Olfactory modulation of visual attention and preference towards congruent food products: an eye tracking study

In multisensory environments, odours often accompany visual stimuli, directing attention towards congruent objects. While previous research shows that people fixate longer on objects that match a recently smelled odour, it remains unclear whether odours directly influence product choices. Since odours persist in real-world settings, we investigated the effects of repeated odour exposure on visual attention and product choice, accounting for potential olfactory habituation. In a within-participant design, 30 participants completed a task where either a lemon odour (experimental condition) or clean air (control) was paired with congruent lemon-based food images, which varied to prevent visual habituation. We measured eye movements and choice preferences for these food products. Results revealed that participants exhibited longer gaze durations and more frequent fixations on food products congruent with the lemon odour. Repeated odour exposure had no effect on gaze patterns, as participants consistently focused on odour-congruent products throughout the experiment. The intensity and pleasantness of the lemon odour remained stable over time, suggesting no olfactory habituation occurred with this food-related odour. Despite this stable visual attention and odour intensity and pleasantness, participants began to diversify their product choices, selecting fewer odour-congruent items over time. These findings suggest that while odours continue to direct attention towards matching products, repeated exposure may reduce their influence on product choice, highlighting the complex role of olfactory stimuli in decision-making. The study provides insights into how odours interact with visual cues and influence consumer behaviour in prolonged exposure scenarios