Parameters

Several aspects of Multilink can be seen as fixated components of the architecture. For instance, there are minimum and maximum values of the activation, there is a fixed relationship between word frequency and resting level activation (RLA), and connection strengths between different codes (orthography, phonology, semantics, and language nodes) are fixated. The simulations of all studies discussed in papers have been conducted with only one setting of the parameters!

Log word frequency is used to set the resting level activation of words to a value between -0.2 and 0.0. It can be shown mathematically that this leads to a good fit with lexical decision data (Thul, Conklin, & Dijkstra, in preparation).

What follows is a listing of the Multilink model parameters, grouped by category.

Network basics

Parameter Description Standard value
min_act Minimum activation value -0.2
max_act Maximum activation value 1.0
decay_rate Decay rate per cycle/tick 0.07
min_rest Minimum resting level -0.2
max_rest Maximum resting level 0.0
max_opb Maximum occurrences per billion 0.6402259325203161

Resting level activations

Parameter Description Standard value
I_rest Input node resting level max_act
L_rest Language node resting level min_rest
O_rest Orthographic node resting level min_rest + opb * (Math.abs(min_rest) / max_obp)
S_rest Semantic node resting level min_rest
P_rest Phonological node resting level min_rest
IO_alpha Input/Output node resting level let score = (max_l - dist) / (double) max_l;
if (score > 0.0) { return IO_multiplier * Math.pow(score, 3); }
else { return 0.0; }

Connection weights

Parameter Connection Kind Standard value
LO_alpha Language/Orthographic Facilitation 0.0
LP_alpha Language/Phonological Facilitation 0.0
OL_alpha Orthographic/Language Facilitation 0.0
OP_alpha Orthographic/Phonological Facilitation 0.03
OS_alpha Orthographic/Semantic Facilitation 0.03
PL_alpha Phonological/Language Facilitation 0.0
PO_alpha Phonological/Orthographic Facilitation 0.03
PS_alpha Phonological/Semantic Facilitation 0.3
SO_alpha Semantic/Orthographic Facilitation 0.03
SP_alpha Semantic/Phonological Facilitation 0.3
LO_gamma Language/Orthographic Inhibition 0.0
LP_gamma Language/Phonological Inhibition 0.0
OL_gamma Language/Orthographic Inhibition 0.0
OO_gamma Orthographic/Orthographic Inhibition 0.0
PL_gamma Phonological/Language Inhibition 0.0
PP_gamma Phonological/Phonological Inhibition 0.0
SS_gamma Semantic/Semantic Inhibition -0.05

Input multipliers

Parameter Description Standard value
IO_multiplier Input/Output weight multiplier 0.2
SS_multiplier Semantic/Semantic association multiplier 0.0

Task weights

Parameter Description Standard value
criterion_value Recognition threshold value 0.72
shortlist_input_threshold Word translation shortlist input value 0.7
shortlist_output_threshold Word translation shortlist output value 0.7
timestep_multiplier Cycle->RT timestep multiplier 1.0
timestep_adder Cycle->RT timestep base value 0.0

Task weights

Parameter Description Standard value
criterion_value Recognition threshold value 0.72
shortlist_input_threshold Word translation shortlist input value 0.7
shortlist_output_threshold Word translation shortlist output value 0.7
timestep_multiplier Cycle->RT timestep multiplier 1.0
timestep_adder Cycle->RT timestep base value 0.0