When you find yourself more alert and focused after basking in bright daylight, science offers an explanation. Recent studies reveal that exposure to increased levels of light can directly influence activity in a vital brain region, the hypothalamus, boosting cognitive performance and promoting wakefulness.
This new study represents a substantial leap forward in understanding the biological effects of light on cognition and neurological well-being. While previous research has shown that light exposure increases alertness, this is one of the first studies to pinpoint how it influences the human brain at the neural level.
The research team selected 26 young adults to undertake cognitive tasks within an MRI scanner while experiencing different degrees of light, ranging from total darkness to exceptionally bright illumination. The auditory tasks assessed executive functions such as working memory and emotional processing. Employing a 7 Tesla functional MRI with high resolution, a method offering improved brain imaging, the researchers investigated the impact of light level alterations on activity within distinct regions of the hypothalamus during the tasks. Their discoveries unveiled a noteworthy pattern.
The researchers observed that as light levels heightened, activity in the posterior part of the hypothalamus intensified. Conversely, activity in the inferior and anterior hypothalamus decreased with greater exposure to light. In essence, various segments of this compact brain area, no larger than an almond, responded differently based on the brightness level.
Upon analyzing the participants’ scores on the executive functioning task, the researchers uncovered a distinct correlation: heightened light levels correlated with enhanced performance on cognitive tasks. Interestingly, this improvement was associated with reduced activity in the posterior hypothalamus. The researchers suggest that this indicates the activity in the posterior hypothalamus is not directly linked to light’s beneficial impact on cognitive performance. Instead, it suggests the involvement of other brain regions.
Under conditions of high light levels, specific brain cells might be enlisted to enhance performance on certain cognitive tasks. The authors underscore the need for further research to examine how light affects entire brain networks and their interaction with the cortex, the outer layer of the brain responsible for higher cognition, in order to comprehensively understand these effects.
The present discoveries offer promising prospects. By illuminating the neurological pathways connecting light exposure to cognitive function, this research unveils opportunities for the development of light therapy interventions. Such treatments could offer assistance to individuals grappling with sleep disturbances and alertness issues, while potentially enhancing mood and cognitive performance throughout the day.
To view the original scientific study click below:
Regional response to light illuminance across the human hypothalamus
