# The effect of age-related decline in physiological activity on the concealed information test

## TL;DR

This study examines how aging affects the accuracy of the Concealed Information Test, a physiological test used in criminal investigations.

## Contribution

The study evaluates the impact of age-related physiological decline on the Concealed Information Test using senior participants.

## Key findings

- Skin conductance response was effective but had a higher proportion of non-responders among seniors.
- Heart rate could detect hidden knowledge with modified baseline correction.
- Respiration was not a diagnostic measure in the test.

## Abstract

A demographic shift towards aging societies necessitates a reexamination of established psychological tests with age-related decline of physiological responsivity in mind. The Concealed Information Test (CIT), a physiological test to detect memory of crime details, is frequently and effectively used in criminal investigations in Japan, a severe case of an aging society. Its validity has been well established, but almost all the support stems from data of young and healthy university students. Yet, the age-related decline in physiological activity is well documented, but it is unclear how the CIT is affected. We examined the robustness of the CIT to the effects of advanced age by subjecting 33 seniors, aged 62-80, to a standard CIT examination, measuring skin conductance response, heart rate, and respiration over two conditions. Once participants were aware of secret information and hid it, and once they were ignorant of the target piece of information. Skin conductance response was an effective measure, but the proportion of non-responders was higher than expected. Heart rate was not diagnostic with the standard transformation procedure, but with a -1-0s baseline correction the test could detect hidden knowledge. Respiration was not diagnostic. Our findings suggest that all three CIT indices are affected by age. Therefore, while modifications to data analysis can partially mitigate age-related effects on CIT accuracy, the overall reduction in physiological indices warrants a cautious approach when faced with senior examinees and highlights the need for further research into age-related physiological changes impacting applied tests such as the CIT.