• Korean Journal of Cognitive Science
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• v.18 no.2
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• pp.159-178
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• 2007

Lee & Kang (2002) showed that simultaneous phonological rehearsal significantly delayed the performance of multiplication but not subtraction, whereas holding an image in the memory delayed subtraction but not multiplication. This result indicated that arithmetic function is related to working memory in a subsystem-specific manner. The aim of the current study was to examine the neural correlates of previous finding using fMRI. For this goal, dual task conditions that required suppression or no suppression were manipulated. In general, several areas were more activated in the interference conditions than in the less interference conditions, although both conditions were dual condition. More important finding is that the specific areas activated in the phonological suppression rendition were right inferior frontal gyrus, left angular, and inferior parietal lobule, while the areas activated in the other condition were mainly in the right superior temporal gyrus and anterior cingulate gyrus. Furthermore, the areas activated in the phonological or visual less suppression condition were right medial frontal gyrus, left middle frontal gyrus, and bilateral medial frontal gyri, anterior cingulate cortices, and parahippocampal gyri, respectively. These results revealed that sharing the processing code invokes interference, and its neural basis.

• Korean Journal of Cognitive Science
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• v.17 no.1
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• pp.1-13
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• 2006

We applied fMRI to examine brain activation at intentionality detection (ID) task. The main purpose of this study was to explore whether brain activation regions involved in intentionality detection (known as the basic mechanism of theory of mind) differ or not, according to prior instruction. Left uncus, superior temporal gyrus and right inferior occipital gyrus, supramarginal gyrus, inferior parietal lobule, thalamus (medial dorsal nucleus), and precuneus were activated with prior instruction. In contrast, ID task with no instruction activated merely inferior parietal lobule and superior parietal lobule. Common activated area between the two instruction conditions was inferiordparietal lobule. Our results suggest thar prior instruction activated ID-related brain regions more explicitly. furtherdinvestigations would be loused on spontaneity of intentionality detector and characteristic of participants.

• Proceedings of the Korean Society for Cognitive Science Conference
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• 2010.05a
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• pp.42-47
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• 2010

Speech shares acoustic features with other sound-based processing, which makes it difficult to distinguish phonological process from acoustic process in speech processing. In this study, we examined the difference between acoustic process and phonological process during repetition tasks. By contrasting various stimuli in different lengths, we localized neural correlates of acoustic process within bilateral superior temporal gyrus, which was consistent with the previous studies. The activated patterns were widely overlapped between words and pseudowords, i.e., contents-free. In contrast, phonological process showed left-lateralized activation in middle temporal gyrus located at anterior temporal areas. It implies that phonological process is contents-specific as shown in our previous study, and at the same time, more language-specific. Thus, we suggest that phonological process is distinguished from acoustic process in that it is always accompanied with the obligatory access to available phonological codes, which can be an entry of the mental lexicon.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2003.09a
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• pp.46-46
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• 2003

Several MRI studies have reported reductions in temporal lobe volumes in Alzheimer´s disease (AD). Measures have been usually obtained with regions of interest (ROI) drawn manually on selected medial and lateral portions of the temporal lobes, with variable choices of anatomical borders across different studies. We used the automated voxel based morphometry (VBM) approach to investigate gray matter abnormalities over the entire extension of the temporal lobe in 11 AD patients (MMSE 14 - 25) and 11 healthy controls. Foci of significantly reduced gray matter volume in AD patients were detected in both medial and lateral temporal regions, most significantly in the right and left posterior parahippocampal gyri. At a more flexible statistical threshold (P<0.001, uncorrected for multiple comparisons), circumscribed foci of significant gray matter reduction were also detected in the right amygdala/enthorinal cortex, the anterior and posterior borders of the superior temporal gyrus bilaterally, and the anterior portion of the left middle temporal gyrus. These VBM results confirm previous findings of temporal lobe atrophic changes in AD, and suggest that these abnormalities may be confined to specific sites within that lobe, rather than showing a widespread distribution.

• The Journal of Korean Physical Therapy
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• v.27 no.3
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• pp.135-139
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• 2015

Purpose: The aim of this study was to compare EEG topographical maps in patients with chronic stroke after action observation physical training. Methods: Ten subjects were recruited from a medical hospital. Participants observed the action of transferring a small block from one box to another for 6 sessions of 1 minute each, and then performed the observed action for 3 minutes, 6 times. An EEG-based brain mapping system with 32 scalp sites was used to determine cortical reorganization in the regions of interest (ROIs) during observation of movement. The EEG-based brain mapping was comparison in within-group before and after training. ROIs included the primary sensorimotor cortex, premotor cortex, superior parietal lobule, inferior parietal lobule, superior temporal lobe, and visual cortex. EEG data were analyzed with an average log ratio in order to control the variability of the absolute mu power. The mu power log ratio was in within-group comparison with paired t-tests. Results: Participants showed activation prior to the intervention in all of the cerebral cortex, whereas the inferior frontal gyrus, superior frontal gyrus, precentral gyrus, and inferior parietal cortex were selectively activated after the training. There were no differences in mu power between each session. Conclusion: These findings suggest that action observation physical training contributes to attaining brain reorganization and improving brain functionality, as part of rehabilitation and intervention programs.

• Korean Journal of Biological Psychiatry
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• v.15 no.2
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• pp.118-125
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• 2008

Objectives : The purpose of this study was to find brain regions in which gray matter volume was reduced and to show the capability of voxel-based morphpmetry(VBM) analysis for lateralizing clinically significant brain regions in dementia of Alzheimer's type patients compared to healthy group. Methods : MR T1-weighted images of the 20 dementia of Alzheimer's type patients were compared with those of the 20 normal controls. Images were transformed to standard MNI space. In order to observe gray matter volume change. Gray matter was smoothed with a Gaussian kernel. After these preprocessing, statistical analysis was performed using statistical parametric mapping software(SPM2). Results : Gray matter volume was significantly reduced in the bilateral parahippocampal gyri, Lt. anterior cingulate gyrus, Lt. posterior cingulate gyrus, bilateral superior temporal gyri Lt. middle temporal gyrus, Lt. superior, bilateral middle, Rt. anterior frontal gyri and Rt. precuneus in dementia of Alzheimer's type patient group. Conclusions : These VBM results confirm previous findings of temporal lobe and limbic lobe atrophic changes in dementia of Alzheimer's type, and suggest that these abnormalities may be confined to specific sites within that lobe, rather than showing a widespread distribution.

• Korean Journal of Cognitive Science
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• v.19 no.1
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• pp.57-74
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• 2008

This study aimed to investigate the preferential brain activations involed in the set size during random number generation (RNG). The BNG condition gave more increased activations in the anterior cingulate cortex (ACC), inferior frontal gyrus (IFG), inferior parietal lobule (IPL), and superior temporal gyrus (STG) than the simple counting condition, which was a control rendition. When the activations were compared by the small set size condition versus the large set size condition, broad areas covering tempore-occipital network, ACC, and postcentral gyrus were more highly activated in the small set size condition than in the large set size condition, while responses of areas including medial frontal gyrus, superior parietal lobule, and lingual gyrus were more increased in the large set size condition than in the small set size condition. The capacity hypothesis of working memory fails to explain the results. On the contrary, strategy selection hypothesis seems to explain the current observations properly.

• Anxiety and mood
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• v.4 no.2
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• pp.148-156
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• 2008

Objective : Although cognitive-behavior therapy (CBT) is effective in patients with panic disorder, its the-rapeutic mechanism of action in the brain remains unclear. This study was performed to investigate regional blood flow changes associated with successful completion of CBT in drug-naive patients with panic disorder. Method : The regional blood flow in 4 patients with panic disorder was compared to that in 11 healthy controls before and after a 12-week group CBT using $^{99m}Tc$-ECD SPECT imaging. Psychopathology was assessed using Panic Disorder Severity Scale. Data were analyzed using software for statistical parametric mapping (SPM2). Results : Before CBT, significantly decreased blood flow was found in the parietal and occipital area in panic patients than normal volunteers. In all the patients who showed remission after CBT, increased blood flow was detected in the right cingulate gyrus, left lingual gyrus, and left superior parietal lobule, whereas decreased blood flow was seen in the left inferior temporal gyrus. Conclusion : These results suggested that CBT is effective for panic disorder and change the activity of cingulate gyrus and left temporal gyrus, a part of the brain areas associated with fear in panic disorder.

• Korean Journal of Cognitive Science
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• v.18 no.2
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• pp.139-157
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• 2007

We compared brain activation areas during participants drawn from contrasting two college majors performed intentionality detection (known as the basic mechanism of theory of mind) task using fMRI. The main purpose of this study was to identify whether individual differences are present in intentionality detection or not. In psychology major, the left inferior frontal gyrus, the fusiform gyrus, the superior temporal gyrus and the right fusiform gyrus, the supramarginal gyrus were activated. In engineering major, the inferior parietal lobule and the superior parietal lobule were found. This result suggests that according to participants' major, different brain areas were activated. The relations between performance of the intentionality detection task and the individual variants of participants were discussed.

• Korean Journal of Cognitive Science
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• v.27 no.3
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• pp.441-467
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• 2016

This fMRI study is aim to investigate effects of competitive environment in cognitive empathic process in human brain. Empathy is known as a crucial factor for human's adaptive behavior in aspects of social cognition and it is almost automatic process, on the other hand competitive situation is psychologically devastated environment to win someone for getting rewards. We hypnotized that reading and understanding of other person's mind are a specific characteristic related to survival evolutionarily, however competition would have an effect on the empathic cognitive process because of mechanisms of competition. To manipulate the competitive atmosphere, one researcher took a role of competitor against participants and they were instructed to get monetary rewards when their performance was better than a competitor. 21 participants(9 males and 12 females) performed to judge the emotional valence of the empathic task consisted of illustrated images with various situation could be experienced in real world as on $1^{st}$ person perspective in both competitive and non-competitive condition, and did same performance with objects stimulus in control condition. In order to examine the competition effects on empathic process,, hemodynamic response were obtained during fMRI session and the imaging data were analyzed to identify brain regions where responses to each condition across the two consecutive runs. Participants' reaction time in competitive condition was faster statistically significant than non-competitive one. Activation for competitive condition increased in the following areas: ACC, mPFC, SMG, thalamus extended caudate and Nacc, parahippocampal gyrus, and for non-competitive condition increased paracingulate gyrus, temporal pole, vmPFC, superior occipital gyrus. As a result of regression analysis using empathic scores as covariance, the rSMG, IFG, fusiform gyrus, thalamus, putamen were correlated with higher empathic levels, and TPJ were correlated with lower empathic scores. We suggest that these observations could mean competitive environment have an effect on neural base of cognitive empathic process.