Modeling confidence and response time in associative recognition

Abstract

Research examining models of memory has focused on differences in the shapes of ROC curves across tasks and has used these differences to argue for and against the existence of multiple memory processes. ROC functions are usually obtained from confidence judgments, but the reaction times associated with these judgments are rarely considered. The RTCON2 diffusion model for confidence judgments has previously been applied to data from an item recognition paradigm. It provided an alternative explanation for the shape of the z-ROC function based on how subjects set their response boundaries and these settings are also constrained by reaction times. In our experiments, we apply the RTCON2 model to data from associative recognition tasks to further test the model’s ability to accommodate non-linear z-ROC functions. The model is able to fit and explain a variety of z-ROC shapes as well as individual differences in these shapes while simultaneously fitting reaction time distributions. The model is able to distinguish between differences in the information feeding into a decision process and differences in how subjects make responses (i.e., set decision boundaries and confidence criteria). However, the model is unable to fit data from a subset of subjects in these tasks and this has implications for models of memory.

Decision making on spatially continuous scales.

“…In a typical confidence judgment procedure, subjects choose which of some small number of categories best describes their degree of confidence (e.g., “sure,” “very sure,” and so on). To model confidence judgments about memory (the RTCON and RTCON2 models, Ratcliff & Starns, 2009, 2013; Voskuilen & Ratcliff, 2016), memory strength was assumed to be distributed and confidence criteria were placed on the strength dimension. The area under the strength distribution between the criteria provided the drift rate for an accumulator for that confidence category.…”

“…When individuals are asked to indicate how confident they are in the correctness of a decision, they typically do so by choosing one of several categorical responses (e.g., very confident, somewhat confident, etc.). Like the two-choice model, multi-choice diffusion models have provided a detailed explanation of choices and RTs (Leite & Ratcliff, 2010; Niwa & Ditterich, 2008; Pleskac & Busemeyer, 2011; Ratcliff & Starns, 2009, 2013; Voskuilen & Ratcliff, 2016). However, despite the tradition in which confidence judgments are measured in discrete categories, confidence should be seen as a continuous dimension in some situations, not a discrete categorical one, and the modeling presented here might apply to such confidence judgments made on a continuous scale.…”

Information and Processes Underlying Semantic and Episodic Memory Across Tasks, Items, and Individuals

“…Such models assume that participants continue to draw samples from an evidence-generating process (in this case, the process is memory retrieval) until they have accumulated enough to commit to a decision. Such models are widely used throughout psychology, including in our three binary choice tasks, lexical decision (Ratcliff, Gomez, & McKoon, 2004), single-item recognition (Ratcliff, 1978;Starns, Ratcliff, & McKoon, 2012;Starns & Ratcliff, 2014), and associative recognition (Ratcliff, Thapar, & McKoon, 2011;Voskuilen & Ratcliff, 2016) 3 . Although other frameworks exist to jointly characterize accuracy and response time, notably accumulator models (Vickers, 1970;Usher & McClelland, 2001;Brown & Heathcote, 2008), in practice when used as measurement models, these , at which time participants commit to a "yes" (upper boundary) or "no" (lower boundary) decision.…”

The Common Time Course of Memory Processes Revealed

“…While single-stage models have mainly been applied to nonassociative tasks, they have also been applied to associative memory tasks. For instance, as Voskuilen and Ratcliff (2016) The experiments to which these models have been applied typically have much less well-learned material than our two experiments (and so analysis of errors becomes critical). One might argue that only experiments with high degrees of practice have a distinct retrieval stage.…”