Individual and ensemble object perception in naturalistic scenes
Tue-Main hall - Z3-Poster 2-6008
Presented by: Yanina E. Tena Garcia
Object positions can be encoded for each object individually or as an ensemble. The comparison of individual and ensemble perception has so far been studied with stimuli presented in front of simplistic backgrounds. Here, we investigated individual and ensemble object perception in complex naturalistic scenes. In the experiment, six kitchen objects were presented in either a structured kitchen background or an unstructured, texturized background, for one of three encoding times (100, 800, or 3200 ms) in the initial, Encoding phase. Later, in the Response phase, participants indicated via mouseclick the remembered position of one specified object (Individual condition) or the average position of all six objects (Ensemble condition) in the empty scene. While we did not find a systematic influence of scene background on individual and ensemble perception, we did find higher locating accuracy in the unstructured compared to the structured background condition for the 100 ms condition. Locating accuracy was also higher for individual compared to ensemble encoding in the 800 and 3200 ms encoding conditions. Additionally, eye movements speak for different strategies for encoding individual and ensemble information: More fixations and larger saccades were performed in individual compared to ensemble trials. Further, more fixations were directed toward the target objects in individual encoding, whereas more fixations were directed between these objects in ensemble encoding. Overall, our findings suggest that there is no general benefit of naturalistic scenes for individual and ensemble object perception, but that such benefits rather depend on stimulus encoding time.
Keywords: spatial perception, scene perception, object localization, eye movements, ensemble perception