in terms of attention, maximum brain activity is reached near the summer solstice, when the level is at its lowest close solstice winter. Regarding the short-term memory, brain activity is highest in autumn and lowest near the spring equinox. The results of the study were published in the journal Proceedings of the National Academy of Sciences of the United States of America (PNAS).

If the mood swings were correlated with the seasons, we know by cons little about how other brain functions vary with the seasons, the researchers from the Cyclotron research Centre ULg. The team measured the activity of the brain function of 28 volunteers at different times of the year.

For each trial, the volunteers, all aged about twenty years, spent five days in the laboratory devoid of any seasonal mark, as the light of day, and access private Internet.

At the end of each period, the researchers measured the cognitive activity of the volunteers by performing two different tests in magnetic resonance imaging (MRI). One of the two tests put into play especially attention (attentional task) volunteers. The second test involved primarily short-term memory (executive task).

The performance of the two tasks remained strong and consistent for all subjects, regardless of the time of year, according to results of the study. Brain resources used to perform the tests, however, changed depending on the season. For the attention task, the maximum brain activity is reached in June, near the summer solstice, when the level is at its lowest close of the winter solstice. In a somewhat unexpected, the brain activity of the executive task (short term memory) was not following this trend, according to researchers from Liège. It was highest in autumn and lowest near the spring equinox.

The subjects met the same parameters (age, light exposure, sleep, activities … ) and had lost all sense of reality, explains Gilles Vandewalle, Cyclotron research center. This therefore assumes that brain activity is reduced or accelerated due to the “memory of the seasons”, assuming that the “endogenous rhythm” would be mitigated if the researchers had the volunteers kept longer.

the study notes that “the brain does not always work the same way depending on the season and this may be more the case for the most vulnerable, who do seasonal depression or have a greater sensitivity to these fluctuations . a stone was knew the man was seasonal but our study can contribute to the building, “said the expert.

additional analyzes show that these results are not related to changes in neurophysiological measures of arousal from sleep quality or endocrine changes in the level of melatonin. These results demonstrate that in addition to their circadian rhythmicity, certain brain cognitive functions therefore also vary with the seasons.