primary goal of the present study was to isolate the effect of compensatory effort on neurovascular demand. Healthy male volunteers participated in a series of visual and auditory divided attention tasks that steadily increased fatigue levels for 2 hours. Functional magnetic resonance imaging scans were performed during the first and last quarter of the study (Pre and Post sessions, respectively). Tasks with low and high attentional load (Low and High conditions, respectively) were administrated in alternating blocks. We assumed that compensatory effort would be greater under the High-attentional-load condition compared with the Low-load condition. The difference was assessed during the two sessions. The effect of compensatory effort on neurovascular demand was evaluated by examining the interaction between load (High vs. Low) and time (Pre vs. Post). Significant fatigue-induced deactivation (i.e., Pre.Post) was observed in the frontal, temporal, occipital, and parietal cortices, in the cerebellum, and in the midbrain in both the High and Low conditions. The interaction was significantly greater in the High than in the Low condition in the midbrain. Neither significant fatigue-induced activation (i.e., Pre,Post), nor its interaction with factor Load, was identified. The observed midbrain deactivation ([PreH -PostH]. [PreE-PostE]) may reflect suppression of the negative feedback system that normally triggers recuperative rest to maintain homeostasis.

Social interaction and concern for others in episodic memory: an fMRI study

Neuroscience Research, 2009

Family structure around a child is one of the strongest environmental factors for his/her social ... more Family structure around a child is one of the strongest environmental factors for his/her social and mental development. To investigate how the behavioral traits of juvenile primate represent human development, we prepared three groups of subjects different in their family structure, that is, bred without other siblings, either by human (H1) or by its own parents (P1), and with another sibling by its own parents (P2). We evaluated their behavioral development in our original meeting test between two or four peers. The multivariate analysis of the test result expressed the different behavioral patterns more distinctly at the contexts in 4 peers than 2. Interestingly, P1's pattern showed the least change from 2-to 4-peer-context, comparing to H1's or P2's. These results suggest that social brain function was sculpted through social interaction between parent-child and peers during development.

Cortical mechanisms of person representation: Recognition of famous and personally familiar names

NeuroImage, 2006

Personally familiar people are likely to be represented more richly in episodic, emotional, and b... more Personally familiar people are likely to be represented more richly in episodic, emotional, and behavioral contexts than famous people, who are usually represented predominantly in semantic context. To reveal cortical mechanisms supporting this differential person representation, we compared cortical activation during name recognition tasks between personally familiar and famous names, using an event-related functional magnetic resonance imaging (fMRI). Normal subjects performed familiar-or unfamiliar-name detection tasks during visual presentation of personally familiar (Personal), famous (Famous), and unfamiliar (Unfamiliar) names. The bilateral temporal poles and anterolateral temporal cortices, as well as the left temporoparietal junction, were activated in the contrasts Personal -Unfamiliar and Famous -Unfamiliar to a similar extent. The bilateral occipitotemporoparietal junctions, precuneus, and posterior cingulate cortex showed activation in the contrasts Personal -Unfamiliar and Personal -Famous. Together with previous findings, differential activation in the occipitotemporoparietal junction, precuneus, and posterior cingulate cortex between personally familiar and famous names is considered to reflect differential person representation. The similar extent of activation for personally familiar and famous names in the temporal pole and anterolateral temporal cortex is consistent with the associative role of the anterior temporal cortex in person identification, which has been conceptualized as a person identity node in many models of person identification. The left temporoparietal junction was considered to process familiar written names. The results illustrated the neural correlates of the person representation as a network of discrete regions in the bilateral posterior cortices, with the anterior temporal cortices having a unique associative role. D

Multiple brain networks for visual self-recognition with different sensitivity for motion and body part

by Yuko Akitsuki and Hyeonjeong Jeong

Neuroimage, Jan 1, 2006

Multiple brain networks may support visual self-recognition. It has been hypothesized that the le... more Multiple brain networks may support visual self-recognition. It has been hypothesized that the left ventral occipito-temporal cortex processes one's own face as a symbol, and the right parieto-frontal network processes self-image in association with motion -action contingency. Using functional magnetic resonance imaging, we first tested these hypotheses based on the prediction that these networks preferentially respond to a static self-face and to moving one's whole body, respectively. Brain activation specifically related to self-image during familiarity judgment was compared across four stimulus conditions comprising a two factorial design: factor Motion contrasted picture (Picture) and movie (Movie), and factor Body part a face (Face) and whole body (Body). Second, we attempted to segregate self-specific networks using a principal component analysis (PCA), assuming an independent pattern of inter-subject variability in activation over the four stimulus conditions in each network. The bilateral ventral occipito-temporal and the right parietal and frontal cortices exhibited self-specific activation. The left ventral occipitotemporal cortex exhibited greater self-specific activation for Face than for Body, in Picture, consistent with the prediction for this region. The activation profiles of the right parietal and frontal cortices did not show preference for Movie Body predicted by the assumed roles of these regions. The PCA extracted two cortical networks, one with its peaks in the right posterior, and another in frontal cortices; their possible roles in visuo-spatial and conceptual self-representations, respectively, were suggested by previous findings. The results thus supported and provided evidence of multiple brain networks for visual self-recognition. D

Context-dependent cortical activation in response to financial reward and penalty: an event-related fMRI study

NeuroImage, 2003

An event-related fMRI technique was used to assess neural responses to financial reward and penal... more An event-related fMRI technique was used to assess neural responses to financial reward and penalty during a simple gambling task. We attempted to determine whether brain activities are dependent on the unique context of an event sequence. Thirty-six healthy volunteers participated in the study. The task was to guess the color of the suit of a card on each trial and to respond by pressing a button. Every correct response ("win") and incorrect response ("loss") was associated with financial reward and penalty, respectively. The magnitude of reward or penalty in each trial did not change; however, the subjects' self-reported emotional arousal was significantly higher for the events of "the fourth win of four wins in a row" and "the fourth loss of four losses in a row." We also found that the bilateral anterior cingulate and medial prefrontal cortices were specifically activated when the subjects experienced "the fourth win of four wins in a row" and "the fourth loss of four losses in a row. "When the subjects experienced "a win following four losses in a row" or "a loss following four wins in a row, "the right dorsolateral prefrontal cortex was specifically activated. Our data indicate that there exist brain activities associated with the event-sequence context in which abstract reward or penalty is received. These context-dependent activities appear to be crucial for adapting oneself to new circumstances and may account for clinical symptoms of various mental illnesses in which dysfunction of these regions has been reported.

Age-related differences in brain activity during extended continuous word recognition in children

NeuroImage, 2009

a b s t r a c t Old/new effect N1 P2 N400 Late positive complex (LPC) Memory Child development Ex... more

Effects of Aging on Hippocampal and Anterior Temporal Activations during Successful Retrieval of Memory for Face–Name Associations

Journal of Cognitive Neuroscience, 2011

Memory for face-name associations is an important type of memory in our daily lives, and often de... more Memory for face-name associations is an important type of memory in our daily lives, and often deteriorates in older adults. Although difficulty retrieving face-name associations is often apparent in the elderly, there is little neuroscientific evidence of age-related decline in this memory. The current fMRI study investigated differences in brain activations between healthy young and older adults during the successful retrieval of people&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s names (N) and job titles (J) associated with faces. During encoding, participants viewed unfamiliar faces, each paired with a job title and name. During retrieval, each learned face was presented with two job titles or two names, and participants were required to choose the correct job title or name. Retrieval success activity (RSA) was identified by comparing retrieval-phase activity for hits versus misses in N and J, and the RSAs in each task were compared between young and older adults. The study yielded three main findings. First, the hippocampus showed significant RSA in both tasks of N and J, and the activity was greater for young compared to older subjects. Second, the left anterior temporal lobe (ATL) showed greater RSA in N than in J, but there was no age difference in the activity in this region. Third, functional connectivity between hippocampal and ATL activities in both retrieval tasks was higher for young than for older adults. Taken together, age-related differences in hippocampal activities and hippocampus-ATL connectivity could contribute to age-related decline in relational memory and to complaints of poor retrieval of people&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s names by older adults.

Anatomical Segregation of Representations of Personally Familiar and Famous People in the Temporal and Parietal Cortices

by Yuko Akitsuki and Yuko Sassa

Journal of Cognitive Neuroscience, 2009

Person recognition has been assumed to entail many types of person-specific cognitive responses, ... more Person recognition has been assumed to entail many types of person-specific cognitive responses, including retrieval of knowledge, episodic recollection, and emotional responses. To demonstrate the cortical correlates of this modular structure of multimodal person representation, we investigated neural responses preferential to personally familiar people and responses dependent on familiarity with famous people in the temporal and parietal cortices. During functional magnetic resonance imaging (fMRI) measurements, normal subjects recognized personally familiar names (personal) or famous names with high or low degrees of familiarity (high or low, respectively). Effects of familiarity with famous people (i.e., high-low) were identified in the bilateral angular gyri, the left supramarginal gyrus, the middle part of the bilateral posterior cingulate cortices, and the left precuneus. Activation preferentially relevant to personally familiar people (i.e., personal-high) was identified in the bilateral temporo-parietal junctions, the right anterolateral temporal cortices, posterior middle temporal gyrus, posterior cingulate cortex (with a peak in the posterodorsal part), and the left precuneus; these activation foci exhibited varying degrees of activation for high and low names. An equivalent extent of activation was observed for all familiar names in the bilateral temporal poles, the left orbito-insular junction, the middle temporal gyrus, and the anterior part of the posterior cingulate cortex. The results demonstrated that distinct cortical areas supported different types of cognitive responses, induced to different degrees during recognition of famous and personally familiar people, providing neuroscientific evidence for the modularity of multimodal person representation.

Cortical Mechanisms Involved in the Processing of Verbs: An fMRI Study

Journal of Cognitive Neuroscience, 2006

In this study, we investigated two aspects of verb processing: first, whether verbs are processed... more In this study, we investigated two aspects of verb processing: first, whether verbs are processed differently from nouns; and second, how verbal morphology is processed. For this purpose, we used functional magnetic resonance imaging to compare three types of lexical processing in Japanese: the processing of nouns, unmarked active verbs, and inflected passive verbs. Twenty-eight healthy subjects were shown a lexical item and asked to judge whether the presented item was a legal word. Although all three conditions activated the bilateral inferior frontal, occipital, the left middle, and inferior temporal cortices, we found differences in the degree of activation for each condition. Verbs elicited greater activation in the left middle temporal gyrus than nouns, and inflected verbs showed greater activation in the left inferior frontal gyrus than unmarked verbs. This study demonstrates that although verbs are basically processed in the same cortical network as nouns, nouns and verbs elicit different degrees of activation due to the cognitive demands involved in lexical semantic processing. Furthermore, this study also shows that the left inferior frontal cortex is related to the processing of verbal inflectional morphology.

Brain training game improves executive functions and processing speed in the elderly: a randomized controlled trial

PloS one, 2012

The beneficial effects of brain training games are expected to transfer to other cognitive functi... more

Mental Visual Synthesis is Originated in the Fronto-temporal Network of the Left Hemisphere

Cerebral Cortex, 2004

Mental visual synthesis is the capacity for experiencing, constructing, or manipulating 'mental i... more Mental visual synthesis is the capacity for experiencing, constructing, or manipulating 'mental imagery'. To investigate brain networks involved in mental visual synthesis, brain activity was measured in right-handed healthy volunteers during mental imagery tasks, in which the subjects were instructed to imagine a novel object, that does not exist in the real world, by composing it from two visually presented words associated with a real object or two achromatic line drawings of a real object, using functional magnetic resonance imaging (fMRI). Both tasks activated the same areas in the inferior frontal and inferior temporal cortices of the left hemisphere. Our results indicate that the source of mental visual synthesis may be formed by activity of a brain network consisting of these areas, which are also involved in semantic operations and visual imagery.

Brain activation during the course of sentence comprehension

Brain and Language, 2006

The purpose of this study is to determine, by functional magnetic resonance imaging, how the acti... more The purpose of this study is to determine, by functional magnetic resonance imaging, how the activated regions of the brain change as a Japanese sentence is presented in a grammatically correct order. In this study, we presented constituents of a sentence to Japanese participants one by one at regular intervals. The results showed that the left lingual gyrus was signiWcantly activated at the beginning of the sentence, then the left inferior frontal gyrus and left supplementary motor area, in the middle of the sentence, and the left inferior temporal gyrus, at the end of the sentence. We suggest that these brain areas are involved in sentence comprehension in this temporal order.

Activity in the primary somatosensory cortex induced by reflexological stimulation is unaffected by pseudo-information: a functional magnetic resonance imaging study

BMC Complementary and Alternative Medicine, 2013

Background: Reflexology is an alternative medical practice that produces beneficial effects by ap... more Background: Reflexology is an alternative medical practice that produces beneficial effects by applying pressure to specific reflex areas. Our previous study suggested that reflexological stimulation induced cortical activation in somatosensory cortex corresponding to the stimulated reflex area; however, we could not rule out the possibility of a placebo effect resulting from instructions given during the experimental task. We used functional magnetic resonance imaging (fMRI) to investigate how reflexological stimulation of the reflex area is processed in the primary somatosensory cortex when correct and pseudo-information about the reflex area is provided. Furthermore, the laterality of activation to the reflexological stimulation was investigated. Methods: Thirty-two healthy Japanese volunteers participated. The experiment followed a double-blind design. Half of the subjects received correct information, that the base of the second toe was the eye reflex area, and pseudoinformation, that the base of the third toe was the shoulder reflex area. The other half of the subjects received the opposite information. fMRI time series data were acquired during reflexological stimulation to both feet. The experimenter stimulated each reflex area in accordance with an auditory cue. The fMRI data were analyzed using a conventional two-stage approach. The hemodynamic responses produced by the stimulation of each reflex area were assessed using a general linear model on an intra-subject basis, and a two-way repeated-measures analysis of variance was performed on an intersubject basis to determine the effect of reflex area laterality and information accuracy. Results: Our results indicated that stimulation of the eye reflex area in either foot induced activity in the left middle postcentral gyrus, the area to which tactile sensation to the face projects, as well as in the postcentral gyrus contralateral foot representation area. This activity was not affected by pseudo information. The results also indicate that the relationship between the reflex area and the projection to the primary somatosensory cortex has a lateral pattern that differs from that of the actual somatotopical representation of the body.

Atypical empathic responses in adolescents with aggressive conduct disorder: a functional MRI investigation.

by Jean Decety, Kalina Michalska, and Yuko Akitsuki

Because youth with aggressive conduct disorder (CD) often inflict pain on others, it is important... more Because youth with aggressive conduct disorder (CD) often inflict pain on others, it is important to determine if they exhibit atypical empathic responses to viewing others in pain. In this initial functional magnetic resonance imaging (fMRI) study, 8 adolescents with aggressive CD and 8 matched controls were scanned while watching animated visual stimuli depicting other people experiencing pain or not experiencing pain. Furthermore, these situations involved either an individual whose pain was caused by accident or an individual whose pain was inflicted on purpose by another person. After scanning, participants rated how painful the situations were. In both groups the perception of others in pain was associated with activation of the pain matrix, including the ACC, insula, somatosensory cortex, supplementary motor area and periaqueductal gray. The pain matrix was activated to a significantly greater extent in participants with CD, who also showed strong amygdala, ventral striatum, and temporal pole activation. When watching situations in which pain was intentionally inflicted, control youth also exhibited signal increase in the medial prefrontal frontal cortex, lateral obitofrontal cortex, and temporoparietal junction, whereas youth with CD only exhibited activation in the insula. Furthermore, connectivity analyses demonstrated that youth with CD exhibited less amygdala/prefrontal coupling when watching pain inflicted by another than did control youth. These preliminary findings suggest that youth with aggressive CD exhibit an atypical pattern of neural response to viewing others in pain that should be explored in further studies.