Implementing TVA as a Bayesian classifier in a foraging task

Journal of Vision. 2021. Vol. 21. No. 9. P. 2363–2363.

Le S. T., MacInnes W., Kristjansson A.

Foraging as a natural visual search for multiple targets has increasingly been studied in humans in recent years. Here, we aimed to model the differences in foraging strategies between feature and conjunction foraging tasks found by Kristjánsson et al.(2014). Bundesen (1990) proposed the Theory of Visual Attention (TVA) as a computational model of attentional function that divides the selection process into filtering and pigeonholing. The theory describes a mechanism by which the strength of sensory evidence serves to categorize elements. We combined these ideas to train augmented Naïve Bayesian classifiers using data from Kristjánsson et al.(2014) as input. Specifically, we attempted to answer whether it is possible to predict how frequently observers switch between different target types during consecutive selections (switch rates) during feature and conjunction foraging using Bayesian classifiers. We formulated eleven new parameters that represent key sensory and bias information that could be used for each selection during the foraging task and tested them with multiple Bayesian models. Separate Bayesian networks were trained on feature and conjunction foraging data, and parameters that had no impact on the model's predictability were pruned away. We report high accuracy for switch prediction in both tasks from the classifiers, although the model for conjunction foraging was more accurate. We also report our Bayesian parameters in terms of their theoretical associations to TVA parameters, π_j (denoting the pertinence value) and β_i (denoting the decision-making bias).

Keywords: visual attention, foraging, naive Bayesian classifier, TVA