if we show images of the kind i've just shown you to the neurons recorded in the thalamus. that neuron will have very little specificity. in fact if you look at this video what you'll be seeing basically is a cell that's firing. again you'll hear it and the audio track is really vigorous whenever there's light in the middle of the screen. this cell just cares about light. >> i just want to elaborate on what tony said because it's so important. this transformation that you see from the cells to the cortex primary visual cortex but it's a spec tack include because it made one realize that the cortex does a lot more. the lateral -- showed response. in the cortex in response to barbsbars, to edges and differet cells will respond to edges of different orientation. vertical, horizontal or oblique. so there's a tremendous specificity in the whole transformation of having circular fields to linear is a major operation that the brain performs. you can imagine at later stages you can put lines together to have corners, ultimately to have faces. so this is the beginning of how the bra