diff --git a/csys/csys.lisp b/csys/csys.lisp
index 7db4da8..cbf7b4a 100644
--- a/csys/csys.lisp
+++ b/csys/csys.lisp
@@ -3,9 +3,7 @@
 (defpackage :scopes/csys
   (:use :common-lisp)
   (:local-nicknames (:actor :scopes/core/actor)
-                    (:async :scopes/util/async)
                     (:config :scopes/config)
-                    (:core :scopes/core)
                     (:message :scopes/core/message)
                     (:shape :scopes/shape)
                     (:util :scopes/util)
@@ -61,7 +59,15 @@
   (destructuring-bind (nmsg nst nsyns) 
         (handle-action msg state syns env :default #'remember)
     (forward nmsg nsyns)
-    (update-neuron #'std-proc nst nsyns env)))
+    (update-neuron (next-proc nst) nst nsyns env)))
+
+;;;; neuron state methods
+
+(defgeneric next-proc (state &optional default)
+  (:method (state &optional (default #'std-proc)) default))
+
+(defgeneric value (state)
+  (:method (state) state))
  
  ;;;; sensors: neurons receiving messages from environment, addressable via message head
 
@@ -78,7 +84,7 @@
     ;(util:lgi key sns)
     sns))
 
-;;;; effectors: pseudo-neurons embedded in environment
+;;;; effector procs for pseudo-neurons embedded in environment
 
 (defun do-log (msg state syns env)
   (util:lgi msg))