Preparing and Motivating Behavior Outside of Awareness

Abstract

T he observation that the mere activation of the idea of a behavioral act moves the human body without the person consciously deciding to take action has long been a topic of scientific interest (1-3). Initially, this ideomotor principle was used to explain extraordinary activities such as compliance under hypnosis, automatic writing, dowsing, and swinging pendulums. Lately, research on social cognition and neuroscience has revealed that seeing or reading about a behavior available in the individual's repertoire increases the tendency to perform it, which has been interpreted as a result of the common code that action concepts share with motor programs. Whereas activating the mental representation of behavior outside of awareness-that is, subliminal priming-indeed prepares people to initiate rapidly the corresponding behavior, an important issue recently addressed is how such subliminal priming effects may acquire an intrinsic motivational property in the sense that people mobilize additional resources and actually spend effort on a task (4). We studied the emergence of such unconscious motivation by examining how subliminal priming of the action concept of physical exertion causes people to spend effort.Building on research on the basic role of affective value in reward learning and motivation, we propose that the mechanism that turns subliminal priming of action concepts into motivation relies on the tagging of positive affect to the action concept (5). Specifically, we investigated that activating the behavior representation of exertion through subliminal priming prepares the execution of the corresponding behavior and that this priming actually motivates effortful behavior when that representation is coactivated with positively valenced stimuli that act as a reward signal. To test this, we subjected 42 participants to a priming task that enabled us to combine the subliminal priming of words representing exertion with briefly presented, although consciously visible positive words [Supporting Online Material (SOM) text]. Accordingly, three different conditions were created: a (control) condition in which only positive stimuli were presented, a (priming) condition in which exertion was subliminally primed but not directly paired with positive stimuli, and a (primingplus-reward) condition in which exertion was subliminally primed and immediately linked to positive stimuli.After the manipulations, we recorded handgrip force, which allowed us to differentiate between action preparation and motivation. Participants were instructed to squeeze a hand grip for 3.5 s when the word "squeeze" appeared on the screen. Results (Fig. 1) showed that participants in the priming and priming-plus-reward conditions started to squeeze earlier and increased their force faster than those in the control condition: The reaction time was shorter, and the initial slope toward the maximal force (rate of increase in applied force) was steeper in these two priming conditions. This faster initiation of the response to squeeze the hand grip ...

How emotion context modulates unconscious goal activation during motor force exertion

“…disappeared. These stimuli presentation durations are similar to those used in other emotion and subliminal word prime experiments (Aarts et al, 2008;Gaillard et al, 2006;Pessiglione et al, 2007;Schmidt et al, 2009;Silvestrini and Gendolla, 2013), adapted for use within an MRI environment and our screen refresh rate constraints.…”

“…A related line of investigation on goal pursuit shows that implicit emotional priming can also modulate the engagement of goal-directed behaviour (Aarts et al, 2008;Custers and Aarts 2005;Marien et al, 2012). Of particular interest, Aarts et al, (2008) demonstrated enhanced effort exertion (increased grip-force production) following combined priming of subliminal exertion words (e.g., vigorous) and consciously visible positive words (whose meaning was unrelated to exertion, e.g., good), compared to priming with either exertion or http://dx.doi.org/10.1016/j.neuroimage.2016.11.002 Received 21 June 2016; Accepted 4 November 2016 positive words alone.…”

“…A visible high arousing (pleasant or unpleasant; matched for arousal) or low arousing (neutral) visual scene was presented, followed by a subliminal word prime related to either action or inaction or had no such meaning (control word). We chose to present the action concept priming subliminally rather than the emotion priming to avoid explicit demand effects due to the visible action meaning, and to maintain consistency with previous concept priming paradigms (e.g., Aarts et al, 2008;Gendolla and Silvestrini, 2010). Following the subliminal word prime, participants generated a maximal force contraction by pressing on a force device using a precision-grip.…”

“…Based on previous behavioural work reviewed above, we predicted that if conceptual and emotional priming share features with extrinsic reward (Zedelius et al, 2014), then positive affect paired with action concepts may activate common goal representations (see for example, Aarts et al (2007); Aarts et al (2008)), so as to enhance motivational value and maximal force output, relative to negative affect paired with inaction concepts, even without conscious awareness of the actioninaction primes. At the brain level, such effects should be accompanied by increased recruitment of emotion, reward, and motor circuits (including amygdala, basal ganglia, ventrolateral PFC, and possibly upper brainstem structures).…”

“…Of particular interest, Aarts et al, (2008) demonstrated enhanced effort exertion (increased grip-force production) following combined priming of subliminal exertion words (e.g., vigorous) and consciously visible positive words (whose meaning was unrelated to exertion, e.g., good), compared to priming with either exertion or http://dx.doi.org/10.1016/j.neuroimage.2016.11.002 Received 21 June 2016; Accepted 4 November 2016 positive words alone. Thus, when tagging action concepts with affect, positive stimuli appear to act as a reinforcing/rewarding signal to promote the mobilization of physical resources for goal attainment, even in the absence of conscious awareness and without any extrinsic reward.…”