Decision-making is commonly impaired in those with cognitive decline. I compared individuals with Mild Cognitive Impairment (MCI; n = 45) and cognitively healthy older adults (n = 45) in their ability to improve their decision-making in the Iowa Gambling Task over time. On each trial, participants chose from one of four decks of cards and received a net gain or loss. The four decks differed in their expected value (EV). They continued choosing among the decks for one hundred trials, trying to maximize their winnings. Results indicate that both groups learned to choose from the higher EV decks over time, but those with MCI learned more slowly. The data were fit to a reinforcement learning model that indicated those with MCI performed worse in part because of task strategy: those with MCI were less likely to perseverate on wins and updated their beliefs more slowly to losses.

Psychologists have used the semantic fluency task fordecades to gain insight into the processes and representationsunderlying memory retrieval. Recent work has suggested thata censored random walk on a semantic network resemblessemantic fluency data because it produces optimal foraging.However, fluency data have rich structure beyond beingconsistent with optimal foraging. Under the assumption thatmemory can be represented as a semantic network, we test avariety of memory search processes and examine how wellthese processes capture the richness of fluency data. Thesearch processes we explore vary in the extent they explorethe network globally or exploit local clusters, and whetherthey are strategic. We found that a censored random walkwith a priming component best captures the frequency andclustering effects seen in human fluency data.

Individual differences in reflectiveness have been found topredict belief in God. We hypothesize that this associationmay be due to a broader inclination for intuitive thinkers toendorse teleological explanations. In support of ourhypothesis, we find that scientifically unfounded teleologicalexplanations are more likely to be endorsed by intuitive compared to analytical thinkers, and that those who endorse teleological explanations are more likely to have religious beliefs.

Magicians often rely on misdirection to fool their audience. Acommon way to achieve this is for the magician to provide aplausible and intuitive (but false) account of how an effect isperformed in order to prevent spectators from uncovering thetruth. We hypothesized that analytical thinkers would be morelikely than intuitive thinkers to seek alternative explanationswhen observing a mental magic effect because generating acoherent explanation requires analytical thought. We foundthat while intuitive thinkers often espoused explanations for amagic trick similar to one provided by the magician,analytical thinkers tended to generate new explanations thatechoed rational principles and relied on physical mechanisms(rather than mental capabilities). This difference was notpredicted by differences in numeracy skills or need forcognition.

People tend to explain events using inherent more than extrinsic factors, a phenomenon known as the inherence bias. This bias is hypothesized to be more pronounced when cognitive resources are scarce. Here, we tested an important prediction of this account: namely, that aging and cognitive impairment should increase the inherence bias in explanation. Participants were shown vignettes of surprising scientific discoveries, and were asked to generate and evaluate explanations for those events. Our results indicate that as age increased, participants were more likely to generate inherent explanations, though age did not lead participants to endorse more inherent explanations when generation was not required. Older adults with Mild Cognitive Impairment generated a similar proportion of inherent explanations as healthy adults on average, though they did not do so increasingly with age. These findings suggest that cognitive deficits due to aging can have downstream effects on how we engage in complex reasoning.

Rock, Paper, Scissors (RPS) is a competitive game. There arethree actions: rock, paper, and scissors. The game’s rules aresimple: scissors beats paper, rock beats scissors and paper beatsrock (all signs stalemate against themselves). Over multiplegames with the same opponent, optimal play according to aNash Equilibrium requires subjects to play with genuinerandomness. To examine randomness judgments in the contextof competition, we tested subjects with identical sequences intwo conditions: one produced from a dice roll, one fromsomeone playing rock, paper, scissors. We compared thesefindings to models of subjective randomness from Falk andKonold (1997) and from Griffiths and Tenenbaum (2001),which explain assessments of randomness as a function ofalgorithmic complexity and statistical inference, respectively.In both conditions the models fail to adequately describesubjective randomness judgements of ternary outcomes. Wealso observe that context influences perceptions of randomnesssuch that some isomorphic sequences produced fromintentional play are perceived as less random than dice rolls.We discuss this finding in terms of the relation betweenpatterns and opponent modeling.

Practitioners of mentalism can perform apparently impossible feats, but when performing for an audience these feats are attributed to pseudoscientific explanations such as advanced psychological skills. Research that has investigated the psychological foundations of mentalism has found a strong tendency for people to believe these explanations. In three experiments, we investigated the strength of this belief by comparing apparently impossible effects relating to mental phenomena with physical phenomena. We observed that mental magic tricks are readily explained in terms of advanced psychological skills, whereas physical tricks are not. This was true: i) even when alternative feasible explanations are explicitly presented; ii) when they are presented as mentalism effects but the effects themselves are classical card tricks; iii) regardless of the context in which the effects are observed (a research laboratory vs. a theater). We interpreted the tendency to appeal to this pseudo-explanation (and the changes in narratives employed by mentalists across the decades) in terms of the community of knowledge framework.

Bilinguals are purported to be more creative than monolinguals, but the mechanism for this bilingual advantage is stillunresolved, with several different accounts proposed. Others have challenged the existence of bilingual advantages ingeneral. We examine existence as well as hypothesized semantic network difference based mechanisms for the relationshipbetween bilingualism and creativity here by measuring creativity and fluency for monolinguals and bilinguals. The fluencymeasure allowed us to analyze the structure of individuals semantic networks (average shortest path length, clusteringcoefficient, and modularity). We found no differences in creativity between monolingual and bilingual participants, with aBayesian test showing substantial evidence for the null hypothesis. We did find that aspects of semantic network structurepredicted creativity. These findings suggest that, contrary to previous work, the bilingual advantage does not exist in therealm of creativity.

Semantic networks have been used extensively in psychologyto describe how humans organize facts and knowledge inmemory. Numerous methods have been proposed to constructsemantic networks using data from memory retrieval tasks,such as the semantic fluency task (listing items in a category).However these methods typically generate group-levelnetworks, and sometimes require a very large amount ofparticipant data. We present a novel computational methodfor estimating an individual’s semantic network usingsemantic fluency data that requires very little data. Weestablish its efficacy by examining the semantic relatedness ofassociations estimated by the model.