Doubts about double dissociations between short- and long-term memory

Historically, psychologists and neuroscientists have distinguished between processes supporting memory for events across retention delays of several seconds (short-term memory, STM), and those supporting memory for events across longer retention delays of minutes or more (long-term memory, LTM). Dissociations reported in some neuropsychological studies have contributed to a popular view that there must be neurally distinct memory stores that differentially support STM and LTM. In this article, we review evidence from recent studies regarding dissociations between STM and LTM. We suggest that the evidence reveals problems with claims of selective STM or LTM impairments, which in turn questions whether theories of memory need to propose neurally distinct stores for short- and long-term retention. We consider alternative ways to explain the neural mechanisms of memory across different retention intervals.     

Differential prefrontal–temporal neural correlates of semantic processing in children

This study used functional magnetic resonance imaging (fMRI) to examine brain–behavior correlations in a group of 16 children (9- to 12-year-olds). Activation was measured during a semantic judgment task presented in either the visual or auditory modality that required the individual to determine whether a final word was related in meaning to one of two previous words (e.g., found–tank–lost). The main finding was that higher performers (i.e., accuracy) were associated with more activation in posterior representational systems including the inferior and middle temporal gyri, whereas lower performers were associated with more activation in anterior regions including the inferior and middle frontal gyri. This pattern of results was interpreted as reflecting an elaborated semantic representational system in temporal areas for the high accuracy performers that allowed them to efficiently and accurately make meaning based judgments. The low accuracy performers may have an inaccurate or weakly interconnected semantic system that results in greater use of frontal areas in a feature selection process.     

Priming of spatial distance enhances children's creative performance

According to construal level theory, psychological distance promotes more abstract thought. Theories of creativity, in turn, suggest that abstract thought promotes creativity. Based on these lines of theorizing, we predicted that spatial distancing would enhance creative performance in elementary school children. To test this prediction, we primed spatial distance by presenting 6- to 9-year-olds with pictures of increasingly distal objects (from their own desk to the galaxy) or increasingly proximal objects (from the galaxy to their own desk) and then assessed the fluency and originality of their ideas in a creativity test. We found, consistent with the hypothesis, that after priming of spatial distance, compared with priming of spatial proximity, children were more creative, as reflected in higher scores of both fluency and originality. This result was not qualified by children's age or gender.     

Bilingualism influences inhibitory control in auditory comprehension

Bilinguals have been shown to outperform monolinguals at suppressing task-irrelevant information. The present study aimed to identify how processing linguistic ambiguity during auditory comprehension may be associated with inhibitory control. Monolinguals and bilinguals listened to words in their native language (English) and identified them among four pictures while their eye-movements were tracked. Each target picture (e.g., hamper) appeared together with a similar-sounding within-language competitor picture (e.g., hammer) and two neutral pictures. Following each eye-tracking trial, priming probe trials indexed residual activation of target words, and residual inhibition of competitor words. Eye-tracking showed similar within-language competition across groups; priming showed stronger competitor inhibition in monolinguals than in bilinguals, suggesting differences in how inhibitory control was used to resolve within-language competition. Notably, correlation analyses revealed that inhibition performance on a nonlinguistic Stroop task was related to linguistic competition resolution in bilinguals but not in monolinguals. Together, monolingual-bilingual comparisons suggest that cognitive control mechanisms can be shaped by linguistic experience.     

A comparison of students studying-behavior produced by daily, weekly, and three-week testing schedules

Time spent in contact with academic course materials as a function of two testing schedules was measured using college undergraduates in an introductory educational psychology course. A within-subject (ABAB) design was employed with all subjects to allow for both individual and group analyses. A study room equipped with an adjacent observation room enabled visual and auditory monitoring of student study behavior. Academic materials were exclusively available to students in the study room and records of durations and distribution of student study time were made by an observer behind a one-way mirror. Daily testing produced consistent duration of study behavior with regular attendance at the study room; weekly and three-week testing produced sporadic bursts of study behavior and frequent instances of non-attendance. The amount of study behavior occurring in weekly and three-week testing conditions increased as the test time drew near (scalloping). Results suggest that daily testing supports more consistent study patterns than do the two larger intertest intervals investigated.     

Cross-linguistic phonotactic competition and cognitive control in bilinguals

The current study examines the relation between cognitive control and linguistic competition resolution at the sublexical level in bilinguals. Twenty-one Spanish–English bilinguals and 23 English monolinguals completed a non-linguistic Stroop task (indexing inhibitory control) and a linguistic priming/lexical decision task (indexing Spanish phonotactic-constraint competition during English comprehension). More efficient Stroop performance (i.e. a smaller Stroop effect) in bilinguals was associated with decreased competition from Spanish phonotactic constraints during English comprehension. This relation was observed when nonword targets overlapped in phonotactic constraints and phonological form with preceding cognate primes (e.g. prime: stable (Spanish: estable)/target: esteriors). Findings suggest a link between non-linguistic cognitive control and co-activation of linguistic structures at the sublexical level in bilinguals.