Working memory in children: tracing age differences and special educational needs to parameters of a formal model

Parameters of a formal working-memory model were estimated for verbal and spatial memory updating of children. The model proposes interference though feature overwriting and through confusion of whole elements as the primary cause of working-memory capacity limits. We tested 2 age groups each containing 1 group of normal intelligence and 1 deficit group. For young children the deficit was developmental dyslexia; for older children it was a general learning difficulty. The interference model predicts less interference through overwriting but more through confusion of whole elements for the dyslexic children than for their age-matched controls. Older children exhibited less interference through confusion of whole elements and a higher processing rate than young children, but general learning difficulty was associated with slower processing than in the age-matched control group. Furthermore, the difference between verbal and spatial updating mapped onto several meaningful dissociations of model parameters.     

Washing away your (good or bad) luck: physical cleansing affects risk-taking behavior

Many superstitious practices entail the belief that good or bad luck can be "washed away." Consistent with this belief, participants who recalled (Experiment 1) or experienced (Experiment 2) an episode of bad luck were more willing to take risk after having as opposed to not having washed their hands, whereas participants who recalled or experienced an episode of good luck were less willing to take risk after having as opposed to not having washed their hands. Thus, the psychological effects of physical cleansings extend beyond the domain of moral judgment and are independent of people's motivation: incidental washing not only removes undesirable traces of the past (such as bad luck) but also desirable ones (such as good luck), which people would rather preserve.     

Today's misery and yesterday's happiness: Differential effects of current life-events on perceptions of past wellbeing

Negative events – such as romantic disappointment, social rejection or academic failure – influence how we feel and what we think. Either component can influence evaluations of our past life, but in opposite ways: when sad feelings serve as a source of information, they give rise to negative evaluations; when current events serve as a standard of comparison, they give rise to positive evaluations. Because comparison requires applicability of the standard, its benefits should be limited to the domain of the event. Consistent with this rationale, three experiments showed a robust paradoxical effect: people who experienced romantic disappointment (Experiment 1), social exclusion (Experiment 2) or academic failure (Experiment 3) were more satisfied with their past romantic, social, or academic life, but less satisfied with all other domains of their past. The negative influence in unrelated domains was mediated by mood, whereas the positive influence in the event domain was not. Thus, last year's social life looks good compared to today's social rejection, but all other aspects of last year's life suffer.     

Rescue of synaptic plasticity and spatial learning deficits in the hippocampus of Homer1 knockout mice by recombinant Adeno-associated viral gene delivery of Homer1c

Homer1 belongs to a family of scaffolding proteins that interact with various post-synaptic density proteins including group I metabotropic glutamate receptors (mGluR1/5). Previous research in our laboratory implicates the Homer1c isoform in spatial learning. Homer1 knockout mice (H1-KO) display cognitive impairments, but their synaptic plasticity properties have not been described. Here, we investigated the role of Homer1 in long-term potentiation (LTP) in the hippocampal CA1 region of H1-KO mice in vitro. We found that late-phase LTP elicited by high frequency stimulation (HFS) was impaired, and that the induction and maintenance of theta burst stimulation (TBS) LTP were reduced in H1-KO. To test the hypothesis that Homer1c was sufficient to rescue these LTP deficits, we delivered Homer1c to the hippocampus of H1-KO using recombinant adeno-associated virus (rAAV). We found that rAAV-Homer1c rescued HFS and TBS-LTP in H1-KO animals. Next, we tested whether the LTP rescue by Homer1c was occurring via mGluR1/5. A selective mGluR5 antagonist, but not an mGluR1 antagonist, blocked the Homer1c-induced recovery of late-LTP, suggesting that Homer1c mediates functional effects on plasticity via mGluR5. To investigate the role of Homer1c in spatial learning, we injected rAAV-Homer1c to the hippocampus of H1-KO. We found that rAAV-Homer1c significantly improved H1-KO performance in the Radial Arm Water Maze. These results point to a significant role for Homer1c in synaptic plasticity and learning.     

Numerical distance effects in visual search

We present three experiments in which observers searched for a target digit among distractor digits in displays in which the mean numerical target?Cdistractor distance was varied. Search speed and accuracy increased with numerical distance in both target-present and target-absent trials (Exp. 1A). In Experiment 1B, the target 5 was replaced with the letter S. The results suggest that the findings of Experiment 1A do not simply reflect the fact that digits that were numerically closer to the target coincidentally also shared more physical features with it. In Experiment 2, the numerical distance effect increased with set size in both target-present and target-absent trials. These findings are consistent with the view that increasing numerical target?Cdistractor distance affords faster nontarget rejection and target identification times. Recent neurobiological findings (e.g., Nieder, 2011) on the neuronal coding of numerosity have reported a width of tuning curves of numerosity-selective neurons that suggests graded, distance-dependent coactivation of the representations of adjacent numbers, which in visual search would make it harder to reject numerically closer distractors as nontargets.     

Eye movements and brain electric potentials during reading

The development of theories and computational models of reading requires an understanding of processing constraints, in particular of timelines related to word recognition and oculomotor control. Timelines of word recognition are usually determined with event-related potentials (ERPs) recorded under conditions of serial visual presentation (SVP) of words; timelines of oculomotor control are derived from parameters of eye movements (EMs) during natural reading. We describe two strategies to integrate these approaches. One is to collect ERPs and EMs in separate SVP and natural reading experiments for the same experimental material (but different subjects). The other strategy is to co-register EMs and ERPs during natural reading from the same subjects. Both strategies yield data that allow us to determine how lexical properties influence ERPs (e.g., the N400 component) and EMs (e.g., fixation durations) across neighboring words. We review our recent research on the effects of frequency and predictability of words on both EM and ERP measures with reference to current models of eye-movement control during reading. Results are in support of the proposition that lexical access is distributed across several fixations and across brain-electric potentials measured on neighboring words.     

Quo Vadis,Dottore? Religious,Philosophical and Medical Perspectives on the Quest for Immortality

Journal of Religion and Health - In the daily practice of medicine, health care providers oftentimes confront the dilemma of offering ‘maximum care’ based on available technologies and...     

Novelty as Opportunity and Risk: A Situated Cognition Analysis of Psychological Control and Novelty Seeking

Novel products present unknown opportunities as well as unknown risks. Past research suggested that low psychological control highlights risks and reduces the adoption of novel products. Consistent with a situated cognition perspective, we show that this depends on the specifics of low control. Across five studies, novelty seeking was lower after consumers thought about instances of low (vs. high) personal influence, but higher after consumers thought about instances of low (vs. high) predictability of the world. Thinking about a lack of personal influence increased the perceived importance of personal capability and in turn impaired the exploration of novel options, whereas thinking about an unpredictable world increased the perceived importance of preparedness for an unknown future and in turn the exploration of novel options. Throughout, perceiving low personal influence benefited familiar products, whereas seeing the world as unpredictable benefited novel products. This highlights that understanding consumers' responses to a lack of control requires joint consideration of the specifics of threat and task, consistent with situated cognition principles.