A central goal of visual neuroscience is to understand how the brain supports perception. A powerful approach to studying the relationship between brain function and perception is to study the processes in parallel during development. View-invariant visual object recognition is a computationally difficult but highly ecologically relevant task. Visual function is poor in infants and emerges over different developmental trajectories depending on the type of visual function. Understanding the developmental trajectory of visual object recognition behaviorally and neurophysiologically will help constrain computational models that quantitatively link neuronal responses to behavior. Recent progress in neurophysiological measurement techniques have demonstrated convincingly that the ventral visual stream, IT cortex in particular, contains a robust representation of objects. The experiments we propose in this grant application aim to explore the links between the behavioral development of invariant object recognition and the functional development of visual area IT. First, we will use psychophysical techniques to longitudinally track the development of object recognition using and easy to train object-oddity task. We will explore shape similarity and identity-preserving image variation, two computational challenges the brain has to overcome to support invariant object recognition. We will also characterize the robustness of object recognition to spatial clutter during development. We will use images of three-dimensional objects placed on natural backgrounds and vary position, pose, and size. Second, we will directly assess neurophysiologically the development of neural response properties and receptive field organization of area IT to the same images of objects. The awake recordings will be interleaved with behavioral assays in the same individuals to directly correlate behavioral and neural development. These experiments will advance our understanding of the role of IT in support of 1) object recognition performance that is robust to identity preserving image variation, and 2) the limitations that neural development pose on the development of perception and cognition. Our greater goal is to elucidate the mechanisms by which the ventral stream processes form to support invariant object recognition.
Disorders of the visual nervous system are a major cause of visual disability. Our research seeks to describe the normal development of cortical areas that support visual object recognition in the macaque. Understanding the function and organization of these cortical areas during development, will expose their role as potential substrates for visual loss and developmental plasticity and will also reveal how the developmental limits on sensory processing constrain behavior.
