¿Qué impacto tiene exponernos a la luz artificial sobre nuestra fisiología y estado psicológico?

SEPEX, SEPNECA and AIP experimental Conference. Madrid, 4 July 2018

Ángel Correa Beatriz Rodríguez-Morilla

Antonio Barba Francisca Padilla

Juan Antonio Madrid (UMU)

2

• Natural light/darkness cycle entrains our circadian rhythms (sleep/wake)

• However, we increasingly expend more time indoors (daylight -> electrical light)

• Impact on health?

THE PANACEA:Improved Visual AcuityReduced FatigueFewer Dental CariesAccelerated MaturationImproved Neural FunctioningReduced Seasonal DepressionReduced BulimiaReduced HyperactivityGreater School AchievementImproved AttendanceGreater AttentivenessImproved Mood

1973Full spectrum fluorescent lamps = health

THE PANACEA:Improved Visual AcuityReduced FatigueFewer Dental CariesAccelerated MaturationImproved Neural FunctioningReduced Seasonal DepressionReduced BulimiaReduced HyperactivityGreater School AchievementImproved AttendanceGreater AttentivenessImproved Mood

1973Only a full spectrum of natural light could promote full health

in plants, animals, and humans 1986

“Health Fraud Notice”: absence of sound scientific evidence in support of the health claims made in the lamp’s labelling

5

Night shift work = probable carcinogen (circadian disruption; WHO).

Artificial light at night, circadian disruption and breast and prostate cancers

2007

2018

New photoreceptor (ipRGC): “blue” wavelength light resets the circadian clock (Berson et al., 2002)2002

Nobel Prize in Physics for the invention of the blue LED2014

2005Blue light at night boosts alertness (melatonin, thermophysiology, heart rate; Cajochen et al., 2005)

full spectrum -> blue light

6

Night shift work = probable carcinogen (circadian disruption; WHO).

Artificial light at night, circadian disruption and breast and prostate cancers

2007

2018

New photoreceptor (ipRGC): “blue” wavelength light resets the circadian clock (Berson et al., 2002)2002

Nobel Prize in Physics for the invention of the blue LED2014

2005Blue light at night boosts alertness (melatonin, thermophysiology, heart rate; Cajochen et al., 2005)

Neurocognitive effects of light1. Beyond alertness 2. Ecological conditions

Subjective Physiological Behavioural

Sleepiness (KSS)

Mood (VAS, PANAS)

Mental effort

Visual confort

Distal temperature Proximal

Distal-Proximal Gradient (DPG)Vigilance Tasks

(PVT, Driving, SART)

Reaction time

Accuracy

Inhibitory control

Subjective Physiological Behavioural

Sleepiness (KSS)

Mood (VAS, PANAS)

Mental effort

Visual confort

Distal temperature Proximal

Distal-Proximal Gradient (DPG)

PVT, Driving, SART

Reaction time

Accuracy

Inhibitory control

Pre-test ADAPTATION TO LIGHT TASK Post-test

10 min 10 min20 min 20 - 60 min

10

Study N Design Task

1 Rodriguez-Morilla et al. 2017 36

Blue Dim

OrangeSimulated Driving

2 Rodriguez-Morilla et al. 2018 17 Blue vs. Dim (within) Simulated Driving

3 Barba et al. 15Blue Dim

OrangeSART

4 Correa et al. 2016 24 Blue vs. Dim (within) SART

5 Barba et al. 45 Blue vs. Dim (within) PVT

11

12

• no effects on subjective somnolence or mood • enhanced arousal (lower temperature gradient) • facilitated fast responding, but… • … impaired driving accuracy

Blue-enriched white light

Differential effects as a function of specific task demands?

13

50 ms

1150 ms or until response Error

No-go

Error

Go

Go

No-go

1200

ms 3

3"

2"

7"Condition Index Process

GO RT automatic

NOGO accuracy controlled

Sustained Attention to Response Task (SART)

Robertson et al, 1997

14

Condition Index Process

GO RT automatic

NOGO accuracy controlled

f a s t e r ‘ a u t o m a t i c ’ responding (go trials) no effect on inhibitory control

15

Study N Somno-lence Mood Arousal

(DPG)Response

speedTask

accuracy

Rodriguez-Morilla et al. 2017

36 x xRodriguez-Morilla et al. 2018

17 x xBarba et

al. 15 x x x xCorrea et al. 2016 24 x x xBarba et

al. 45 x x

16

Study N Somno-lence Mood Arousal

(DPG)Response

speedTask

accuracy

Rodriguez-Morilla et al. 2017

36 x xRodriguez-Morilla et al. 2018

17 x xBarba et

al. 15 x x x xCorrea et al. 2016 24 x x xBarba et

al. 45 x x

Rightskewedp-curve=presenceofeviden6alvalue

p-curvedoesnotindicateeviden/alvalue

Lighting effects on Reaction Time

¿Qué impacto tiene exponernos a la luz artificial sobre nuestra fisiología y estado psicológico?

En nuestras condiciones de iluminación (sur de España), en muestras de adultos jóvenes sin trastornos

circadianos ni del sueño,

la exposición aguda a la luz enriquecida en azul no tiene un impacto claro sobre la ejecución de tareas

cognitivas, ni sobre la fisiología circadiana, ni sobre el estado de ánimo.

Ángel Correa Beatriz Rodríguez-Morilla, Antonio Barba,

Francisca Padilla y Juan Antonio Madrid (UMU)

¿Qué impacto tiene exponernos a la luz artificial sobre nuestra

fisiología y estado psicológico?

SEPEX, SEPNECA and AIP experimental Conference. Madrid, 4 July 2018