NB204
Spring 2013
Unit #1 (Jan. 27 & Feb. 1), Receptive fields: what, where, why?
Rachel Wilson (rachel_wilson@hms.harvard.edu)
In Wednesday’s lecture, we will explore the idea of a neural “receptive field” as a filter on the world.
We will discuss how receptive fields are estimated, and we will explore some difficulties in this task.
We will also introduce the concept of natural statistics, and we will consider receptive field structures in
this context.
On Monday we will discuss the following paper in class:
T. Gollisch and M. Meister (2008) Rapid neural coding in the retina. Science 319:1108-1111.
Please look over the Supplementary Material published with the paper, but don’t feel that you need to
understand every detail of the methods and analysis. In particular, we will not cover the details of
information theory in the Week 1 lecture, and so you may set aside the methods section pertaining to
these analyses.
As you are reading, please consider the following questions. You do not necessarily need to directly
address these questions in your written assignment—they are mainly intended to guide your reading.
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How does the neural coding scheme this paper proposes differ from more conventional schemes?
What is the motivation behind investigating the plausibility of this scheme?
How exactly do the authors detect the spikes they are analyzing?
Why is it potentially problematic for decoding that neural responses to the same stimulus exhibit
trial-to-trial variation? Why is it interesting that trial-to-trial variability in first spike latency is
correlated in simultaneously recorded cells?
Why is it potentially problematic for decoding that retinal responses to visual stimuli can vary
strongly with stimulus contrast? Why is it interesting that latency tuning doesn’t depend much on
contrast? Why is it interesting that changing contrast shifts latencies in a similar fashion across
cells?
Your assignment this week is to write a summary on this paper. Please see the course website for
detailed guidelines and a sample (http://wilson.med.harvard.edu/nb204/).
Homework (as always) must be submitted to nb204homework[at]gmail.com before 10:00am Monday.
See the course website for guidelines on how to name and save your file.
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