Irrelevant background context decreases mnemonic discrimination and increases false memory

Abstract

One of the greatest commonplaces in memory research is that context improves recall and enhances or leaves recognition intact. Here we present results which draw attention to the fact that the reappearance of irrelevant and unattended background contexts of encoding significantly impairs memory discrimination functions. This manuscript presents the results of two experiments in which participants made indoor/outdoor judgements for a large number of object images presented together with individual, irrelevant and presumably unattended background scenes. On a subsequent unexpected recognition test participants saw the incidentally encoded target objects, visually similar lures or new foil objects on the same or new background scenes. Our results showed that although the reappearance of the background scene raised the hit rate for target objects, it decreased mnemonic discrimination, a behavioral score for pattern separation, a hippocampal function that is affected in early dementia. Furthermore, the presence of the encoded background scene at the recognition test increased the false recognition of lure objects, even when participants were explicitly instructed to neglect the context scene. Altogether these results gave evidence that if context increases recognition hits for target memories, it does so at the cost of increasing false recognition and diminished discriminability for similar information.

The impact of context on pattern separation for objects among younger and older apolipoprotein ϵ4 carriers and noncarriers

“…Objects and contexts are hypothesized to be processed holistically and automatically rather than two separate components, making recognition of the object more difficult when it is shifted to a novel scene (Hasher & Zacks, 1979; Hayes et al, 2007). Keeping contexts consistent between encoding and retrieval have shown benefits for recognition memory for objects (Gutchess et al, 2007; Hayes et al, 2005; Hayes et al, 2007; Memel & Ryan, 2017; Racsmány et al, 2021), words (Craik & Schloerscheidt, 2011), and faces (Hayes et al, 2010). These benefits are true for tasks that use semantically related scenes (Hayes et al, 2007) and for tasks that superimpose objects on irrelevant backgrounds (Racsmány et al, 2021).…”

“…Keeping contexts consistent between encoding and retrieval have shown benefits for recognition memory for objects (Gutchess et al, 2007; Hayes et al, 2005; Hayes et al, 2007; Memel & Ryan, 2017; Racsmány et al, 2021), words (Craik & Schloerscheidt, 2011), and faces (Hayes et al, 2010). These benefits are true for tasks that use semantically related scenes (Hayes et al, 2007) and for tasks that superimpose objects on irrelevant backgrounds (Racsmány et al, 2021). Unlike the experiments described in Hayes et al (2007), objects in this task were not embedded naturalistically as objects from this task were superimposed on backgrounds.…”

“…In regard to object identification, the presence of a familiar context can both aid in quick judgements regarding the identity of objects typically found in those contexts (Bar & Aminoff, 2003; Bar, 2003, 2004; Biederman, 1981; Fenske et al, 2006; Palmer, 1975), while also leading to misidentification of objects when similar features are shared with one another (Palmer, 1975; Bar & Ullman, 1996). In studies of memory, where objects are embedded in backgrounds, the repetition of the same background will increase the accuracy of recognition for repeated objects, while shifting the background will disrupt accurate recognition (Feenan & Snodgrass, 1990; Hayes et al, 2005; Racsmány et al, 2021; Gutchess et al, 2007), even if participants are instructed to focus solely on the object and disregard the background (Hayes et al, 2007).…”

“…However, some novel objects in this study may have inadvertently appeared perceptually similar to the repeated objects, making it difficult to distinguish between the impact of repeated backgrounds versus object similarity. In another recent study, Racsmány et al (2021) evaluated the effect of irrelevant scenes on pattern separation in younger adults and found that repeated backgrounds decreased correct identifications of similar objects. Potentially, older adults would make even more errors due to their increased sensitivity to repeated contexts.…”

The Effect of One Night of Sleep on Mnemonic Discrimination of Emotional Information

“…To successfully discriminate targets from lure items, participants need to create a detailed representation of these items. This ability to discriminate between similar items is commonly referred to as mnemonic discrimination [ 5 ]. For this specific task, it is usually assessed using the Lure Discrimination Index (LDI).…”