Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia.
Proc Natl Acad Sci U S A. 2014 Apr 1;111(13):5006-11. doi: 10.1073/pnas.1323297111. Epub 2014 Mar 17.
Attention allows animals to respond selectively to competing stimuli, enabling some stimuli to evoke a behavioral response while others are ignored. How the brain does this remains mysterious, although it is increasingly evident that even animals with the smallest brains display this capacity. For example, insects respond selectively to salient visual stimuli, but it is unknown where such selectivity occurs in the insect brain, or whether neural correlates of attention might predict the visual choices made by an insect. Here, we investigate neural correlates of visual attention in behaving honeybees (Apis mellifera). Using a closed-loop paradigm that allows tethered, walking bees to actively control visual objects in a virtual reality arena, we show that behavioral fixation increases neuronal responses to flickering, frequency-tagged stimuli. Attention-like effects were reduced in the optic lobes during replay of the same visual sequences, when bees were not able to control the visual displays. When bees were presented with competing frequency-tagged visual stimuli, selectivity in the medulla (an optic ganglion) preceded behavioral selection of a stimulus, suggesting that modulation of early visual processing centers precedes eventual behavioral choices made by these insects.
注意力使动物能够对竞争刺激做出选择性反应,使一些刺激引发行为反应,而忽略其他刺激。大脑如何做到这一点仍然是个谜,尽管越来越明显的是,即使是大脑最小的动物也具有这种能力。例如,昆虫对显著的视觉刺激做出选择性反应,但尚不清楚这种选择性在昆虫大脑中发生在哪里,或者注意力的神经相关性是否可以预测昆虫的视觉选择。在这里,我们研究了行为蜜蜂(Apis mellifera)中视觉注意力的神经相关性。使用闭环范式,允许系绳行走的蜜蜂在虚拟现实竞技场中主动控制视觉物体,我们表明,闪烁的频率标记刺激的神经元反应随着行为固定而增加。当蜜蜂无法控制视觉显示时,在回放相同视觉序列期间,光脑中的类似注意的效应减少。当蜜蜂呈现竞争的频率标记视觉刺激时,丘脑中(视神经节)的选择性先于对刺激的行为选择,这表明早期视觉处理中心的调制先于这些昆虫最终做出的行为选择。