Talk to My Right Ear

Humans prefer to be addressed in the right ear and are more likely to perform a task when the request is received in the right ear.  In a series of three studies, Luca Tommasi and Daniele Marzoli from the Gabriele d”Annunzio University in Chieti, Italy, showed that a natural side bias is exhibited in everyday human behavior. 

Tommasi and Marzoli’s three studies specifically observed ear preference during interactions in noisy social environments.  In the first study, in which 286 participants were observed while they were talking with loud music in the background, 72% of interactions occurred on the right side of the listener.  These results are consistent with the right-ear preference found in both laboratory studies and questionnaires and demonstrate that the side bias is displayed spontaneously outside the laboratory.

The two other studies used variations on communication in similar environments.  Taken together, these results confirm a right ear/left hemisphere advantage for verbal communication and distinctive specialization of the two halves of the brain for approach and avoidance behavior.  Visit the September 2009 (Vol.96, No. 9 issue of Naturwissenschaften at www.springerlink.com/content/100479.

The Genetics of ADHD

Researchers have found evidence that attention deficit/hyperactivity disorder (ADHD) is a genetic condition in which small DNA segments are duplicated or missing.  Researchers analyzed the genomes of 366 children diagnosed with ADHD and 1,000 controls.  Rare copy number variants were almost twice as common in children with ADHD compared to the control sample and even higher for children with learning disabilities.  Search “ADHD genetics” at www.thelancet.com.

Specific Language Impairment

In a study of children with specific language impairment (SLI) and their family members, researchers have identified a gene on chromosome 6 for SLI.  The gene is associated with variability in language abilities as well as speech and reading abilites.  The finding suggests a common pathway that could contribute to overlapping strenghths or deficiencies across speech, language, and reading.  The study was published in the Journal of Neurodevelopmental Disorders (www.springerlink.com/content/121295/?k=SLI).

Diagnosing Autism by MRI

From the ASHA Leader: (December 21, 2010)

Researchers are honing in on a diagnostic tool to identify autism spectrum disorders (ASD).  Using MRI and fMRI, researchers have identified “hot spots” where the left and right hemispheres of the brains of people with ASD do not communicate properly with one another.  Other than an increased brain size in young children with ASD, these hot spots are the only other difference researchers have found.  Visit www.physorg.com/news/2010-10-autism-mri-closer.html.