Unilateral Muscle Contractions Enhance Creative Thinking
Goldstein, Abraham, Revivo, Ketty, Kreitler, Michal, Metuki, Nili, Psychonomic Bulletin & Review
Following the notion of relative importance of the right hemisphere (RH) in creative thinking, we explored the possibility of enhancing creative problem solving by artificially activating the RH ahead of time using unilateral hand contractions. Participants attempted to complete the Remote Associates Test after squeezing a ball with either their left or right hand. As predicted, participants who contracted their left hand (thus activating the RH) achieved higher scores than those who used their right hand and those who did not contract either hand. Our findings indicate that tilting the hemispheric balance toward the processing mode of one hemisphere by motor activation can greatly influence the outcome of thought processes. Regardless of the specific mechanism involved, this technique has the potential for acting as a therapeutic or remedial manipulation and could have wide applications in aiding individuals with language impairments or other disorders that are believed to be related to hemispheric imbalances.
Creative thinking entails the formation of associative links between otherwise unrelated concepts in order to solve problems in novel ways. As such, it is thought to require divergent thinking, which involves simultaneously considering various ideas, meanings, and approaches in order to derive a solution (Mednick, 1962). One possible approach to investigating the cognitive processes underlying the complex phenomenon of creative thinking is to examine the neural circuits involved. A widely held notion is that the information-processing style used by the right hemisphere (RH) facilitates this type of thinking (Fiore & Schooler, 1998) and has been supported in a recent metaanalytic review (Mihov, Denzler, & Förster, 2010). For example, the RH was found to be involved in reasoning about incompletely specified situations and in the maintenance of ambiguous mental representations (Goel et al., 2007), as well as in set-shift problems (Goel & Vartanian, 2005). Analogously, psycholinguistic studies have shown that the RH induces diffuse activation of a broader semantic field that includes distant, unusual, and seemingly unrelated features, relative to the more constrained activation caused by the left hemisphere (LH; Jung-Beeman, 2005). For instance, studies have documented the relative importance of the RH in divergent semantic processing (Howard-Jones, Blakemore, Samuel, Summers, & Claxton, 2005), in the generation of unusual verbs for presented nouns (Seger, Desmond, Glover, & Gabrieli, 2000), and in comprehending novel metaphors (Arzouan, Goldstein, & Faust, 2007).
Obviously, this approach does not maintain that creativity resides in the RH. As with any other high-level cognitive task, creative thinking involves a wide number of brain regions in both hemispheres working in a complex manner. Nevertheless, the wealth of findings associating RH activity with creative thinking indicate that the mode of operation of the RH (e.g., broad semantic fields, divergence) is particularly advantageous during such tasks; thus, conditions that enhance RH activity might lead to better performance.
The involvement of the RH in creativity has been demonstrated mainly in correlative studies showing a connection between RH activation and creative thinking performance. Our aim in this study was to explore the possibility of enhancing creative thinking by artificially activating or priming the RH ahead of time. Showing that a direct manipulation of the hemispheric balance has an effect on creativity would strengthen the case for the involvement of RH mechanisms. One method to achieve asymmetrical hemispheric activation is by way of unilateral muscle contractions. A number of studies have shown that contraction of the hand or face muscles has an effect on emotion and motivation, presumably by activating the motor and sensory areas of the hemisphere contralateral to the hand (Baumann, Kuhl, & Kazén, 2005; Harmon-Jones, 2006; Peterson & Harmon-Jones, 2008; Schiff, Esses, & Lamon, 1992; Schiff & Lamon, 1989, 1994; Shrira & Martin, 2005). …