Attentional Dynamics Explain the Elusive Nature of Context Effects

Abstract

Context effects in multi-alternative, multi-attribute choice are pervasive and yet, paradoxically, elusive at the same time. For example, simple changes to the spatial layout of alternatives on the screen can nullify or reverse the effects. Despite the success of dynamic decision models in explaining the occurrence of context effects, a coherent theory for understanding their elusiveness is currently lacking. We introduce a novel theoretical framework that relies on attention modulated comparisons to explain the elusive nature of context effects. We show via simulation that our model produces the attraction, compromise, and similarity effects simply by assuming that more time is spent comparing alternatives that are more similar. However, when more time is spent comparing dissimilar alternatives, model simulations reveal a reversal of the attraction and compromise effects. The empirical support for this model-based prediction is assessed by manipulating similarity-based attention in separate experiments for the three context effects (total N = 317). Further, by allowing the spatial organization of information to constrain the attention process, the model can explain changes in context effects induced by display layout. We show that the model's spatial attention mechanism allows it to capture presentation order effects in a reanalysis of previously published data. Finally, we develop a continuous approximation of the full model that permits fitting of choices and response times. In summary, the proposed framework provides a new tool for understanding not only the existence of context effects in choice, but also the attentional factors that lead to null or reversed context effects.

The Role of Salience in Multialternative Multiattribute Choice

“…For instance, when the target and the decoy are presented beside each other on the information display, the attraction effect is strengthened (Evans, Holmes, Dasari, & Trueblood, 2021;Hasan, Liu, Owens, & Trueblood, 2023). Computational modeling has revealed that this might be accounted for by additional comparisons between neighboring options (Trueblood et al, 2022). Thus while visual factors might impact the comparative process, it seems to be independent of bottom-up salience.…”

“…We used a sequential sampling model framework, called the comparison sampling framework, to model the decisionmaking process in our task (Trueblood et al, 2022). As shown in Figure 4, this framework delineates a preference accumulation process and an attentional process, making it suitable for modeling our hypotheses.…”

“…To make the model fitting procedure tractable, we derived a continuous approximation to the model (Trueblood et al, 2022). We calculated the stationary matrix of the attentional Markov matrix (Ross, 2014).…”

“…For example, a decision between three computers (such as the one shown in Figure 1) might require one to integrate information about their speed and memory size before deciding which one to buy. Prominent theories of multialternative choice hypothesize that a decision maker sequentially attends to the different attributes and integrates them before making a decision (Trueblood, Liu, Murrow, Hayes, & Holmes, 2022;Noguchi & Stewart, 2018;Roe, Busemeyer, & Townsend, 2001;Bhatia, 2013;Yang & Krajbich, 2023;Krajbich & Rangel, 2011). This type of sequential sampling process suggests that attention likely plays a critical role in multi-alternative decisions (Trueblood, 2022;Smith & Krajbich, 2019).…”

“…Leading models of multiattribute choice describe choice resulting from a comparative process between choice options (Trueblood et al, 2022;Noguchi & Stewart, 2018;Roe et al, 2001;Bhatia, 2013). For example, in the attraction effect trial presented in Figure 1, the choice share of the top option (target) relative to the middle option -(competitor) increases in the presence of the bottom option -attraction decoy, since the target (but not the competitor) dominates the decoy, making the target appear superior.…”