Toni Cunillera

Background: Attentional bias (AB) for palatable foods has been linked to overeating, yet data on its modulation with body-mass index (BMI) and hunger/satiety are inconsistent. We tested whether hunger, sensory-specific satiety and BMI interact to shape automatic capture of attention by real high-calorie snack foods. Methods: Two emotional-attentional-blink (EAB) experiments presented food distractors either 300 msec (lag-3) or 900 msec (lag-9) before a neutral target. Experiment 1 (N = 183; whole BMI range) randomly assigned participants to taste (non-satiated), satiated or non-eating conditions; the snacks eaten (or not eaten) subsequently re-appeared as distractors in the EAB task. Experiment 2 (N = 61; 31 overweight/obese, 30 normal-weight) manipulated hunger/satiety states and snack type (consumed vs. novel) orthogonally, in a double session design. Results: Experiment 1— food images presented at lag-3 reduced target detection compared with lag-9 (OR = 0.61, CI 0.50–0.75, p <.01. Higher BMI predicted a larger AB when hungry, but a smaller AB when satiated (OR = 0.65, CI 0.48–0.88, p < 0.01). Experiment 2— For novel snacks, an interaction revealed that participants with overweight/obesity retained robust AB after satiation, whereas AB declined for participants with normal-weight (OR = 2.45, CI 1.09–5.51, p = 0.03). For snacks just eaten, AB remained significant in both groups (lag-3 vs. lag-9: OR = 0.37, CI 0.25–0.55, p <.001). Conclusions: Real-food cues automatically biased attention regardless of metabolic state, with BMI modulating this effect: even when satiated, individuals with overweight/obesity continue to orient their attention toward both familiar and novel high-calorie foods. These findings suggest that satiety signals alone may be insufficient to curb attentional capture by food in obesity, highlighting the need for interventions that target attentional control and limit food availability.

Food cues that appear in the visual field capture our attention easily and can influence eating behavior. The current study investigated the influence of food-related stimuli on visual attention, considering the macronutrient composition of food items. Images representing sweet and savory foods were employed, the latter consisting primarily of high-protein foods. The participants were primed with these images prior to performing the attentional task. We found that both sets of food images elicited an emotional attentional blink (EAB), but a stronger EAB was observed for the high-protein foods, and this observation was further supported by a negative correlation between the attentional bias (ABias) and the proportion of protein consumed by the participants before the experiment, with participants who consumed less protein exhibiting a stronger ABias toward high-protein foods. These findings suggest that an ABias might also arise to facilitate the consumption of high-protein foods when prior consumption of this macronutrient is low.

Despite the apparent simplicity of the go/no-go (GNG) task, in which individuals selectively respond or withhold responses, there is strong evidence supporting its efficacy in terms of modulating food preferences. Herein, we manipulated sweet taste perception and investigated the no-go devaluation effect that is typically observed due to GNG training with respect to sweet and savory food items. Prior to engaging in a GNG task, one group of participants rinsed their mouths with a liquid solution containing gymnemic acid, thereby transiently and selectively inhibiting sweet taste perception, while another group used a placebo solution. The participants who rinsed their mouths with gymnemic acid exhibited a stronger overall decrease in food evaluations from pre to post training. Furthermore, a pronounced no-go devaluation effect was observed for sweet foods, irrespective of the rinsing solution. Overall, our results support the notion that training in the GNG task can induce changes in the valuation of food stimuli, particularly for sweet foods.

Response inhibition is a fundamental brain function that must be flexible enough to incorporate proactive goal-directed demands, along with reactive, automatic and well consolidated behaviors. However, whether proactive inhibitory processes can be explained by response competition, rather than by active top-down inhibitory control, remains still unclear. Using a modified version of the Eriksen flanker task, we examined the behavioral and electrophysiological correlates elicited by manipulating the degree of inhibitory control in a task that involved the fast amendment of errors. We observed that restraining or encouraging the correction of errors did not affect the behavioral and neural correlates associated to reactive inhibition. We rather found that an early, sustained and bilateral activation, of both the correct and the incorrect response, was required for an effective proactive inhibitory control. Selective unilateral patterns of response preparation were instead associated with defective response suppression. Our results provide behavioral and electrophysiological evidence of a simultaneous dual pre-activation of two motor commands, likely underlying a global operating mechanism suggesting competition or lateral inhibition to govern the amendment of errors. These findings are consistent with the response inhibitory processes already observed in speed-accuracy tradeoff studies, and hint at a decisive role of early response competition to determine the success of multiple-choice action selection.

The metabolic and cognitive systems interact to create the motivational drive that occasionally leads to disrupted consummatory eating behaviors. In this study, we investigated whether stimulus-specific alterations of the inhibitory function are present following a period of food deprivation. Twenty-six participants with normal weight performed the Stop Signal Task (SST) and the Go/No-go (GNG) task to measure response inhibition to food images containing high or low caloric content after following –or not- a 12-hour fasting period. Response inhibition performance in the SST did not exhibit significant differences when considering neither fasting, stimulus type nor food caloric content. We instead found a higher percentage of commission errors in the No-go trials of the GNG task in the fasting session, and specially with high-caloric food items. In contrast, the accuracy in the Go trials was similar between conditions. A mixed logistic regression model confirmed the remarkable impact of fasting on the performance of response inhibition. Overall, our findings support an interpretation of the motivational drive to eat strongly associated with aspects of the inhibitory function underlying high attentional control, rather than to a proper response inhibition per se.