Abstract
The human brain is the most important as well as the most complex organ in the human body. From previous chapters, we by now know that the cerebral cortex is the part of the brain that functions to make human beings unique. Distinctly human traits including higher thought, language, and human consciousness as well as the ability to think, reason, and imagine all originate in the cerebral cortex. The cerebral cortex is the outermost portion that can be divided into the four lobes of the brain. Each bump on the surface of the brain is known as a gyrus, while each groove is known as a sulcus. In this chapter, the authors discuss the parietal and occipital lobes of the cortex. It then highlights their functional issues.
TopChapter Outline
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Introduction
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Neuroanatomy of Parietal lobe
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Functioning of Parietal Lobe
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Parietal lobe dysfunction
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Neuroanatomy of Occipital lobe
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Functioning of Occipital Lobe
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Occipital lobe dysfunction
Learning objectives
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To describe neuroanatomy of parietal lobe
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To describe the functioning of parietal lobe
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To explain the various signs and symptoms of parietal lobe dysfunction
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To describe neuroanatomy of occipital lobe
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To describe the functioning of occipital lobe
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To explain the various signs and symptoms of occipital lobe dysfunction
TopParietal Lobe Function
The initial insights into the functions of parietal lobe came for the in depth analysis of the deficits of patients with lesions of the parietal lobe (Critchley, 1953). Subsequent understandings into the mechanisms of parietal function came from neuroanatomical and neurophysiological studies. Inside each hemisphere of parietal lobe, the somatosensory cortex serves the skin area on the contralateral surface of the body. Being divided into the left and right hemisphere, some definite structures play important roles in parietal lobe functioning. These areas with their respective functions are listed below:
Posterior Parietal Cortex coordinates movements and has important role in spatial reasoning which in turn plays a vital role in attention to the new stimulus.
Key Terms in this Chapter
Colour Perception: Color perception is a part of the larger visual system and is mediated by a complex process between neurons that begins with differential stimulation of different types of photoreceptors by light entering the eye. Colour perception for humans is three dimensional.
Apraxias: Apraxia is a motor disorder caused by damage to the brain (specifically the posterior parietal cortex) in which the individual has difficulty with the motor planning to perform tasks or movements when asked, provided that the request or command is understood and the individual is willing to perform the task.
Agnosia: Is the inability to process sensory information. Often there is a loss of ability to recognize objects, persons, sounds, shapes, or smells while the specific sense is not defective nor is there any significant memory loss.
Occipital Lobe: The occipital lobe is one of the four major lobes of the cerebral cortex in the brain of mammals. The occipital lobe is the visual processing center of the mammalian brain containing most of the anatomical region of the visual cortex.
Reading: Reading is the complex cognitive process of decoding symbols to derive meaning. It is a form of language processing. Success in this process is measured as reading comprehension. Reading is a means for language acquisition, communication, and sharing information and ideas.
Space Perception: Space perception is a process through which humans and other organisms become aware of the relative positions of their own bodies and objects around them. Space perception provides cues, such as depth and distance, that are important for movement and orientation to the environment.
Writing: Writing is the process of using symbols to communicate thoughts and ideas in a readable form. Writing is a medium of human communication that represents language with signs and symbols. For languages that utilize a writing system, inscriptions can complement spoken language by creating a durable version of speech that can be stored for future reference or transmitted across distance.
Parietal Lobe: The parietal lobes are one of the four main lobes or regions of the cerebral cortex. The parietal lobes are positioned behind the frontal lobes and above the temporal lobes. These lobes are important to the function and processing of sensory information, understanding spatial orientation and body awareness.