Dissociating the Impact of Object-Color Expectations and Object-Color Violations on Visual Feature Memory

Study events that are consistent with our prior expectations are often better remembered than expectation-unrelated events. Paradoxically, events that violate our expectations are also better remembered. What remains unclear is whether visual memory for expectation-consistent and expectation-violating events are supported by qualitatively different processes. Here we explore whether visual memory for expectation-related events are differentially impacted by mechanisms that underlie recognition and recall processes. We further assessed how the degree of expectation-consistency impacts memory for other features of study events. Across four experiments, we manipulated the degree to which study events adhered to people’s prior expectations (i.e., the color of objects) and then assessed memory (recall and recognition) for expectation-relevant features (i.e., object-color) and expectation-irrelevant features (object-shape). We propose an account that allows for competing mechanisms in memory encoding, storage, and retrieval, helping to explain the paradox in prior studies. Since recognition memory is backed by efficient encoding and storage processes, expectation-consistent events are better recognized because noise in the system is biased towards category expectations in storage. Expectation-violating events are better recognized because expectation-violating events lead to more resources spent on encoding all features of the study event. In contrast, recall is backed by boosted encoding and memory search processes for retrieving stored events, which are also biased toward expectations. Thus, expectation-consistent events are boosted in recall, but not expectation-violating events. Across experiments, we find evidence supporting both the “boosted encoding/storage” and “memory search” mechanisms. Expectation-consistent events were better recognized and recalled, while expectation-violating events were better recognized. Also, the advantage of expectation-violation, but not expectation-consistency, extended to memory for expectation-irrelevant features of the study event. These findings suggest that expectation-consistent and expectation-violating information are qualitatively dissociable in their impact on recognition and recall processes as well as their influence on memory for expectation-irrelevant features of study events.