Evidence for working memory storage operations in perceptual cortex

Isolating the short-term storage component of working memory (WM) from the myriad of associated executive processes has been an enduring challenge. Recent efforts have identified patterns of activity in visual regions that contain information about items being held in WM. However, it remains unclear (1) whether these representations withstand intervening sensory input and (2) how communication between multimodal association cortex and the unimodal perceptual regions supporting WM representations is involved in WM storage. We present evidence that the features of a face held in WM are stored within face-processing regions, that these representations persist across subsequent sensory input, and that information about the match between sensory input and a memory representation is relayed forward from perceptual to prefrontal regions. Participants were presented with a series of probe faces and indicated whether each probe matched a target face held in WM. We parametrically varied the feature similarity between the probe and target faces. Activity within face-processing regions scaled linearly with the degree of feature similarity between the probe face and the features of the target face, suggesting that the features of the target face were stored in these regions. Furthermore, directed connectivity measures revealed that the direction of information flow that was optimal for performance was from sensory regions that stored the features of the target face to dorsal prefrontal regions, supporting the notion that sensory input is compared to representations stored within perceptual regions and is subsequently relayed forward. Together, these findings indicate that WM storage operations are carried out within perceptual cortex.     

Police Overestimation of Criminal Career Homogeneity

Police presumptions about criminal career trajectories have been little studied. The exploratory study reported here involved 42 police staff of varying rank and experience. Participants were asked to complete a questionnaire that asked them to predict the type of offence that an individual with a specified prior record would most probably commit next. Participating police personnel substantially overstated the homogeneity of criminal careers, that is, the nature of prior offences determined their prediction of their next offence more than available official data would deem reasonable. An incidental finding was that officers who rated the probability of further offending highest were also those who thought criminal careers most specialised. The implications for operational police decision‐making were discussed and held to be profound. Copyright © 2013 John Wiley & Sons, Ltd.     

Comparing the accuracy of experimental estimates to guessing: a new perspective on replication and the “Crisis of Confidence” in psychology

We develop a general measure of estimation accuracy for fundamental research designs, called v. The v measure compares the estimation accuracy of the ubiquitous ordinary least squares (OLS) estimator, which includes sample means as a special case, with a benchmark estimator that randomizes the direction of treatment effects. For sample and effect sizes common to experimental psychology, v suggests that OLS produces estimates that are insufficiently accurate for the type of hypotheses being tested. We demonstrate how v can be used to determine sample sizes to obtain minimum acceptable estimation accuracy. Software for calculating v is included as online supplemental material (R Core Team, 2012).     

Granger Causality—Statistical Analysis Under a Configural Perspective

The concept of Granger causality can be used to examine putative causal relations between two series of scores. Based on regression models, it is asked whether one series can be considered the cause for the second series. In this article, we propose extending the pool of methods available for testing hypotheses that are compatible with Granger causation by adopting a configural perspective. This perspective allows researchers to assume that effects exist for specific categories only or for specific sectors of the data space, but not for other categories or sectors. Configural Frequency Analysis (CFA) is proposed as the method of analysis from a configural perspective. CFA base models are derived for the exploratory analysis of Granger causation. These models are specified so that they parallel the regression models used for variable-oriented analysis of hypotheses of Granger causation. An example from the development of aggression in adolescence is used. The example shows that only one pattern of change in aggressive impulses over time Granger-causes change in physical aggression against peers.     

Sensory memory of illusory depth in structure-from-motion

When multistable displays (stimuli consistent with two or more equally plausible perceptual interpretations) are presented intermittently, their perceptions are stabilized by sensory memory. Independent memory traces are generated not only for different types of multistable displays (Maier, Wilke, Logothetis, & Leopold, Current Biology 13:1076–1085, 2003), but also for different ambiguous features of binocular rivalry (Pearson & Clifford, Journal of Vision 4:196–202, 2004). In the present study, we examined whether a similar independence of sensory memories is observed in structure-from-motion (SFM), a multistable display with two ambiguous properties. In SFM, a 2-D planar motion creates a vivid impression of a rotating 3-D volume. Both the illusory rotation and illusory depth (i.e., how close parts of an object appear to the observer) of an SFM object are ambiguous. We dissociated the sensory memories of these two ambiguous properties by using an intermittent presentation in combination with a forced-ambiguous-switch paradigm (Pastukhov, Vonau, & Braun, PLoS ONE 7:e37734, 2012). We demonstrated that the illusory depth of SFM generates a sensory memory trace that is independent from that of illusory rotation. Despite this independence, the specificities levels of the sensory memories were identical for illusory depth and illusory rotation. The history effect was weakened by a change in the volumetric property of a shape (whether it was a hollow band or a filled drum volume), but not by changes in color or size. We discuss how these new results constrain models of sensory memory and SFM processing.     

Around the world,adolescence is a time of heightened sensation seeking and immature self‐regulation

The dual systems model of adolescent risk‐taking portrays the period as one characterized by a combination of heightened sensation seeking and still‐maturing self‐regulation, but most tests of this model have been conducted in the United States or Western Europe. In the present study, these propositions are tested in an international sample of more than 5000 individuals between ages 10 and 30 years from 11 countries in Africa, Asia, Europe and the Americas, using a multi‐method test battery that includes both self‐report and performance‐based measures of both constructs. Consistent with the dual systems model, sensation seeking increased between preadolescence and late adolescence, peaked at age 19, and declined thereafter, whereas self‐regulation increased steadily from preadolescence into young adulthood, reaching a plateau between ages 23 and 26. Although there were some variations in the magnitude of the observed age trends, the developmental patterns were largely similar across countries.     

The development of cognitive empathy and concern in preschool children: A behavioral neuroscience investigation

This developmental neuroscience study examined the electrophysiological responses (EEG and ERPs) associated with perspective taking and empathic concern in preschool children, as well as their relation to parental empathy dispositions and children's own prosocial behavior. Consistent with a body of previous studies using stimuli depicting somatic pain in both children and adults, larger early (~200 ms) ERPs were identified when perceiving painful versus neutral stimuli. In the slow wave window (~800 ms), a significant interaction of empathy condition and stimulus type was driven by a greater difference between painful and neutral images in the empathic concern condition. Across early development, children exhibited enhanced N2 to pain when engaging in empathic concern. Greater pain‐elicited N2 responses in the cognitive empathy condition also related to parent dispositional empathy. Children's own prosocial behavior was predicted by several individual differences in neural function, including larger early LPP responses during cognitive empathy and greater differentiation in late LPP and slow wave responses to empathic concern versus affective perspective taking. Left frontal activation (greater alpha suppression) while engaging in affective perspective taking was also related to higher levels of parent cognitive empathy. Together, this multilevel analysis demonstrates the important distinction between facets of empathy in children; the value of examining neurobehavioral processes in development. It provides provoking links between children's neural functioning and parental dispositions in early development.     

Reduction of implicit cognitive bias with cathodal tDCS to the left prefrontal cortex

Implicit associations can interfere with cognitive operations and behavioral decisions without direct intention. Enhancement of neural activity with anodal transcranial direct current stimulation (tDCS) was proposed to reduce implicit associations by means of improved cognitive control. However, a targeted reduction of distractive implicit associations by inhibitory cathodal tDCS, recently shown in spatial–numerical associations, provides an interesting alternative approach to support goal-directed behavior with transcranial brain stimulation. To test this rationale with a sham-controlled cross-over design, a standardized Implicit Association Test (IAT) was performed by 24 healthy participants parallel to 1 mA cathodal or sham tDCS to the left prefrontal cortex. In this double-classification task, insect versus flower pictures and negative versus positive words are mapped together onto two shared response keys with crossed response assignments in separate blocks. Responses were faster when insect + negative and flower + positive stimuli required the same answer (IAT effect). Most critically, the IAT effect was reduced during cathodal tDCS as compared to sham stimulation. Thus, results are consistent with the proposed stimulation rationale, with previous observations, and complementary to previous studies using different tDCS configurations.