Translational Rodent Models of Korsakoff Syndrome Reveal the Critical Neuroanatomical Substrates of Memory Dysfunction and Recovery

Investigation of the amnesic disorder Korsakoff Syndrome (KS) has been vital in elucidating the critical brain regions involved in learning and memory. Although the thalamus and mammillary bodies are the primary sites of neuropathology in KS, functional deactivation of the hippocampus and certain cortical regions also contributes to the chronic cognitive dysfunction reported in KS. The rodent pyrithiamine-induced thiamine deficiency (PTD) model has been used to study the extent of hippocampal and cortical neuroadaptations in KS. In the PTD model, the hippocampus, frontal and retrosplenial cortical regions display loss of cholinergic innervation, decreases in behaviorally stimulated acetylcholine release and reductions in neurotrophins. While PTD treatment results in significant impairment in measures of spatial learning and memory, other cognitive processes are left intact and may be recruited to improve cognitive outcome. In addition, behavioral recovery can be stimulated in the PTD model by increasing acetylcholine levels in the medial septum, hippocampus and frontal cortex, but not in the retrosplenial cortex. These data indicate that although the hippocampus and frontal cortex are involved in the pathogenesis of KS, these regions retain neuroplasticity and may be critical targets for improving cognitive outcome in KS.     

Task practice differentially modulates task-switching performance across the adult lifespan

Cued-trials task-switching paradigms have been used extensively to examine ageing-related changes in cognitive control. Many studies report an increase in mixing cost (i.e., cost of repeating the same task in a single-task vs. a mixed-task block) and a less reliable increase in switch cost (i.e., cost of switching vs. repeating tasks in a mixed-task block) in old as compared to young adults. However, there is substantial variability between studies in the emergence and size of age effects on mixing and/or switch cost. In this study, we examined variation in mixing cost and switch cost as a function of task practice and preparation interval across the adult lifespan (18-79 years) using a paradigm that promotes advance preparation and reduces cue encoding differences between switch and repeat trials. Both preparation interval and task practice modulated mixing cost and switch cost-but task practice mediated the effects of preparation interval and age differentially for mixing cost and switch cost. Mixing cost was consistently larger in older participants, reduced with preparation and varied little with task practice. In contrast, the effect of preparation interval on switch cost varied with task practice. Reduction in switch cost with preparation interval emerged in younger participants by the second practice session and even later in older participants. When fully practiced, older participants showed greater mixing cost but less switch cost than younger participants. Age effects on both mixing cost and switch cost were mediated by changes in processing of repeat trials, indicative of reduced differentiation between switch and repeat trials in mixed-task blocks. This is consistent with reduced cognitive flexibility with increasing age.     

Affective state influences perception by affecting decision parameters underlying bias and sensitivity

Studies of the effect of affect on perception often show consistent directional effects of a person's affective state on perception. Unpleasant emotions have been associated with a "locally focused" style of stimulus evaluation, and positive emotions with a "globally focused" style. Typically, however, studies of affect and perception have not been conducted under the conditions of perceptual uncertainty and behavioral risk inherent to perceptual judgments outside the laboratory. We investigated the influence of perceivers' experienced affect (valence and arousal) on the utility of social threat perception by combining signal detection theory and behavioral economics. We compared 3 perceptual decision environments that systematically differed with respect to factors that underlie uncertainty and risk: the base rate of threat, the costs of incorrect identification threat, and the perceptual similarity of threats and nonthreats. We found that no single affective state yielded the best performance on the threat perception task across the 3 environments. Unpleasant valence promoted calibration of response bias to base rate and costs, high arousal promoted calibration of perceptual sensitivity to perceptual similarity, and low arousal was associated with an optimal adjustment of bias to sensitivity. However, the strength of these associations was conditional upon the difficulty of attaining optimal bias and high sensitivity, such that the effect of the perceiver's affective state on perception differed with the cause and/or level of uncertainty and risk.     

Face-to-face interference in typical and atypical development

Visual communication cues facilitate interpersonal communication. It is important that we look at faces to retrieve and subsequently process such cues. It is also important that we sometimes look away from faces as they increase cognitive load that may interfere with online processing. Indeed, when typically developing individuals hold face gaze it interferes with task completion. In this novel study we quantify face interference for the first time in Williams syndrome (WS) and Autism Spectrum Disorder (ASD). These disorders of development impact on cognition and social attention, but how do faces interfere with cognitive processing? Individuals developing typically as well as those with ASD (n = 19) and WS (n = 16) were recorded during a question and answer session that involved mathematics questions. In phase 1 gaze behaviour was not manipulated, but in phase 2 participants were required to maintain eye contact with the experimenter at all times. Looking at faces decreased task accuracy for individuals who were developing typically. Critically, the same pattern was seen in WS and ASD, whereby task performance decreased when participants were required to hold face gaze. The results show that looking at faces interferes with task performance in all groups. This finding requires the caveat that individuals with WS and ASD found it harder than individuals who were developing typically to maintain eye contact throughout the interaction. Individuals with ASD struggled to hold eye contact at all points of the interaction while those with WS found it especially difficult when thinking.     

Assessing Perceptions of Sexual Harassment Behaviors in a Manufacturing Environment

This pilot study, conducted in a manufacturing plant, investigated employee perceptions of the behaviors of supervisors and co-workers that constitute quid pro quo and hostile work environment sexual harassment. Responses indicated that the majority of employees can accurately identify behaviors that are frequently associated with quid pro quo harassment, but cannot identify behaviors that are used to establish evidence of a hostile work environment. Comparisons of employees' scores demonstrated that male workers, relative to female workers, were more frequently accurate in identifying behaviors of both supervisors and co-workers that constitute sexual harassment. Perceptions of harassment varied according to job classification. Women in white-collar jobs were significantly more knowledgeable about what behaviors constitute sexual harassment than women in blue-collar jobs.     

A Mixed Methods Study of the Stages of Implementation for an Evidence-Based Trauma Intervention in Schools

A mixed methods study was conducted to examine the implementation process of 26 urban school-based mental health clinics that took part in a training and implementation support program for an evidence-based school trauma intervention. Implementation process was observed using the Stages of Implementation Completion (SIC) measure. Qualitative interviews were conducted with clinic leaders in order to gain insight into clinic processes related to the SIC. Results showed that almost all of the clinics engaged in some activities related to pre-implementation (engagement, feasibility, and readiness), but only 31% of the sites formally started delivering the program to youth. Completing more pre-implementation activities, particularly those related to readiness, predicted program start-up. Qualitative analysis comparing those that implemented the program to those that did not revealed critical differences in decision-making processes, leadership strategies, and the presence of local champions for the program. This study documented the patterns of clinic behavior that occurs as part of large-scale training efforts, suggests some unique challenges that occur in schools, and highlights the importance of engaging in particular implementation activities (i.e., readiness planning, stakeholder consensus and planning meetings) as part of program start-up. Findings indicate that pre-implementation and readiness-related consultation should be employed as part of broad-scale implementation and training efforts.     

Gender-Typing of Children’s Toys: Causes,Consequences, and Correlates

Gender differences in children’s toy interests and play behaviors are large and may lead to gender differentiation of physical, cognitive, and social development among children. In this Special Issue, we gather together cutting-edge research on the factors that affect gender differences in children’s toy interests, how subtle gender-related messages affect children’s performance and behaviors, and how adults create these gender-related messages and affect children’s interests. We illustrate themes found in the current literature, but also comment on issues that need to be addressed by future research. We also identify points of intervention in which stereotypes about toys and gender differentiated play behaviors and toy interests can be reduced in an effort to promote greater diversity of children’s play.     

The relation between infants' activity with objects and attention to object appearance

The authors examined the relation between infants' motor skills and attention to objects features in events in which a hand acted on an object (e.g., squeezed it) that then produced a sound (e.g., squeaking). In this study, 6- to 7-month-old infants (N = 41) were habituated to a single event and then tested with changes in appearance and action. Infants robustly responded to changes in action, but as a group did not respond to changes in appearance. Moreover, more skilled activity with objects during naturalistic play was associated with longer looking in response to a change in appearance, but not to a change in action. Implications for the relation between perception and action in infancy are discussed. (     

The Role of Neuropsychological Assessment in the Functional Outcomes of Children with ADHD

The value of evidence-based services is now recognized both within clinical communities and by the public at large. Increasingly, neuropsychologists must justify the necessity of often costly and time-consuming neuropsychological assessments in the diagnosis and treatment of common childhood disorders, such as Attention-deficit/Hyperactivity Disorder (ADHD). Published medical guidelines and prominent researchers, however, have argued against the need for formal neuropsychological assessment of ADHD. The present review examines the literature on developmental outcomes in childhood ADHD, with emphasis on the utility of formal neuropsychological assessment among children diagnosed and treated in primary care settings. The review yields three central findings: 1) adherence to published diagnostic guidelines for ADHD is poor among pediatric and primary care physicians; 2) ADHD most often co-exists with other disorders, thus diagnoses made without formal psychometric assessment can be incomplete or incorrect, ultimately increasing treatment costs; and, 3) untreated children with ADHD, and those who have untreated comorbidities, are at greater risk for poor outcomes in social, academic, vocational, and practical settings. The available literature suggests that neuropsychological assessment provides information that can potentially reduce risks for poor outcomes and improve quality of life among children with ADHD. Controlled studies directly examining the impact of neuropsychological assessments in improving outcomes among children with ADHD are needed.     

Disorganized Attachment and Inhibitory Capacity: Predicting Externalizing Problem Behaviors

The aim of the present study was to investigate whether attachment insecurity, focusing on disorganized attachment, and the executive function (EF) component of inhibition, assessed at age 5, were longitudinally related to general externalizing problem behaviors as well as to specific symptoms of ADHD and Autism spectrum disorder (ASD), and callous-unemotional (CU) traits. General externalizing problem behaviors were also measured at age 5 to allow for a developmental analysis. Outcome variables were rated by parents and teachers. The sample consisted of 65 children with an oversampling of children with high levels of externalizing behaviors. Attachment was evaluated using a story stem attachment doll play procedure. Inhibition was measured using four different tasks. The results showed that both disorganized attachment and poor inhibition were longitudinally related to all outcome variables. Controlling for initial level of externalizing problem behavior, poor inhibition predicted ADHD symptoms and externalizing problem behaviors, independent of disorganized attachment, whereas for ASD symptoms no predictive relations remained. Disorganized attachment independently predicted CU traits.