Feature-based attention increases the selectivity of population responses in primate visual cortex
Feature-based attention increases the selectivity of population responses in primate visual cortex
复制标题
DOI：
10.1016/j.cub.2004.04.028
复制
发表时间：
2004-05-04
期刊：
影响因子：
9.2
通讯作者：
Treue, S
中科院分区：
文献类型：
--
作者：
Martinez-Trujillo, JC;Treue, S
背景：关注视觉刺激的空间位置或非空间特征可以调节灵长类动物视觉皮层的神经元反应。空间注意的调节改变了感觉神经元的增益，加强了对被注意位置的表征，而不改变神经元的选择性，如方向性，即对首选和反首选运动方向的反应比例。基于特征的注意力是否以类似的方式起作用尚不清楚。结果：为了澄清这一问题，我们记录了两只猕猴的中颞区（MT） 135个方向选择神经元对位于神经元接受野的无人参与的移动随机点模式（分心物）的反应，而动物则关注位于相反半野的第二个移动模式。只要注视的方向保持不变，对不同方向的反应受到相同因子（约12%）的调节。另一方面，系统地将注意方向从神经元的首选方向改变为其反首选方向，导致注意调制从增强到抑制的系统变化，方向性增加约20%。结论:结果表明：(1)基于特征的注意对神经元响应施加乘法调制，并且这种调制的强度取决于所关注的特征与细胞首选特征之间的相似性，符合特征相似性增益模型；(2)在神经元群体水平上，基于特征的注意通过增加倾向于该特征值的神经元的反应，而减少调谐到相反特征值的神经元的反应，从而增加了对被关注特征的选择性。
Background: Attending to the spatial location or to nonspatial features of visual stimuli can modulate neuronal responses in primate visual cortex. The modulation by spatial attention changes the gain of sensory neurons and strengthens the representation of attended locations without changing neuronal selectivities such as directionality, i.e., the ratio of responses to preferred and anti-preferred directions of motion. Whether feature-based attention acts in a similar manner is unknown.Results: To clarify this issue, we recorded the responses of 135 direction-selective neurons in the middle temporal area (MT) of two macaques to an unattended moving random dot pattern (the distractor) positioned inside a neuron's receptive field while the animals attended to a second moving pattern positioned in the opposite hemifield. Responses to different directions of the distractor were modulated by the same factor (approximately 12%) as long as the attended direction remained unchanged. On the other hand, systematically changing the attended direction from a neuron's preferred to its anti-preferred direction caused a systematic change of the attentional modulation from an enhancement to a suppression, increasing directionality by about 20%.Conclusions: The results show that (1) feature-based attention exerts a multiplicative modulation upon neuronal responses and that the strength of this modulation depends on the similarity between the attended feature and the cell's preferred feature, in line with the feature-similarity gain model, and (2) at the level of the neuronal population, feature-based attention increases the selectivity for attended features by increasing the responses of neurons preferring this feature value while decreasing responses of neurons tuned to the opposite feature value.