# HG changeset patch
# User Robert McIntyre <rlm@mit.edu>
# Date 1398652069 14400
# Node ID 97d45f796ad622db505a4040390104ebd1648203
# Parent  d947636fe0eef5b2d332a50d60c60fa9d7ffbe24
write more contributions, per Winston.

diff -r d947636fe0ee -r 97d45f796ad6 thesis/cortex.org
--- a/thesis/cortex.org	Sun Apr 27 21:58:26 2014 -0400
+++ b/thesis/cortex.org	Sun Apr 27 22:27:49 2014 -0400
@@ -3381,23 +3381,38 @@
 
 * Contributions
   
-  In this thesis you have seen the =CORTEX= system, a complete
-  environment for creating simulated creatures. You have seen how to
-  implement five senses: touch, proprioception, hearing, vision, and
-  muscle tension. You have seen how to create new creatures using
-  blender, a 3D modeling tool. I hope that =CORTEX= will be useful in
-  further research projects. To this end I have included the full
-  source to =CORTEX= along with a large suite of tests and examples. I
-  have also created a user guide for =CORTEX= which is included in an
-  appendix to this thesis.
-
-  You have also seen how I used =CORTEX= as a platform to attack the
-  /action recognition/ problem, which is the problem of recognizing
-  actions in video. You saw a simple system called =EMPATH= which
-  identifies actions by first describing actions in a body-centered,
-  rich sense language, then inferring a full range of sensory
-  experience from limited data using previous experience gained from
-  free play.
+  The big idea behind this thesis is a new way to represent and
+  recognize physical actions -- empathic representation. Actions are
+  represented as predicates which have available the totality of a
+  creature's sensory abilities. To recognize the physical actions of
+  another creature similar to yourself, you imagine what they would
+  feel by examining the position of their body and relating it to your
+  own previous experience.
+  
+  Empathic description of physical actions is very robust and general.
+  Because the representation is body-centered, it avoids the fragility
+  of learning from example videos. Because it relies on all of a
+  creature's senses, it can describe exactly what an action /feels
+  like/ without getting caught up in irrelevant details such as visual
+  appearance. I think it is important that a correct description of
+  jumping (for example) should not waste even a single bit on the
+  color of a person's clothes or skin; empathic representation can
+  avoid this waste by describing jumping in terms of touch, muscle
+  contractions, and the brief feeling of weightlessness. Empathic
+  representation is very low-level in that it describes actions using
+  concrete sensory data with little abstraction, but it has the
+  generality of much more abstract representations!
+
+  Another important contribution of this thesis is the development of
+  the =CORTEX= system, a complete environment for creating simulated
+  creatures. You have seen how to implement five senses: touch,
+  proprioception, hearing, vision, and muscle tension. You have seen
+  how to create new creatures using blender, a 3D modeling tool.
+
+  I hope that =CORTEX= will be useful in further research projects. To
+  this end I have included the full source to =CORTEX= along with a
+  large suite of tests and examples. I have also created a user guide
+  for =CORTEX= which is included in an appendix to this thesis.
 
   As a minor digression, you also saw how I used =CORTEX= to enable a
   tiny worm to discover the topology of its skin simply by rolling on
@@ -3411,7 +3426,9 @@
      creatures using Blender, a free 3D modeling program.
 
    - =EMPATH=, which uses =CORTEX= to identify the actions of a
-     worm-like creature using a computational model of empathy.
+     worm-like creature using a computational model of empathy. This
+     empathic representation of actions is an important new kind of
+     representation for physical actions.
 
 #+BEGIN_LaTeX
 \newpage