Autism spectrum disorders are generally described as disorders of brain development that present early in life and whose phenomenology is a manifestation of the cumulative results of an atypical developmental trajectory. However, some children develop an autism-like condition after an extended period of typical development. The most extreme, late-onset cases of this regressive form of autism have been described by the diagnostic category Childhood Disintegrative Disorder (CDD).

Attention is a complex psychological construct that taps into multiple brain mechanisms, and it is thought that attentional abnormalities are common in children with autism spectrum disorders. However, not all aspects of attention are deficient in these children. Yuhong Jiang and her colleagues at the University of Minnesota investigated the integrity of one type of attention in autism: stimulus-driven attention that is guided by implicit (unconscious) learning.

During the first few years of life, children rapidly incorporate signals from their surrounding enviroment into what will become their behavioral, social and language repertoires. This experience-dependent sculpting of brain circuits occurs during distinct critical periods, and it is during these periods that symptoms of autism spectrum disorders become evident. Many of these symptoms indicate a disruption in sensory processing.

Vikaas Sohal and his colleagues set out to test the hypothesis that excessive entry of calcium into neurons within the medial prefrontal cortex (mPFC) impairs social behavior and contributes to additional aspects of autism. The researchers learned that the excessive entry of calcium does not affect all neurons in the mPFC equally. Rather, neurons in the mPFC can be divided into different subpopulations, and the excessive entry of calcium has a profound effect on one of these subpopulations.

Christian Hansel and his colleagues at the University of Chicago examined whether memory mechanisms in the cerebellar cortex are affected in autism. They found that motor coordination and learning are impaired in a mouse model of 15q duplication syndrome, an autism spectrum disorder involving duplication of the chromosomal region 15q11-13. This copy number variant occurs in roughly 5 percent of autism cases and is the most prevalent cause of autism known to date.

Atypical control of attention is a core component of autism spectrum disorders. Eric Knudsen and his colleagues at Stanford University in California set out to develop a new model system (chickens) to accelerate the discovery of neural mechanisms that control attention. The researchers have developed behavioral protocols for controlling and measuring the effects of attention in chickens.

This was a one-year project designed to obtain initial electrophysiological data from individuals with autism undergoing neurosurgery. The goal of the study was twofold: to obtain single-neuron recordings from the brains of these individuals (a rare opportunity) and to establish a consortium of hospitals with collaborating neurosurgeons.

Perturbations in the fundamental brain processes that underlie eye movement may be linked to the psychological and neural abnormalities seen in individuals with autism spectrum disorders. To test this hypothesis, researchers must be able to characterize eye movements of participants during behavioral tasks and in functional magnetic resonance imaging (fMRI) studies.

Ruth O’Hara and her colleagues at Stanford University investigated the types of sleep disorders that are most prevalent in autism. Their findings provide a clearer picture of sleep disorders associated with autism and, in turn, increase our knowledge of which treatments may be most effective at improving sleep in autism.