Emergent conditional discrimination in children: Matching to compound stimuli

This study reports two experiments that first taught preschool children identity-matching to compound sample and compound comparison stimuli. A compound stimulus consisted of a colour and a form superimposed on one another. Test sessions assessed whether children related the form and colour elements of a particular compound stimulus. The test for this was matching to sample in which an arbitrary conditional discrimination was required. A majority of the children selected the correct colour comparison in the presence of each form sample. The children also showed the reverse sample-comparison relations: they matched form comparisons to the corresponding colour samples, respectively. In the context of these arbitrary relations, new colours were paired with the form elements of the samples (Experiment 1), and new form elements were paired with the colour elements of the comparisons (Experiment 2). Subsequent tests assessed whether the new stimulus elements had control over responding when presented as single samples or comparisons. Test results showed that most subjects were able to relate the new stimulus elements to the corresponding colour and form elements, respectively. The study demonstrated that matching to compound stimuli in training and testing conditionsMaygenerate conditional relations between the individual stimulus elements.     

Effects of cohabitation with another female on aggressive behaviour in pregnant mice

Pregnant, nonpregnant (but mated) and virgin females were individually housed or lived with a pregnant or nonpregnant cagemate. They were subjected to a series of successive daily encounters with a male intruder, the cagemate being excluded. The most aggressive subjects were pregnant females living with a pregnant cagemate. Isolated pregnant females were as aggressive as pregnant females with a nonpregnant cagemate. Nonpregnant and virgin females were the least aggressive. Nevertheless nonpregnant subjects living with a pregnant cagemate generated higher aggressive scores than nonpregnant females living alone. The way in which a pregnant cagemate influences the aggressive behaviour of another pregnant or nonpregnant female is discussed.     

Perspectives on Factors Impacting Youth’s Reentry into Residential Care: An Exploratory Study

Multiple placements in therapeutic residential care is expensive, and is associated with poor outcomes; thus, identifying barriers to successful reintegration into the home and community school settings is essential for developing appropriate post-discharge supports, and reducing societal costs. Participants were seven youth (four female; three White/Caucasian, one Black/African American, one Hispanic/Latino, two multi-racial) recently readmitted to a therapeutic residential care program and five of their primary caregivers (four female; four White/Caucasian, one Black/African American). Through semi-structured interviews with caregivers and youth, this exploratory study investigated (1) the perceptions of preparedness for the youth’s successful transition from therapeutic residential care to the home setting, (2) the post-discharge factors that contributed to the youth’s return to care, and (3) the lessons learned about the youth’s transition from therapeutic residential care to home. The results of this exploratory, qualitative study revealed rich information about youth and their caregivers’ perspectives about their experiences prior to returning to care, such as the importance of healthy relationships (family and peers), transition planning, and post-discharge supports at the individual, family, and school levels.     

Communication of Genetic Risk Information to Daughters in Families with Fragile X Syndrome: The Parent’s Perspective

Parental approaches to communicating information about genetic disorders to their children may be an important determinant in how the children manage stress as well as their adjustment and adaptation to that information. We explored communication patterns through structured interviews with 46 parents of daughters who learned about their genetic risk status as minors. Three different levels of knowledge about fragile X syndrome were explored: 1) informing that it has been diagnosed in the family and is an inherited disorder, 2) informing about the possibility of a daughter being a carrier, and 3) if testing had been done, informing the daughter of her actual carrier status. Additionally, parental perceptions of their daughter’s understanding of the information were explored along with frequency of discussions. We found that communication about genetic risk was initiated by the parents. Five disclosure patterns were identified with variations in style, content, and frequency of communication related to the information that was being disclosed. Aspects of resilient communication were present for all levels of disclosure; however, as the information became more personally relevant for the daughter such as disclosure about the possibility of “being a carrier” for fragile X syndrome and there was uncertainty regarding potential outcomes, the conversations included fewer resilient characteristics. Uncertainty about what and how to present information may negatively affect a parent’s ability to include elements of resilient communication when disclosing genetic risk information.     

Working memory deficits, increased anxiety-like traits, and seizure susceptibility in BDNF overexpressing mice

BDNF regulates components of cognitive processes and has been implicated in psychiatric disorders. Here we report that genetic overexpression of the BDNF mature isoform (BDNF-tg) in female mice impaired working memory functions while sparing components of fear conditioning. BDNF-tg mice also displayed reduced breeding efficiency, higher anxiety-like scores, high self-grooming, impaired prepulse inhibition, and higher susceptibility to seizures when placed in a new empty cage, as compared with wild-type (WT) littermate controls. Control measures of general health, locomotor activity, motor coordination, depression-related behaviors, and sociability did not differ between genotypes. The present findings, indicating detrimental effects of life-long increased BDNF in mice, may inform human studies evaluating the role of BDNF functional genetic variations on cognitive abilities and vulnerability to psychiatric disorders.     

Rapid reacquisition of native phoneme contrasts after disuse: you do not always lose what you do not use

Infants attune to their birth language during the second half of infancy. However, internationally adopted children are often uniquely required to attune to their birth language, and then reattune to their adoptive language. Children who were adopted from India into America at ages 6-60 months (N = 8) and had minimal further exposure to their birth languages were compared to age-matched American non-adopted controls. Without training, neither group could discriminate a phonemic contrast that occurs in their birth language but not in English. However, after training on the contrast, the adopted group (N = 8) improved significantly and discriminated the contrast more accurately than their non-adopted peers. While English had explicitly replaced the birth language of the adopted sample, traces of early exposure conferred privileges on subsequent learning. These findings are consistent with behavioral and neurophysiological data from animals that have identified some of the mechanisms underlying such a 'retention without further use' phenomenon.     

Expectation and temperament moderate amygdala and dorsal anterior cingulate cortex responses to fear faces

A chronic tendency to avoid novelty is often the result of a temperamental bias called inhibited temperament, and is associated with increased risk for anxiety disorders. Neuroimaging studies have demonstrated that an inhibited temperament is associated with increased amygdalar blood-oxygenation-level-dependent (BOLD) response to unfamiliar faces that were not expected; however, the effects of variations in expectancy remain unknown. Using functional magnetic resonance imaging (fMRI), we studied BOLD response to infrequently encountered fear faces that were either expected or not expected in 42 adults with an inhibited or an uninhibited temperament. Individuals with an inhibited temperament had greater amygdala, but less dorsal anterior cingulate cortex (dACC), BOLD response when the stimuli were expected. In contrast, those with an uninhibited temperament had a smaller amygdala but larger dorsal anterior cingulate cortex BOLD response when expecting to see fear faces. These findings demonstrate temperament differences in expectancy effects and provide preliminary evidence for the dACC as a neural substrate mediating differences in inhibited temperament. Enhanced amygdala sensitivity coupled with weak inhibitory control from the dACC may form a neural circuit mediating behaviors characteristic of inhibited temperament and risk for anxiety disorders.     

Defensive and offensive behaviours in a Kleefstra syndrome mouse model

Animal Cognition - Kleefstra syndrome in humans is characterized by a general delay in development, intellectual disability and autistic features. The mouse model of this disease (Ehmt1±)...     

Reliability and construct validity of the Dutch psychopathy checklist: youth version: findings from a sample of male adolescents in a juvenile justice treatment institution

The present study examines the reliability and construct validity of the Dutch version of the Psychopathy Check List: Youth Version (PCL:YV) in a sample of male adolescents admitted to a secure juvenile justice treatment institution (N = 98). Hare's four-factor model is used to examine reliability and validity of the separate dimensions of psychopathy. Interrater reliabilities are good to excellent for the PCL:YV total score and most factor scores, except for the affective factor. Several suggestions are offered for optimizing reliability of this factor. Finally, meaningful associations between PCL:YV scores and scores on the Minnesota Multiphasic Personality Inventory-Adolescent and the Interpersonal Checklist-Revised support the construct validity of the PCL:YV total score as well as the four factors in the Dutch context.