Object, face and body representations in the human brain

这项研究的目的是了解我们是如何看到我们所看到的：大脑是如何分析通过眼睛视网膜的光线来产生一个充满物体、人和事物的世界的？在过去的一年里，我们专注于位置变化对视觉对象识别的影响。人们通常认为，视觉物体识别与视野中的位置无关，我们识别物体的能力不受物体位置变化的影响。事实上，一些物体识别模型提出，大脑对物体产生一种抽象的视觉表征，这种表征与物体的具体位置或大小无关，然后可以与语义或概念知识相互作用。然而，对当前行为学文献的回顾发现，支持这一观点的文献很少。为了研究位置在物体识别中的作用，我们开展了一系列广泛的行为实验。我们的初步结果表明，位置的变化确实对物体识别有很大的影响，并表明大脑可能包含视野中不同位置的物体的多个表示。为了证实这些结果，我们现在正在进行功能性磁共振成像（fMRI）实验，以观察位置的变化如何影响大脑中物体的神经表征，以及参与者正在执行的任务是否调节了这些表征的性质。

The goal of this research is to understand how we see what we see: how does the brain analyze the light coming through the retina of the eye to produce a world full of objects, people and things? During the past year we have focused on the effect of position changes on visual object recognition. It is typically assumed that visual object recognition is independent of position in the visual field, that our ability to recognize an object is unaffected by changes in the position of that object. Indeed, some models of object recognition propose that the brain produces an abstract visual representation of an object that is independent of its specific position or size, for example, which is then available to interact with semantic or conceptual knowledge. However, a review of the current behavioral literature found little support for this view. To investigate the role of position in object recognition, we have initiated an extensive series of behavioral experiments. Our initial results show that changes in position do have a large impact on object recognition and suggest that the brain may contain multiple representations of objects at different positions in the visual field. To confirm these results we are now conducting functional magnetic resonance imaging (fMRI) experiments to see how changes in position affect the neural representations of objects in the brain and whether the task the participant is performing modulates the nature of these representations. We have also started to investigate how we recognize different body parts (our own and others). Previous fMRI studies have identified a region of the brain that responds more when people view body parts (e.g. legs, arms, feet) than when they view objects (e.g. chair, car, hammer). Although it has been suggested that this brain region may be important for our ability to recognize bodies, no study has shown that this region can discriminate between different body parts. We are now conducting fMRI experiments to investigate brain activity in this brain region while participants view images of different body parts in different positions in the visual field taken from perspectives corresponding either to a view of their own body or to a view of someone elses body. Elucidating how the brain enables us to recognize objects, faces and bodies will provide important insights into the nature of our internal representations of the world around us.