Amnesics Have a Disproportionately Severe Memopry Deficit for Interactive Context

Two experiments were used to compare the recognition memory of amnesic and normal subjects for intentionally encoded words (targets) and for incidentally encoded words that were meaningfully related to the targets and presented at the same time (interactive context). In both experiments the target recognition of the two groups was matched at a high level by presenting the amnesics with much shorter lists of words to remember. Experiment 1 compared 20 amnesics and their matched controls and showed that whereas the amnesics' recognition of the target words did not benefit significantly when they were presented together with their interactive context words (relative to their recognition when the target words were presented alone), that of the controls did. Experiment 2 compared 14 amnesics and their matched controls and showed that when patients and their controls were matched on their target word recognition in isolation, then the patients still showed worse recognition for the interactive context words. These effects were not found only in Korsakoff patients, and their size did not correlate with behavioural measures of frontal-lobe damage. It is concluded that amnesics may be more impaired at recognizing incidentally encoded interactive context than they are at recognizing target material, and this deficit may be an essential feature of the syndrome.     

Substance use risk across three generations: the roles of parent discipline practices and inhibitory control.

This study used 3 generations and 21 years of prospective data to test models of intergenerational transmission of substance use and substance use risk. Thus, the study extends prior studies in the field that have focused predominantly on substance abuse. The association between the grandparental generation's (G1 mother and father) and the parental generation's (G2 father) alcohol use and illicit drug use was hypothesized to be mediated by G2's poor inhibitory control. Additionally, G1's poor discipline of G2 was hypothesized to be directly associated with G2's substance use as well as to partially mediate the association between G1's substance use and G2's inhibitory control. In turn, G2's substance use in late adolescence was expected to be associated with its offspring's (G3) poor inhibitory control at age 3 years. Findings partially supported the predictions and varied by substance. For alcohol use, only cross-generational associations in use were found. For illicit drugs, both poor inhibitory control and poor discipline played some mediational role in cross-generational use.     

Cumulative Effects of Prenatal Substance Exposure and Early Adversity on Foster Children's HPA Axis Reactivity During a Psychosocial Stressor

Dysregulated hypothalamic-pituitary-adrenocortical (HPA) axis stress response has been reported among individuals with prenatal substance exposure and those with early adversity. However, few researchers have examined the combined effects of these risk factors. Patterns of HPA reactivity among maltreated foster children with and without prenatal substance exposure (N = 53; ages 9-12 years) were examined using the Trier Social Stress Test for Children. Area under the curve with respect to increase (AUC(I)) analyses revealed that prenatal substance exposure or physical abuse significantly increased the likelihood of a negative AUC(I) (i.e., little or no HPA reactivity). Among children with prenatal substance exposure and physical abuse, 85% exhibited a negative AUC(I). The results underscore the importance of addressing this combined risk.     

Irrational action and irrational belief

Many philosophers agree with Socrates that it is not possible to perform an akratic action consciously and freely. They take this view because they assimilate the internal irrationality of such a performance to the internal irrationality of drawing a theoretical conclusion which contadicts one's premisses. This article develops some arguments against that assimilation. The extreme cost of theoretical self-contradiction is forming the belief both that something is so and that it is not so. This is impossible for anyone who understands what he is doing, and the impossibility can be explained: nothing could conceivably make such a conjunction of beliefs true. But the conjunction of a value-judgement judgment and an action that gets against it is different. Although it too is internally irrational, there is no property like truth which the value-judgement and his action ought both to possess, but cannot both possess. This article proposes a different model for akratic action, which might serve as a basis for disagreement with Socrates' view of it.     

Effects of motor intention on the perception of somatosensory events: a behavioural and functional magnetic resonance imaging study

The intention to execute a movement can modulate our perception of sensory events, and this modulation is observed ahead of both ocular and upper limb movements. However, theoretical accounts of these effects, and also the empirical data, are often contradictory. Accounts of "active touch", and the premotor theory of attention, have emphasized how movement intention leads to enhanced perceptual processing at the target of a movement, or on the to-be-moved effector. By contrast, recent theories of motor control emphasize how internal "forward" model (FM) estimates may be used to cancel or attenuate sensory signals that arise as a result of self-generated movements. We used behavioural and functional brain imaging (functional magnetic resonance imaging, fMRI) to investigate how perception of a somatosensory stimulus differed according to whether it was delivered to a hand that was about to execute a reaching movement or the alternative, nonmoving, hand. The results of our study demonstrate that a somatosensory stimulus delivered to a hand that is being prepared for movement is perceived to have occurred later than when that same stimulus is delivered to a nonmoving hand. This result indicates that it takes longer for a tactile stimulus to be detected when it is delivered to a moving limb and may correspond to a change in perceptual threshold. Our behavioural results are paralleled by the results of our fMRI study that demonstrated that there were significantly reduced blood-oxygen-level-dependent (BOLD) responses within the parietal operculum and insula following somatosensory stimulation of the hand being prepared for movement, compared to when an identical stimulus was delivered to a nonmoving hand. These findings are consistent with the prediction of FM accounts of motor control that postulate that central sensory suppression of somatosensation accompanies self-generated limb movements, and with previous reports indicating that effects of sensory suppression are observed in higher order somatosensory regions.     

School readiness in children living in non-parental care: Impacts of Head Start

The current study examines the effects of Head Start on the development of school readiness outcomes for children living in non-parental care. Data were obtained from the Head Start Impact Study, a randomized controlled trial of Head Start conducted with a nationally representative sample of Head Start programs and families. The sample included 253 children living in non-parental care (defined as a primary caregiver who self-identified as someone other than a biological, adoptive, or step-parent), who experienced elevated rates of child and family risk factors. Results revealed modest direct short-term and indirect longer-term impacts of Head Start on school readiness outcomes (increased pre-academic skills, more positive teacher–child relationships, and reductions in behavior problems) for children living in non-parental care. Limitations of this study and directions for future research are discussed.