A model of pavlovian conditioning: Variations in representations of the unconditional stimulus

We present a model of Pavlovian excitatory conditioning in which associative strength and malleable central representations of unconditional stimuli determine the strength of conditional responding. Presentation of a conditioned stimulus acts through an experientially determined associative bond to activate a representation of the unconditional stimulus. The activation of the representation produces a conditioned response. A striking feature of the model is its ability to describe changes in conditioned response magnitude in terms of alterations of representations of the unconditional stimulus. Another is its acknowledgement of the capacity of associative bonds to survive behavioral extinction. The model describes much of the data reported from excitatory conditioning experiments and predicts counterintuitive phenomena. This work was supported by Natural Sciences and Engineering Research Council grant #U0262 awarded to the first author.     

The effects of experimentally induced stress on false recognition.

The fallibility of memory has become an issue of considerable practical and theoretical importance. Here we studied the impact of experimentally induced stress on the ability of human participants to accurately recognise words presented on a list. We found that stress selectively disrupted participants' ability to distinguish words that were presented for study from critical lure words that were semantically related, but not presented for study. This finding indicates that stress, possibly through its impact on the hippocampus and prefrontal cortex, can potentiate false memories.     

Negative intergroup contact makes group memberships salient: explaining why intergroup conflict endures

Drawing from the intergroup contact model and self-categorization theory, the authors advanced the novel hypothesis of a valence-salience effect, whereby negative contact causes higher category salience than positive contact. As predicted, in a laboratory experiment of interethnic contact, White Australians (N = 49) made more frequent and earlier reference to ethnicity when describing their ethnic contact partner if she had displayed negative (vs. positive, neutral) nonverbal behavior. In a two-wave experimental study of retrieved intergenerational contact, American young adults (N = 240) reported age to be more salient during negative (vs. positive) contact and negative contact predicted increased episodic and chronic category salience over time. Some evidence for the reverse salience-valence effect was also found. Because category salience facilitates contact generalization, these results suggest that intergroup contact is potentially biased toward worsening intergroup relations; further implications for theory and policy making are discussed.     

Does adolescent heavier alcohol use predict young adult aggression and delinquency? Parallel analyses from four Australasian cohort studies

While the association between heavy alcohol consumption and aggression has been well documented, the causal direction of this association, particularly at a population level, is disputed. A number of causal sequences have been proposed. First, that aggression leads to heavy alcohol use. Second, that heavy alcohol use leads to aggression. Third, that the association between alcohol use and aggression is due to confounding by (a) sociodemographic variables or (b) delinquency. We report here data from four Australasian prospective longitudinal studies of adolescents, to assess the temporal sequence of heavy drinking and aggression over the period from adolescence to young adulthood. The four cohort studies provide a total sample of 6,706 persons (Australian Temperament Project, n = 1701; Christchurch Health and Development Study, n = 931; Mater-University of Queensland Study of Pregnancy, n = 2437; Victorian Adolescent Health Cohort Study, n = 1637). We use multinomial logistic regression to determine whether early adolescent aggression predicts subsequent age of onset of heavy episodic drinking (HED), after adjustment for concurrent sociodemographic factors and delinquency. We then consider whether HED predicts subsequent aggression, after adjusting for past aggression, concurrent delinquency, and a range of confounders. There are broadly consistent findings across the four cohort studies. Early aggression strongly predicts subsequent HED. HED predicts later aggression after adjustment for prior aggression and other confounders. Policies that alter population levels of alcohol consumption are likely to impact on levels of aggression in societies where HED linked to aggression is more common.     

Inferential Transitions

This paper provides a naturalistic account of inference. We posit that the core of inference is constituted by bare inferential transitions (BITs), transitions between discursive mental representations guided by rules built into the architecture of cognitive systems. In further developing the concept of BITs, we provide an account of what Boghossian [2014] calls ‘taking’—that is, the appreciation of the rule that guides an inferential transition. We argue that BITs are sufficient for implicit taking, and then, to analyse explicit taking, we posit rich inferential transitions (RITs), which are transitions that the subject is disposed to endorse.     

Fatigue following Paediatric Acquired Brain Injury and its Impact on Functional Outcomes: A Systematic Review

Fatigue is a commonly reported sequela following an acquired brain injury (ABI), and can have a negative impact on many areas of a child’s life. However, there is minimal research that focuses on fatigue specifically, and so factors such as its occurrence, duration, and impact on functioning remain uncertain. This systematic review aims to provide a comprehensive summary of the research to date, bringing together a number of studies with a focus on paediatric ABI and fatigue. Terms were searched in relevant databases (PsycInfo, Medline, CINAHL), and articles were included or excluded based on specified criteria. Of the 1177 papers identified in the original search, a total of 9 papers met inclusion criteria, and were categorised as traumatic brain injury (TBI; n?=?4), meningitis and meningococcal disease (n?=?2), brain tumours (n?=?2), and mixed ABI group (n?=?1). Key findings suggest that fatigue is a problem encountered by a significant proportion of patients in all the studies reviewed, and often occurred regardless of the cause; fatigue was also associated with poor academic achievement, limited physical activity, and social and emotional problems. Injuries of greater severity were associated with higher levels of fatigue and worse outcomes. Several management options were suggested, though their efficacy was not reported. Future research is required with a suggested focus on using multiple time points to better understand the trajectories of fatigue following childhood ABI, and to build an evidence base to determine which management options are most suitable.     

A critical commentary on follow-up studies and “desistance” theories about transgender and gender-nonconforming children

ABSTRACT

Background: It has been widely suggested that over 80% of transgender children will come to identify as cisgender (i.e., desist) as they mature, with the assumption that for this 80%, the trans identity was a temporary “phase.” This statistic is used as the scientific rationale for discouraging social transition for pre-pubertal children. This article is a critical commentary on the limitations of this research and a caution against using these studies to develop care recommendations for gender-nonconforming children.

Methods: A critical review methodology is employed to systematically interpret four frequently-cited studies that sought to document identity outcomes for gender-nonconforming children (often referred to as “desistance” research).

Results: Methodological, theoretical, ethical, and interpretive concerns regarding four “desistance” studies are presented. The authors clarify the historical and clinical contexts within which these studies were conducted to deconstruct assumptions in interpretations of the results. The discussion makes distinctions between the specific evidence provided by these studies versus the assumptions that have shaped recommendations for care. The affirmative model is presented as a way to move away from the question of, “How should children's gender identities develop over time?” toward a more useful question: “How should children best be supported as their gender identity develops?”

Conclusion: The tethering of childhood gender diversity to the framework of “desistance” or “persistence” has stifled advancements in our understanding of children's gender in all its complexity. These follow-up studies fall short in helping us understand what children need. As work begins on the 8th version of the Standards of Care by the World Professional Association for Transgender Health, we call for a more inclusive conceptual framework that takes children's voices seriously. Listening to children's experiences will enable a more comprehensive understanding of the needs of gender-nonconforming children and provide guidance to scientific and lay communities.     

Pathways maintaining physical health problems from childhood to young adulthood: The role of stress and mood

Objective: Poor physical health in childhood is associated with a variety of negative health-related outcomes in adulthood. Psychosocial pathways contributing to the maintenance of physical health problems from childhood to young adulthood remain largely unexamined, despite evidence that factors such as negative mood and stress impact physical health.

Design: The current study tested the direct and indirect effects of ongoing health, chronic stress, health-related chronic stress, and depressive symptoms at age 20 on the link between health problems in childhood and young adulthood (age 21) in a longitudinal sample (n = 384).

Main Outcome Measures: The hypotheses were tested using a multiple mediation path analysis framework; the primary outcome measure was a composite index of health status markers in young adulthood.

Results: The proposed model provided an adequate fit for the data, with significant total indirect effects of the four mediators and significant specific indirect effects of health-related chronic stress and depressive symptoms in maintaining health problems from childhood into young adulthood.

Conclusions: Health problems are maintained from early childhood into young adulthood in part through psychosocial mechanisms. Depressive symptoms and health-related chronic stress have significant, unique effects on the relationship between health problems in early childhood and young adulthood.