Subjects will perform experiments in an at home-setting. The effect of caffeine in coffee will be tested in subjects with computer tests on attention and alertness. Comparison of the results with published results from controlled experiments will indicate the effectiveness of home experiments.

There is increasing interest in the general public in measuring health parameters at home, instead of in a medical setting. Many tests for measuring health parameters are commonly available in drug stores as well as online. When structured, this trend may also be used for performing a randomized intervention trial.

The current study is aimed to evaluate the procedure of performing a non invasive intervention study by subjects themselves performing the tests at home.

The study is designed as a randomized, placebo-controlled, double blind, crossover study.

Subjects have to consume a cup of coffee after an overnight fast. Coffee will be prepared from instant coffee containing either regular coffee or decaff coffee. Each intervention will be given twice.

Effects on alertness and attention will be established by three computerized tests provided by Quantified Mind. The tests will be performed by the subjects at t=0 (baseline, prior to coffee consumption) and t=1h, one hour after coffee consumption, in one go. Each test will be performed during 5 minutes. During the training session the participants will be instructed to get acquainted with the task.

The evaluation of the study concerns the effect of caffeine in the at home setting versus published results, as well as reproducibility of the results.

Inclusion Criteria:

1. Healthy as assessed by the:

   • health and lifestyle questionnaire

2. Adult age (>18y)

3. Able to perform computerized tests

4. Voluntary participation

5. Having given written informed consent

6. Willing to comply with the study procedures

7. Moderate caffeine users

8. Able to use a desk top or laptop with internet access at home

9. Willing to accept use of all nameless data, including publication, and the confidential use and storage of all data 10 Willing to accept the disclosure of the financial benefit of participation in the study to the authorities concerned

Exclusion Criteria:

1. Having a history of medical or surgical events that may significantly affect the study outcome, including attention (ADHD etc), psychological or psychiatric disorders
2. Physical, mental or practical limitations in using computerized systems
3. Use of concomitant medication including medication known for its effects on mood and/or attention (anti-depressives, sleep medication, etc)
4. Alcohol consumption > 28 units/week for males and > 21 units (drinks)/week for females
5. Personnel of TNO of location Zeist or of location Soesterberg, their partner and their first and second-generation relatives