BRAIN AND LANGUAGE

Psycholinguistic is the study about how language is represented and processed in the brain.

The human brain
The human brain’s weight is about 1400 gram. The task of brain science (or neuroscience) is to understand how the breadth and depth of human experience is coded in brain matter. The brain is composed of nerve cells or neurons that are the basic information processing units of the nervous system. The brain is a mass of interconnected neurons. It is composed of structures which seem to play specific roles in the integrated functioning of the brain.

The cerebral cortex
Comparing with the animal brain, the human brain has the greatest proportion of cortex. The cortex is a grey wrinkled mass that sits like cap over the rest of the brain. It is the human cortex that the secrets of language representation and processing are to be found.

The cerebral hemispheres
The folds of the cortex have two parts: sulci, which are areas where the cortex is folded in, and gyri which are areas where the cortex is folded out towards surface. A very prominent feature is the deep sulcus which extends from the front of the brain to the back. Because of its size, it is called fissure. This fissure is known as the longitudinal fissure. It separates the left and right cerebral hemispheres. There are two reasons why it is considered as the left brain and the right brain. The first reason is that the hemispheres are almost completely anatomically separate. The main connection between them is a bundle of nerve fibres known as the corpus collasum, whose primary function is to allow the hemispheres to communicate with one another. The other reasons for considering the hemispheres to be seperate brains is that they show considerable functional distinctness. In terms of muscle movement and sensation, each hemispheres is responsible for half the body oddly enough. In cognitive function, the left hemispheres seems to excels in analytic tasks such as arithmetic, whereas the right hemispheres excels in tasks which require an overall appreciation of complex patterns such as the recognition of familiar faces and melodies. The left-handers are generally less literalized for language. A consideration of language representation in the brains of left-handers makes matters even more complex. Contrary to what might be expected, few left-handers have a mirror image representation for language (that is, language localization in the right hemisphere).

The lobes of the cortex
Each hemisphere contains substructures which appear to have distinct responsibilities. The substructures of the cortex in each hemisphere are called lobes. The lobes of the cortex can be located with reference to prominent fissures, sulci, and gyri which are useful as orientation point. The central sulcus and lateral fissure are important in the delineation of the cerebral lobes. The frontal lobes lies in front of the central sulcus and the parietal lobe lies behind it. The temporal lobe is the area beneath the lateral fissure. The occipital lobe can be identified as the area to the rear of the angular gyrus. Frontal lobes are responsible in planning, prediction, speech, discrete movements of the body. While parietal lobe are responsible in reading ability, sensation of pain, temperature, touch, pressure and taste. Temporal lobe is for audition, memory processing, sensory integration. And occipital lobe is for visual processing.