Does Tactile Stimulation of the Face Affect the Processing of Other Faces? Neural and Behavioural Effects of Facial Touch

ABSTRACT

The integration of vision and touch is proposed as a critical factor for processing one’s own body and the bodies of others in the brain. We hypothesize that tactile stimulation on an individual’s face may change the ability to process the faces of other, but not the processing of other visual images. We aimed to determine if facial touch increased the activity of the mirror system and face recognition memory of the observer. Therefore, mu suppression was measured to compare the effect of facial touch in performing two visual tasks. The participants observed faces and non-face visual images under two sets of conditions. In the first condition, a robotic finger touched the participant’s cheek while in the second condition, no touch occurred. Upon each observational task, the participants were given in a recognition test. Behavioral results indicated that facial touch improved recognition performance for faces, but not for non-face visual images. Tactile stimulation increased mu suppression in both occipital and central electrodes during face processing; however, the suppression did not significantly change during non-face visual processing. Our findings support the concept that the brain uses a self-body representation, as a reference to understand the mental states or behaviors of others.

KEYWORDS:

• Tactile stimulation
• face processing
• face recognition
• mu suppression

Acknowledgements

We thank Bedirhan Sürücü and Recep Tayyip Çam for developing the robotic finger.

We thank Sevil Turan Turgut and Fırat Uzun for being involved in the project.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Ethical approval

All procedures performed in studies involving human participants were conducted in accordance with the ethical standards of the institutional research committee (Akdeniz University Ethical Committee for Social Sciences) and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards.

Informed consent

Informed consent was obtained from all individual participants included in the study.

Additional information

Funding

This study was supported by the Akdeniz University Scientific Research Projects Coordination Unit. Project Number 2954.