Hitachi Ltd. (TSE:6501) and Foundation for Brain Function and Diseases (Institute of 
Neuropathology) today announced that they have achieved the world's first observation of infant 
brain functions using optical topography1).  The method used by the team (see Fig.1) images 
blood volume within the cerebral cortex by illuminating the subject's scalp with very weak near-
infrared light2).  As the method is little affected by head movements, brain activity can be 
monitored while the subject behaves normally.  The research team used optical topography to 
obtain a first-ever view of infant brain plasticity. This breakthrough is expected to speed up 
development of examination and research tools for elucidating the process of brain development 
in infants.

The extremely high plasticity of an infant's brain suggests the possibility of at least partially 
overcoming brain-related disorders by functional training if the underlying abnormality can be 
discovered early.  This is one reason why brain scientists have shown increasing interest in how 
brain functions develop, stage by stage, in the earliest years of life. Although safety is the first 
concern when working with infants, special care must also be taken to avoid a frightening 
experience.  This means that examinations should be conducted under the most natural 
conditions possible. Conventional technologies employed to observe brain functions, such as 
functional MRI and magnetoencephalography, fail on this point because they require the head to 
be stationary during the examination.  The infant has to be put under anesthesia or given a 
sleeping drug.  Brain images usable to analyze the development of high-level cognitive 
functions such as language and image recognition have therefore been hard to obtain.

The optical topography used by the Hitachi and Institute researchers offers a new method of 
brain function observation that can tolerate more head movement than the earlier methods.  
Since the infant's head does not have to be immobilized, the examination can be conducted with 
the baby resting normally.

Fig.2 shows an image of the brain of an eight-year-old girl obtained with an optical topography 
system of Hitachi Medical Corporation.  Owing to an accident at birth, the central nerves of the 
girl's parietal lobe - the nerves responsible for sensing stimuli and controlling body movement - 
almost completely atrophied on both sides and were thought to be substantially extinct.  When 
the girl's brain was examined by optical topography, however, it was found that the frontal lobe 
was compensating for the impaired functions. The girl can today respond to a greeting by smiling 
and moving her limbs, proof that a positive training program can promote functional 
development.

In Fig.3, the examination results are shown for a one-year-old girl who had lost all but a portion 
of the cerebrum and had been diagnosed as totally blind.  The functioning of the remaining brain 
was checked by operating a stroboscope in front of the girl's eyes while simultaneously 
measuring the brain's reaction at the rear of the head.  A distinct increase was detected in the 
amount of blood in the examined region, indicating response of the brain to the light stimulus.  
The girl clearly had the ability to sense light even though much of the brain was missing.

These two cases show that observation of brain plasticity has been made possible for the first 
time by optical topography.

With applications also expected in the field of education, the need for observation and 
measurement of brain development is expected to increase.  Hitachi intends to move forward 
with broad-ranging research both in the basic fields of cognitive neuroscience and in medical and 
welfare applications.

A paper outlining some aspects of the research is to be read at the International Symposium on 
Cerebral Blood Flow and Metabolism (Brain '99) that opens in Copenhagen on June 13.


Notes:
*1 Optical topography
   A new technique of using light to obtain two-dimensional images of the cerebral cortex.  Optical 
fibers are used to project light and pick up reflected light.  To produce images of brain functions, 
optical fibers are arranged in a two-dimensional array and reflected light corresponding to each 
point is measured simultaneously.  Since the apparatus is portable and simple to operate, it can be 
used to carry out examinations virtually anywhere, including at the bed-side.

*2 Near infrared light
  This refers to light having a wavelength of 800 nm to 2000 nm.  While it varies from person to 
person, light of around 800 nm is perceived as being a faint red.  Near infrared light is more 
readily transmitted by the body than visible or infrared light.