Valkee designers had the goal of creating a headset with ear-buds that rest and stay comfortably inside a variety of ear types better than any other in-ear headset in the market, while providing the optimal light exposure through custom LEDs. The result is a breakthrough for in-ear headsets. It’s called the LedSet®.
The Valkee 2 Bright Light Headset supplements sunlight and its natural, positive effects. It channels light through the ear canal to photosensitive regions of the brain, which has an uplifting effect on your mood, energy level and cognitive performance.
Why is exposure to enough light so vital to our wellbeing?
Our daily life and wellbeing is synchronized to the 24h solar day. The organ that keeps us synchronized is called the biological clock and it’s located in the hypothalamus in our brain.
Light is the strongest signal that keeps our biological clock synchronized. If we don’t get enough light during the day or at the wrong time of the day, e.g. during shift-work or jet-lag, the biological clock can go out of sync and the production of hormones that affect our sleep and wellbeing, such as melatonin, serotonin and dopamine, can be disturbed. This can have a negative effect on how we feel and function during the day and how we sleep during the night.
Figure 1: The core photosensitive brain areas and their functions
How does our biological clock sense light?
The light information is received via light-sensitive receptors in the retina called opsins. The receptors convert the photic energy into electrical potential in neurons and directly project to the biological as well as to other brain areas. This increases signalling and influences hormone production (e.g. melatonin, serotonin and dopamine).
The light-sensitive receptors are not only found in the retina but also in multiple locations in the brain, for instance in the cerebellum and the hypothalamus [Starck et al, 2012; Nissilä et al, 2011& 2012].
Why administer light through the ear canal?
The ear canal is a very convenient passageway to reach the photosensitive brain tissue. The light only needs to travel a short distance to reach for instance the light sensitive receptors in the cerebellum.
The light passes through the transparent eardrum and the thin bone structure and activates the neural networks of the brain [Abou-Elseoud et al., 2011; Starck et al., 2012].
Figure 2: anatomy of ear and mechanism how light activates the brain
Key research findings and scientific evidence
BIOLOGICAL EVIDENCE: How can light through the ear activate the brain?
Light sensitive receptors have been found in multiple locations in the human and animal brain besides the retina (Nissilä et al., 2011, Nissilä et al., 2012,)
Study 1: Human post-mortem brain and peripheral tissue (N=10) was analyzed for the presence of OPN3 and OPN4 with Western blotting. Results showed the presence of OPN3 and OP4 at 18 different sites of the human brain and peripheral tissue, indicating a potential light-sensitivity of the brain.
Figure 3: 18 brain locations where light-sensitive opsins where found in the human brain (modified from Nissilä et al.,2012)
Figure 4: Opsin expression in the human hypothalamus (modified from Nissilä et al., 2012).
BRAIN IMAGING EVIDENCE: How does light through the ear activate the brain?
Study 2: 50 healthy subjects were randomized into two groups (N=24 light group; N=26 sham, placebo control group) of which one received 12 min of light in the ear, whereas the other one received no light (sham), meanwhile a fMRI scan of their brain activity was conducted.
Results showed a significant increased activation of the visual cortex as well as sensor-motor areas in the light group compared to the sham group, which suggests a general light sensitivity of the brain (modified from Starck et al., 2012, World Journal of Neuroscience 2:81-90).
Figure 5: Stimulus set-up (left) and position of light source in the ear canal
Figure 6: Lateral visual network (warm colours) and greater functional connectivity in the light stimulus group.
CLINICAL EVIDENCE: What are the benefits of light in the ear?
One might argue that only because the light activates the brain, it does not necessarily mean that it benefits our health. This is why the actual benefits have been studied in controlled human trials.
Study 3: Seasonal Affective Disorder (SAD) is characterized by the recurrence of depressive symptoms during the winter months. In a 4 week trial, 89 patients suffering from SAD were randomly assigned to one of three treatment groups and received either a low (1 lumen), medium (4 lumen), or high dose (9 lumen) of daily bright light in the ear for 12 minutes in the morning. Depressive symptoms and cognitive performance were assessed using standard psychiatric instruments such as the Beck Depression Inventory (BDI) and the Trial Making Test (TMT) at the beginning, during, and at the end of the trial. Results showed a significant reduction of depressive symptoms (74-79%) according to the BDI in all three treatment groups as well as a significant improvement of cognitive performance compared to baseline (modified from Jurvelin et al., submitted). The result is comparable with traditional bright light lamp studies.
￼Figure 7: Reduction in Depressive symptoms according to BDI. Values above 7 indicate depression, values below 7 indicate a normal level of symptoms.
CONSUMER SATISFACTION: What do Valkee customers say?
87% of users recommend Valkee (Apex Healthcare Research, Feb 2013. N=100)
1. Abou-Elseoud A, Littow H, Remes J, Starck T, Nikkinen J, Nissilä J, Timonen M, Tervonen O, Kiviniemi V. Group-ICA model order highlights patterns of functional brain connectivity. Front Syst Neurosci 2011;5(37):1-17.
2. Jurvelin H, Takala T, Nissilä J, Timonen M, Jokelainen J, Räsänen P. Transcranial bright light ￼treatment via ear canals in seasonal affective disorder: a randomized controlled double-blind ￼dose-response study. Poster presentation at International Forum on Mood and Anxiety Disorders ￼(IFMAD) 9.-11.2011, Budapest , Hungary. Manuscript submitted.
3. Nissilä J, Mänttäri S, Särkioja T, Tuominen H, Takala T, Timonen M, Saarela S.
￼J Comp Physiol A Neuroethol Sens Neural Behav Physiol. 2012 Nov;198(11):833-9
￼4. Nissila J, Mänttäri S, Tuominen H, Särkioja T, Takala T, Timonen M, Saarela S. The abundance and distribution of melanopsin (OPN4) protein in the human brain. Poster presentation in the 20th European Congress of Psychiatry (EPA), Prague, Czech Republic, 3-6 March, 2012.
5. Nissila J, Mänttäri S, Tuominen H, Särkioja T, Takala T, Timonen M, Saarela S. The abundance and distribution of encephalopsin (OPN3) protein in the human brain. Acta Physiol 2012,206(S691). Poster presentation in Society Scandinavian Physiological Society (SPS) 24.- 26.8.2012 in Helsinki, Finland.
6. Starck T, Nissilä J, Aunio A, Abou-Elseoud A, Remes J, Nikkinen J, Timonen M, Takala T, Tervonen O, Kiviniemi V. Stimulating brain tissue with bright light alters functional connectivity in brain at the resting state. World Journal of Neuroscience 2012;2:81-90.