Functional magnetic resonance imaging (fMRI) was used to study the activated brain areas of human during simple and complex digital calculation, and to investigate the role of cortical and subcortical structures involved in the mental calculation. Sixteen right-handed healthy volunteers performed mental calculation of simple and complex addition/subtraction respectively, while the fMRI data were recorded by a Seimens 1.5 T MR machine. Block-design was used in the tasks. Two calculation tasks and one base-line tasks were performed for the block-design. Simple calculation task was single-digit addition and subtraction, while the complex was multi-digit addition and subtraction. The base-line task was to tell whether the two numbers were the same in every trial. Statistical parametric mapping (SPM99) was employed to process data and localize functional areas. We compared the average activation intensity of each activated brain regions in the same calculation task and the activation intensity of the same regions in both tasks respectively. Both the cortex and the subcortical structures including basal ganglia and thalamus were activated during simple and complex mental calculations. Similar brain regions in subjects including frontal lobe, parietal lobe, occipital lobe, cingulate gyrus, thalamus and cerebellum were engaged in simple and complex addition/subtraction. In the same task, activation intensity of all activated brain areas differed insignificantly. Compared with the complex task, the right parietal lobe was not activated in the simple one. The subcortical structures such as the caudate nucleus and the left marginal division of the striatum (MrD) were activated in both two calculation tasks. The cortical regions involved in both simple and complex addition/subtraction were similar. In conclusion, both the cortex and the subcortical structures were activated during the mental calculation. The cortex including the frontal cortex, parietal cortex, and cingulate gyrus were activated during mental calculation, while the subcortical structures such as the caudate nucleus, the globus pallidum and the left marginal division of the striatum also played a critical role in the neural networks of the calculation at the same time. Right parietal lobe (supramarginal gyrus) was engaged only in the complex task, which suggested that this region might be involved in the visuospatial memory and processing.
Brain ; physiology ; Brain Mapping ; Humans ; Magnetic Resonance Imaging ; Parietal Lobe ; physiology ; Thinking ; physiology

OBJECTIVETo investigate the neural mechanism of mind wandering.

METHODSEvent-related potentials (ERP) was recorded from 10 healthy college students while having a sustained attention to response task (SART), which consisted of frequent stimuli and rare stimuli with varied probability ratios. The fault response to the rare stimulus suggested the occurrence of an episode of mind wandering. The ERP of the frequent stimuli before the erroneous or correct responses of the rare stimuli were analyzed with two-way ANOVA of repeated-measurement [(wandering: yes, no)×(probability ratio: 0.1/0.9, 0.2/0.8, 0.3/0.7)].

RESULTSThe reaction time of the error response was shorter than that of the correct one. Significant probability effects were also found: the larger the frequent probability, the shorter its reaction time and the lower its accuracy. The sensitivity d' had no significant effect. The statistical parametric mapping of ERP suggested an interaction effect in the bilateral parietal areas (500-600 ms) and frontal areas (800-900 ms); the probability effect occurred in the left prefrontal lobe and the right parietal lobe (300-350 ms) and mind wandering effect in the bilateral occipital lobes (150-350 ms), frontal poles (250-300 ms), bilateral frontal-temporal-parietal regions (400-600 ms) and left prefrontal (800-900 ms).

CONCLUSIONSDuring mind wandering, the activation of cognitive processing for environment information decreases and speedy responses are more common with faults. The functional failure of the executive attention system influenced by the probability structure of SART may cause the occurrence of mind wandering.

Adult ; Attention ; physiology ; Awareness ; physiology ; Cognition ; physiology ; Evoked Potentials ; physiology ; Female ; Humans ; Male ; Spatio-Temporal Analysis ; Thinking ; physiology ; Young Adult

Electroencephalogram (EEG) signals of different mental tasks were preprocessed using Independent Component Analysis (ICA). Auto-Regressive (AR) model was used to extract the feature, and Back-Propagation (BP) network as the classifier. When features were extracted from 20-100 Hz high frequency range, the classification accuracy was the same as that taken from the whole frequency range and was more higher than the result of 2-35 Hz normal EEG rhythm. The explanation of this phenomenon is: brain displays different rhythm assimilation during different mental task under the effect of 60 Hz power frequency, so the high frequency components of EEG include more mental modulated information which is useful for improving the classification accuracy. The result presents a new evidence for the brain rhythm assimilation phenomenon and gives a novel feature extraction method for realizing high accuracy real-time BCI based on mental task.
Brain ; physiology ; Electroencephalography ; methods ; Evoked Potentials ; physiology ; Humans ; Principal Component Analysis ; Signal Processing, Computer-Assisted ; Thinking ; physiology

This is a research carried out to explore a pragmatic way of BCI based imaging movement, i. e. to extract the feature of EEG for reflecting different thinking by searching suitable methods of signal extraction and recognition algorithm processing, to boost the recognition rate of communication for BCI system, and finally to establish a substantial theory and experimental support for BCI application. In this paper, different mental tasks for imaging left-right hands movement from 6 subjects were studied in three different time sections (hint keying at 2s, 1s and 0s after appearance of arrow). Then we used wavelet analysis and Feed-forward Back-propagation Neural Network (BP-NN) method for processing and analyzing the experimental data of off-line. Delay time delta t2, delta t1 and delta t0 for all subjects in the three different time sections were analyzed. There was significant difference between delta to and delta t2 or delta t1 (P<0.05), but no significant difference was noted between delta t2 and delta t1 (P>0.05). The average results of recognition rate were 65%, 86.67% and 72%, respectively. There were obviously different features for imaging left-right hands movement about 0.5-1s before actual movement; these features displayed significant difference. We got higher recognition rate of communication under the hint keying at about 1s after the appearance of arrow. These showed the feasibility of using the feature signals extracted from the project as the external control signals for BCI system, and demon strated that the project provided new ideas and methods for feature extraction and classification of mental tasks for BCI.
Algorithms ; Brain ; physiology ; Electroencephalography ; methods ; Evoked Potentials, Motor ; physiology ; Hand ; physiology ; Humans ; Movement ; physiology ; Neural Networks (Computer) ; Pattern Recognition, Physiological ; Signal Processing, Computer-Assisted ; Thinking ; physiology ; User-Computer Interface

PURPOSE: The present study examined the positive-thinking and life satisfaction of the general Korean population. In particular, we examined the role of positive-thinking on participants' life satisfaction. MATERIALS AND METHODS: We conducted a telephone survey of 409 respondents (194 males, 215 females). The participants provided self-reports on their positive thinking, life satisfaction and demographic information. ReESULTS: The results showed that age, education, occupation, and family income had an influence on positive- thinking as well as life satisfaction in Korea. Specifically, younger respondents and persons with high incomes or higher education degrees were more likely to have higher positive scores and thus higher life satisfaction scores. However, after controlling for the demographic variables, positive thinking significantly affected life satisfaction(R(2) Change=0.170, F= 88.56, p < 0.001). CONCLUSION: We provided empirical evidence that positive thinking may indeed play a significant role in life satisfaction. Therefore, positive thinking would offer important direction for the growth of life satisfaction and interventions aiming to remediate the effects of demographic variables on life satisfaction.
Adult ; Analysis of Variance ; Attitude ; Educational Status ; Female ; Humans ; Income ; Interviews as Topic ; Korea ; Male ; Middle Aged ; Occupations ; *Personal Satisfaction ; Quality of Life/*psychology ; Questionnaires ; Thinking/*physiology

PURPOSE: The present study examined the positive-thinking and life satisfaction of the general Korean population. In particular, we examined the role of positive-thinking on participants' life satisfaction. MATERIALS AND METHODS: We conducted a telephone survey of 409 respondents (194 males, 215 females). The participants provided self-reports on their positive thinking, life satisfaction and demographic information. ReESULTS: The results showed that age, education, occupation, and family income had an influence on positive- thinking as well as life satisfaction in Korea. Specifically, younger respondents and persons with high incomes or higher education degrees were more likely to have higher positive scores and thus higher life satisfaction scores. However, after controlling for the demographic variables, positive thinking significantly affected life satisfaction(R(2) Change=0.170, F= 88.56, p < 0.001). CONCLUSION: We provided empirical evidence that positive thinking may indeed play a significant role in life satisfaction. Therefore, positive thinking would offer important direction for the growth of life satisfaction and interventions aiming to remediate the effects of demographic variables on life satisfaction.
Adult ; Analysis of Variance ; Attitude ; Educational Status ; Female ; Humans ; Income ; Interviews as Topic ; Korea ; Male ; Middle Aged ; Occupations ; *Personal Satisfaction ; Quality of Life/*psychology ; Questionnaires ; Thinking/*physiology

Antipsychotic Agents ; therapeutic use ; Brain ; physiopathology ; Cognition Disorders ; genetics ; Gene-Environment Interaction ; Genetic Variation ; genetics ; Humans ; Schizophrenia ; genetics ; physiopathology ; Schizophrenic Psychology ; Social Behavior ; Thinking ; physiology