The RETHINK Study: Could pain catastrophising explain why some women are more likely to attend hospital during the latent phase of labour.

OBJECTIVE: To examine the prevalence of pain catastrophising and identify whether it impacts on the timing of hospital admission when in labour. METHODS: A longitudinal cohort study. Nulliparous women, experiencing an uncomplicated pregnancy in England, were recruited between 25 and 33 weeks gestation. Participants completed two online questionnaires, (1) on recruitment, including the Pain Catastrophizing Scale (PCS) and the Wijma Delivery Expectancy Questionnaire (WDEQ-A) (2) at three weeks postnatal. RESULTS: A total of 389 eligible participants entered the study. The percentage of women who were pain catastrophisers (PCS ≥ 20) was 28.1 %, while 7.6 % had a high pain catastrophising score (PCS ≥ 30). There was no association between pain catastrophising and the timing of hospital admission. The percentage of women reporting fear of childbirth (WDEQ-A score of ≥ 85) was 10.6 %. Fear of childbirth was highly associated with PCS scores (p <.001) at both the lower (≥20) and higher (≥30) thresholds. CONCLUSION: Although not statistically significant, there was a tendency for women who pain catastrophise to present to hospital in the latent phase. The highly significant association between PCS and WDEQ-A scores has implications for the identification of these women and suggests that the PCS can be used as a screening tool to identify those women who have heightened fear around pain and who may also go on to develop clinically relevant fear of childbirth. Further studies are needed to confirm the acceptability of the PCS as a screening tool with women.

Strategies that reduce Stroop interference.

A remarkable example of reducing Stroop interference is provided by the word blindness post-hypnotic suggestion (a suggestion to see words as meaningless during the Stroop task). This suggestion has been repeatedly demonstrated to halve Stroop interference when it is given to highly hypnotizable people. In order to explore how highly hypnotizable individuals manage to reduce Stroop interference when they respond to the word blindness suggestion, we tested four candidate strategies in two experiments outside of the hypnotic context. A strategy of looking away from the target words and a strategy of visual blurring demonstrated compelling evidence for substantially reducing Stroop interference in both experiments. However, the pattern of results produced by these strategies did not match those of the word blindness suggestion. Crucially, neither looking away nor visual blurring managed to speed up incongruent responses, suggesting that neither of these strategies is the likely underlying mechanism of the word blindness suggestion. Although the current results did not unravel the mystery of the word blindness suggestion, they showed that there are multiple voluntary ways through which participants can dramatically reduce Stroop interference.

Can unconscious intentions be more effective than conscious intentions? Test of the role of metacognition in hypnotic response.

While several theories assume that responses to hypnotic suggestions can be implemented without executive intentions, the metacognitive class of theories postulate that the behaviors produced by hypnotic suggestions are intended and the accompanying feeling of involuntariness is only a consequence of strategically not being aware of the intention. Cold control theory asserts that the only difference between a hypnotic and non-hypnotic response is this metacognitive one, that is, whether or not one is aware of one's intention to perform the relevant act. To test the theory, we compared the performance of highly suggestible participants in reducing the Stroop interference effect in a post-hypnotic suggestion condition (word blindness: that words will appear as a meaningless foreign script) and in a volitional condition (asking the participants to imagine the words as a meaningless foreign script). We found that participants had equivalent expectations that the posthypnotic suggestion and the volitional request would help control the conflicting information. Further, participants felt they had more control over experiencing the words as meaningless with the request rather than the suggestion; and they experienced the request largely as imagination and the suggestion largely as perception. That is, we set up the interventions we required for the experiment to constitute a test of cold control theory. Both the suggestion and the request reduced Stroop interference. Crucially, there was Bayesian evidence that the reduction in Stroop interference was the same between the suggestion and the volitional request. That is, the results support the claim that responding hypnotically does not grant a person greater first order abilities than they have non-hypnotically, consistent with cold control theory.