summary: A new study investigates how different light levels affect cognitive function by influencing activity in the brain’s hypothalamus. This study utilized advanced 7 Tesla fMRI to show that higher levels of light improve cognitive performance during complex tasks.
This link between light exposure and brain function suggests that light-based treatments may increase alertness and cognitive performance throughout the day. The discovery paves the way for further research into how light affects different brain structures and could help develop non-invasive treatments for cognitive fatigue and sleep disorders.
Important facts:
- Higher levels of light exposure correlated with increased activity in the posterior hypothalamus and improved performance on cognitive tasks.
- The study used 7 Tesla fMRI to provide high-resolution insight into how light affects hypothalamic activity.
- Increased light levels improved cognitive performance, but the exact neural mechanisms and brain regions involved require further investigation.
sauce: e-life
Exposure to higher levels of light may increase people’s sense of alertness and improve cognitive performance, possibly by affecting the activity of part of the brain region called the hypothalamus, according to a new study. .
The study was published today as a reviewed preprint. e-lifewhich the editors say is of fundamental importance and represents a significant advance in our understanding of how different levels of light influence human behavior.
The strength of the evidence is compelling and is lauded as supporting the authors’ analysis of the complex interactions between light exposure, hypothalamic activity, and cognitive function.
With further research, the results could lead to a variety of light therapy treatments that can improve an individual’s sleep quality and emotional state, allowing them to feel more awake and better able to perform tasks throughout the day. May be used to provide information.
The biological effects of light exposure have been well documented in recent years. High illumination has been shown to stimulate attention and cognitive abilities. These effects primarily depend on a subclass of light-sensitive cells in the retina called ipRCGs.
Although these cells project to multiple regions of the brain, projections are most densely found within the hypothalamus, where they are typically associated with the regulation of circadian rhythms, sleep and wakefulness, and cognitive function.
However, this knowledge of the brain circuits underlying the biological effects of light derives almost entirely from studies in animals.
“Translating research findings about how light exposure affects the brain in animal models to humans is a difficult process, as the slower maturation of the human cortex allows for more complex cognitive processing. ,” explains lead author and former GIGA PhD student Ira Campbell. -CRC Human Imaging – Her PhD – University of Liege, Belgium.
“In particular, the question of whether hypothalamic nuclei contribute to the stimulating effects on light perception remains to be established.”
To better understand the effects of light on human cognition, Campbell and colleagues enrolled 26 healthy young adults in their study.
They asked each participant to complete two auditory perception tasks. An execution task that is an improved version of the “n-back task.” The participant is asked to judge whether the current sound is the same as the sound she heard two items ago or contains the letter “K.” The other was an emotional task in which participants were asked to identify the gender of a voice uttered in either a neutral or angry tone.
Each task was completed while subjects were alternately placed in darkness and briefly exposed to light at four lighting levels.
Using a technique called 7 Tesla functional magnetic resonance imaging, which has higher resolution and signal-to-noise ratio compared to standard 3 Tesla MRI, the research team investigated different light levels on hypothalamic activity during task. We evaluated the impact of .
They found that higher levels of light caused increased activity in the posterior hypothalamus during both tasks. In contrast, the inferior and anterior hypothalamus followed a seemingly opposite pattern, showing decreased activity under higher levels of light.
Next, the team sought to determine whether these changes in local activity in the hypothalamus were associated with changes in cognitive performance. Since solving this requires a higher level of cognition, they focused on assessing participants’ performance during executive tasks.
Their analysis revealed that higher levels of light actually led to better performance on the task, which showed improved cognitive performance. Importantly, improved cognitive performance under higher illuminance was found to be significantly negatively correlated with posterior hypothalamic activity.
This suggests that activity in the posterior hypothalamus is unlikely to directly mediate the positive effects of light on cognitive performance and suggests that other brain regions may be involved, requiring further research. It is.
On the other hand, posterior hypothalamic activity was found to be associated with increased behavioral responses to emotional challenges. This suggests that the association between cognitive performance and posterior hypothalamic activity may be context-dependent. Some tasks may recruit specific hypothalamic nuclei or neuron populations to improve performance, whereas others do not.
The authors aimed to assess the effects of light on other structures and overall brain networks, and to elucidate how changes in light levels alter crosstalk and interactions with the cortex, resulting in behavioral changes. calls for further research in this area.
“It’s important to answer the questions left in our study, because light stand behavior can reduce fatigue throughout the day, improve cognitive impairment, and improve restfulness while minimizing costs and side effects. “It’s a promising and easy-to-implement solution to getting a good night’s sleep,” says Campbell.
“Our results show that the human hypothalamus does not respond uniformly to different levels of light while engaging in cognitive tasks,” said Co-Director of the GIGA-CRC Human Imaging at the University of Liege. said lead author Jill Vandewall.
“Higher levels of light have been found to be associated with higher cognitive performance, and our results indicate that this stimulating effect is partially mediated by the posterior hypothalamus. I am.
“This region, along with other extra-hypothalamic brain structures that regulate arousal, may be coupled with decreased activity in the anterior hypothalamus and hypothalamus.”
“Targeted lighting for therapeutic applications is an exciting prospect. However, we need a more comprehensive understanding of how light affects the brain, particularly at the subcortical level. Our findings represents an important step toward this goal at the hypothalamic level,” said Campbell.
About this cognitive research news
author: emily packer
sauce: e-life
contact: Emily Packer – eLife
image: Image credited to Neuroscience News
Original research: Open access.
“Local responses to light irradiance across the human hypothalamusWritten by Ira Campbell et al. e-life
abstract
Local responses to light irradiance across the human hypothalamus
Light has multiple non-imaging biological effects on physiological functions, including stimulation of attention and cognition. However, the subcortical circuits underlying the stimulatory effects of light have not been established in humans.
We used 7 Tesla functional magnetic resonance imaging to examine the thalamus in healthy young adults (N=26, 16 females, 24.3±2.9 years) while they completed two auditory cognitive tasks. The influence of changes in light illuminance on the local activity of the lower part was evaluated.
We found that high illuminance induced increased activity in the posterior hypothalamus, which includes part of the tubercle mammary nucleus and the posterior part of the lateral hypothalamus, in both executive and affective tasks.
In contrast, increased illuminance caused a decrease in activity across the anterior and ventral parts of the hypothalamus, particularly including the suprachiasmatic nucleus and another part of the tuberomammillary nucleus.
Importantly, performance on executive tasks improved with increasing illuminance and was negatively correlated with activity in the posterior hypothalamus.
These findings reveal distinct local dynamics in different hypothalamic regions that underlie the effects of light on cognition. They may suggest that light affects the quality of wakefulness by acting on orexin and histamine systems.
