On March 8, the CEU Cognitive Development Center (CEU Department of Philosophy) hosted Jozsef Fiser, Assistant Professor, The Volen National Center for Complex Systems, Department of Psychology, Brandeis University, US, for a colloquium entitled: Developing internal representations in the mind to understand the visual world.
It is widely accepted that every conscious thought and decision in the brain is generated with the help of stored knowledge about the important causes and consequences of the outside world. Fiser’s talk presented experimental and computational evidence focusing on two questions.
First, in an abstract computational sense, he looked at how this knowledge is acquired in the brain, and second, how such computations can be carried out by the neural machinery of the brain. Using behavioral studies, the first part of the talk demonstrated that both adults and infants use very sophisticated probabilistic processes to extract intricate statistical descriptions of the sensory inputs they experience. These processes seem to be available from a very early age, possibly even from birth providing a suitable tool for continuous learning through life.
The second part sketched up the so called “sampling hypothesis”, a proposal about how such probabilistic abstract computations can be realistically implemented in the cortex. The main idea of the proposal was that in order to make such a system work, it is necessary that the dynamical processes of the brain utilize the help of spontaneously occurring internal neural patterns which represent the internal knowledge of the system in a sampling-based manner. As pointed out before, such an mechanism would give a functional role to dreams, and would explain bi-stable perception and trial-by-trial variability.
Jozsef Fiser's areas of expertise are visual perception and learning, neural coding, and computational analysis of sensory information processing.