Gaze-dependent evidence accumulation predicts multi-alternative risky choice behaviour

Abstract

Choices are influenced by gaze allocation during deliberation, so that fixating an alternative longer leads to increased probability of choosing it. Gaze-dependent evidence accumulation provides a parsimonious account of choices, response times and gaze-behaviour in many simple decision scenarios. Here, we test whether this framework can also predict more complex context-dependent patterns of choice in a three-alternative risky choice task, where choices and eye movements were subject to attraction and compromise effects. Choices were best described by a gaze-dependent evidence accumulation model, where subjective values of alternatives are discounted while not fixated. Finally, we performed a systematic search over a large model space, allowing us to evaluate the relative contribution of different forms of gaze-dependence and additional mechanisms previously not considered by gaze-dependent accumulation models. Gaze-dependence remained the most important mechanism, but participants with strong attraction effects employed an additional similarity-dependent inhibition mechanism found in other models of multi-alternative multi-attribute choice.

Theories of Context Effects in Multialternative, Multiattribute Choice

“…They found that decoys result in more consecutive shifts of attention between the decoy and target, suggesting an increase in comparing target and decoy options during choice. Molter et al (2021) found that target options received greater relative dwell time than competitor options in both the attraction and compromise effects. Overall, these results show that attention and how it shifts during deliberation plays a key role in understanding context effects.…”

“…Some of these models, such as Multi-alternative Decision Field Theory (MDFT; Roe, Busemeyer, & Townsend, 2001), have been studied and tested extensively over the years. Other models, such as the Normalization and Urgency Model (Tajima, Drugowitsch, Patel, & Pouget, 2019) and the Gaze-dependent Leaky Accumulator (GLA; Molter, Thomas, Huettel, Heekeren, & Mohr, 2021) are relatively new theories and thus have been studied less. Looking at Table 1, one might wonder which model is the "best".…”

“…Some of these models, such as multialternative decision field theory (MDFT; Roe et al, 2001), have been studied and tested extensively over the years. Other models, such as the normalization and urgency model (Tajima et al, 2019) and the gaze-dependent leaky accumulator (Molter et al, 2021), are relatively new theories and thus have been studied less. Looking at Table 1, one might wonder which model is the “best.” That is, which model provides the best account of context effects and multialternative, multiattribute choice more generally?…”

Theories of Context Effects in Multi-alternative, Multi-attribute Choice

“…They found that decoys result in more consecutive shifts of attention between the decoy and target, suggesting an increase in comparing target and decoy options during choice. Molter et al (2021) found that target options received greater relative dwell time than competitor options in both the attraction and compromise effects.…”

Attentional Dynamics Explain the Elusive Nature of Context Effects

“…It does not however attempt to understand the process responsible for the allocation of attention. Recently, gaze-dependent evidence accumulation models have also been leveraged to study context effects in multi-alternative, multi-attribute choice (Molter et al, 2022). However, because attention is treated as an exogenous variable in the aDDM and other gaze-dependent models, the models make no predictions for the effect that different spatial layouts, for example, will have on attention and (consequently) decision making.…”