Build the artificial mind with a central variable akin to time "t"
so the sensory and motor memory channel arrays will automatically
be indexed in chronological order.  Declare or initialize "midway"
as a point not exactly halfway back in time but rather far enough
that the advancing front of consciousness will loop associatively
through recent occurrences of whatever words or concepts it needs.

Keep in mind that PDAI differs from CNSI in that the central ner-
vous system makes redundant associations with massive parallelism,
whereas your PDAI will associate confidently to any first engram.

If you are not programming with massive parallelism, then a local
variable such as "unk" for "unknown" may be used in different mod-
ules of mind and not cause schizophrenia--especially if you reset
the variable to blank or zero in between the modules of the mind:

  /^^^^^^^^^^^\ Mind-grid Arrays{ } in Robot PDAI /^^^^^^^^^^^\
 /visual memory\                   _________     /  auditory   \
|      /--------|---------\       / LANG-UK \   |   memory      |
|      |  recog-|nition   |       \_________/---|-------------\ |
|   ___|___     |         | flush-vector|       |   ________  | |
|  /image  \    |     ____V_        ____V__     |  /        \ | |
| / percept \   |    /psi{ }\------/ uk{ } \----|-/ ear{ }   \| |
| \ engrams /---|---/concepts\----/ lexicon \---|-\ phonemes /  |
|  \_______/    |   \________/    \_________/   |  \________/   |
--
http://www.***.com/ ~mentifex/ to "The Art of Computer Mindmaking"