Rémi Radel

Evidence of Motivational Influences in Early Visual Perception Hunger Modulates Conscious Access

The New Look approach to perception (Bruner, 1957) posits that perception is a constructive process based on several topdown factors, such as individuals’ expectations, needs, and desires. Many classical experiments from the New Look era have provided striking illustrations of the effect of motivation on perception. For example, they have revealed that poor children have a bias to overrate coin size (Bruner & Goodman, 1947) and that hungry people have a bias to overrate the brightness of pictures of food (Gilchrist & Nesberg, 1952). This line of research has not gone without criticisms (e.g., Erdelyi, 1974; McCurdy, 1956), but recent experiments have largely confirmed its validity (Aarts, Dijksterhuis, & De Vries, 2001; Balcetis & Dunning, 2006, 2010). Despite the evidence of an effect of motivation on perception, it is still unknown at which point in the perceptual process motivational influences occur. Visual perception is generally regarded as a serial process that starts with a purely perceptual stage (i.e., early vision), in which features are extracted in visual processing areas of the brain. Early vision is followed by a postperceptual, decision stage, in which the perceptual output is categorized. Top-down influences were traditionally thought to bias only the decision stage, and early vision was described as cognitively impenetrable (e.g., Pylyshyn, 1999; Riesenhuber & Poggio, 2000). However, consistent with the idea that higher-level representations can shape the perceptual stage by a tuning process that influences which features are selected for processing (Schyns, Goldstone, & Thibaut, 1998), recent studies have revealed the existence of top-down influences on perceptual processing (e.g., influences of attention—Carrasco, Ling, & Read, 2004—and conceptual category—Lupyan, Thompson-Schill, & Swingley, 2010). Here, we report a study in which we aimed to test whether motivation can also penetrate and guide early visual processing. All previous research on the effect of motivation on perception has employed clearly visible stimuli: In most of these studies, researchers simply observed how ambiguous stimuli were interpreted. In contrast, in this experiment, we monitored conscious access to masked visual stimuli. This enabled us to focus on the early perceptual encoding stage that occurs unconsciously. Inspired by the method used by Gaillard et al. (2006), we presented words close to the threshold of conscious perception. We expected that participants who had fasted (and were therefore motivated by food) would be more likely than satiated participants to perceive masked food-related words.

The role of (dis)inhibition in creativity: Decreased inhibition improves idea generation

There is now a large body of evidence showing that many different conditions related to impaired fronto-executive functioning are associated with the enhancement of some types of creativity. In this paper, we pursue the possibility that the central mechanism associated with this effect might be a reduced capacity to exert inhibition. We tested this hypothesis by exhausting the inhibition efficiency through prolonged and intensive practice of either the Simon or the Eriksen Flanker task. Performance on another inhibition task indicated that only the cognitive resources for inhibition of participants facing high inhibition demands were impaired. Subsequent creativity tests revealed that exposure to high inhibition demands led to enhanced fluency in a divergent thinking task (Alternate Uses Task), but no such changes occurred in a convergent task (Remote Associate Task; studies 1a and 1b). The same manipulation also led to a hyper-priming effect for weakly related primes in a Lexical Decision Task (Study 2). Together, these findings suggest that inhibition selectively affects some types of creative processes and that, when resources for inhibition are lacking, the frequency and the originality of ideas was facilitated.

Reflective and impulsive processes explain (in)effectiveness of messages promoting physical activity: A randomized controlled trial

OBJECTIVE The present study tested whether taking into account both the reflective and the impulsive processes of physical activity (PA) is helpful in understanding how, and for whom, PA-promoting messages will be (in)effective in changing behavior. METHOD Participants (N = 101) were presented with a persuasive message promoting either PA (experimental condition) or healthy eating (control condition). Reflective intentions to be physically active were assessed both at baseline and after exposure to the message. Impulsive approach tendencies toward PA (IAPA) and sedentary behaviors (IASB) were assessed using a manikin task. The main outcome variable was accelerometer-assessed free time spent in moderate to vigorous physical activity (MVPA) over 1 week after exposure to the message. RESULTS Although the PA-promoting message had no direct effect on MVPA, the results showed that (a) this message increased intentions to practice PA, notably among participants with low or moderate (but not high) baseline intentions; (b) objective MVPA was positively predicted by postmessage PA intentions and IAPA, and negatively predicted by IASB; and (c) postmessage PA intentions predicted MVPA for individuals with low or moderate (but not high) IASB. A follow-up moderated mediation analysis corroborated these earlier results, showing that PA-promoting messages positively predicted MVPA through postmessage intentions only among individuals with low or moderate baseline intentions and low or moderate IASB. CONCLUSIONS By identifying 2 boundary conditions, this study revealed important insights in explaining when PA-promoting messages will be effective to predict objective MVPA and when they will not.

Pushing to the limits: The dynamics of cognitive control during exhausting exercise

This study aimed at investigating concurrent changes in cognitive control and cerebral oxygenation (Cox) during steady intense exercise to volitional exhaustion. Fifteen participants were monitored using prefrontal near-infrared spectroscopy and electromyography of the thumb muscles during the completion of an Eriksen flanker task completed either at rest (control condition) or while cycling at a strenuous intensity until exhaustion (exercise condition). Two time windows were matched between the conditions to distinguish a potential exercise-induced evolutive cognitive effect: an initial period and a terminal period. In the initial period, Cox remained unaltered and, contrary to theoretical predictions, exercise did not induce any deficit in selective response inhibition. Rather, the drop-off of the delta curve as reaction time lengthened suggested enhanced efficiency of cognitive processes in the first part of the exercise bout. Shortly before exhaustion, Cox values were severely reduced - though not characteristic of a hypofrontality state - while no sign of deficit in selective response inhibition was observed. Despite this, individuals susceptibility to making fast impulsive errors increased and less efficient online correction of incorrect activation was observed near exhaustion. A negative correlation between Cox values and error rate was observed and is discussed in terms of cerebral resources redistribution.

The differential effects of prolonged exercise upon executive function and cerebral oxygenation

HighlightsDifferential effects upon executive processes occur during 60 min heavy exercise.Type of cognitive task assessed contributes to variability in responses to heavy exercise.Prefrontal haemodynamics do not mirror executive performance over time.Exercise‐related hyperfrontality, rather than hypofrontality, is observed. Abstract The acute‐exercise effects upon cognitive functions are varied and dependent upon exercise duration and intensity, and the type of cognitive tasks assessed. The hypofrontality hypothesis assumes that prolonged exercise, at physiologically challenging intensities, is detrimental to executive functions due to cerebral perturbations (indicated by reduced prefrontal activity). The present study aimed to test this hypothesis by measuring oxygenation in prefrontal and motor regions using near‐infrared spectroscopy during two executive tasks (flanker task and 2‐back task) performed while cycling for 60 min at a very low intensity and an intensity above the ventilatory threshold. Findings revealed that, compared to very low intensity, physiologically challenging exercise (i) shortened reaction time in the flanker task, (ii) impaired performance in the 2‐back task, and (iii) initially increased oxygenation in prefrontal, but not motor regions, which then became stable in both regions over time. Therefore, during prolonged exercise, not only is the intensity of exercise assessed important, but also the nature of the cognitive processes involved in the task. In contrast to the hypofrontality hypothesis, no inverse pattern of oxygenation between prefrontal and motor regions was observed, and prefrontal oxygenation was maintained over time. The present results go against the hypofrontality hypothesis.

Understanding narrative effects in physical activity promotion: the influence of breast cancer survivor testimony on exercise beliefs, self-efficacy, and intention in breast cancer patients

PurposeResearch in health communication has shown that narratives contribute more positively to changing health behaviors than informational messages. The main purposes of this study were to examine and to compare the effects of two messages promoting physical activity, one narrative and the other informational, on the perceptions and behavioral intentions of cancer patients.MethodsA total of 158 women with breast cancer, undergoing chemotherapy and sedentary, were assigned to read the testimony of a breast cancer survivor who had been physically active during and after treatment (TE group), a content-equivalent message composed of expert recommendations about physical activity in breast cancer patients (RE group), or no message (control group).ResultsSource trust was higher in TE group than RE group (p < 0.001). Exercise self-efficacy and exercise intention were higher in TE group than RE and control groups (p < 0.001). However, scores in RE group were higher than those of TE group for beliefs about exercise benefits (p < 0.001) and lower than those of TE and control groups for beliefs about exercise risks (p < 0.001). Source trust, exercise self-efficacy, and beliefs about exercise benefits and risks mediated the relationship between the message and exercise intention.ConclusionsThe results suggest that narratives may be more effective in improving perceived physical abilities and involvement in physical activity, whereas informational messages seem to be more appropriate to convey the benefits and the absence of risks related to physical activity.

Effects of psychosocial stress on the goal-directed and habit memory systems during learning and later execution

Instrumental learning occurs through both goal-directed and habit memory systems, which are supported by anatomically distinct brain systems. Interestingly, stress may promote habits at the expense of goal-directed performance, since stress before training in an instrumental task was found to cause individuals to carry on with the learned association in spite of a devalued outcome. These findings nevertheless left pending questions, and it has been difficult to determine which system is primarily affected by stress (an improved habit system, an impaired goal-directed system, or both) and at what point the stress acts (at the moment of learning by making more resistant habits, or after devaluation by making individuals less sensitive to change in the outcome value). The present study (N=72 participants, 63 males and 9 females) aimed to answer these questions with (i) an instrumental task that dissociates the two memory systems and (ii) three conditions of psychosocial stress exposure (Trier Social Stress Test): stress induced before learning, before devaluation, and not induced for the control group. The study confirms that exposure to psychosocial stress leads to habitual performance. Moreover, it provides new insight into this effect by locating its origin as an impairment in the capacity of the goal-directed system rather than a reinforcement in habit learning. These results are discussed in light of recent neurobiological models of stress and memory.

Relative age effect and soccer refereeing: A ‘Strategic Adaptation’ of relatively younger children?

Abstract Previous research suggested that the relative age effect (RAE) has a psychological influence on children and their decision to engage in a particular sport. Relatively younger children seem to have lower self-esteem. Indeed, because of the disadvantages of being younger, it is assumed that these players experience more situations of failure and inferiority. Because of these negative performance cues, it is likely that these young players feel less competent, which eventually leads to a higher dropout rate. These children can also decide to participate in sports in which physical attributes are less important. This shift from one sport to another can be interpreted as a ‘strategic adaptation’. The purpose of this study was thus to investigate whether refereeing could be another form of ‘strategic adaptation’. If a child chooses a specific sport but then does not feel competent enough to be a player, refereeing might be an alternate path followed to stay in the environment of a sport they like. Given the minimal age limits for refereeing, two hypotheses were formulated: (1) ‘reversed’ RAE would be observed in district referees younger than 18 years old and (2) no RAE would be observed in district referees older than 18 years old, regional referees and national referees. The birthdates of all official male soccer referees (n=13,952) were collected from the federation database. Results show that the distribution of all district referees was significantly unbalanced (χ2=18.73, df=3, P<0.001) with an over-representation of individuals who were born in the second half of the competitive year. As expected, this imbalance was exclusively located in district referees of 18 years old and less (χ2=8.03, df=3, P<0.05), while the distribution was uniform for adults (χ2=5.17, df=3, P<0.16). Concerning regional referees (χ2=2.09, df=3, P<0.554) and national referees (χ2=3.75, df=3, P<0.290), the results also provide support for our initial hypothesis as uniform distributions were found for both groups. This study brings to light new elements in the potential relationship between relative age and refereeing. Qualitative and/or longitudinal research is needed to confirm our quantitative data.

Behavioral and Neural Evidence of the Rewarding Value of Exercise Behaviors: A Systematic Review

BackgroundIn a time of physical inactivity pandemic, attempts to better understand the factors underlying the regulation of exercise behavior are important. The dominant neurobiological approach to exercise behavior considers physical activity to be a reward; however, negative affective responses during exercise challenge this idea.ObjectiveOur objective was to systematically review studies testing the automatic reactions triggered by stimuli associated with different types of exercise behavior (e.g. physical activity, sedentary behaviors) and energetic cost variations (e.g. decreased energetic cost, irrespective of the level of physical activity). We also examined evidence supporting the hypothesis that behaviors minimizing energetic cost (BMEC) are rewarding.MethodsTwo authors systematically searched, screened, extracted, and analyzed data from articles in the MEDLINE database.ResultsWe included 26 studies. Three outcomes of automatic processes were tested: affective reactions, attentional capture, and approach tendencies. Behavioral results show that physical activity can become attention-grabbing, automatically trigger positive affect, and elicit approach behaviors. These automatic reactions explain and predict exercise behaviors; however, the use of a wide variety of measures prevents drawing solid conclusions about the specific effects of automatic processes. Brain imaging results are scarce but show that stimuli associated with physical activity and, to a lesser extent, sedentary behaviors activate regions involved in reward processes. Studies investigating the rewarding value of behaviors driving energetic cost variations such as BMEC are lacking.ConclusionReward is an important factor in exercise behavior. The literature based on the investigation of automatic behaviors seems in line with the suggestion that physical activity is rewarding, at least for physically active individuals. Results suggest that sedentary behaviors could also be rewarding, although this evidence remains weak due to a lack of investigations. Finally, from an evolutionary perspective, BMEC are likely to be rewarding; however, no study has investigated this hypothesis. In sum, additional studies are required to establish a strong and complete framework of the reward processes underlying automatic exercise behavior.

Testing the effect of text messaging cues to promote physical activity habits: a worksite-based exploratory intervention

This study aims to test the efficacy of text messaging cues (SMS) to promote physical activity (PA) habit formation in the workplace. Employees (N = 49; 28 females and 21 males, Mage = 47.5 ± 8.29 years) were randomized into two parallel groups: a PA group enrolled in a 28‐week supervised PA program and a PA+SMS group enrolled in the same PA program with text messaging cues received before their PA sessions. The exercise habit was assessed every week from self‐reports on an online application. PA maintenance and several physical fitness measures were also assessed prior to and after the intervention to evaluate its general impact. Mixed model analysis of the 603 observations indicated a small but significant effect of the SMS cues on the speed at which participants engaged in PA behaviors, as the significant interaction effect revealed that the slope of the exercise habit over time was slightly steeper in the PA+SMS group (B = 0.0462, P = 0.0001) than in the PA group (B = 0.0216, P = 0.01). SMS delivery had a marginal effect on the maintenance of PA behaviors 1 year after the intervention. The results suggest that text messaging can help to form PA habits at the workplace and might facilitate long‐term maintenance of PA behaviors.