Event Abstract

Identifying the neural signature of thermic comfort sensation: neuroergonomic evaluation of a new ventilating system integrated in car seat

  • 1 myBrain Technologies, Cognitive Neuroscience Research, France
  • 2 Faurecia, Faurecia Automotive Seating, France
  • 3 École Polytechnique, I3 - Centre de Recherche Gestion, France

Physical comfort is a central notion of neuroergonomics. Automotive industry is investing great efforts in innovative designs and technologies to improve the efficiency of its products in terms of comfort. This is particularly true for the firms that design and build automotive seats and systems combined with seats. In that domain, the thermal regulation of seat's occupant is of major interest, and brand new systems are emerging. Air pulling system has been selected versus pushing system, mainly because it appears to be more efficient in reducing occupant sweating, one of the main pain point of end-user’s thermal comfort. Nevertheless, the efficiency of such system on thermal comfort remains to be demonstrated and neuroergonomics studies are required to reach this objective. A large number of researches conducted on the human thermal perception already investigated the influence of environmental factors (ambient temperature, air humidity, etc…) on the sensation of thermal comfort using mainly subjective reports. Although some of these studies included also physiological measurements, such as heart rate variations, skin temperature or sudation, these data are not sufficient to fully describe the neurocognitive model associated with the representation of thermal comfort. This communication presents a study conducted for that purpose. First we aimed at characterizing the oscillatory brain pattern associated with modulations of thermal comfort sensation, considering both subjective and electrophysiological measurements. Second we evaluated the efficiency of two different ventilating systems in restoring an optimal level of thermal comfort. This research was done in partnership with Faurecia, an automotive firm developing, among others, innovative systems associated with seats. Faurecia air-pulling system was tested in the current study. To mimic realistic temperature variations, the experiment was performed in a climate chamber in which two car seats, integrating two different ventilating systems (the Faurecia air-pulling system and a competitor pushing one’s) were placed. The protocol was divided in three 5-min phases, corresponding to three distinct thermal conditions: (i) a pre stimulation phase; corresponding to a neutral (ambient) thermal condition used as a baseline, (ii) a heat stress phase corresponding to a hot thermal environment (45°C), and (iii) a recovery phase corresponding to the activation of the two different ventilating systems. We recorded the EEG signal, the behavioral response (reaction time in a Go/NoGo task) and the subjective appreciation of temperature, comfort and awareness during these three phases. Eighty-eight participants were included in this study and were associated either to the Faurecia's or to the competitor's ventilating system. EEG data were collected using a wireless EEG headset composed of eight dry electrodes, built by myBrain Technologies. We focused on power modulation of specific oscillatory components known to be sensitive to thermal comfort variations and EEG-based indexes such as the Approach Withdrawal (AW), reflecting the asymmetry of alpha power between the left and right hemisphere, and the Coherence level, depicting the correlation in frequency between two distinct cortical regions. We investigated two low frequencies components, the theta (4 – 8 Hz) and alpha (8 – 13 Hz) waves, and one in high frequency band, the beta waves (18 – 30 Hz). Three key findings emerged from this study: i) subjective, behavioral and electrophysiological data were influenced by the temperature ii) distinct EEG-based indexes were directly correlated with the thermal comfort modulations and iii) subjective, behavioral and EEG results allowed us to discriminate between the two air ventilating systems. Psychometric results indicated that temperature perception, comfort sensation and awareness level were modulated by the temperature. In addition, participants displayed also longer reaction times (RT) in the Go/NoGo task during the heat stress phase; suggesting an impairment of motor programming skills. The recovery phase, corresponding to the activation of the two ventilating systems during 5 minutes, was associated with a general improvement of the three introspective measures (temperature sensation, comfort and awareness) and a RT decrease. It is however worth noting that only participants in the Faurecia air-pulling system group perceived the temperature as lower, and the comfort as higher in the recovery phase as in the pre stimulation phase. They were also as fast at performing the behavioral task in the recovery phase as in the pre stimulation period (Figure 1). At the electrophysiological level, oscillatory components in different frequency bands were also modulated by the thermic conditions and the ventilating systems. Power in the theta band increased in the heat stress phase, compared to the pre-stimulation and the recovery phases. We observed the opposite dynamic for the Approach Withdrawal index (AW), which was sensitive to the ventilating system used (Figure 2). Additionnally, participants showed a beta power increase during the heat stress compared to the prestimulation and recovery phases, mainly in the central and parietal regions. In the litterature, this oscillatory component was already considered as a specific marker of the thermoregulatory system activation. The beta waves were also influenced by the ventilating system used, as revealed by the power difference observed in the recovery phase (Figure 3). Finally, significant coherence levels were reported mainly during the recovery phase, in the theta and in the alpha band. In particular, the highest levels of coherence were found first, between central and parietal electrodes and second, between frontal and central electrodes. Previous studies already mentioned that the activation of the thermoregulatory system is characterized by a synchronization of the EEG signal between the frontal, central and parietal regions, in the theta and alpha bands. In conclusion, this study allowed to propose a neurocognitive model asssociated with the representation of thermal comfort. It also demonstrated that the subjective and the electrophysiological data are extremely sensitive to heat stress and thermal recovery. The correlations between specific EEG indexes and psychometric reports support the characterization of comfort perception. From an industrial point of view, this research revealed the positive impact of its system on the thermal comfort of seat occupants under thermic stress conditions. Taken together, these results brought new insights on the representation of the comfort sensation in the brain. They also open avenues for further studies designed to optimize automotive systems and based on physiological and electrophysiological evidences.

Figure 1
Figure 2
Figure 3


We would like to gratefully thank Martin Vandendriessche, Nicolas Pourchier and Geoffrey Pradier for the design and the building the EEG headset used in this study, Etienne Garin for developing the EEG acquisition software, Jonathan Derou-Bernal for his assistance in the EEG acquisitions, Samuel Baudu, Mathieu Cluet and Sylvie Bros for their precious help in the participants' recruitment process and their investment in the whole experimental procedure.


Chang, Peng Fei, Lars Arendt-Nielsen, and Andrew C.N. Chen. (2005) Comparative Cerebral Responses to Non-Painful Warm vs. Cold Stimuli in Man: EEG Power Spectra and Coherence. International Journal of Psychophysiology 55(1): 73–83.

Davidson, Richard J. (1992) Anterior Cerebral Asymmetry and the Nature of Emotion. Brain and Cognition 20(1): 125–151.

Davidson, Richard J. (2004) What Does the Prefrontal Cortex “do” in Affect: Perspectives on Frontal EEG Asymmetry Research. Biological Psychology 67(1–2): 219–234.

Dowman, Robert, Daniel Rissacher, and Stephanie Schuckers. (2008) EEG Indices of Tonic Pain-Related Activity in the Somatosensory Cortices. Clinical Neurophysiology 119(5): 1201–1212.

Lv, Bin, Chang Su, Lei Yang, and Tongning Wu. (2017) Effects of Stimulus Mode and Ambient Temperature on Cerebral Responses to Local Thermal Stimulation: An EEG Study. International Journal of Psychophysiology 113: 17–22.

Nybo, Lars (2007) Exercise and Heat Stress: Cerebral Challenges and Consequences. In Progress in Brain Research Pp. 29–43.

Riniolo, T, and L Schmidt (2006) Chronic Heat Stress and Cognitive Development: An Example of Thermal Conditions Influencing Human Development. Developmental Review 26(3): 277–290.

Yao, Ye, Zhiwei Lian, Weiwei Liu, and Qi Shen (2008) Experimental Study on Physiological Responses and Thermal Comfort under Various Ambient Temperatures. Physiology & Behavior 93(1–2): 310–321.

Keywords: Thermal comfort, Automotive ventilating system, Heat stress, Frontal Alpha Asymmetry (FAA), Motor planning speed, Beta Oscillations, coherence analysis

Conference: 2nd International Neuroergonomics Conference, Philadelphia, PA, United States, 27 Jun - 29 Jun, 2018.

Presentation Type: Oral Presentation

Topic: Neuroergonomics

Citation: Breton A, Ronca V, Mallet-Dacosta A, Longatte F, Servajean-Hilst R and Attal Y (2019). Identifying the neural signature of thermic comfort sensation: neuroergonomic evaluation of a new ventilating system integrated in car seat. Conference Abstract: 2nd International Neuroergonomics Conference. doi: 10.3389/conf.fnhum.2018.227.00008

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Received: 30 Mar 2018; Published Online: 27 Sep 2019.

* Correspondence:
PhD. Audrey Breton, myBrain Technologies, Cognitive Neuroscience Research, Paris, 75010, France, audrey.breton@mybraintech.com
Dr. Vincenzo Ronca, myBrain Technologies, Cognitive Neuroscience Research, Paris, 75010, France, vincenzo.ronca@mybraintech.com