Long Term Memory: Answers

Copyright © Simon Dennis, 1997. Exercise 1: The Art name unit, Junior High, 40s, Jet, Single, Pusher and Ralph instance units become active after 10 cycles.

Exercise 2: Both the Bookie and Pusher units drop in activation because they are mutually inhibitory. However, the Pusher unit also has positive weights to the active Art instance unit. Consequently, it wins the competition driving the Bookie unit down and allowing its own activation to increase when the Bookie unit is no longer inhibiting it.

Exercise 3: The value of the unit decreases quickly at first and then more slowly as it gets closer to the rest value of -0.1.

Exercise 4: The activation is below one after the first cycle.

Exercise 5: The equilibrium point is 0.9. The simulation should settle quickly to that value.

Exercise 6: let a_i = 0 and solve for a_i
0 = (a _i - min) net_i - decay (a_i - rest)
a _i decay - a _i net_i = decay rest - min net_i
a _i = (decay rest - min net_i) / (decay - net_i)

If rest = 0 this simplifies to:

a _i = min net_i / (net_i - decay)

General 0.893 0.527 1.117 0.463 0.511 0.633 0.564 0.356 0.861 0.558 0.75 0.203 0.766 0.619 0.591 0.466 0.861 0.457 0.44 0.382 0.906 0.739 0.692 0.561 1.399 0.509 0.8 0.977 0.885285714 0.577428571 0.707714286 0.486857143 Study 0.741 0.9 1.388 0.589 0.505 0.707 0.469 0.272 1.076 0.696 0.508 0.326 0.807 0.858 0.627 0.512 0.818 0.716 0.277 0.315 0.947 0.674 0.364 0.353 1.384 0.624 0.946 0.879 0.896857143 0.739285714 0.654142857 0.463714286

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