Department of Psychology, Bournemouth University, Poole, UK.
Department of Psychology, University of Sussex, Brighton, UK.
Eur J Neurosci. 2021 Apr;53(8):2819-2834. doi: 10.1111/ejn.15105. Epub 2021 Jan 28.
The mechanisms underpinning the apparently remarkable levels of cognitive and behavioural control following hypnosis and hypnotic suggestion are poorly understood. Numerous independent studies have reported that Stroop interference can be reduced following a post-hypnotic suggestion that asks participants to perceive words as if made up of characters from a foreign language. This effect indicates that frontal executive functions can be more potent than is generally accepted and has been described as resulting from top-down control not normally voluntarily available. We employed eye tracking and pupillometry to investigate whether the effect results from voluntary visuo-attentional strategies (subtly looking away from the word to prevent optimal word processing), reduced response conflict but not overall conflict, Stroop effects being pushed from response selection to response execution (response durations) or increased proactive effortful control given enhanced contextual motivation (as indexed via pupil dilation). We replicated the reduction in Stroop interference following the suggestion despite removing any trials on which eye movements were not consistent with optimal word processing. Our data were inconclusive with regards to conflict type affected by the suggestion in the latency data, although preserved semantic conflict was evident in the pupil data. There was also no evidence of Stroop effects on response durations. However, we show that baseline-corrected pupil sizes were larger following the suggestion indicating the socio-cognitive context and experimental demands motivate participants to marshal greater effortful control.
催眠和催眠暗示后表现出的明显高水平认知和行为控制的潜在机制尚未被充分理解。许多独立研究报告称，在催眠后暗示参与者将单词视为由外语字符组成后，可以减少斯特鲁普干扰。这种效果表明，额叶执行功能可能比通常认为的更有效，并且被描述为来自自上而下的控制，而这种控制通常不是自愿的。我们使用眼动追踪和瞳孔测量法来研究这种效果是否源于自愿的视知觉策略（微妙地将目光从单词上移开以防止最佳单词处理），减少了反应冲突但不是总体冲突，斯特鲁普效应从反应选择推到反应执行（反应持续时间），或者由于增强了上下文动机而增加了积极的努力控制（通过瞳孔扩张来索引）。尽管排除了任何不符合最佳单词处理的眼动试验，但我们仍然复制了暗示后斯特鲁普干扰的减少。关于潜伏期数据中建议影响的冲突类型，我们的数据没有结论性，尽管瞳孔数据显示出明显的保留语义冲突。在反应持续时间上也没有斯特鲁普效应的证据。然而，我们表明，建议后基线校正的瞳孔大小更大，这表明社会认知环境和实验要求促使参与者调动更大的努力控制。
