Brain measurement apparatus

A brain measurement apparatus comprising:

• a magnetoencephalograph having:
• a cell in which alkali metal vapor is filled,
• a pump laser configured to emit pump light for exciting alkali metal atoms constituting the alkali metal vapor,
• a probe laser configured to emit probe light for detecting a change in electron spin in an excited state of the alkali metal atoms to a sensitivity region intersecting the pump light in the cell,
• an optical sensor configured to detect a polarization plane angle of the probe light having passed through the sensitivity region,
• a bias magnetic field coil configured to apply a bias magnetic field in a same direction as a direction of the pump light and determine a resonance frequency of the electron spin, and
• a bias magnetic field gradient correction coil configured to correct a gradient of the bias magnetic field;
• and
• an MRI apparatus having:
• a static magnetic field coil for applying a static magnetic field,
• a gradient magnetic field coil for applying a gradient magnetic field,
• a transmission coil for transmitting a transmission pulse of a predetermined frequency, and
• a receiver coil configured to detect a nuclear magnetic resonance signal generated by transmission of the transmission pulse, wherein
• at least one of the static magnetic field coil and the gradient magnetic field coil is configured by a same coil as the bias magnetic field coil or the bias magnetic field gradient correction coil.