Object recognition within context
Look around you. You see hundreds of things within just a few seconds. You may also note that you are really good at recognizing objects. In this study we investigated the brain regions involved in this. From previous studies we know that one brain region, the lateral occipital cortex (LOC) is active when recognizing objects. Another region, the occipital place area (OPA), is important for recognizing scenes.
The aim of the first experiment was to confirm findings from previous studies, by testing a large group of people.
Have you ever noticed that it is easier to recognize objects when it is in the right surroundings? You would expect a toothbrush in the bathroom, but not in the kitchen. We hypothesized that brain regions for object and scene recognition communicate with each other. The goals of the second study was investigate these interactions. NOTE: We are still working on the article for the second experiment. Therefore, you will not find the results here yet. But stay tooned, they will come soon!
Methods experiment 1
We stimulated the object region and scene region with TMS (read more about TMS in the Neuroscience Methods section). The TMS was applied to interfere with the activity in these brain region when people looked at images. First, they saw images of objects, specifically cars, chairs, cameras and shoes. To make it a little more difficult images were shown quickly and were slightly pixelated. We expected that TMS over the object area (LOC) would make recognition of objects harder. Second, people saw images of scenes, specifically woods, beaches, cities, and kitchens. We expected that TMS over the scene area (OPA) would make recognition of scenes harder. We compared this to stimulation over a control condition (vertex), which is involved in vision.
Results experiment 1
Our results confirmed our expectations and findings from previous research. Interfering with activity in the object region (LOC), with TMS, made it harder to recognize objects. This was indicated by a lower percentage of correctly categorizing objects. Interfering with the scene region (OPA), with TMS, made it harder to recognize scenes. In this situation participants made fewer choices correctly identifying scene categories.
Methods experiment 2
Stay tuned, more info follows after we published our article.
Results experiment 2
Stay tuned, more info follows after we published our article.
Discussion
In the first experiment we replicated previous findings. The lateral occipital cortex is mainly involved in object recognition. The occipital place area is mainly involved in scene recognition.
In the second experiment we found that object and scene regions don't work independent. The communicate with each other. That is why you more easily recognize an object if it is placed in the correct context. Stay tuned, more info follows after we published our article.
Source
Wischnewski & Peelen (2021). Causal evidence for a double dissociation between object-and scene-selective regions of visual cortex: A pre-registered TMS replication study. J Neurosci , 41(4), 751-756. https://doi.org/10.1523/JNEUROSCI.2162-20.2020