# Figure 7: Étude du méchanisme et de l'expression du muscle frontal chez un vieillard: à droit, attention; à gauche, repos

- By: Guillaume-Benjamin-Amand Duchenne (de Boulogne) (French, 1806–1875)
- By: Adrien Tournachon (French, 1825–1903)
- Date: c. 1856, printed 1862
- Medium: Albumen print from glass plate negative
- Classification: Photograph
- Dimensions: Image: 16.2 x 11.9 cm (6 3/8 x 4 11/16 in.); Paper: 23.5 x 17.9 cm (9 1/4 x 7 1/16 in.); Mounted: 41.2 x 27.4 cm (16 1/4 x 10 13/16 in.)
- Credit line: Severance and Greta Millikin Trust
- Museum: [Cleveland Museum of Art](https://clevelandart.org/art/2018.8)
- Rights: [Public domain (CC0)](https://creativecommons.org/publicdomain/zero/1.0/)
- Picture: https://openaccess-cdn.clevelandart.org/2018.8/2018.8_web.jpg
- Who can see it: Tweens profiles and older (museums give no ratings; placed by Invisible Network from the museum's own words)

Duchenne embarked on the first scientific, systematic exploration of the physiology of human facial expression and hoped, through photographs of his experiments, to teach artists how to portray those emotions. The experiments were performed by applying electrical stimulation to a single muscle on one side of the face, so that the viewer could clearly see the impact of the muscular contraction.