Medical Research Council Cognition and Brain Sciences Unit, Cambridge, CB2 7EF, UK.
J Neurosci. 2011 Oct 12;31(41):14592-9. doi: 10.1523/JNEUROSCI.2616-11.2011.
Frontoparietal cortex is thought to be essential for flexible behavior, but the mechanism for control remains elusive. Here, we demonstrate a potentially critical property of this cortex: its dynamic configuration for coding of task-critical information. Using multivoxel pattern analysis of human functional imaging data, we demonstrate an adaptive change in the patterns of activation coding task-relevant stimulus distinctions. When task demands made perceptual information more difficult to discriminate, frontoparietal regions showed increased coding of this information. Visual cortices showed the opposite result: a weaker representation of perceptual information in line with the physical change in the stimulus. On a longer timescale, a rebalancing of coding was also seen after practice, with a diminished representation of task rules as they became familiar. The results suggest a flexible neural system, exerting cognitive control in a wide range of tasks by adaptively representing the task features most challenging for successful goal-directed behavior.
额顶皮质被认为对灵活的行为至关重要,但控制的机制仍然难以捉摸。在这里,我们展示了这个皮质的一个潜在关键特性:其动态配置用于对任务关键信息进行编码。使用人类功能成像数据的多体素模式分析,我们证明了激活编码任务相关刺激区别的模式的自适应变化。当任务要求使感知信息更难以区分时,额顶区域显示出对该信息的编码增加。视觉皮层则呈现出相反的结果:与刺激的物理变化一致,感知信息的表示减弱。在更长的时间尺度上,在实践之后也可以看到编码的再平衡,随着任务规则变得熟悉,其表示也会减少。结果表明,一个灵活的神经系统通过自适应地表示最具挑战性的任务特征来对广泛的任务施加认知控制,从而实现有目标的行为。