We may think of our eyes as cameras, faithfully photographing the things we see and projecting them directly into the brain. In fact, the visual system works more like a sketch artist, piecing together the most likely representation of reality with plenty of interpretation and improvisation. Scientists used to think that specific nerve cells in the brain created ‘maps’ of information about objects, such as how big and which way up they are, by detecting their edges. But what seem like definite shapes and structures may be tricks of the light – for example, strong shadows can fool us into thinking they are edges too. Researchers are now using sophisticated techniques to measure brain activity while volunteers watch images like these, zooming in from big picture to tiny detail or zooming out in the opposite direction, to understand more about how the brain constructs our view of the world around us.
Written by Kat Arney
BPoD stands for Biomedical Picture of the Day. Managed by the MRC London Institute of Medical Sciences the website aims to engage everyone, young and old, in the wonders of biomedicine. Images are kindly provided for inclusion on this website through the generosity of scientists across the globe.