Tag Archives: Koch

Neurons and decision making

neuron1This blog has included about a dozen posts that mention neurons so I have decided to mine them for the most noteworthy ideas. This was tougher than I thought it would be.

Fun facts about neurons that impact decisions

Relative judgments

Since neurons encode changes in stimulation (rather than absolute levels), absolute judgments on any dimension are much more difficult than relative judgments. This lies at the root of Ernst Weber’s 1834 observation that detectable increases in visual or auditory signal intensity are proportional to the starting value, i.e., need to be larger for larger starting values. (from post First Half of 2009 JDM Research Summary)


There is a hierarchy of neurons and there are a lot of them. So it is quite likely that I have a neuron dedicated to Salma Hayek, etc.


Neural responses are noisy.  As an example, a radiologist may have tumor detecting neurons. These hypothetical tumor detectors will give noisy and variable responses. After one glance at a scan of a healthy lung, our hypothetical tumor detectors might fire 10 spikes per second. After a different glance at the same scan and under the same conditions, these neurons might fire 40 spikes per second. (from post Signal Detection Theory)

Neuronal Recycling

In Reading in the Brain, Dehaene introduces the idea of “neuronal recycling” whereby portions of our ventral visual system are turned over to reading and writing.  He says that after centuries of trial and error, writing systems evolved to a form adapted to our brain circuits. (from post Toward a Culture of Neurons)

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Consciousness, Confessions of a Romantic Reductionist

consciousChristof Koch, a professor at California Institute of Technology and Chief Scientist at the Allen Institute, has written this book, Consciousness, published in 2012. It is both a science book and a personal book.  Although judgment and decision making are not the subject, free will versus determinism is one of the subjects.  This seems to be near the essence of judgment.

Koch says that classical determinism is out, but the strong version of free will is also out.  That version of free will  is the belief that if you were placed in exactly the same circumstances again, including the identical brain state as previously, you could will yourself to act differently.  To me that is a stronger version of free will than I imagined. Koch adopts a more pragmatic concept called compatibilism.  You have free will if you follow your own desires and preferences. Koch points to experiments that show the brain decides before you will something. By the time you say to yourself in your head to sit up and get out of bed, your brain beat you by half a second.

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