Left Cerebral Hemisphere

The left cerebral hemisphere is one of the two longitudinal cerebral halves of the human brain. Like its opposite, it is divided into four lobes; frontal, temporal, parietal, and occipital. The left cerebral hemisphere is connected to the right hemisphere through the corpus callosum.

The left cerebral hemisphere motor strip controls movement of the right side of the body. Depending on the severity, a stroke affecting the left cerebral hemisphere may result in functional loss or motor skill impairment of the right side of the body, and may also cause loss of speech.

Linear and analytical reasoning and language skills such as oral articulation of words and grammar comprehension are often lateralized to the left hemisphere of the brain, which contains the Broca's cortical area and the Wernicke's. Dyscalculia is a neurological syndrome associated with damage to the left temporo-parietal junction.

Cerebral Hemispheres

The cerebral hemispheres are the two longitudinal halves into which the cerebrum is divided. The cerebrum (brain) is divided into two hemispheres; a left cerebral hemisphere and a right cerebral hemisphere. These two hemispheres are joined together by the corpus callosum, which is a thick band of white matter made up of myelinated axons connecting the left hemisphere cortex to the right hemisphere cortex. Each cerebral hemisphere takes care of one side of the body, but the motor controls are crossed: the right hemisphere controls the left side of the body, whereas the left hemisphere controls the muscular contractions of the right side of the body.

Although the cerebral hemispheres are very similar in appearance, they differ in their function in most people. The left hemisphere is analytical, logical, and linear, whereas the right is wholistic, intuitive, creative and imaginative. But the most concrete evidence of hemispheric lateralization for one specific ability is language. The major areas involved in language skills, Broca's area and Wernicke's area, are in the left hemisphere. Perceptual information from the eyes, ears, and rest of the body is sent to the opposite hemisphere, as motor impulses are sent out to the opposite side of the body; this is due to the crossing over of motor fibers at the pyramid of the medulla oblongata.