u

Note: Applicable in all mechanisms except the Rescorla-Wagner mechanism. (In the Rescorla-Wagner mechanism, use lambda to specify reinforcement values.)

Specifies the reinforcement values for stimulus elements, used when updating v-values. See The mechanisms.

The parameter u 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.

Syntax

u = e1: v1, e2: v2, ..., en: vn, default: d
u = v1

where v1,v2,...,vn are scalar expressions.

Description

u = 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:

  u = e1:v1, e2:v2, default:d

  is the same as

  u = 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
  u = e1:v1, e2:v2
  

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u = v1 sets the reinforcement value for all stimulus elements to v1.

• u = v1 is the same as u = default: v1.

Dependencies

• The property stimulus_elements must be specified before u.

• Each stimulus element used in the specification of u must be present in the parameter stimulus_elements.

• Not applicable in the Rescorla-Wagner mechanism.

Examples

@variables x = 1
u = 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.

u = element1: 0.5, default:0

sets the reinforcement value for element1 to 0.5, and for the remaining stimulus elements to 3.

u = 0.1

sets the reinforcement value for all stimulus elements to 0.1.