Words Have Power: Talking Yourself Towards Changes in Visual Control and Movement Execution
Words have power, they can change how we look at and move within our environments. Words are thought to particularly shape movements supported by strategic processes, actions relying on thinking and open to consciousness for inspection or manipulation, but the specific conditions under which verbalizations influence action and the limits of these interactions remain largely unknown. We investigate whether effects of verbalization on concomitant movements are due to visual-effects (i.e. shifts in the visual information used to locate targets) or semantic-effects (i.e. influenced by word meaning). To evaluate these explanations, four studies were conducted in which conscious monitoring and control of actions (strategic process) was induced by having participants evaluate spatial target features (i.e. ordinal location, comparative distance, comparative direction) and verbalize their decision for the appropriate locative response while moving towards the target. Visual contexts and semantic content were manipulated to investigate the associated movement biases. Visual-effects were evident in all studies, but did not increase with verbalization. Semantic related biases were absent when the locative expression was a number referring to ordinal target location and when the word was arbitrarily uttered and not related to a judgement. However, when the spoken word required consideration of the visual contextual surroundings and the word meaning was aligned with the task at hand, a semantic-visual context effect emerged on movement endpoints, with biases in accordance with the word meaning. This indicates that for semantic-effects at movement endpoint, verbalizations must force examination of the contextual spatial surroundings of the intended target.