Language functions are influenced by environment and
genetic makeup. Advances in genetic analyses have uncovered several
genes associated with language development and abilities.
genetic influences affect language-related brain activities in left
frontal area of the brain, revealed Osaka University-led researchers who examined the brain activity in
monozygotic and dizygotic Japanese twins.
‘Environmental and genetic influences affect language-related brain activities in left frontal area of the brain.’
cortical regions are involved in processing language function.
Event-related desynchronizations (ERDs) are attenuations of brain
activities in specific frequency band and have been associated with
language processing. However, little is known about how genetic and
environmental factors affect language-related ERDs. Furthermore, it is
not clear how language-related ERDs differ among individuals and how
they affect verbal ability.
In a new study, Masayuki Hirata, Toshihiko Araki and their group
members at Osaka University used magnetoencephalography (MEG) to measure
the brain activity of monozygotic (100% genetic similarity) and
dizygotic (50% genetic similarity) elderly Japanese twins.
activity was measured while the participants silently read a series of
words and generate a verb associated with them. The ERDs in the 25-50 Hz
frequency band called low gamma ERDs had the highest power in the left
frontal area of the brain. This brain region is important for language
The study authors compared the power of low gamma ERDs in the left
frontal area of monozygotic and dizygotic twins using a quantitative
genetic analysis called structural equation modelling. These analyses
showed that the power of ERDs is equally affected by genetic and
Interestingly, the genetic control of ERDs in the
left frontal area was preserved even after the siblings had been living
apart, in different environments, for many years. This suggests that
genetic factors strongly affected the power of language-specific ERDs.
To determine how language-related ERDs affect verbal ability, the
researchers examined correlations between the ERD powers and verbal test
scores. Individuals with higher test scores had lower-power ERDs in the
left frontal area, showing that verbal memory is associated with
Verbal memory often deteriorates in elderly
individuals. The authors suggest that the verbal task in this study
placed a higher demand on the elderly participants, thereby increasing
the power of low gamma ERDs.
The findings provide novel insights into how genes and the environment shape the development of verbal ability.