Enhancing equation comprehension with index finger writing: An fMRI study

Learning is a complicated process composed of vision, interpretation, comprehension and memory. This study for the first time compared activities in the brain for equation reading and writing by selected professionals using functional magnetic resonance imaging (fMRI). Finger writing did not change the message pathway in brain, but on the other hand intensified stimuli on the information integration and language processing centers by hand movement. Writing practice can assist students to integrate and comprehend the lectures delivered in the chemical engineering classrooms. However, this practice cannot help a student to extract abstract meaning in the equation.     

Human navigation that requires calculating heading vectors recruits parietal cortex in a virtual and visually sparse water maze task in fMRI.

Spatial navigation in the real-world is a complex task that involves many functions, such as landmark identification, orientation, and the calculation of heading vectors. This study uses a 2 × 2 experimental design with fMRI to isolate mnemonic and navigational processes that accompany the calculation of heading vectors. The conditions are based on a working memory version of the Morris water maze task and navigation takes place in a visually austere virtual environment. In an allocentric condition, subjects navigate around a circular arena where there is one small red square on the wall. Each trial begins with an encoding phase in which subjects locate and navigate to a visible coin. Then, in a test phase, after being randomly repositioned, they retrieve the coin when it is invisible. In a control task, there are eight distinct cues around the arena that provide direct cue-place information. Results show significant interaction effects in bilateral posterior parietal cortex, which is compatible with evidence that parietal cortex helps translating between allocentric coordinates and egocentric directions. There was also greater activation for the allocentric task in right posterior hippocampus and left retrosplenial cortex, which could be related to self-localization and orientation. The findings are also compatible with the recent proposal by Kubie and Fenton (2009) that navigation primarily depends on heading vectors between salient places. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Relation of reward from food intake and anticipated food intake to obesity: A functional magnetic resonance imaging study.

The authors tested the hypothesis that obese individuals experience greater reward from food consumption (consummatory food reward) and anticipated consumption (anticipatory food reward) than lean individuals using functional magnetic resonance imaging (fMRI) with 33 adolescent girls (mean age = 15.7, SD = 0.9). Obese relative to lean adolescent girls showed greater activation bilaterally in the gustatory cortex (anterior and mid insula, frontal operculum) and in somatosensory regions (parietal operculum and Rolandic operculum) in response to anticipated intake of chocolate milkshake (vs. a tasteless solution) and to actual consumption of milkshake (vs. a tasteless solution); these brain regions encode the sensory and hedonic aspects of food. However, obese relative to lean adolescent girls also showed decreased activation in the caudate nucleus in response to consumption of milkshake versus a tasteless solution, potentially because they have reduced dopamine receptor availability. Results suggest that individuals who show greater activation in the gustatory cortex and somatosensory regions in response to anticipation and consumption of food, but who show weaker activation in the striatum during food intake, may be at risk for overeating and consequent weight gain. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Unmixing functional magnetic resonance imaging data using matrix factorization

Functional magnetic resonance imaging (fMRI) data is processed by different techniques for detection of activated voxels including principal component analysis (PCA), independent component analysis (ICA), non‐negative matrix factorization (NMF), and so on. In this work, a modified version of NMF method is proposed in which data is not supposed to be non‐negative. The proposed scheme is applied to synthetic fMRI data along with NMF conventional method. The results of the proposed scheme show that it is not only computationally efficient but also has good quality results as compared to that of NMF in terms of average correlation. Finally, proposed method is applied to monkey's fMRI data, and the results are compared with that of NMF and ICA. © 2012 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 22, 195–199, 2012     

An efficient automated z-shim based method to correct through-slice signal loss in EPI at 3T

Object  To develop an efficient, automated method to correct through-slice signal loss in gradient-echo EPI at 3T. Material and methods  The optimal choice of two z-shim values for signal recovery was determined from simulations and experiments. The specific required z-shim values are determined using a rapid calibration method that combines information about the slice profile with a sparse set of measurements. The proposed correction method was implemented for a language fMRI study which suffers from signal loss near the auditory canals, and tested on 12 volunteers. Results  Using a square root sum of squares combination of two z-shim values full signal restoration (to within 2% of the correct value) was achieved in 96% of all correctable brain pixels for 3 mm slices, and partial correction in pixels outside this range. In all subjects, language processing activation was recovered in the inferior and lateral areas of the left temporal lobe which was not detectable with conventional fMRI. Conclusion  The careful choice of two z-shim values by the proposed method achieves through-slice signal loss correction for the majority of pixels in the brain for 3 mm slices at 3T.     

Selective attention to emotion in the aging brain.

A growing body of research suggests that the ability to regulate emotion remains stable or improves across the adult life span. Socioemotional selectivity theory maintains that this pattern of findings reflects the prioritization of emotional goals. Given that goal-directed behavior requires attentional control, the present study was designed to investigate age differences in selective attention to emotional lexical stimuli under conditions of emotional interference. Both neural and behavioral measures were obtained during an experiment in which participants completed a flanker task that required them to make categorical judgments about emotional and nonemotional stimuli. Older adults showed interference in both the behavioral and neural measures on control trials but not on emotion trials. Although older adults typically show relatively high levels of interference and reduced cognitive control during nonemotional tasks, they appear to be able to successfully reduce interference during emotional tasks. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Neuroticism and brain responses to anticipatory fear.

Personality is known to influence cognitive and affective functioning as well as the risk of psychiatric disorders. Exploration of the neurobiological correlates of personality traits has the potential to enhance understanding of their significance in development of related psychopathological states. The authors examined the association between individual differences in neuroticism and brain activity in response to threat of electric shocks. Fourteen right-handed healthy men underwent functional MRI during a 5-min experiment that involved repeated presentations of two 30-s alternating conditions. In 1 of these conditions, subjects were told to expect mild but painful electric shocks; there was no possibility of receiving shocks in the other condition. The results revealed that neuroticism correlated positively with the ratings of fear of shock and negatively (indicating suppression) with brain activity from safe to shock conditions in the anterior and posterior cingulate, superior/middle temporal gyrus extending to the hippocampus, precuneus, putamen, thalamus, and middle occipital gyrus. The observations support recent psychophysiological research that has demonstrated reduced processing of pain in subjects with higher levels of neuroticism, especially the anxiety component of this trait. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

What is in a word? No versus Yes differentially engage the lateral orbitofrontal cortex.

[Correction Notice: An erratum for this article was reported in Vol 7(4) of Emotion (see record 2007-17748-007). The supplemental materials link should appear as follows: http://dx.doi.org/10.1037/1528-3542.7.3.649.supp.] The words "No" and "Yes" are involved in conditioning to prohibit or encourage behavior, respectively. The authors, therefore, hypothesized that these words would be attributed to endogenous valence, activating neuronal circuits involved with valence and emotional control. Functional MRI (fMRI) at 4 Tesla was used to record regional brain activity while participants were exposed to emphatic vocalizations of the words. Results showed that No and Yes were associated with opposite brain-behavior responses; while No was negatively valenced, produced slower response times, and evoked a negative signal in the right lateral orbitofrontal cortex (OFC), Yes was positively valenced, produced faster response times, and evoked a positive signal in a contiguous region of the OFC. Attribution of negative valence to No and trait anger control were associated with increased responsivity of the OFC to No. Inasmuch as sensitivity to the prohibitive command No develops during childhood through interaction with primary caregivers as the first social objects, our findings may implicate the lateral OFC in the neurobiology of emotion regulation and subsequent social development. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Neurological correlates of reward responding in adolescents with and without externalizing behavior disorders.

Opposing theories of striatal hyper- and hypodopaminergic functioning have been suggested in the pathophysiology of externalizing behavior disorders. To test these competing theories, the authors used functional MRI to evaluate neural activity during a simple reward task in 12- to 16-year-old boys with attention-deficit/hyperactivity disorder and/or conduct disorder (n = 19) and in controls with no psychiatric condition (n = 11). The task proceeded in blocks during which participants received either (a) monetary incentives for correct responses or (b) no rewards for correct responses. Controls exhibited striatal activation only during reward, shifting to anterior cingulate activation during nonreward. In contrast, externalizing adolescents exhibited striatal activation during both reward and nonreward. Externalizing psychopathology appears to be characterized by deficits in processing the omission of predicted reward, which may render behaviors that are acquired through environmental contingencies difficult to extinguish when those contingencies change. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

基于宽度学习系统的fMRI数据分类方法

提出基于宽度学习系统的功能性磁共振成像（fMRI）数据分类方法,通过简单结构提取fMRI数据的深层特征,加快分类速度. 使用fMRI中感兴趣区域体素均值的时间序列构造输入数据,分别提取fMRI数据的浅层和深层特征,映射为宽度学习的特征节点和增强节点并构建模型框架,利用岭回归逆计算分类模型的连接权值,实现对fMRI数据的分类. 使用ABIDE Ⅰ、ABIDE Ⅱ和ADHD-200数据集,将所提方法与6种分类方法进行对比实验,结果表明,所提方法可以在保持良好的分类准确率的同时,大幅度降低训练时间.