106 Are the Androids Dreaming Yet? s LTT | OCR. A Ce ™: E \s ity } es, 4 2 " i ad . i 5 ‘a 4 h ;' ce; ven be Uae , ei ies i oe “j Runs ie bs y j ty } gy NEAR REARS eg r=-0.40 — i : r=0.81 r= 0.87 r=-0.47 LASTS aa. IA TY iF eae \: Rah FoR hes Hulk Odd vied ge | eas ile ] rs Runs [oa & 4 ZF 1 tee , ‘ Sy } 1 : aie ay ©) 4 y ee sgh By Response ws) Response yy to Faces pa toHouses ja mie fMRI second later, and so on down to your feet. What you see at any one time is a slice through a specific section of the body. You can then build up 3D images from these slices and look at the soft watery tissue rather than the hard bone you can see with an X-ray. MRI scans give detailed images but today there are many more imaging tricks you can play. Give the patient gadolinium to eat — a type of paramagnetic material — and this contrast agent will highlight active parts of the brain. You can ‘see’ which parts are active: the location of emotions such as love, joy and even the effect of smells as the brain experiences things. This is still coarse grained information; it shows only the general area of excitation and it does not tell us what is going on at the nerve level, but the images are fascinating. Another recent development in imaging is the diffusion MRI. If you remember your school physics, molecules travel with a random walk: they diffuse along pathways just as people wander along a corridor. If the corridor is full of people, they are jostled around and make little progress. If the corridor is empty, they move in straight lines. This difference in jostling affects the reading in an MRI and allows you to color code the image according to the rate of motion of water along the pathways. You can therefore ‘see’ the rate at which signals flow in the brain and not only locate thoughts, but also see the links between them. HOUSE_OVERSIGHT_015796