Bentley P, Husain M, Dolan R J
Wellcome Department of Imaging Neuroscience, 12 Queen Square, London WC1N 3BG, UK.
Neuron. 2004 Mar 25;41(6):969-82. doi: 10.1016/s0896-6273(04)00145-x.
We compared behavioral and neural effects of cholinergic enhancement between spatial attention, spatial working memory (WM), and visual control tasks, using fMRI and the anticholinesterase physostigmine. Physostigmine speeded responses nonselectively but increased accuracy selectively for attention. Physostigmine also decreased activations to visual stimulation across all tasks within primary visual cortex, increased extrastriate occipital cortex activation selectively during maintained attention and WM encoding, and decreased parietal activation selectively during maintained attention. Finally, lateralization of occipital activation as a function of the visual hemifield toward which attention or memory was directed was decreased under physostigmine. In the case of attention, this effect correlated strongly with a decrease in a behavioral measure of selective spatial processing. Our results suggest that, while cholinergic enhancement facilitates visual attention by increasing activity in extrastriate cortex generally, it accomplishes this in a manner that reduces expectation-driven selective biasing of extrastriate cortex.
我们使用功能磁共振成像（fMRI）和抗胆碱酯酶药物毒扁豆碱，比较了在空间注意力、空间工作记忆（WM）和视觉控制任务中胆碱能增强对行为和神经的影响。毒扁豆碱非选择性地加快了反应速度，但对注意力有选择性地提高了准确性。毒扁豆碱还降低了初级视觉皮层内所有任务对视觉刺激的激活，在持续注意力和WM编码期间选择性地增加了枕叶外皮层的激活，并在持续注意力期间选择性地降低了顶叶的激活。最后，在毒扁豆碱作用下，枕叶激活随注意力或记忆所指向的视觉半视野的变化而产生的偏侧化减少。在注意力方面，这种效应与选择性空间处理行为测量的降低密切相关。我们的结果表明，虽然胆碱能增强通常通过增加枕叶外皮层的活动来促进视觉注意力，但它是以减少枕叶外皮层预期驱动的选择性偏差的方式来实现的。
