Fetal programming effects of testosterone on the reward system and behavioral approach tendencies in humans.

Background: Sex differences are present in many neuropsychiatric conditions that affect emotion and approach-avoidance behavior. One potential mechanism underlying such observations is testosterone in early development. Although much is known about the effects of testosterone in adolescence and adulthood, little is known in humans about how testosterone in fetal development influences later neural sensitivity to valenced facial cues and approach-avoidance behavioral tendencies.

Fetal testosterone influences sexually dimorphic gray matter in the human brain.

In nonhuman species, testosterone is known to have permanent organizing effects early in life that predict later expression of sex differences in brain and behavior. However, in humans, it is still unknown whether such mechanisms have organizing effects on neural sexual dimorphism. In human males, we show that variation in fetal testosterone (FT) predicts later local gray matter volume of specific brain regions in a direction that is congruent with sexual dimorphism observed in a large independent sample of age-matched males and females from the NIH Pediatric MRI Data Repository.

Effects of fetal testosterone on visuospatial ability.

This study investigated whether fetal testosterone (FT) measured from second trimester amniotic fluid was related to specific aspects of visuospatial ability, in children aged 7-10 years (35 boys, 29 girls). A series of tasks were used: the children's Embedded Figures Test (EFT) (a test of attention to detail), a ball targeting task (measuring hand-eye coordination), and a computerized mental rotation task (measuring rotational ability). FT was a significant predictor for EFT scores in both boys and girls, with boys also showing a clear advantage for this task.

Why are autism spectrum conditions more prevalent in males?

Autism Spectrum Conditions (ASC) are much more common in males, a bias that may offer clues to the etiology of this condition. Although the cause of this bias remains a mystery, we argue that it occurs because ASC is an extreme manifestation of the male brain. The extreme male brain (EMB) theory, first proposed in 1997, is an extension of the Empathizing-Systemizing (E-S) theory of typical sex differences that proposes that females on average have a stronger drive to empathize while males on average have a stronger drive to systemize.

Can emotion recognition be taught to children with autism spectrum conditions?

Children with autism spectrum conditions (ASC) have major difficulties in recognizing and responding to emotional and mental states in others' facial expressions. Such difficulties in empathy underlie their social-communication difficulties that form a core of the diagnosis. In this paper we ask whether aspects of empathy can be taught to young children with ASC.

Organizational effects of fetal testosterone on human corpus callosum size and asymmetry.

Previous theory and research in animals has identified the critical role that fetal testosterone (FT) plays in organizing sexually dimorphic brain development. However, to date there are no studies in humans directly testing the organizational effects of FT on structural brain development. In the current study we investigated the effects of FT on corpus callosum size and asymmetry.

Enhancing emotion recognition in children with autism spectrum conditions: an intervention using animated vehicles with real emotional faces.

This study evaluated The Transporters, an animated series designed to enhance emotion comprehension in children with autism spectrum conditions (ASC). n = 20 children with ASC (aged 4-7) watched The Transporters everyday for 4 weeks. Participants were tested before and after intervention on emotional vocabulary and emotion recognition at three levels of generalization.

Talent in autism: hyper-systemizing, hyper-attention to detail and sensory hypersensitivity.

We argue that hyper-systemizing predisposes individuals to show talent, and review evidence that hyper-systemizing is part of the cognitive style of people with autism spectrum conditions (ASC). We then clarify the hyper-systemizing theory, contrasting it to the weak central coherence (WCC) and executive dysfunction (ED) theories. The ED theory has difficulty explaining the existence of talent in ASC.

IQ, fetal testosterone and individual variability in children's functional lateralization.

Previous event-related potential (ERP) studies have revealed that faces and words show a robust difference in the lateralization of their N170. The present study investigated the development of this differential lateralization in school-age boys. We assessed the potential role of fetal testosterone (FT) level as a factor biasing the prenatal development of lateralization, and the role of reading skill and Verbal IQ as factors predicting left lateralization for words in childhood.

Fetal testosterone predicts sexually differentiated childhood behavior in girls and in boys.

Mammals, including humans, show sex differences in juvenile play behavior. In rodents and nonhuman primates, these behavioral sex differences result, in part, from sex differences in androgens during early development. Girls exposed to high levels of androgen prenatally, because of the genetic disorder congenital adrenal hyperplasia, show increased male-typical play, suggesting similar hormonal influences on human development, at least in females.

Fetal testosterone and autistic traits: a response to three fascinating commentaries.

This article is an author response to three previous commentaries on 'Fetal testosterone and autistic traits' (Auyeung et al., 2009).

Eagle-eyed visual acuity: an experimental investigation of enhanced perception in autism.

Background: Anecdotal accounts of sensory hypersensitivity in individuals with autism spectrum conditions (ASC) have been noted since the first reports of the condition. Over time, empirical evidence has supported the notion that those with ASC have superior visual abilities compared with control subjects. However, it remains unclear whether these abilities are specifically the result of differences in sensory thresholds (low-level processing), rather than higher-level cognitive processes.

Fetal testosterone and autistic traits.

Studies of amniotic testosterone in humans suggest that fetal testosterone (fT) is related to specific (but not all) sexually dimorphic aspects of cognition and behaviour. It has also been suggested that autism may be an extreme manifestation of some male-typical traits, both in terms of cognition and neuroanatomy. In this paper, we examine the possibility of a link between autistic traits and fT levels measured in amniotic fluid during routine amniocentesis.