Magnetic stimulation studies of visual cognition

The panoply of non-invasive techniques for brain imaging is responsible for much of current excitement in cognitive neuroscience; sensory, perceptual and cognitive behaviour can now be correlated with cerebral blood flow as assessed by functional imaging, the electrical fields generated by populations of neurons or changes in magnetic fields created by electrical activity. Correlations between localized brain and behaviour, however, do not of themselves establish that any brain area is necessary for a particular task; necessity is the domain of the lesion technique. al magnetic stimulation (TMS) is a technique that can be used non-invasively duce reversible functional disruption and has already been used to investigate detection, discrimination, attention and plasticity. The power of TMS as a 'lesion' technique lies in the opportunity to combine reversible disruption with high degrees of and temporal resolution. In this review we trace some of the major,developments in the use of TMS as a technique for the investigation of visual cognition.