Converging evidence for de-automatization as a function of suggestion.

At least for some individuals, suggestion seems capable of easing certain automatic processes back into the purview of control. Unrelated to hypnosis and suggestion, a number of accounts have challenged the automaticity of the Stroop effect, demonstrating reduction of Stroop interference (Besner, 2001; Besner and Stolz, 1999a, 1999b, 1999c; Besner, Stolz & Boutilier, 1997; Dishon-Berkovits & Algom, 2000; Kuhl and Kazén, 1999; Long and Prat, 2002; Melara and Algom, 2003; Pansky and Algom, 2002). Furthermore, as Kihlstrom (2011) acknowledges and as we expound on elsewhere in this issue (Lifshitz, Campbell & Raz, 2012), findings from meditative practices coincide with the effects of suggestion on Stroop performance. In this paper we review converging evidence from multiple independent groups of researchers replicating the removal of Stroop interference as a function of suggestion, and expound on nuances of nomenclature regarding suggestibility (Kihlstrom, 2011). In line with our own results using a classic Stroop paradigm (Raz, 2004; Raz & Campbell, 2011; Raz, Fan, & Posner, 2005; Raz, Moreno-Iniguez, Martin, & Zhu, 2007; Raz, Shapiro, Fan, & Posner, 2002; Raz et al., 2003), several research groups have independently reported reduced Stroop interference following suggestion. Casiglia et al. (2010), for example, reproduced our findings showing that a posthypnotic suggestion for ‘‘alexia’’ diminished the word-color Stroop interference effect in highly suggestible individuals (HSIs). Furthermore, research groups from Italy (Augustinova & Ferrand, 2012) and England (Parris, Dienes, & Hodgson, 2012) have recently reported data demonstrating improved performance on standard Stroop tasks as a function of suggestion, although the improvement did not appear to generalize to a ‘‘semantic’’ variant of the task (Augustinova & Ferrand, 2012). In addition to these contemporary accounts, an esoteric report by Sun (1994), written in Chinese, examined the influence of suggestion on Stroop interference. Following a hypnotic induction, HSIs and LSIs performed a Stroop task with and without the following suggestion: