The senses of smell, taste, vision, hearing and touch enable perception and interaction with the external environment. Dedicated areas of the brain receive and interpret input from the sense organs of the body. Disruption of any of the senses can provoke marked disability, requiring significant adaptation to overcome the loss of sensory input.
Multiple Brain Areas Involved in Sense of Smell
The perception and interpretation of odors involves multiple areas of the brain. From the odor receptors in the nose, signals travel to the olfactory bulb, thalamus and amygdala on the underside of the brain in a region termed the limbic system. Odor signals from the limbic system relay to the temporal and frontal lobes. These brain areas participate in odor memory and discrimination. In an article entitled, "Smell and Taste Disorders" published in the journal, "American Family Physician," Dr. Steven Bromley reports that approximately 10 percent of patients with head trauma experience impairment in the sense of smell due to damage in brain areas involved in odor perception.
Taste and Odor Perception Interrelated
Taste sensations generated by chemical receptors in the tongue, roof of the mouth and throat enter the brain via the brain stem. As explained in the medical reference text, "Neuroscience: Exploring the Brain," taste signals travel to the limbic system, which also receives and processes sensory input for odors. Information forwards to an area of the brain between the frontal and temporal lobes. The proximity of the brain pathways that process taste and odor helps explain the close interconnection between these two senses.
Occipital Lobes Critical for Vision
The National Institute of Neurological Disorders and Stroke explains that the occipital lobes at the back of the brain process visual input via the optic nerves from the eyes. The occipital lobes share interconnections with other parts of the brain to assist with functions related to vision such as remembering people or places previously seen, naming perceived objects, and emotional associations with visual input.
Temporal Lobes Receive Auditory Input
The auditory cortex of the temporal lobes receives and interprets sound stimuli from the ears, explains "The Merck Manual for Healthcare Professionals." Communications between the auditory cortex and the frontal and parietal lobes of the brain enable the recollection of sounds, the association of sounds with specific circumstances, and identification of the direction from which a sound originates.
Physical Sensations Received by Parietal Lobes
The parietal lobes of the brain enable the capacity to perceive, identify and interpret physical sensations such as touch, temperature, texture, pain, pleasure and pressure, explains psychologist Dr. C. George Boeree of Shippensburg University. Touch perception occurs primarily in the region of the parietal lobe termed the somatosensory cortex. Different areas of the body possess widely varying capacities for touch discrimination. For example, the skin of the finger pads proves significantly more sensitive than the skin of the back.
References
- "American Family Physician"; Smell and Taste Disorders: A Primary Care Approach; Steven M. Bromley, M.D.; January 2000
- "PLoS Biology"; The Human Sense of Smell: Are We Better Than We Think?; Gordon M Shepherd, M.D.; May 2004
- Medline Plus: Limbic System
- "Neuroscience: Exploring the Brain"; Mark F. Bear, Barry W. Connors, Michael A. Paradiso; 2007
- National Institute of Neurological Disorders and Stroke: Brain Basics
