Question

How does taste and smell differ from vision and hearing in terms of the pathway from stimulus to the brain?

My subject is Psychology

Answer 1

The stimuli from each sensing organ in the body are relayed to different parts of the brain through various pathways. Sensory information is transmitted from the peripheral nervous system to the central nervous system. A structure of the brain called the thalamus receives most sensory signals and passes them along to the appropriate area of the cerebral cortex to be processed. Sensory information regarding smell, however, is sent directly to the olfactory bulb and not to the thalamus. Visual information is processed in the visual cortex of the occipital lobe, sound is processed in the auditory cortex of the temporal lobe, smells are processed in the olfactory cortex of the temporal lobe, touch sensations are processed in the somatosensory cortex of the parietal lobe and taste is processed in the gustatory cortex in the parietal lobe. The sensory information is then further processed as it progresses, via the ascending sensory systems (pathways), to the cerebral cortex or to the cerebellum.

Taste - Gustatory information is then transmitted to neurons in the parabrachial nucleus (except in humans, where this step is bypassed), then to the thalamic gustatory area, and gustatory cortex.

Smell - the olfactory nerve is responsible for our sense of smell. The odor information originates in the epithelium of the nasal cavity and is transported to the brain via components of the olfactory nerve (cranial nerve 1 - CNI) and the olfactory pathway.

Vision - The visual pathway is the pathway over which a visual sensation is transmitted from the retina to the brain. This includes a cornea and lens that focuses images on the retina, and nerve fibers that carry the visual sensations from the retina through the optic nerve.

Hearing - The auditory pathway conveys the special sense of hearing. Information travels from the receptors in the organ of Corti of the inner ear (cochlear hair cells) to the central nervous system, carried by the vestibulocochlear nerve.