Task-dependent individual differences in prefrontal connectivity.
Task-dependent individual differences in prefrontal connectivity.
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DOI：
10.1093/cercor/bhp284
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发表时间：
2010-09
期刊：
影响因子：
--
通讯作者：
Rypma B
中科院分区：
文献类型：
--
作者：
Biswal BB;Eldreth DA;Motes MA;Rypma B
神经影像学的最新进展已经允许测试关于个体差异的神经基础的假设，但是这一新兴文献的特点是不一致的结果。为了验证任务要求的差异可能导致大脑-行为关系的研究间变异性的假设，我们让参与者执行两项认知参与程度不同的任务。我们使用格兰杰因果分析（GCA）研究了低需求警戒任务和高需求数字符号视觉搜索任务期间大脑区域之间的连接。我们的研究结果表明：1）低需求和高需求任务之间的额顶叶连接数量存在显着差异; 2）GCA可以检测到与任务需求变化相对应的活动变化; 3）速度较快的参与者比速度较慢的参与者表现出更多的警惕相关活动，但视觉搜索活动较少。这些结果表明，相对低需求的认知性能取决于自发的双向波动的网络活动，而高需求的性能取决于一个有限的，单向的网络。大脑-行为关系的性质可能会因认知需求的程度而异。高需求网络活动可能反映了个体需要自上而下的行为执行指导以成功完成任务的程度。低需求的网络活动可能反映了任务和性能监控，最大限度地减少了行为指导的执行要求。
Recent advances in neuroimaging have permitted testing of hypotheses regarding the neural bases of individual differences, but this burgeoning literature has been characterized by inconsistent results. To test the hypothesis that differences in task demands could contribute to between-study variability in brain-behavior relationships, we had participants perform 2 tasks that varied in the extent of cognitive involvement. We examined connectivity between brain regions during a low-demand vigilance task and a higher-demand digit–symbol visual search task using Granger causality analysis (GCA). Our results showed 1) Significant differences in numbers of frontoparietal connections between low- and high-demand tasks 2) that GCA can detect activity changes that correspond with task-demand changes, and 3) faster participants showed more vigilance-related activity than slower participants, but less visual-search activity. These results suggest that relatively low-demand cognitive performance depends on spontaneous bidirectionally fluctuating network activity, whereas high-demand performance depends on a limited, unidirectional network. The nature of brain-behavior relationships may vary depending on the extent of cognitive demand. High-demand network activity may reflect the extent to which individuals require top-down executive guidance of behavior for successful task performance. Low-demand network activity may reflect task- and performance monitoring that minimizes executive requirements for guidance of behavior.
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DOI：
10.1523/jneurosci.1776-08.2008
发表时间：
2008-10-01
期刊：
The Journal of neuroscience : the official journal of the Society for Neuroscience
影响因子：
--
作者：
Bressler SL;Tang W;Sylvester CM;Shulman GL;Corbetta M
通讯作者：
Corbetta M
影响因子：
5.7
作者：
Bianciardi M;Fukunaga M;van Gelderen P;Horovitz SG;de Zwart JA;Duyn JH
通讯作者：
Duyn JH
DOI：
10.1073/pnas.0308538101
发表时间：
2004-06-29
影响因子：
11.1
作者：
Brovelli, A;Ding, MZ;Bressler, SL
通讯作者：
Bressler, SL
影响因子：
5.7
作者：
Cohen, MS
通讯作者：
Cohen, MS
DOI：
10.1093/geronj/36.5.591
发表时间：
1981-01-01
期刊：
JOURNALS OF GERONTOLOGY
影响因子：
--
作者：
BERES, CA;BARON, A
通讯作者：
BARON, A