The Role of Texture, Shape and Orientation of an Object in the Context of the “Compatibility Effect” of Action Performance and Target Stimuli in Visual Search

Background. Knowledge about how to interact with an object can influence the speed of its identification and categorization. This phenomenon is known as the compatibility effect (CE). Despite extensive research, views on the underlying mechanisms of CE remain inconsistent. A key research question concerns the specific object features that can activate a motor programme, as well as the range of tasks within which CE can emerge. Objectives. The study is aimed at examining the possibility of CE occurrence in a visual search task under controlled conditions, including movement differentiation, distractor congruency, and a limited set of target stimuli (1–2 objects). An additional objective was to explore the role of object shape, orientation, and texture in the selection of a congruent motor programme and the emergence of CE during visual search. Study Participants. Fifty-nine participants aged 18 to 30 years (M = 21.7; SD = 2.52; 44 females) took part in Experiment 1. In Experiment 2, 63 individuals aged 18 to 30 years (M = 20.3; SD = 1.77; 51 females). Methods. In two experiments, participants performed a visual search task while executing a hand movement. It was hypothesised that the texture of the target object could influence the congruent motor programme: grasping a fresh cucumber or tomato would involve a full-hand grip (engaging all fingers), whereas interacting with pickled vegetables would be more compatible with a pinch grip (involving only two fingers). Both experiments followed a mixed design: the type of movement (grasp or pinch) was the between-subjects factor, and the combinations of texture and shape (Experiment 1), and texture and orientation (Experiment 2) were the within-subject factors. Realistic images were used as stimuli. Results. No CE or influence of object texture (“pickling effect”) was found in the visual search task. Search performance was determined by target-distractor colour and heterogeneity, rather than by motor programme congruency. It is assumed that affordance activation requires conditions that are not achievable in a visual search context—such as the presence of a formed intention to act upon the object. Conclusions. Knowledge about how to interact with an object does not affect attentional guidance during visual search. The role of shape, orientation, and texture in selecting a congruent motor programme is more appropriately studied in identification and categorisation tasks that involve an intention to act.