The effects of diurnal variability and modality on false memories formation

The main objective of the current study was to investigate the effect of time of day on visual and auditory, short-term memory (STM), and long-term memory (LTM) distortions using a hybrid Deese-Roediger-McDermott procedure. In Experiment 1, we used semantically related words, whereas in Experiment 2 - words were characterized by phonological similarity. The results showed a relationship between modality and types of stimuli. In STM, more semantic errors were found in the evening for items presented visually and more errors following auditory presentation for phonologically similar words. In LTM, the analysis revealed a higher rate of semantic distortions in the evening hours for auditorily presented words. For words with phonological similarity, we observed more errors in the evening without the effect of modality. The results support the hypothesis that more reliance is placed on elaborative processing in the evening and more on maintenance processing in the morning; however, this is not modality invariant.

Asymmetry in Similarity Formation: Extension of Similarity Theory to Open Sets of Features

The current work shows the extension of similarity theory to open sets of features. Increasing similarity between two objects while deleting distinctive features and adding common features results in different effects depending on the original similarity. When the similarity is greater than 0.5, deleting distinctive features is more effective. When the similarity value is less than 0.5, adding common features is more effective. When we compare an object with its ideal, common features are positive and distinctive features are negative, whereas when we compare an object with its anti-ideal, common features are negative and distinctive features are positive. Consequently, greater strength of negative or positive features in increasing similarity depends on both the value of original similarity and whether the object is compared with its ideal or to its anti-ideal. In this way the positive–negative asymmetry is revealed. Theoretical simulations and a brief empirical demonstration of how the model works have shown that for similarity exceeding 0.5 of a compared object to its ideal, deleting negative features had a stronger effect on the positive image of a particular object than adding positive features of the same value. The mechanism presented is universal and refers to estimation and comparison of all natural stimuli, which can be defined by means of open sets of features.

Misremembering what you see or hear: Dissociable effects of modality on short- and long-term false recognition

False working memories readily emerge using a visual item-recognition variant of the converging associates task. Two experiments, manipulating study and test modality, extended prior working memory results by demonstrating a reliable false recognition effect (more false alarms to associatively related lures than to unrelated lures) within seconds of encoding in either the visual or auditory modality. However, false memories were nearly twice as frequent when study lists were seen than when they were heard, regardless of test modality, although study-test modality mismatch was generally disadvantageous (consistent with encoding specificity). A final experiment that varied study-test modality using a hybrid short- and long-term memory test (Flegal, Atkins & Reuter-Lorenz, 2010) replicated the auditory advantage in the short term but revealed a reversal in the long term: The false memory effect was greater in the auditory study-test condition than in the visual study-test condition. Thus, the same encoding conditions gave rise to an opposite modality advantage depending on whether recognition was tested under short-term or long-term memory conditions. Although demonstrating continuity in associative processing across delay, the results indicate that delay condition affects the availability of modality-dependent features of the memory trace and, thus, distinctiveness, leading to dissociable patterns of short- and long-term memory performance.