Jem Hebden is currently Director of the Biomedical Optics Research Laboratory (BORL) and Head of the UCL Department of Medical Physics & Bioengineering. BORL is Europe’s largest research facility devoted to biomedical optics, and has pioneered the development of optical instruments and techniques for imaging and monitoring biological tissue. Jem’s group has developed various novel imaging systems for diffuse optical tomography of the brain and female breast. The group has produced the first whole-brain images of evoked functional activity in the newborn infant, and this work is currently focused on the study of hypoxic-ischemic brain injury and infant seizures. In addition, systems have been built for mapping the haemodynamic response in the cortex to sensory stimulation and other cognitive activity in adults, children, and babies, and to acquire EEG measurements simultaneously.