Feature and location interactions in visual object processing

• Applicant: Professor Benjamin de Haas, Ph.D.
• Subject Area: General, Cognitive and Mathematical Psychology ; Human Cognitive and Systems Neuroscience
• Term: from 2015 to 2017
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 270845599

The proposed project aims to understand how feature and location preferences interact in visual object recognition in humans, including the perceptual consequences of such interactions and their underlying neural mechanisms. Humans are remarkably good at recognising complex visual objects, especially faces. How do our brains enable this? Visual recognition is thought to rely on neural processing in the inferior temporal cortex (IT). Neural responses of IT subregions show a clear preference for different visual object categories (e.g. faces or places), and are traditionally portrayed as 'location invariant' (that is, independent of where on the retina a visual object appears). However, a range of findings point to a role of stimulus location for object recognition and show that neurons in IT can be highly spatially selective. How can visual recognition work on this basis? Recent findings from the applicant and independent studies in monkeys suggest the following: Feature and location preferences are matched in a way reflecting common input properties. The proposed project will test this idea in behavioural and neuroimaging experiments and how it relates to other aspects of face perception in health and disease. For instance, previous results show that eyes and mouths of faces appear most often in the upper and lower visual field, respectively - even across eye movements of the observer. Furthermore, observers are indeed better at recognising isolated eyes and mouths when they appear at their respective typical visual field position. This could be explained neural populations with a preference for eyes or mouths having a matching spatial preference. The proposed project develops experimental paradigms to test this hypothesis, as well as the ones that such interactions between spatial and feature sensitivity can explain long-studied perceptual effects of turning faces upside down and symptoms of prosopagnosia ('face-blindness'). Finally, it will test whether such feature-location interactions extend to written word recognition, a type of visual object for which visual expertise is acquired.

• DFG Programme: Research Fellowships
• International Connection: United Kingdom
• Hosts: Dr. Dietrich Samuel Schwarzkopf; Professor Martin Sereno, Ph.D.