LIGHTCAP: Light, Cognition, Attention, Perception

Project Information

LIGHTCAP

Grant agreement ID: 860613

DOI

10.3030/860613

Project closed

EC signature date 5 February 2020

Start date 1 March 2020

End date 31 August 2024

Funded under

• EXCELLENT SCIENCE - Marie Skłodowska-Curie Actions

Total cost

€ 4 165 704,72

EU contribution

€ 4 165 704,72

Coordinated by

TECHNISCHE UNIVERSITEIT EINDHOVEN
Netherlands

Periodic Reporting for period 2 - LIGHTCAP (LIGHTCAP: Light, Cognition, Attention, Perception)

Reporting period: 2022-03-01 to 2024-08-31

Summary of the context and overall objectives of the project

Cognition, Attention and Perception (CAP) are crucial for professional success, core to educational success, essential to productive, safe and healthy functioning. Yet cognition is hard work, attention is fragile, and perception is selective. Recent research has shown that light directly and indirectly helps CAP, in particular via the activation of a recently discovered photoreceptor in the human eye. Light triggers this photoreceptor, but large-scale migration to cities, increased time spent indoors, and our 24-hour economy have impacted on our light exposure. Disturbance of sleep/wake cycles, fatigue and cognitive failure, mood disorders and even cancer pathologies may be the consequences of ignoring findings on human light processing.

LIGHTCAP was an international, interdisciplinary, cross-sectional and translational training program, with experts from neurobiology, cognitive neuroscience, chronobiology, psychology and lighting technology. Our young researchers were trained to look beyond the borders of their discipline and understand the implications of their findings. Our consortium was unique in its approach to study non-image forming effects of light (NIF) from different perspectives: architectural, animal and human biological, ecological and neuropsychological. The project targeted questions around non-image forming effects of light on Cognition, Attention, and Perception. But our investigations also covered themes as health and sleep, as well as those on safety.

New methods in light dosimetry and simulation were developed, innovative research protocols and measurements were employed, and under-investigated groups were targeted. We gained important insights on the biological mechanisms of the non-image forming (NIF) impact of light, and investigated interaction with ageing, disease, stress, arousal and light characteristics. We translated our insights into implications and recommendations for design and research and contemplated how we can support designers to realize better light environments, and which challenges still lie ahead in the field of lighting research.

For details we direct the reader to the published and forthcoming manuscripts.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

Many investigations of the LIGHTCAP project have involved manipulating the properties of light to better understand its mechanisms of action. In particular, identifying which of the photoreceptors, or a combination of them, is the main driver of the multiple effects of light is an important step towards understanding how light interacts with the brain.
Across the project a wide variety of lighting conditions and light stimuli were used and/or measured. In general, studies can be differentiated by the way in which light was applied, the type of light source(s) used, the range of light levels, the exposure duration, the devices with which the lighting conditions were measured/verified, and the way in which the consistency of the lighting conditions was verified over time.
Light(ing) manipulations varied in spectral, spatial, and temporal distribution of light and its dose or intensity.

We conducted investigations into retinitis pigmentosa in a mouse model and evaluated the pupil size in human subjects. Neuroimaging studies in humans and animal studies using invasive biological techniques enriched our research by providing a more holistic understanding of how light affects several NIF effects. Animal studies also allowed researchers to explore the effects of light in several contexts using biological protocols. For example, we looked for biomarkers related to Alzheimer's in mice, aiming to determine if light exposure could potentially slow down the disease progression. Several projects used objective measurements rather than subjective reports to unravel biological mechanisms. They focused on the activity and functional connectivity of the brain using fMRI, on pupillometry as a direct read out of the impact of light on the brain, on neuronal responsiveness using TMS-EEG, on brain waves as markers of attention, alertness and sleepiness using EEG, on actimetry as a readout of rest-activity regulation, and on melatonin suppression as one of the well-established measures for the impact of light. The studies also included behavioural measures that can be linked to the biological mechanism uncovered. For subjective sleepiness, the Karolinska Sleepiness Scale (KSS) was the most commonly used method across the ESRs (KSS). Notably, one researcher used different subjective sleepiness measures and found out that each of them evaluates a different dimension of sleepiness : KSS is more connected to (a lack of) alertness, Epworth Sleepiness Scale (ESS) to sleep propensity, and Stanford Sleepiness Scale (SSS) to feelings of sleepiness. They also explored measures of fatigue, the Visual Analog Scale to Evaluate Fatigue Severity (VAS-F) and Patient related outcome measure system for daily fatigue (PROMIS). Other commonly self-reported items were visual comfort and mood/emotional valence'. Psychomotor Vigilance Task was the most commonly used measure for sustained attention (PVT). Other reaction time tasks used were the n-back, always in the 0-back and 2-back variations. Several ESRs data collected personal light exposure over longer periods of time (days – weeks), through personally worn light meters.

Our ESRs have presented at numerous conferences. At the formal closing of the project, we have counted already 22 publications in scientific peer-reviewed journals and 6 full papers have been published in peer-reviewed proceedings. The majority of these have been published gold open access, the remaining ones green open access.
The outlets reflect the quality, and the multi- and interdisciplinarity of the work performed in LIGHTCAP. At the same time they are also just the beginning, as most of our ESRs have journal manuscripts currently under review or in preparation.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

The goal of LIGHTCAP was to prepare the next generation of experts able to deliver on the promise of truly intelligent, integrative, human-centric lighting.

We trained 15 ESRs to become independent researchers.
We organized seminars and lectures open to all researchers and a closing conference with participants from academia and industry.
Insights were disseminated through established communication channels and conferences of the CIE, LightingEurope, and national lighting associations.
The researchers have presented at numerous conferences and participated in many science events for the general public.

New methods in light dosimetry and simulation were developed, we gained important insights on the biological mechanisms of the non-image forming (NIF) impact of light, and investigated interaction with ageing, disease, stress, arousal and light characteristics. Implications and recommendations for design and research were formulated.

Our consortium has jointly developed four Coursera LIGHTCAP MOOCs, teaching the basics of relevant disciplines in lighting. These are freely available via Coursera. This collection of MOOCS will become a persistent training resource for young researchers and hence serves the field on a longer term than the project duration.

The LIGHTCAP research program has added - and will continue to do so - substantially to the field's integral understanding of the multifaceted impact of light on cognition, attention and perception, and, in a broader sense, on human health and wellbeing.

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