Abstract:
Perceiving numerosity, i.e. the set size of a group of items, is an evolutionarily preserved ability found in humans and animals. A useful method to infer the neural underpinnings of a given perceptual property is sensory adaptation. Like other primary perceptual attributes, numerosity is susceptible to adaptation. Recently, we have shown numerosity-selective neural populations with a topographic organization in the human brain. Here, we investigated whether numerosity adaptation can affect the numerosity selectivity of these populations using ultra-high field (7 Tesla) functional magnetic resonance imaging (fMRI). Participants viewed stimuli of changing numerosity (1 to 7 dots), which allowed the mapping of numerosity selectivity. We interleaved a low or high numerosity adapter stimulus with these mapping stimuli, repeatedly presenting 1 or 20 dots respectively to adapt the numerosity-selective neural populations. We analyzed the responses using custom-build population receptive field neural models of numerosity encoding and compared estimated numerosity preferences between adaptation conditions. We replicated our previous studies where we found several topographic maps of numerosity-selective responses. We found that overall, numerosity adaptation altered the preferred numerosities within the numerosity maps, resulting in predominantly attractive biases towards the numerosity of the adapter. The differential biases could be explained by the difference between the unadapted preferred numerosity and the numerosity of the adapter, with attractive biases being observed with higher difference. The results could link perceptual numerosity adaptation effects to changes in neural numerosity selectivity.
摘要:
感知数字,即一组项目的设置大小,是人类和动物的进化保存能力。推断给定感知特性的神经基础的有用方法是感觉适应。像其他主要的感知属性一样,数字容易适应。最近,我们已经显示了在人脑中具有地形组织的数字选择性神经种群。这里,我们使用超高场(7特斯拉)功能磁共振成像(fMRI)研究了数字适应是否会影响这些群体的数字选择性.参与者查看了数字变化的刺激(1到7点),这允许映射数量选择性。我们将低或高数字适配器刺激与这些映射刺激交织在一起,分别重复呈现1或20个点以适应数字选择性神经群体。我们使用数字编码的自定义种群接受场神经模型分析了响应,并比较了适应条件之间的估计数字偏好。我们复制了以前的研究,在那里我们发现了一些数字选择性响应的地形图。我们发现总的来说,数字适应改变了数字映射中的首选数字,导致对适配器数量的主要有吸引力的偏见。差异偏差可以通过未适应的首选数字和适配器的数字之间的差异来解释,观察到有吸引力的偏见,差异更大。结果可以将感知数字适应效果与神经数字选择性的变化联系起来。