Overview
The work links 3D acquisition and quantification of the face with research on facial asymmetry and morphological identification from images. A further focus is reliability, observer variability, and the distinction between properties of a feature and properties of an observer judgement.
From features to judgements
Visible cues become informative when they are recognisable under concrete image conditions and can be related to observers’ judgements. How reliably a cue itself can be assessed is an empirical question.
Visible ageing cues
Earlier work with 3D data of head and face addressed visible ageing cues, especially wrinkle, furrow, and line structures. This material remains important because ageing cues are visible, but not automatically unambiguous age cues.
Faces as a model of visual assessment
Faces provide multiple potentially relevant cues at once, including shape, contour, skin texture, expression, and hair features. Which of these cues is associated with a particular judgement is an empirical question.
Age estimates, similarity ratings, and same/different decisions are distinct response formats. Comparing them can help separate effects of the stimulus from effects introduced by the task and its decision requirements.
3D data and facial asymmetry
A sample of 130 individuals aged 9 to 85 years from the 3D facial dataset was used for the published asymmetry study. Ten operationalised asymmetry traits described, among other structures, the overall facial axis, eye axis, ear position, nose, mouth, and chin. The results also illustrate why morphological frequency and visual salience need to be distinguished: not every frequent asymmetry was clearly visible to the unaided eye.
When several features are considered jointly, separate feature labels should not be taken to imply statistical independence. Shared anatomical regions or geometric reference systems can contribute to observed associations.
Selected published prior work
Lächler, S.; Hirthammer, B. J.; Rösing, F. W. (2020). Quantifying the Asymmetries of the Human Face. HOMO – Journal of Comparative Human Biology, 71(2), 91–99.
Hirthammer, B. J.; Rösing, F. W. (2021). Identifikation von Personen auf Bildern. In: Münchener Anwaltshandbuch Strafverteidigung, 3rd ed., C.H. Beck, 2901–2916.
Rösing, F. W.; Hirthammer, B. J.; Funke, K. (2013). Bilder als Beweis. Die morphologische Identifikation im Strafverfahren. Richter ohne Robe, 25(1), 7–9.
Research areas
- visual age perception and visible ageing cues
- facial comparison, similarity, and same/different decisions
- confidence, uncertainty, and metacognitive calibration
- observer variability, consensus, dissent, and repeatability
- image quality, view, and stimulus variation