Object, face and body representations in the human brain

这项研究的目的是了解我们如何看到我们所看到的：大脑如何分析通过眼睛视网膜的光线，从而产生一个充满物体、人和事物的世界？在过去的一年里，我们一直专注于位置变化对视觉物体识别的影响。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该物体位置变化的影响。事实上，一些物体识别的模型提出，大脑产生一个抽象的视觉表示的对象，这是独立于其特定的位置或大小，例如，然后可用于与语义或概念知识进行交互。然而，对当前行为学文献的回顾发现，几乎没有人支持这一观点。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在视野中不同位置的物体的多种表征。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会调节这些表征的性质。 我们还开始研究我们如何识别不同的身体部位（我们自己的和其他人的）。先前的功能性磁共振成像研究已经确定了大脑的一个区域，当人们看到身体部位（例如腿，手臂，脚）时，比看到物体（例如椅子，汽车，锤子）时反应更大。虽然有人认为这个大脑区域可能对我们识别身体的能力很重要，但没有研究表明这个区域可以区分不同的身体部位。我们现在正在进行功能性磁共振成像实验，以研究这一大脑区域的大脑活动，同时参与者在视野中的不同位置观察不同身体部位的图像，这些图像是从与自己身体或他人身体相对应的角度拍摄的。 阐明大脑如何使我们识别物体，面孔和身体将为我们对周围世界的内部表征的本质提供重要的见解。

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.