Temporal Lobe Function

The human brain is the key element of the nervous system, consisting of about 100 billion nerve cells, called neurons. These cells pass signals to each other through synaptic connections. The brain is responsible for monitoring and regulating body's actions and reactions. It analyzes the sensory information or signals received through the neurons, and continuously responds, controlling the actions and functions of the body.

The brain is divided into two cerebral hemispheres, which are covered by gray matter called cerebral cortex. The cerebral cortex is nearly symmetrical with left and right hemisphere, and is divided into four sections or lobes, namely, frontal lobe, parietal lobe, occipital lobe, and the temporal lobe. Each lobe has a specific function.

Temporal Lobe Facts

The temporal lobe is situated on either sides of the brain, just above the ears. It is a region of the cerebral cortex located anterior to the occipital lobe, and beneath the Sylvian fissure. It is further divided into superior, middle, and inferior temporal gyri (bumps or folds are called gyri, while the deep grooves are called sulci).

The primary auditory cortex, which is responsible for interpreting sounds is located in the temporal lobe. The right temporal lobe controls the left side of the body, and the left lobe controls the right side of the body.

The temporal lobe is mainly associated with processing of auditory stimuli, memory, and speech. Primary dysfunctions of the temporal lobe can result in temporal lobe epilepsy (TLE), memory disorders, and Alzheimer's Disease.

✦ Speech

Speech is governed by the temporal lobe. Wernicke's area, the area at the temporal-parietal lobe junction, is responsible for controlling the mental processing necessary for speech. This part of the brain controls the processes related to speech comprehension and verbal memory.

Damage to the temporal lobe and the underlying white matter results in receptive aphasia (Wernicke's aphasia). Due to this, the person is unable to recognize words or comprehend speech. The person can speak, but is not able to express himself/herself meaningfully. He/she won't understand that what he/she speaks lacks meaning.

✦ Memory

The hippocampus, which plays a crucial role in long term memory retention is located in the temporal lobe. It stores the essential components of memory, that you can recall consciously and describe. These memories can be anything like, facts, events, people, and places.

Thus, the lobe plays an important role in retrieving information stored in the brain. Although occipital lobe function involves visual processing, the formation of visual memories by the temporal lobe helps recognize the objects or persons.

✦ Reading

Reading comprehension and retention entirely depends on the temporal lobe. It processes the sounds and written words into meaningful information. The temporal lobe allows you to remember what you read, and stores the information for you to recollect later.

✦ Emotional Responses

The amygdalae, located deep within the temporal lobes play an important role in processing memory of emotional responses. They enhance mood stability. Any deflection in the activity of these lobe can cause fluctuating or unpredictable moods and behavior. The temporal lobe is also concerned with the expression of fear.

The lobes help classify the memory, and add emotional tone to sensory information. Researchers say that the temporal lobes may be stimulated during spiritual or religious experiences. Those with temporal lobe epilepsy appear to be highly sensitive to extraordinary experiences.

Temporal lobe damage can lead to problems concentrating, long-term memory problems, changes in personality, and changes in sexual behavior.

✦ Auditory Responses

A section in the temporal lobe, known as the primary auditory cortex, is responsible for receiving and interpreting the information that is collected through auditory responses. It responds to different sound frequencies, and helps in determining the location of a particular sound. Temporal lobe dysfunction can lead to deafness.

✦ Visual Processing

The visual memory is processed and interpreted by the lower portions of the temporal lobe. Feelings of conviction and insight are also due to the temporal lobes. So, dysfunction of the lobe can lead to visual agnosia (difficulty recognizing familiar objects) and prosopagnosia (inability to recognize people, faces, unique individual facial features, etc.).

This was all about the temporal lobe and its functions. Trauma, stroke, ischemic or hemorrhagic damage, inflammation in the brain due to certain diseases, tumors, etc., can cause lesions in the temporal lobe. Symptoms of a temporal lobe lesion depend upon what part of the lobe is affected.