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Introduction: The neural mechanism underlying decision‐making, which is an important component of executive function, is complex and not fully understood. Few studies have directly investigated the two types of decision‐making functions – under ambiguity and under risk – in patients with brain tumors in different brain regions. Methods: Participants were classified into the ventral prefrontal cortex tumor group (VPFC, n = 27), the dorsolateral prefrontal cortex tumor group (DLPFC, n = 29), and matched healthy controls (HCs, n = 32). All participants were given a battery of neuropsychological tests, and they then performed the Iowa Gambling Task (IGT) and the Game of Dice Task (GDT) to assess their decision‐making under ambiguity and under risk, respectively. Results: The two patient groups performed significantly worse on attention, memory, information processing, and executive function. Additionally, patients in the DLPFC group performed significantly worse on the memory and information processing tests compared with the VPFC and HC groups. Conclusion: This study found that the decision‐making functions of participants in the VPFC and DLPFC tumor groups were impaired to varying degrees. Among them, there was decision‐making impairment under ambiguity and under risk in the VPFC group, and there was decision‐making impairment under risk in the DLPFC group. [ABSTRACT FROM AUTHOR]

Aims We utilized multi-voxel proton magnetic resonance spectroscopy (1 H- MRS) to detect biochemical abnormalities in dorsolateral prefrontal white matter and anterior cingulate gray matter and to determine the correlation of biochemical changes with memory function in depressed adolescents. Methods A total of 24 depressed patients and 23 healthy controls were enrolled in this study. MRS was performed to assess the N-acetylaspartate ( NAA)/creatine Cr and choline ( Cho)/ Cr ratios in dorsolateral prefrontal white matter and anterior cingulate gray matter of participants. Memory function was measured on the basis of Wechsler Memory Scale scores, and depression was diagnosed on the basis of clinical observation, interview, and Hamilton Depression Rating Scale scores. Results Compared with controls, depressed patients had significantly lower NAA/ Cr and Cho/ Cr ratios in left dorsolateral prefrontal white matter and lower NAA/ Cr ratios in right dorsolateral prefrontal white matter ( P < 0.05). No biochemical differences were identified in the bilateral anterior cingulate gray matter between the two groups. Nevertheless, the depressed patients showed significantly lower memory quotient than controls ( P < 0.05). The NAA/ Cr ratio in dorsolateral prefrontal white matter positively correlated with memory quotient (left: P < 0.01; right: P < 0.05). Conclusions These findings suggest that biochemical abnormalities in prefrontal white matter are involved in the pathophysiology of adolescent depression. In particular, such abnormalities are already present at the early stage of the disorder, and low NAA/ Cr in bilateral anterior frontal white matter may be associated with memory impairment and related neuropathology. [ABSTRACT FROM AUTHOR]

This study sought to demonstrate and evaluate a novel spectral fitting method to improve quantification accuracy in the presence of large magnetic field distortion, especially with high fields. MRS experiments were performed using a point-resolved spectroscopy (PRESS)-type sequence at 7 T. A double-echo gradient echo (GRE) sequence was used to acquire B0 maps following MRS experiments. The basis set was modified based on the measured B0 distribution within the MRS voxel. Quantification results were obtained after fitting the measured MRS data using the modified basis set. The proposed method was validated using numerical Monte Carlo simulations, phantom measurements, and comparison of occipital lobe MRS measurements under homogeneous and inhomogeneous magnetic field conditions. In vivo results acquired from voxels placed in thalamus and prefrontal cortex regions close to the frontal sinus agreed well with published values. Instead of noise-amplifying complex division, the proposed method treats field variations as part of the signal model, thereby avoiding inherent statistical bias associated with regularization. Simulations and experiments showed that the proposed approach reliably quantified results in the presence of relatively large magnetic field distortion. Published 2015. This article is a U.S. Government work and is in the public domain in the USA. [ABSTRACT FROM AUTHOR]

This study investigated how color stimuli that consisted of green foliage plants (Epipremnum aureum) with same sized area of Kalanchoe spp. plants with four different flower colors (white, yellow, pink, and red; Kalanchoe spp.) on a dark green background influenced the brain waves and emotions of 30 undergraduate students. Electroencephalography tests were performed in order to monitor the brain-wave responses in the prefrontal, frontal, parietal, and occipital lobes in response to the different plant color stimuli. Fourteen pairs of adjectives on the semantic differential scale were used to measure emotional changes. A statistical analysis showed that all of the color stimuli correlated with some emotional keywords and physiological responses. Green plants (E.aureum) produced more positive attitudes, and brain functions were more active compared to those observed after the participants were exposed to white, yellow, pink, or red flowers on a green background. In addition, when participants looked at the green plants, the relative fast alpha power spectrum increased, indicating the involvement of improved concentration, creativity, and attention. However, optical stimuli from the yellow flowers had a positive effect on the parietal and occipital lobes, producing a high relative theta power spectrum and indicating that concentration was improved and that the subjects were happier. The choice of adjectives and the EEG patterns were weakly but significantly correlated. These results may have practical applications because green plants can be used in places where comfort and high concentration are required, plants with white and yellow flowers can be used to make a place more pleasant, and red flowering plants can be used to create a luxurious environment. © 2012 Wiley Periodicals, Inc. Col Res Appl, 39, 307-316, 2014; Published online 28 December 2012 in Wiley Online Library (). DOI 10.1002/col.21788. [ABSTRACT FROM AUTHOR]

Near-infrared spectroscopy (NIRS) is an optical method to determine oxygenated and deoxygenated hemoglobin concentration changes in the human cerebral cortex. The purpose of this study was to examine the hemodynamic response of the prefrontal area during words memory learning using NIRS. A total of 23 healthy subjects participated in the present study. Hemodynamic response in the prefrontal cortex was measured using a NIRS system. The number of words recalled and stimulus category repetition (SCR) were analyzed by the words memory learning task. During the words memory learning task, oxygenated hemoglobin concentrations increased and deoxygenated hemoglobin concentrations decreased. This typical pattern was maintained during each memory stage, but the degree of change of [oxyHb] during encoding from the first condition to the second condition was significantly larger than that during retrieval. This suggests that memory organization is facilitated during encoding of the first condition, and that the retrieval period through two conditions still involves more activation in the prefrontal area than the encoding period. An increase of [oxyHb] was not recognized and activation was inhibited when the strategy was applied. Subjects produced more SCR in the second condition than in the first condition in spite of strategy instruction. This result suggests healthy people can find out implicit category by themselves following learning even without instruction. There were no significant relationships between the behavior indices and the changes in hemoglobin. Further studies are needed to clarify usefulness of NIRS in patients with psychiatric disorder. [ABSTRACT FROM AUTHOR]