Children of low socioeconomic status work harder to filter out irrelevant environmental information than those from a high-income background because of learned differences in what they pay attention to, according to new research published in the open access journal Frontiers in Human Neuroscience.
Numerous studies in the past few years have begun to reveal how poverty affects brain development and function. In 2008, Amedeo D'Angiulli of Carleton University in Ottawa, Canada and his colleagues used electroencephalography (EEG) to measure the brain wave patterns associated with an auditory selective attention task in children of high and low socioeconomic status (SES).
They found that the two groups of children exhibited differences in theta brain waves in the frontal lobe, which plays an important role in attention. This suggested that each group of children recruits different neural mechanisms for this particular type of task, and that the lower SES children allocate additional resources to attending to irrelevant information.
"Socioeconomic environment shapes the way our neurocognitive functions develop in childhood and influence the way we learn to process information when we are adults so that we can be well adapted in a certain specific type of social environment," says D'Angiulli.
For their latest study, D'Angiulli and his colleagues recruited 28 children aged 12-14 from two schools in neighborhoods of disparate socioeconomic status. One of them was attended predominantly by children from a high income background, and the other largely by children from a low income background.
The researchers performed the study at the schools during an ordinary school day. Working in a mobile lab - a van equipped with all the apparatus needed - they took saliva samples from the participants throughout the day, to measure changes in the levels of the stress hormone cortisol, and asked them to complete three questionnaires about their emotional and motivational state, at different times.
In the afternoon, the participants' brain waves were recorded while they performed a task in which they heard different sounds being played simultaneously into both ears, and were required to press a button as fast as possible when they heard one particular sound.