"Research into the adult brain has shown that gamma activity is the 'glue' that binds together perceptions, thoughts and memories. Little research, however, has been conducted into the development of gamma activity in the infant brain and its possible connection to cognitive and language skills," says study leader April Benasich, a professor of neuroscience.
She claims that her team is the first to look at "resting" gamma power in the frontal cortex, the "thinking" part of the brain, in children 16, 24 and 36 months old.
A research article in the online edition of the journal Behavioral Brain Research says that the new findings provide a window into their cognitive development, and may open the way for more effective intervention for those likely to experience language problems.
Gamma waves are fast, high-frequency, rhythmic brain responses that have been shown to spike when higher cognitive processes are engaged. Lower levels of gamma power may hinder the brain's ability to efficiently package information into coherent images, thoughts, and memories.
During the study, Benasich and her colleagues analysed the children's EEGs (electroencephalograms), and found that those with higher language and cognitive abilities had correspondingly higher gamma power than those with poorer language and cognitive scores.
The researchers further observed that children with better attention and inhibitory control - the ability to moderate or refrain from behaviour when instructed - also had higher gamma power.
According to them, there were no differences in gamma power based on gender or socio-economic status.
Separate tests were conducted to evaluate the children for their emerging language and cognitive skills. The team studied children from families with normal language development as well as those at higher risk for problems because they were born into families with a history of language disorders.
The researchers observed that the group of children with a family history of language impairments showed lower levels of gamma activity.
"We believe that maturation of the brain mechanisms that support gamma activity and those critical for mounting normal language and cognitive development may be occurring simultaneously. We seem to have identified a window, during a period of sustained and dramatic linguistic and cognitive growth, that can help us to better determine where a child is developmentally," says Benasich.
Based on their observations, the researchers came to the conclusion that the emergence of strong gamma activity is critical for linguistic and cognitive development, and that children at risk for language impairments may lag in this process.
"Having strong bursts of gamma appears to assist the brain in making the neural connections needed for effective language development. By measuring gamma activity in the frontal cortex, which is the last brain area to mature and is used to make decisions and solve problems, we may be able to tell how well the brain is developing in general," says Benasich.
"Lower levels of gamma power in the resting brain may provide a 'red flag' indicating that a child will experience language or attentional problems. Knowing that may allow us to provide effective intervention during this critical learning period," she adds.