Stimuli encoded shortly before an aversive event are typically well remembered. Traditionally, this emotional memory enhancement has been attributed to beneficial effects of physiological arousal on memory formation. Here, we proposed an additional mechanism and tested whether memory formation is driven by the unpredictable nature of aversive…

Recent semantic space models learn vector representations for word meanings by observing statistical redundancies across a text corpus. A word's meaning is represented as a point in a high-dimensional semantic space, and semantic similarity between words is quantified by a function of their spatial proximity (typically the cosine of the angle…

Are associative memories forgotten more quickly than item memories, and does the level of original learning differentially influence forgetting rates? In this study, we addressed these questions by having participants learn single words and word pairs once (Experiment 1), three times (Experiment 2), and six times (Experiment 3) in a massed…

We compared the ability of three different contextual models of lexical semantic memory (BEAGLE, Latent Semantic Analysis, and the Topic model) and of a simple associative model (POC) to predict the properties of semantic networks derived from word association norms. None of the semantic models were able to accurately predict all of the network…

This study adjudicates between two opposing accounts of morphological productivity, using English past-tense as its test case. The single-route model (e.g., Bybee & Moder, 1983) posits that both regular and irregular past-tense forms are generated by analogy across stored exemplars in associative memory. In contrast, the dual-route model…

Fifty years ago, Mednick ["Psychological Review", 69 (1962) 220] proposed an elaborate model that aimed to explain how creative ideas are generated and why creative people are more likely to have creative ideas. The model assumes that creative people have flatter associative hierarchies and as a consequence can more fluently retrieve…

According to the retrieved context theory of episodic memory, the cue for recall of an item is a weighted sum of recently activated cognitive states, including previously recalled and studied items as well as their associations. We show that this theory predicts there should be compound cuing in free recall. Specifically, the temporal contiguity…

Humans are remarkably sensitive to the statistical structure of language. However, different mechanisms have been proposed to account for such statistical sensitivities. The present study compared adult learning of syntax and the ability of two models of statistical learning to simulate human performance: Simple Recurrent Networks, which learn by…

In this article, we present a perspective on the role of the hippocampal system in generalization, instantiated in a computational model called REMERGE (recurrency and episodic memory results in generalization). We expose a fundamental, but neglected, tension between prevailing computational theories that emphasize the function of the hippocampus…

This dissertation uses the processing of anaphoric relations to probe how linguistic information is encoded in and retrieved from memory during real-time sentence comprehension. More specifically, the dissertation attempts to resolve a tension between the demands of a linguistic processor implemented in a general-purpose cognitive architecture and…

Participants studied naturalistic pictures presented for varying brief durations and then received a recognition test on which they indicated whether each picture was old or new and rated their confidence. In 1 experiment they indicated whether each "old"/"new" response was based on memory for a specific feature in the picture…

Word properties like imageability and word frequency improve cued recall of verbal paired-associates. We asked whether these enhancements follow simply from prior effects on item-memory, or also strengthen associations between items. Participants studied word pairs varying in imageability or frequency: pairs were "pure" (high-high, low-low) or…

A longstanding and fundamental debate in developmental science is whether knowledge is acquired through domain-specific or domain-general mechanisms. To date, there exists no tool to determine whether experimental data support one theoretical approach or the other. In this article, we argue that the U- and N-shaped curves found in a number of…

The role of the "foraging" ("for)" gene, which encodes a cyclic guanosine-3',5'-monophosphate (cGMP)-dependent protein kinase (PKG), in food-search behavior in "Drosophila" has been intensively studied. However, its functions in other complex behaviors have not been well-characterized. Here, we show experimentally in "Drosophila" that the "for"…

Memory systems are known to be influenced by feedback and error processing, but it is not well known what aspects of outcome contingencies are related to different memory systems. Here we use the Rescorla-Wagner model to estimate prediction errors in an fMRI study of stimulus-outcome association learning. The conditional probabilities of outcomes…