Connectionists: Neural accumulator model, superior colliculus, antisaccade task, decision making

[Vassilis Cutsuridis]

The following article is now available at: 
http://www.cs.stir.ac.uk/~vcu/papers/CutSmyEvdPer.pdf

Cutsuridis, V, Smyrnis, N, Evdokimidis, I, Perantonis, S. (2007)
A Neural Model of Decision Making by the Superior
Colliculus in an Antisaccade Task
Neural Networks, 20(6): 690-704
 
ABSTRACT
In the antisaccade paradigm subjects are instructed to perform 
eye movements in the opposite direction from the location of a 
visually appearing stimulus while they are fixating on a central 
stimulus. A recent study investigated saccade reaction times 
(SRTs) and percentages of erroneous prosaccades (towards 
the peripheral stimulus) of 2006 young men performing visually 
guided antisaccades. A unimodal distribution of SRTs (ranging 
from 80 to 600 ms) as well as an overall 25% of erroneous 
prosaccade responses was reported in that large sample. In 
this article, we present a neural model of saccade initiation 
based on competitive integration of planned and reactive 
saccade decision signals in the intermediate layer of the superior
colliculus. In the model the decision processes grow nonlinearly 
towards a preset criterion level and when they cross it, a movement
is initiated. The resultant model reproduced the unimodal distributions
of SRTs for correct antisaccades and erroneous prosaccades as 
well as the variability of SRTs and the percentage of erroneous 
prosaccade responses. 



Keywords: Eye movements; Antisaccades; Buildup neurons; 
Burst neurons; Nonlinear accumulator model; Decision making; 
Saccade reaction times; Superior colliculus


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