De knipperreflex als maat voor therapie-effect van EMDR?The eye blink reflex as a measure of therapy effect of EMDR?

Earlier studies have shown that horizontal eye movements (EM) during retrieval of a negative memory reduce its emotionality and vividness. The reduction of emotionality and vividness is measured with a Visual Analogue Scale (VAS). This is a self-report measurement. Self-report measurements are known to be susceptible to biases, such as responding socially desirable, or simply wanting to do your very best on a test, even when there is no ‘right’ or ‘wrong’ answer. The solution for this problem lies in the measurement of physiological reactions, such as skin conduction and the startle reflex or more specifically, the eye blink reflex. Earlier research on the use of the eye blink reflex in combination with emotional imagery and emotional pictures shows promising results. EMDR however, is done through autobiographical memories and it is not known how the eye blink reflex reacts combined with autobiographical memories. To fill in the gaps in our knowledge we ran a pilot study examining the essential information needed in order to set up an experiment using EM and the eye blink reflex. This study examined the habituation of the tone used to elicit the eye blink reflex, whether there is a difference in eye blink amplitude between negative, positive and neutral memories, and whether the emotionality, difficulty to retrieve, and vividness of the memories will change after retrieving it multiple times. Results showed that the tone used to elicit the startle response is very easily habituated and dishabituated. A proper habituation process turns out to be essential. Concerning the eye blink amplitude between the different memories no significant differences were found. This is probably due to insufficient habituation before and during the experiment. Concerning the difficulty to retrieve, the vividness and emotionality, results showed that those characteristics are affected by retrieving a memory multiple times. However there were no significant differences yet, meaning a memory can be retrieved at least ten times (with hearing up to 22 stimuli), without significantly altering the emotionality, vividness and difficulty retrieving the memory. The implications and recommendations for future research based on this study are discussed

Dissertation/Thesis

Dutch

J. M. Bakker

Bakker, J. M. (2015). [The eye blink reflex as a measure of therapy effect of EMDR?]. Master's thesis, University of Utrecht). Dutch