How habits become compulsions? Exploring habit perseveration in OCD.

Paula Banca, a researcher with the Department of Psychology at the University of Cambridge is working on a study exploring habit perseveration in OCD.

The study is testing whether compulsions might result from a disruption in the balance between two distinct but interactive brain systems: the goal directed system, which supports behaviors that are intentional and sensitive to goal value and the habitual system, which underlies more automatic actions. To look at this, this study will implement real habits in the laboratory to directly investigate the neural mechanisms underlying the transition from habits to compulsions.

The purpose of this study is to investigate how people acquire new habits and how habits can sometimes become inflexible, leading to compulsions, which is a major component in Obsessive-Compulsive Disorder.

Why have I been invited?

You have been invited because we are looking for individuals who are affected with OCD to take part in this study and you have expressed a potential interest in participating in this research study.

Do I have to take part?

It is up to you to decide. We will describe the study and go through this information sheet, which we will then give to you. We will then ask you to sign a consent form to show you have agreed to take part. You are free to withdraw at any time, without giving a reason. This would not affect the standard of care you receive.

What does the procedure involve?

If you are eligible to participate in the study, you will be invited to attend two test sessions of approximately three hours each. Each of them will comprise a brain scan and computerised tasks that involve judging items and making decisions. There will also be practising at home of the finger sequence task on your app for 5-10 minutes daily for 1 month. The sessions will be at the Wolfson Brain Imaging Centre, at Addenbrooke’s Hospital, Cambridge. In the first session, you will complete two simple computerised tasks (your choices will be made by pressing buttons and using a joystick) as well as a brain scan (max. 60 min). Then you will be asked to fill in a few questionnaires about your mood and behaviour and download an application to your mobile phone.

If you don’t own a smart phone which can support our application, we will provide you with one for the full duration of the experiment. You will be required to return the borrowed mobile device at the conclusion of the study as these are the property of the University of Cambridge. We will ask you to use this app at home to practice two different finger movement sequences, similar to playing 2 small melodies on a piano (tapping your fingers on the screen). The app is self-instructed so you will be guided on learning the finger sequences.

This training will last for a month and a minimum daily practice will be required, which will take no more than 5 to 10 minutes. You don’t have to practice at particular times but whenever you can. The second session will take place 4 weeks after your first visit (when your “piano training” is completed). This session will be similar to the previous one, comprising a brain scan and two last computerised tasks. This second session will also last 3 hours.

In some of the computerised tasks, you will be receiving feedback consisting of mild electric shocks or aversive noises. These stimuli will be adjusted to your experience such that you perceive it as unpleasant but not painful. This adjustment, comprising a work-up procedure, will be done before the experiments. In this procedure, you will be first given a very mild shock (or noise), which is so low that most people can't even detect it! Then, a series of shocks (or noises) gradually increasing in intensity will be given until reaching a level you indicate as “uncomfortable, but not painful”. This rating is done using a scale from 0 (no pain) to 10 (excruciating pain), in which “uncomfortable, but not painful” should correspond to a rating of 6-7. This pre-test procedure ensures that the intensity of the shocks and noises are tailored for you. Once the intensity of these aversive stimuli is defined, the experiment will start and those levels are kept constant throughout the test.

We will also capture your skin conductance responses to measure your level of arousal. This recording is not uncomfortable or invasive. If you participate in a brain scan a member of staff will ask you some questions to ensure that you have no metal within you before you enter the strong magnetic field.

What are the possible benefits of participating in this study?

We will pay you in total approximately £140, more or less depending on your performance in the tasks. We will also cover your travel expenses. Apart from the monetary compensation, there might not be direct therapeutic benefits of taking part in this study. However, you will have the pleasure of knowing that you have made a significant contribution to our understanding of OCD, which hopefully will help many patients in future.

Will I be contacted for further studies?

In the consent form, you will be asked whether you agree to be contacted for further studies. You may or may not be contacted. However, if you are contacted, you are under no obligation to participate in a further study if you do not wish to. In addition, you are free to withdraw from a study at any time without giving a reason.

If you are interested you can get in touch with Paula Banca. You can either email her on or call her at: 07481 807290.

The study has received HRA approval, which is attached below. For further information, please read the Participant Information Sheet and Project Summary.