lambda¶
Note: Only applicable in the Rescorla-Wagner mechanism.
Specifies the reinforcement values for stimulus elements, used when updating vss-values in the Rescorla-Wagner mechanism,
used in the updating of vss
-values. See The mechanisms.
The parameter lambda
can be set to certain values for certain particular stimulus elements.
It can also be specified as a single value, in which case the same reinforcement value is used for all
stimulus elements. Wildcards (*) may be used to set several values at once.
Syntax¶
lambda = e1: v1, e2: v2, ..., en: vn, default: d
lambda = v1
lambda = *:v1 # Same as above
where v1,v2,...,vn
are scalar expressions.
Description¶
lambda = e1: v1, e2: v2, ..., en->bn: vn, default: d
sets the reinforement value for
e1 to v1,
e2 to v2, …,
en to vn,
and the reinforcement value for all other stimulus elements to d.
The specification is independent of the list order:
lambda = e1:v1, e2:v2, default:d
is the same as
lambda = e2:v2, default:d, e1:v1
.default
need not be specified if all stimulus elements are present in the list. For example,stimulus_elements = e1, e2 lambda = e1:v1, e2:v2
lambda = v1
sets the reinforcement value for all stimulus elements to v1.
lambda = v1
is the same aslambda = default: v1
.
Dependencies¶
The property
stimulus_elements
must be specified beforelambda
.Each stimulus element used in the specification of
lambda
must be present in the parameterstimulus_elements
.Applicable only in the Rescorla-Wagner mechanism.
Examples¶
@variables x = 1
lambda = element1: x, element2: x+1, default:x+2
sets the reinforcement value for element1 to 1 and for element2 to 2, and for the remaining stimulus elements to 3.
lambda = element1: 0.5, default:0
sets the reinforcement value for element1 to 0.5, and for the remaining stimulus elements to 3.
lambda = 0.1
sets the reinforcement value for all stimulus elements to 0.1.