Testing different types of genotype-environment correlation: an extended children-of-twins model

This study presents an extended children-of-twins model, which allowed the authors to test the direction of the association between parenting and child adjustment. Three mechanisms were examined: direct phenotypic influence of parenting on child behavior (controlling for both parental and child genotype), passive genotype-environment correlation, and evocative genotype-environment correlation. This model was tested with Monte Carlo simulations. The authors generated data sets consisting of 1,000 twin parent pairs together with their children and 1,000 twin children pairs together with their parents. These simulated data sets were then used to estimate the model, and the procedure was repeated 1,000 times. The simulation results showed that this model recovered the true values of parameters with high precision. The model was also applied to an observed data set to analyze, as a first example, the association between maternal emotional overinvolvement and child internalizing problems. The results showed that this association was best explained by evocative genotype-environment correlation.     

Maternal provision of structure in a deliberate memory task in relation to their preschool children's recall

Strategic remembering emerges gradually during the preschool years. Socialization practices, specifically mother–child social interactions, might provide the foundation for the development of skills necessary for effective organization of information in memory. In the current study, 48 mothers and their 40-month-olds were engaged in the process of remembering (i.e., study and recall) categorically related picture stimuli in a laboratory context. Children’s recall was reliably predicted by the way in which mothers structured both the study and recall periods of the deliberate memory task. Specifically, maternal verbal and physical behaviors that focused on organization of items, such as sorting items into distinct groups and providing the name of a category, were most beneficial in supporting children’s memory. Moreover, some mothers employed a number of different mnemonic techniques that emphasized categorical connections among items, suggesting systematic approaches in the manner in which mothers help children to learn effective ways of remembering.     

Cognitive Neuropsychology of HIV-Associated Neurocognitive Disorders

Advances in the treatment of the human immunodeficiency virus (HIV) have dramatically improved survival rates over the past 10 years, but HIV-associated neurocognitive disorders (HAND) remain highly prevalent and continue to represent a significant public health problem. This review provides an update on the nature, extent, and diagnosis of HAND. Particular emphasis is placed on critically evaluating research within the realm of cognitive neuropsychology that aims to elucidate the component processes of HAND across the domains of executive functions, motor skills, speeded information processing, episodic memory, attention/working memory, language, and visuoperception. In addition to clarifying the cognitive mechanisms of HAND (e.g., impaired cognitive control), the cognitive neuropsychology approach may enhance the ecological validity of neuroAIDS research and inform the development of much needed novel, targeted cognitive and behavioral therapies. The research described was supported by MH73419 and MH62512 from the National Institutes of Health. The views expressed in this article are those of the authors and do not reflect the official policy or position of the Department of the Navy, Department of Defense, nor the United States Government.     

Large sex difference in adolescents on a timed line judgment task: attentional contributors and task relationship to mathematics

Visuospatial performance, assessed with the new, group-administered Judgment of Line Angle and Position test (JLAP-13), varied with sex and mathematical competence in a group of adolescents. The JLAP-13, a low-level perceptual task, was modeled after a neuropsychological task dependent upon functioning of the posterior region of the right hemisphere [Benton et al, 1994 Contributions to Neuropsychological Assessment: A Clinical Manual (New York: Oxford University Press)]. High-school boys (N = 52) performed better than girls (N = 62), with a large effect for sex (d = 1.11). Performance increased with mathematical competence, but the sex difference did not vary significantly across different levels of mathematics coursework. On the basis of earlier work, it was predicted that male, but not female, performance in line judgment would decline with disruptions to task geometry (page frame), and that the sex difference would disappear with disruptions to geometry. These predictions were supported by a number of univariate and sex-specific analyses, although an omnibus repeated-measures analysis did not detect the predicted interaction, most likely owing to limitations in power. Thus, there is partial support for the notion that attentional predispositions or strategies may contribute to visuospatial sex differences, with males more likely than females to attend to, and rely upon, internal or external representations of task geometry. Additional support for this hypothesis may require development of new measures or experimental manipulations with more powerful geometrical disruptions.     

Conditioned fear extinction and reinstatement in a human fear-potentiated startle paradigm

The purpose of this study was to analyze fear extinction and reinstatement in humans using fear-potentiated startle. Participants were fear conditioned using a simple discrimination procedure with colored lights as the conditioned stimuli (CSs) and an airblast to the throat as the unconditioned stimulus (US). Participants were extinguished 24 h after fear conditioning. Upon presentation of unsignaled USs after extinction, participants displayed significant fear reinstatement. In summary, these procedures produced robust fear-potentiated startle, significant CS+/CS- discrimination, within-session extinction, and significant reinstatement. This is the first demonstration of fear extinction and reinstatement in humans using startle measures.     

Skill training,retention, and transfer: The effects of a concurrent secondary task

In two experiments, we examined training, retention, and transfer of a duration production skill in a prospective paradigm. Participants were trained with feedback and then were either tested immediately for transfer without feedback or retrained with feedback 1 week later. There were three training and retraining conditions, two involving secondary tasks. Retention of the duration production skill was perfect across the 1-week delay when the secondary task condition was unchanged, but there was no skill transfer when that condition was changed. These findings demonstrate specificity of training, with the assumption that the cognitive operations learned during duration production training incorporate requirements of the secondary task. More generally, this study challenges the current practice in which training conditions often do not match eventual testing conditions.     

Interoceptive fear conditioning and panic disorder: the role of conditioned stimulus-unconditioned stimulus predictability

Interoceptive fear conditioning is at the core of contemporary behavioral accounts of panic disorder. Yet, to date only one study has attempted to evaluate interoceptive fear conditioning in humans (see Acheson, Forsyth, Prenoveau, & Bouton, 2007). That study used brief (physiologically inert) and longer-duration (panicogenic) inhalations of 20% CO(2)-enriched air as an interoceptive conditioned (CS) and unconditioned (US) stimulus and evaluated fear learning in three conditions: CS only, CS-US paired, and CS-US unpaired. Results showed fear conditioning in the paired condition, and fearful responding and resistance to extinction in an unpaired condition. The authors speculated that such effects may be due to difficulty discriminating between the CS and the US. The aims of the present study are to (a) replicate and expand this line of work using an improved methodology, and (b) clarify the role of CS-US discrimination difficulties in either potentiating or depotentiating fear learning. Healthy participants (N=104) were randomly assigned to one of four conditions: (a) CS only, (b) contingent CS-US pairings, (c) unpaired CS and US presentations, or (d) an unpaired "discrimination" contingency, which included an exteroceptive discrimination cue concurrently with CS onset. Electrodermal and self-report ratings served as indices of conditioned responding. Consistent with expectation, the paired contingency and unpaired contingencies yielded elevated fearful responding to the CS alone. Moreover, adding a discrimination cue to the unpaired contingency effectively attenuated fearful responding. Overall, findings are consistent with modern learning theory accounts of panic and highlight the role of interoceptive conditioning and unpredictability in the etiology of panic disorder.