Association Fibersare white matter fibers which connect :
Corresponding areas in two cerebral hemisphere
Cerebral cortex with lower level in brain
Different cortical areas in the same hemisphere
Different cranial nerve nuclei
Association fibers: Connect different cortical areas in the same hemisphere
Projection Fibers: Connect cerebral cortex with lower level in brain (Eg. Brainstem, spinal cord)
Commissural fibers: Connect corresponding areas in the two cerebral hemispheres