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1.
Adolescence is marked by a steep increase in risk-taking behavior. The serious consequences of such heightened risk taking raise the importance of identifying protective factors. Despite its dynamic change during adolescence, family relationships remain a key source of influence for teenagers. Using a longitudinal fMRI approach, we scanned 23 adolescents twice across a 1.5-year period to examine how changes in parent–child relationships contribute to changes in adolescent risk taking over time via changes in adolescents’ neural reactivity to rewards. Results indicate that although parent–child relationships are not associated with adolescent risk taking concurrently, increases in positive parent–child relationships contribute to declines in adolescent risk taking. This process is mediated by longitudinal decreases in ventral striatum activation to rewards during risk taking. Findings highlight the neural pathways through which improvements in positive parent–child relationships serve to buffer longitudinal increases in adolescent risk taking. 相似文献
2.
A typical time series in functional magnetic resonance imaging (fMRI) exhibits autocorrelation, that is, the samples of the time series are dependent. In addition, temporal filtering, one of the crucial steps in preprocessing of functional magnetic resonance images, induces its own autocorrelation. While performing connectivity analysis in fMRI, the impact of the autocorrelation is largely ignored. Recently, autocorrelation has been addressed by variance correction approaches, which are sensitive to the sampling rate. In this article, we aim to investigate the impact of the sampling rate on the variance correction approaches. Toward this end, we first derived a generalized expression for the variance of the sample Pearson correlation coefficient (SPCC) in terms of the sampling rate and the filter cutoff frequency, in addition to the autocorrelation and cross‐covariance functions of the time series. Through simulations, we illustrated the importance of the variance correction for a fixed sampling rate. Using the real resting state fMRI data sets, we demonstrated that the data sets with higher sampling rates were more prone to false positives, in agreement with the existing empirical reports. We further demonstrated with single subject results that for the data sets with higher sampling rates, the variance correction strategy restored the integrity of true connectivity. 相似文献
3.
The specific role of postsynaptic activity for the generation of a functional magnetic resonance imaging (fMRI) response was determined by a simultaneous measurement of generated field excitatory postsynaptic potentials (fEPSPs) and blood oxygen level-dependent (BOLD) response in the rat hippocampal CA1 region during electrical stimulation of the contralateral CA3 region. The stimulation electrode was placed either in the left CA3a/b or CA3c, causing the preferentially basal or apical dendrites of the pyramidal cells in the right CA1 to be activated. Consecutive stimulations with low-intensity stimulation trains (i.e., 16 pulses for 8 seconds) resulted in clear postsynaptic responses of CA1 pyramidal cells, but in no significant BOLD responses. In contrast, consecutive high-intensity stimulation trains resulted in stronger postsynaptic responses that came along with minor (during stimulation of the left CA3a/b) or substantial (during stimulation of the left CA3c) spiking activity of the CA1 pyramidal cells, and resulted in the generation of significant BOLD responses in the left and right hippocampus. Correlating the electrophysiologic parameters of CA1 pyramidal cell activity (fEPSP and spiking activity) with the resultant BOLD response revealed no positive correlation. Consequently, postsynaptic activity of pyramidal cells, the most abundant neurons in the CA1, is not directly linked to the measured BOLD response. 相似文献
4.
Marlen Z. Gonzalez Lane Beckes Joanna Chango Joseph P. Allen James A. Coan 《Social cognitive and affective neuroscience》2015,10(7):921-928
Neuroimaging studies using the social-exclusion paradigm Cyberball indicate increased dorsal anterior cingulate cortex (dACC) and right insula activity as a function of exclusion. However, comparatively less work has been done on how social status factors may moderate this finding. This study used the Cyberball paradigm with 85 (45 females) socio-economically diverse participants from a larger longitudinal sample. We tested whether neighborhood quality during adolescence would predict subsequent neural responding to social exclusion in young adulthood. Given previous behavioral studies indicating greater social vigilance and negative evaluation as a function of lower status, we expected that lower adolescent neighborhood quality would predict greater dACC activity during exclusion at young adulthood. Our findings indicate that young adults who lived in low-quality neighborhoods in adolescence showed greater dACC activity to social exclusion than those who lived in higher quality neighborhoods. Lower neighborhood quality also predicted greater prefrontal activation in the superior frontal gyrus, dorsal medial prefrontal cortex and the middle frontal gyrus, possibly indicating greater regulatory effort. Finally, this effect was not driven by subsequent ratings of distress during exclusion. In sum, adolescent neighborhood quality appears to potentiate neural responses to social exclusion in young adulthood, effects that are independent of felt distress. 相似文献
5.
6.
目的应用BOLD-MfRI研究正常人及脑肿瘤患者听觉性中英文语言皮层定位并探讨其对脑肿瘤的临床应用价值。方法应用MarconiEclipse1.5T超导型磁共振机,30例受试者,行听觉性中、英文语言刺激的BOLD-MfRI,以定位正常人和脑肿瘤患者的语言皮层。结果正常人听觉性中英文语言任务激活区域均以左侧大脑半球为主,主要有双侧颞横回、Wernicke区、Broca区和SMA区。中文语言任务刺激时脑区激活面积和程度比英文语言任务大,但英文语言任务时可见更明显的Broca区和角回激活。累及功能皮层的脑肿瘤患者患侧半球可见残留部分功能激活区,但激活区移位,分布弥散,激活程度及范围较正常人略增高。未累及功能皮层者功能区定位与正常人大致相同。结论BOLD-MfRI是一种有效而无创的功能皮层定位方法,有利于脑肿瘤的精确定位诊断并指导临床治疗。 相似文献
7.
Pedophilia is linked to reduced activation in hypothalamus and lateral prefrontal cortex during visual erotic stimulation. 总被引:2,自引:0,他引:2
Martin Walter Joachim Witzel Christine Wiebking Udo Gubka Michael Rotte Kolja Schiltz Felix Bermpohl Claus Tempelmann Bernhard Bogerts Hans Jochen Heinze Georg Northoff 《Neuropsychopharmacology》2007,62(6):698-701
BACKGROUND: Although pedophilia is of high public concern, little is known about underlying neural mechanisms. Although pedophilic patients are sexually attracted to prepubescent children, they show no sexual interest toward adults. This study aimed to investigate the neural correlates of deficits of sexual and emotional arousal in pedophiles. METHODS: Thirteen pedophilic patients and 14 healthy control subjects were tested for differential neural activity during visual stimulation with emotional and erotic pictures with functional magnetic resonance imaging. RESULTS: Regions showing differential activations during the erotic condition comprised the hypothalamus, the periaqueductal gray, and dorsolateral prefrontal cortex, the latter correlating with a clinical measure. Alterations of emotional processing concerned the amygdala-hippocampus and dorsomedial prefrontal cortex. CONCLUSIONS: Hypothesized regions relevant for processing of erotic stimuli in healthy individuals showed reduced activations during visual erotic stimulation in pedophilic patients. This suggests an impaired recruitment of key structures that might contribute to an altered sexual interest of these patients toward adults. 相似文献
8.
目的利用血氧水平依赖性功能性磁共振成像(BOLD-fMR I)技术,探索人类近视性屈光参差是否对大脑皮层功能和结构造成影响。方法采用无磁MR I专用眼镜纠正屈光不正,以1.5T磁共振成像系统采集8例近视性屈光参差者枕叶视皮层兴趣区BOLD-fMR I数据,比较双眼皮层激活部位及范围的不同,及视力较差眼屈光纠正前后皮层激活情况的变化,分析其改变特点及机制。结果矫正屈光基础上,近视性屈光参差者双眼激活范围没有明显差异(P>0.05);视力较差眼屈光矫正前后皮层激活范围有明显差异(P<0.05)。结论人类近视性屈光参差可能没有发生明显的皮层功能损害及优势眼的转移;配镜可明显提高视力较差眼的皮层激活,应尽早配镜或手术矫正。 相似文献
9.
Mani N Pavuluri Megan Marlow O'Connor Erin Harral John A Sweeney 《Neuropsychopharmacology》2007,62(2):158-167
BACKGROUND: Facial emotions are central to human interaction. Identifying pathophysiology in affect processing circuitry that supports the ability to assess facial emotions might facilitate understanding of affect regulation in pediatric bipolar disorder. METHODS: Ten euthymic, unmedicated pediatric bipolar patients and 10 healthy control subjects matched for age, gender, race, socioeconomic status, and IQ were scanned with functional magnetic resonance imaging. Angry, happy, and neutral faces were presented in 30-sec blocks, with a 20-sec rest period between blocks. Subjects were asked to press a button when each face appeared, to ensure that attention was maintained on-task. RESULTS: In bipolar patients, in response to both angry and happy faces relative to neutral faces, we observed reduced activation of right rostral ventrolateral prefrontal cortex together with increased activity in right pregenual anterior cingulate, amygdala, and paralimbic cortex. Bipolar patients also showed reduced activation of visual areas in occipital cortex together with greater activation in higher-order visual perceptual areas, including superior temporal sulcus and fusiform gyrus with angry faces and posterior parietal cortex with happy faces. CONCLUSIONS: Findings document a disturbance in affective neurocircuitry in pediatric bipolar disorder. Reduced activation in ventrolateral prefrontal cortex might reflect diminished top-down control that leads to the observed exaggerated activation in amygdala and paralimbic areas. Changes in occipital areas might represent an effort to gate sensory input when affective responses to the faces could not be successfully modulated. Disturbances in affect processing circuitry could contribute to emotional dysregulation and social cognitive difficulties in bipolar youth. 相似文献
10.
Genetic variation in serotonin transporter alters resting brain function in healthy individuals. 总被引:1,自引:0,他引:1
Hengyi Rao Seth J Gillihan Jiongjiong Wang Marc Korczykowski Geena Mary V Sankoorikal Kristin A Kaercher Edward S Brodkin John A Detre Martha J Farah 《Neuropsychopharmacology》2007,62(6):600-606
BACKGROUND: Perfusion functional magnetic resonance imaging (fMRI) was used to investigate the effect of genetic variation of the human serotonin transporter (5-HTT) gene (5-HTTLPR, SLC6A4) on resting brain function of healthy individuals. METHODS: Twenty-six healthy subjects, half homozygous for the 5-HTTLPR short allele (s/s group) and half homozygous for the long allele (l/l group), underwent perfusion functional and structural magnetic resonance imaging during a resting state. The two genotype groups had no psychiatric illness and were similar in age, gender, and personality scores. RESULTS: Compared with the l/l group, the s/s group showed significantly increased resting cerebral blood flow (CBF) in the amygdala and decreased CBF in the ventromedial prefrontal cortex. The effect of functional modulation in these regions by 5-HTTLPR genotype cannot be accounted for by variations in brain anatomy, personality, or self-reported mood. CONCLUSIONS: The 5-HTTLPR genotype alters resting brain function in emotion-related regions in healthy individuals, including the amygdala and ventromedial prefrontal cortex. Such alterations suggest a broad role of the 5-HTT gene in brain function that may be associated with the genetic susceptibility for mood disorders such as depression. 相似文献