The first study of its kind, published in the journal Communications Psychology  and funded by Wellcome Trust, also showed that stable light exposure across a week and uninterrupted exposure during a day had similar effects.

Participants in the study experienced improved subjective sleepiness, the ability to  maintain focused attention and 7-10% faster reaction speeds under bright light when compared to recent dim conditions.

Compared with their peers who went to bed later, participants with earlier bedtimes tended to be both more reliably wakeful under bright morning light - and sleepy under dimmer evening -light.

Lead author Dr Altug Didikoglu from The University of 野狼社区 said: 鈥淥ur findings show that outside controlled laboratory conditions, where participants continue their daily routines, both recent and long-term light exposure positively influences cognitive performance.

鈥淭he beneficial effects were associated with short-term bright light and habitual light exposure patterns characterized by brighter daytimes, earlier bedtimes, and higher consistency in light exposure.鈥�

鈥淭hese improvements in cognitive performance may have practical implications for health, safety, and work efficiency, particularly in low-light workplaces, during extended work hours, or night shifts.鈥�

Being exposed to bright, stable daytime light was linked to enhanced and more sustained attention in a visual search task in which participant were asked to find a specific target on a page.

Higher daytime light exposure and less switches between light and dark were linked to improved cognitive.

And higher daytime light exposure and earlier estimated bedtimes were also associated with stronger relationships between recent light exposure and subjective sleepiness.

However, neither the time of day nor time awake significantly impacted cognitive performance; the effect of light was stronger than the effect of time of day.

The effects, argue the scientists, are likely initiated by activation of the ipRGC system in the thin layer of light-sensitive tissue at the back of the eye that converts light into signals we interpret as vision, known as the retina.

Special photosensitive retinal cells in the ipRGC system containing the photopigment melanopsin are particularly sensitive to blue-green light and are  responsible for non-image-forming functions, such as regulating circadian rhythms, the pupillary light reflex, and mood.

The effects of personal ambient light exposure were measured in a sample of 58 adults over seven days of daily life.

The participants wore a special daylight exposure monitor on their wrists which effectively told the scientists how well light exposure influenced their internal body clock.

In addition, a smartphone app called Brightertime, developed at the University of 野狼社区, provided data on human cognitive performance compared to light exposure in their everyday life.

Forty-one of the  participants also attended a lab session which investigated how their eye pupils responded to light and compared actual light levels and their perception of light. However, this does not directly predict how light affects cognitive performance in everyday life

Dr Altug added:鈥淟ight is a fundamental environmental cue that governs numerous biological processes in humans, including body clocks, sleep, and cognition

鈥淗owever, despite substantial findings from controlled laboratory studies, little is known about how these effects translate to real-world environments, where light exposure is dynamic and intertwined with daily routines.

鈥淲e think this study is an important addition to our understanding of this area of research.

鈥�  Scientists already know that exposure to electrical light at night is known to disrupt sleep quality and delays the biological clock.

鈥淥ur new study paper now shows that bright daytime light is also critical by supporting cognitive function.鈥�

• The paper Relationships between light exposure and aspects of cognitive function in everyday life published in Communications Psychology is available . DOI:
• The study authors previously led a on recommended healthy lighting levels: bright light during the day, dim light before sleep, and darkness at night. They also previously that meeting recommended light levels support our sleep .The current results align with these recommendations and suggest that following them long-term may also support cognitive performance.

In the study, published in , 26 people were shown pictures of objects that were either natural, such as fruit, tress, flowers,  or man-made such as a computer mouse and telephone.

In the study funded by the Wellcome Trust, the scientists trained the participants to expect man-made or natural objects using cues such as a triangle or a square.

The whole experiment was then repeated with another 24 people having a functional MRI scan to reveal which regions of the brain were used to learn and retrieve the information.

When an expected event 鈥� such as a triangle preceding a man-made object  - followed a similar but unexpected event 鈥� a triangle preceding a natural object 鈥� the participants鈥� memory was boosted.

The second study in the MRI scanner gave exactly the same behavioural results, and showed activation in the brain鈥檚 hippocampus 鈥� the memory centre , midbrain regions 鈥� which release dopamine, and occipital cortex - the vision centre.

In contrast, a sequence of two unexpected similar events also triggered visual areas in the brain, but did not enhance memory performance.

Lead author Dr Darya Frank, a cognitive neuroscientist from The University of 野狼社区, said: 鈥淲e already know that if expectation is violated before or during learning, it triggers an adaptive mechanism resulting in better memory for unexpected events.

鈥淭his experiment shows how the mechanism is also affected when we are trying to retrieve information.鈥�

The hippocampus encodes  - or creates -  memories but also  retrieves memories. With only a finite amount of resource to allocate to either, the two mechanisms  are in conflict.

So when something unexpected happens, our brain focuses on the outside environment so it can learn something new, something it did not initially expect.

Scientists already know that surprise turns on the brain鈥檚 learning mode, add link however, the current study is the first to investigate how the brain uses the mechanism when we are trying to retrieve information.

Dr Frank added: 鈥淭hough our study did not assess the impact of these findings on exam revision and performance, it is logical to see its implications.

鈥淪o when the goal is to retrieve information -  encountering surprising events like revising in a caf茅 or other unfamiliar surroundings would engage an encoding mechanism that may enhance memory for a future exam.

鈥淏ut the reverse is also true: when trying to remember something already learned during the exam itself, a familiar and expected environment could be helpful, and support retrieving information from memory.