Patients with chronic itching often cannot focus their attention on anything else. Psychologists want to help them, but they need more knowledge about itching and attention. Jennifer Becker therefore investigated this relationship in healthy individuals. She will defend her PhD thesis on 25 June.
Why did you, as a psychologist, conduct research into itching?
'After completing my research master's in cognitive neuroscience, I was given the opportunity to pursue a PhD in Antoinette van Laarhoven's project, which investigates the psychological aspects of itching and pain. A large group of people suffer from chronic pain or itching that cannot be remedied medically. From a psychological perspective, we therefore started to think about what we could do for them. Quite a lot of research has been done on pain, but almost none on itching. And that needs to change, because itching can be very severe. People with severe burns, for example, first experience severe pain, and when the wounds heal, they experience severe itching. They often say that this is even worse.'
How did you approach this?
'I conducted research on healthy test subjects, and I focused on attention. Itching and pain are both signals from the body that something is wrong, that your health is at risk. Itching is seen as a warning signal that attracts attention. We know from experience that itching is also "contagious". If I tell you something about lice, you might immediately start scratching. And if you see someone else scratching, you might start itching yourself. Patients with chronic itching often say that itching is so distracting that they can't think about anything else.
'That is why I have conducted research into what we call attentional bias. We looked in particular at the reaction times of test subjects who looked at a computer screen with two images: an arm being scratched and a neutral arm. We also induced itching with small electrodes on the skin and combined this with a reaction task. In follow-up experiments, we tried to manipulate attention using a training method that is also being investigated in people with anxiety disorders, for example. Our hypothesis was that the scratching images and the itching sensations would attract attention more quickly, both subconsciously and consciously, and that it might be possible to distract that attention.'
And what did you discover?
'Almost nothing was as we had expected. Sometimes the outcome was not entirely clear, but in most experiments, the itch images and itch sensations did not attract attention any faster than their neutral counterparts.
Was that demotivating?
'When I published my articles one by one, I did think: why is nothing ever coming of this? Although I knew that a negative result is also a valuable result. But when I looked at it as a whole for the composition of my thesis, I was very happy. We figured it all out and learned a lot. And it has also been very valuable methodologically. We conducted quite complicated experiments, sometimes with more than 120 subjects.
'Moreover, the outcome brought me back to another idea, namely that it may be a matter of attention avoidance. From an evolutionary point of view, this could also be a plausible explanation. When someone is scratching, you may subconsciously think that they have a contagious skin condition and that you should stay away. And if you see a source of itching, such as a nettle, you also take a step aside. Attention avoidance in the case of itching has hardly been studied directly, so that would be interesting.'
Can your research already benefit patients with chronic itching?
'No, and to be honest, I don't think the attention responses of healthy people say anything about patients, I think that other mechanisms are at work. Virtually no attention research has been done on patients with chronic itching, and we have now set up and carried out some great experiments. We can incorporate that knowledge into patient studies.'
What are you working on now?
'I am currently a postdoc in large research projects conducted by Health~Holland and the Ministry of Health, Welfare and Sport on pandemic preparedness. This is more behavioural and policy-oriented research, with many different people, including external parties, involved, and it is also very interesting and educational. It will end later this year, and then I would very much like to return to medical psychology. I now know exactly which questions I would like to work on, and I love devising and conducting experiments.
