Rapid eye movement (REM) in premature neonates and developmental outcome at 6 months

Different aspects of early sleep organization have been associated with subsequent development in premature infants. The aim of the present study was to assess the relations between rapid eye movement (REM) activity in premature neonates and infants' developmental outcomes at 6 months. Participants were 81 premature infants (47 males). Sleep-wake states and REM were observed across 4 consecutive evening hours (7-11 PM) in 10-s frames when infants were between 32 and 36 weeks post-menstrual age. Developmental outcome was assessed at 6 months with the mental development index (MDI) of the Bayley II. Infants with low-REM activity spent more time in less growth-promoting states, including crying and unfocused alert states in the neonatal period and had lower MDI scores at 6 months corrected age compared to infants with high-REM. Differences between the high- and low-REM groups were independent of neonatal medical risk. Low-REM activity may serve as an indicator of developmental risk among premature neonates.     

An empirical and computational investigation of perceiving and remembering event temporal relations

Events have beginnings, ends, and often overlap in time. A major question is how perceivers come to parse a stream of multimodal information into meaningful units and how different event boundaries may vary event processing. This work investigates the roles of these three types of event boundaries in constructing event temporal relations. Predictions were made based on how people would err according to the beginning state, end state, and overlap heuristic hypotheses. Participants viewed animated events that include all the logical possibilities of event temporal relations, and then made temporal relation judgments. The results showed that people make use of the overlap between events and take into account the ends and beginnings, but they weight ends more than beginnings. Neural network simulations showed a self-organized distinction when learning temporal relations between events with overlap versus those without.     

Navigating through abstract decision spaces: Evaluating the role of state generalization in a dynamic decision-making task

Research on dynamic decision-making tasks, in which the payoffs associated with each choice vary with participants’ recent choice history, shows that humans have difficulty making long-term optimal choices in the presence of attractive immediate rewards. However, a number of recent studies have shown that simple cues providing information about the underlying state of the task environment may facilitate optimal responding. In this study, we examined the mechanism by which this state knowledge influences choice behavior. We examined the possibility that participants use state information in conjunction with changing payoffs to extrapolate payoffs in future states. We found support for this hypothesis in an experiment in which generalizations based on this state information worked to the benefit or detriment of task performance, depending on the task’s payoff structure.     

What is pressure? Evidence for social pressure as a type of regulatory focus

Previous research (Markman, Maddox, & Worthy, 2006) suggests that pressure leads to choking when one is learning to classify items on the basis of an explicit rule, but it leads to excelling when one is learning to classify items on the basis of an implicit strategy. In this article, we relate social pressure to regulatory focus theory. We propose that the effects of pressure on performance arise because pressure induces a prevention focus that interacts with the more local reward structure of the task. To test this hypothesis, we repeated previous research, but using a losses reward structure, so that participants under pressure were in a regulatory fit. We also successfully replicated previous results by using a gains reward structure. In contrast with participants who attempted to maximize gains on each trial, participants who attempted to minimize losses choked on the implicit-learning task but excelled on the explicit-learning task. The results suggest a three-way interaction between pressure level, task type, and reward structure.     

Biological and environmental initial conditions shape the trajectories of cognitive and social‐emotional development across the first years of life

Human development is thought to evolve from the dynamic interchange of biological dispositions and environmental provisions; yet the effects of specific biological and environmental birth conditions on the trajectories of cognitive and social‐emotional growth have rarely been studied. We observed 126 children at six time‐points from birth to 5 years. Intelligence, maternal sensitivity, and child social engagement were repeatedly tested. Effects of neonatal vagal tone (VT) and maternal postpartum depressive symptoms on growth‐rates were assessed. Cognitive development showed a substantial growth‐spurt between 2 and 5 years and social engagement increased rapidly across the first year and more gradually thereafter. VT improved cognitive and social‐emotional growth‐rates across the first year, whereas maternal depressive symptoms interfered with growth from 2 to 5 years. Differences between infants with none, one, or two non‐optimal birth conditions increased with age. Findings shed light on the dynamics of early development as it is shaped by biological and environmental initial conditions.     

Processing of Syllables in Production and Recognition Tasks

Empirical evidence for a functional role of syllables in visual word processing is abundant, however it remains rather heterogeneous. The present study aims to further specify the role of syllables and the cognitive accessibility of syllabic information in word processing. The first experiment compared performance across naming and lexical decision tasks by manipulating the number of syllables in words and non-words. Results showed a syllable number effect in both the naming task and the lexical decision task. The second experiment introduced a stimulus set consisting of isolated syllabic and non-syllabic trigrams. Syllable frequency was manipulated in a naming and in a decision task requiring participants to decide on the syllabic status of letter strings. Results showed faster responses for syllables than for non-syllables in both tasks. Syllable frequency effects were observed in the decision task. In summary, the results from these manipulations of different types of syllable information confirm an important role of syllabic units in both recognition and production.