# Face inversion effect and exposure duration on age classification accuracy

## TL;DR

This study explores how face orientation and viewing time affect the accuracy of determining if a face belongs to someone over or under 18 years old.

## Contribution

The study introduces a novel examination of face inversion and exposure duration effects on age classification, which has been less studied compared to identity recognition.

## Key findings

- Inverting faces impaired age classification accuracy.
- Longer exposure duration improved accuracy when participants viewed faces for the full duration.
- There was no interaction between exposure duration and face orientation.

## Abstract

The effect of face orientation and exposure duration on facial identity recognition and matching are well-documented but has scarcely been examined for facial age perception. Using a facial age categorisation task (i.e., classifying faces as over and under the age of 18) with ambient faces, we manipulated facial orientation (upright and inverted) and exposure duration (250 and 2000 ms) to examine their unique and interactive effects on age classification accuracy. Across two experiments, age classification accuracy was impaired by inverting faces. Additionally, overall accuracy was improved when participants were required to view the faces for the full length of the long duration (2000 ms) (experiment 2), but not when they had the opportunity to respond earlier than the end of stimuli (experiment 1). However, there was no interactive effect of exposure duration and facial orientation. These findings suggest that accurate age classification relies on facial information that is disrupted when inverted.