For video footage from past you can visit the individual event pages, or go to our YouTube Channel.
To filter by event category, click on the event category link in the table below or use the menu on the right.
List of Past Events
A scale-invariant neural architecture for cognitive computation (talk recording available)
Dr. Marc Howard
Tuesday, October 06, 2015, 01:00pm - 02:00pm
Boston University, Department of Psychological and Brain Sciences and Center for Memory and Brain
The Weber-Fechner law is among the oldest quantitative relationships in experimental psychology. Neural codes with Weber-Fechner spacing are widely-observed in the nervous system, most famously extrafoveal retinal position. We show new evidence suggesting that a neural representation for time in the rodent hippocampus obeys Weber-Fechner spacing; preliminary evidence suggests a similar relationship may also hold in the mPFC and striatum. We describe a neural mechanism for constructing Weber-Fechner scales. The mechanism relies on taking the Laplace transform of incoming experience and can be applied to generate scale-invariant representations of time, space and number. The apparent ubiquity of Weber-Fechner scales in the brain and the Laplace method for constructing representations of time, space, and number suggest a general framework for cognitive computation. Operations such as translation, convolution, and cross-correlation can be efficiently computed in the Laplace domain, enabling flexible computation on scale-invariant representations. Circuits constructed in this way obey properties such as compositionality that are challenging for traditional connectionist models. A simple circuit for performing subtraction is demonstrated.