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James W. Kalat. Biological Psychology, 8th Edition. Chapter 7: The Other Sensory Systems and Attention. 1 of 52. Chapter Seven The Other Sensory Systems and Attention. James W. Kalat. Biological Psychology, 8th Edition. Chapter 7: The Other Sensory Systems and Attention. 2 of 52.
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James W. Kalat Biological Psychology, 8th Edition Chapter 7: The Other Sensory Systems and Attention 1 of 52 Chapter SevenThe Other Sensory Systems and Attention
James W. Kalat Biological Psychology, 8th Edition Chapter 7: The Other Sensory Systems and Attention 2 of 52 Sound and the Ear • Sound waves are periodic compressions of air, water or other media • we hear when the sound waves strike our ear • Sound waves vary in amplitude and frequency • amplitude of a wave is the intensity (amplitude must double before it is perceived louder) • frequency is the number of waves per second (if frequency increases we perceive an increase in pitch) • We can hear 15 to 20,000 hertz (Hz, cycles per second) • ability to hear high frequencies falls off with age and repeated loud noises • mice and other small animals can hear higher frequencies
James W. Kalat Biological Psychology, 8th Edition Chapter 7: The Other Sensory Systems and Attention 3 of 52 Figure 7.1 Figure 7.1 Four sound waves. The time between the peaks determines the frequency of the sound, which we experience as pitch. Here the top line represents five sound waves in 0.1 second, or 50 Hz—a very low-frequency sound that we experience as a very low pitch. The other three lines represent 100 Hz. The vertical extent of each line represents its amplitude or intensity, which we experience as loudness.
James W. Kalat Biological Psychology, 8th Edition Chapter 7: The Other Sensory Systems and Attention 4 of 52 Structures of the Ear • Outer ear or pinna • cartilage attached to the side of the head that alters reflections and helps us locate sounds • Middle ear • the tympanic membrane or eardrum vibrates at the same frequency as incoming sound wave • middle ear bones, hammer, anvil and stirrup provide 20:1 step down of vibration • increases force on oval window of inner ear
James W. Kalat Biological Psychology, 8th Edition Chapter 7: The Other Sensory Systems and Attention 5 of 52 Structures of the Ear cont. • Inner ear or cochlea • vibration on oval window, membrane leading to inner ear, moves fluid in three fluid-filled tunnels: • scala vestibuli • scala media • scala tympani • Fluid moves basilar membrane across tectorial membrane and this excites hair cells • hair cells sensitive to movement of 0.1 nanometer or more • Hair cells excite cells of auditory nerve
James W. Kalat Biological Psychology, 8th Edition Chapter 7: The Other Sensory Systems and Attention 6 of 52 Figure 7.2 Figure 7.2 Structures of the ear. When sound waves strike the tympanic membrane in (a), they cause it to vibrate three tiny bones—the hammer, anvil, and stirrup—that convert the sound waves into stronger vibrations in the fluid-filled cochlea (b). Those vibrations displace the hair cells along the basilar membrane in the cochlea. (c) A cross section through the cochlea. The array of hair cells in the cochlea is known as the organ of Corti. (d) A closeup of the hair cells.
James W. Kalat Biological Psychology, 8th Edition Chapter 7: The Other Sensory Systems and Attention 7 of 52 Pitch Perception • Frequency theory • basilar membrane vibrates at same frequency of sound, causing auditory neurons to produce action potentials at the same frequency. • but, neurons can’t fire above 1000 Hz • Place theory • each area of basilar membrane vibrates to a different frequency • but, basilar membrane is bound together and no part can vibrate separately
James W. Kalat Biological Psychology, 8th Edition Chapter 7: The Other Sensory Systems and Attention 8 of 52 Figure 7.4 Figure 7.4 The basilar membrane of the human cochlea. High-frequency sounds produce their maximum displacement near the base. Low-frequency sounds produce their maximum displacement near the apex.
James W. Kalat Biological Psychology, 8th Edition Chapter 7: The Other Sensory Systems and Attention 9 of 52 Pitch Perception cont. • Current theory • up to 100Hz, basilar membrane vibrates in synchrony and auditory neurons produce one action potential per wave • at higher frequencies neurons fire only to some of the waves but are phase locked to peaks of cells • Volley principle • the auditory nerve as a whole can have volleys of impulses up to about 4,000 Hz per second • most hearing above 4,000 Hz not important in human speech or music
James W. Kalat Biological Psychology, 8th Edition Chapter 7: The Other Sensory Systems and Attention 10 of 52 Pitch Perception in the Cerebral Cortex • Auditory pathway • output of inner ear goes to several subcortical structures • crossover occurs at midbrain so that each hemisphere of forebrain gets major input from opposite ear • Primary auditory cortex • a cell responds best to one tone and cells preferring a given tone cluster together • damage impairs ability to recognize complex sounds such as music or conversation; simple sounds not affected
James W. Kalat Biological Psychology, 8th Edition Chapter 7: The Other Sensory Systems and Attention 11 of 52 Pitch Perception in the Cerebral Cortex cont. • Secondary auditory cortex • each cell responds to a complex combination of sounds • Ventral and Dorsal Pathways • ventral pathway to prefrontal cortex tells “what “ the sounds represent • dorsal pathway to prefrontal cortex tells “where
James W. Kalat Biological Psychology, 8th Edition Chapter 7: The Other Sensory Systems and Attention 12 of 52 Figure 7.5 Figure 7.5 Route of auditory impulses from the receptors in the ear to the auditory cortex. The cochlear nucleus receives input from the ipsilateral ear only (the one on the same side of the head). All later stages have input originating from both ears.
James W. Kalat Biological Psychology, 8th Edition Chapter 7: The Other Sensory Systems and Attention 13 of 52 Figure 7.6 Figure 7.6 The human primary auditory cortex. Cells in each area respond mainly to tones of a particular frequency. Note that the neurons are arranged in a gradient, with cells responding to low-frequency tones at one end and cells responding to high-frequency tones at the other end.
James W. Kalat Biological Psychology, 8th Edition Chapter 7: The Other Sensory Systems and Attention 14 of 52 Hearing Loss • Conductive or middle ear deafness • bones of the middle ear fail to transmit sound waves but normal cochlea and auditory nerve • caused by tumors, infection, disease • usually corrected by surgery or hearing aids • can hear own voice as sounds bypass the middle ear
James W. Kalat Biological Psychology, 8th Edition Chapter 7: The Other Sensory Systems and Attention 15 of 52 Hearing Loss cont. • Nerve or inner ear deafness • damage to cochlea, hair cells or auditory nerve • usually treated with hearing aids if no extensive damage • caused by genetics, disease, ototoxic drugs, repeated exposure to loud noises, inadequate thyroid gland, etc. • tinnitus, ringing in the ears, common in old age with loss of high frequency hearing • with loss of cochlea output to forebrain, other axons may invade areas responsive to sound
James W. Kalat Biological Psychology, 8th Edition Chapter 7: The Other Sensory Systems and Attention 16 of 52 Hearing Loss; CNN Today: Biological Psychology, Volume I
James W. Kalat Biological Psychology, 8th Edition Chapter 7: The Other Sensory Systems and Attention 17 of 52 Localization of Sound • At high frequencies, your head creates a sound shadow • sound is loudest in nearest ear • wavelength much shorter than width of head; most accurate between 2-3000 Hz • Low frequencies create phase difference • sounds arrive out of phase dependent on low frequencies where wavelength is less than width of head • accurate up to about 1500 Hz
James W. Kalat Biological Psychology, 8th Edition Chapter 7: The Other Sensory Systems and Attention 18 of 52 Figure 7.9 Figure 7.9 Phase differences between the ears as a cue for sound localization. Note that a low-frequency tone from straight ahead (a) arrives at the ears slightly out of phase. A tone that arrives at an angle (b) can arrive in different phases at the two ears. With high-frequency sounds the phases can become ambiguous.
James W. Kalat Biological Psychology, 8th Edition Chapter 7: The Other Sensory Systems and Attention 19 of 52 Localization of Sound cont. • Time of arrival • arrives at one ear first • about 600 ms delay when sound comes directly from side • good for sudden onset of sound • Mice • small head provides poor localization of low frequencies • good sound shadow for accurate localization of high frequencies • Elephant • large head good localization of low frequencies • but, upper limit of hearing at 10,000 Hz
James W. Kalat Biological Psychology, 8th Edition Chapter 7: The Other Sensory Systems and Attention 20 of 52 The Mechanical Senses • Mechanical senses respond to pressure, bending, or other distortions of a receptor • Vestibular organ monitors movement of head, directs eye compensation and maintains balance • when head tilts, two otolith organs, utricle and saccule push against different hair cells • also, when head moves, jelly-like substance in three semicircular canals cause bending of hair cells • action potentials from cells travel through 8th cranial nerve to brain stem and cerebellum
James W. Kalat Biological Psychology, 8th Edition Chapter 7: The Other Sensory Systems and Attention 21 of 52 Figure 7.10 Figure 7.10 Structures for vestibular sensation. (a) Location of the vestibular organs. (b) Structures of the vestibular organs. (c) Cross section through an otolith organ. Calcium carbonate particles, called otoliths, press against different hair cells depending on the direction of tilt and rate of acceleration of the head.
James W. Kalat Biological Psychology, 8th Edition Chapter 7: The Other Sensory Systems and Attention 22 of 52 Somatosensation • Somatosensory receptors vary in complexity and stimuli that they respond to, e.g.: • Pacinian corpuscle detects sudden displacements or high-frequency vibrations on the skin • Meissners corpuscles • elaborate neuronal endings detect sudden displacement and low frequency vibrations on skin • free nerve endings detect pain, warmth and cold • Ruffini endings detect stretch of skin • Merkels disks detect indentation of skin
James W. Kalat Biological Psychology, 8th Edition Chapter 7: The Other Sensory Systems and Attention 23 of 52 Somatosensation cont • Input to the spinal cord and the brain • touch information from head enters CNS through cranial nerves • below the head, information enters via 31 spinal nerves connecting to 31 dermatomes • sensory pathways to cortex remain separate • Ex: two parallel strips respond to light touch, two others respond mostly to deep touch and movement of the joints and muscles • somatosensory cortex receives input from the contralateral side of the body
James W. Kalat Biological Psychology, 8th Edition Chapter 7: The Other Sensory Systems and Attention 24 of 52 Figure 7.14 Figure 7.14 Dermatomes innervated by the 31 sensory spinal nerves. Areas I, II, and III of face are not innervated by the spinal nerves, but instead by three branches of the fifth cranial nerve. Although this figure shows distinct borders, the dermatomes actually overlap one another by about one-third to one-half of their width.
James W. Kalat Biological Psychology, 8th Edition Chapter 7: The Other Sensory Systems and Attention 25 of 52 Pain • Transmission • for moderate pain axons release glutamate • stronger pain: axons release glutamate and substance P • mice without substance P cannot detect severe injury
James W. Kalat Biological Psychology, 8th Edition Chapter 7: The Other Sensory Systems and Attention 26 of 52 Pain cont. • Opoid mechanisms in brain reduce pain • endorphins, e.g., neurotransmitters met-enkephalin and leu-enkephalin, bind to opiate receptors • endorphins are stimulated by pain, especially inescapable pain, sex, long-distance running and thrilling music • supports gate theory of pain that non-pain stimuli can reduce pain • Endorphins released in the periaqueductal gray area results in blocking release of substance P, reducing pain
James W. Kalat Biological Psychology, 8th Edition Chapter 7: The Other Sensory Systems and Attention 27 of 52 Figure 7.15 Figure 7.15 Synapses responsible for pain and its inhibition. The pain afferent neuron releases substance P as its neurotransmitter. Another neuron releases enkephalin at presynaptic synapses; the enkephalin inhibits the release of substance P and therefore alleviates pain.
James W. Kalat Biological Psychology, 8th Edition Chapter 7: The Other Sensory Systems and Attention 28 of 52 Painful Heat • Body has special heat receptors that respond to burns or high heat above 43 degrees centigrade • capsaicin stimulates heat receptors and causes neurons to release substance P, increasing pain • but, capsaicin leaves you temporarily insensitive to pain because neurons are quickly depleted of substance P
James W. Kalat Biological Psychology, 8th Edition Chapter 7: The Other Sensory Systems and Attention 29 of 52 Pain and Emotion • Hurt is an emotion • we can ignore serious injury at times, e.g., soldier in battle • placebo, drug with no effect, can relieve pain anesthesia • also, analgesic is more effective when you know it is being given
James W. Kalat Biological Psychology, 8th Edition Chapter 7: The Other Sensory Systems and Attention 30 of 52 Pain and Emotion cont. • Cingulate cortex reacts to emotional aspect of pain, not the sensation • painful stimulus to skin results in response • no response to pin prick when person is told it will not hurt • expectation of pain leads to response to moderately warm stimulus • when damaged in rats, they will react to pain on foot but will not learn to avoid the place where it was received
James W. Kalat Biological Psychology, 8th Edition Chapter 7: The Other Sensory Systems and Attention 31 of 52 Sensitization, Pain Control and Itching • Damaged tissue increases number of sodium gates in nearby receptors to magnify pain • facilitates activity at capsaisin receptors, increasing pain • anti-inflammatory drugs, e.g., ibuprofen, decrease pain by reducing the release of chemicals from damaged tissues • Morphine for pain control • very effective it reducing serious pain • post-surgical use recommended
James W. Kalat Biological Psychology, 8th Edition Chapter 7: The Other Sensory Systems and Attention 32 of 52 Sensitization, Pain Control and Itching cont. • Itch • caused by release of histamines when skin is irritated • inhibitory relationship with pain, e.g., when novocaine wears off, you feel itch but face is still numb
James W. Kalat Biological Psychology, 8th Edition Chapter 7: The Other Sensory Systems and Attention 34 of 52 Chemical Senses • Sensory and auditory systems operate on principle of “across fiber pattern” coding • each receptor responds to a wider range of stimuli and contributes to the perception of them • Ex: only three types cones in retina but ratio of three responses determines many colors • Ex: hair cell receptors respond to certain frequency tone and in phase with a number of tones • Also, in taste and smell systems, the meaning of a particular response by a receptor depends on the context of responses by other receptors
James W. Kalat Biological Psychology, 8th Edition Chapter 7: The Other Sensory Systems and Attention 35 of 52 Taste • Taste influenced by smell • lose sense of smell and taste is impaired • Taste receptors • modified skin cells that are sloughed off and replaced every 10-14 days • also, like neurons, they have excitable membranes and release neurotransmitters • in taste buds, located in papillae • mainly along outside edge of tongue • some on tip and posterior third of tongue • virtually nonexistent in center of tongue
James W. Kalat Biological Psychology, 8th Edition Chapter 7: The Other Sensory Systems and Attention 36 of 52 Figure 7.18 Figure 7.18 The organs of taste. (a) The tip, back, and sides of the tongue are covered with taste buds. Taste buds are located in papillae. (b) Photo showing cross section of a taste bud. Each taste bud contains about 50 receptor cells.
James W. Kalat Biological Psychology, 8th Edition Chapter 7: The Other Sensory Systems and Attention 37 of 52 Taste cont. • At least 4-5 kinds of taste receptors and their mechanisms • sweet, bitter, and, likely, umami (glutamate) • receptors operate much like a metabotropic synapse activating a G protein that releases a second messenger within cell • salty: detects the presence of sodium • the higher the concentration the stronger the response • sour: closes potassium channels preventing potassium from leaving the cell creating a depolarization
James W. Kalat Biological Psychology, 8th Edition Chapter 7: The Other Sensory Systems and Attention 38 of 52 Taste cont. • Taste adaptation • decreased sensation from repeated stimulus • Ex: soak your tongue in sour solution and then other sour solutions taste less sour • Cross adaptation: reduced response in one taste after exposure to another but very little adaptation across the five tastes
James W. Kalat Biological Psychology, 8th Edition Chapter 7: The Other Sensory Systems and Attention 39 of 52 Taste cont. • Coding of taste depends on a pattern of responses across fibers, e.g. sweetness excites sweet receptors and other receptors to determine how sweet substance is • Anterior two-thirds of tongue carried to brain by chorda tympani, a branch of 7th cranial nerve • loss of taste here and the posterior of tongue would still provide taste sensations and would be more sensitive to bitter, somewhat more sensitive to sour and sweet, and less to salt • posterior becomes more active and may release tastes when nothing is there
James W. Kalat Biological Psychology, 8th Edition Chapter 7: The Other Sensory Systems and Attention 40 of 52 Taste cont. • Taste nerves project to nucleus of the tractus solitarius (NTS) in medulla • then branches to the pons, the lateral hypothalamus, the amygdala, the ventral-posterior thalamus, • and two areas of cortex, one for taste and one for sense of touch
James W. Kalat Biological Psychology, 8th Edition Chapter 7: The Other Sensory Systems and Attention 41 of 52 Taste cont. • Differences in taste • some people have a gene for tasting phenythiocaramide (PTC) and others do not • nontasters also less sensitive to bitter, sour, salt tastes • supertasters have highest sensitivity to all tastes • Unlikely to enjoy black coffee, strong beer, tart fruits, dark bead, brussels sprouts, cauliflower, etc.
James W. Kalat Biological Psychology, 8th Edition Chapter 7: The Other Sensory Systems and Attention 42 of 52 Figure 7.19 Figure 7.19 Major routes of impulses related to the sense of taste in the human brain. The thalamus and cerebral cortex receive impulses from both the left and the right sides of the tongue. (Source: Based on Rolls, 1995).
James W. Kalat Biological Psychology, 8th Edition Chapter 7: The Other Sensory Systems and Attention 44 of 52 Olfaction • Cilia (dendrites) of receptors extend to mucous of the sinus • receptors survive for little over a month and are replaced • rapid adaptation to scent • each receptor axon sends impulses to olfactory bulb • each odor excites same receptors and same part of olfactory bulb • Olfactory bulb sends axons to precise areas of cortex • each odor sends information to same cluster of cells
James W. Kalat Biological Psychology, 8th Edition Chapter 7: The Other Sensory Systems and Attention 45 of 52 Figure 7.21 Figure 7.21 Olfactory receptors. (a) Location of receptors in nasal cavity. (b) Closeup of olfactory cells.
James W. Kalat Biological Psychology, 8th Edition Chapter 7: The Other Sensory Systems and Attention 46 of 52 Olfaction cont. • Identifying olfactory receptors • people have specific anosmias for isobutyric acid, and musky, fishy, urinous and malty odors • perhaps 26 other specific types of anosmia • one receptor can identify approximate nature of odor • a family of proteins have been identified within receptors • its estimated that humans have several hundred proteins • mice have about 1000 proteins and can distinguish odors that seem the same to humans
James W. Kalat Biological Psychology, 8th Edition Chapter 7: The Other Sensory Systems and Attention 47 of 52 Vomeronasal Organ (VNO) • Located near olfactory receptors but structurally different • Receptors respond only to pheromones, chemicals released by animal that affects sexual behavior of other animals • Tiny in adult humans but responds to skin secretions • cause increased activity in hypothalamus, area important for sexual behavior • women who spend time together have synchronized menstrual cycles • Intimate relationships increase regularity of menstrual cycle
James W. Kalat Biological Psychology, 8th Edition Chapter 7: The Other Sensory Systems and Attention 48 of 52 Attention • Sight or sound too brief to register in conscious still has effect • brief smiling (or frowning) face causes facial muscles to start to smile (or frown) • related words are identified quicker • unmasked stimuli reach consciousness, masked do not • Strong stimuli enter consciousness from “bottom up” by arousing brain and focusing attention • Conscious focusing of attention is a “top down” process
James W. Kalat Biological Psychology, 8th Edition Chapter 7: The Other Sensory Systems and Attention 49 of 52 Neglect • We can see, hear, touch and smell more if we direct our attention to those areas • person with damage to auditory cortex could report start and stop of sounds when asked to do so • persons with spatial neglect of left side of body can still focus attention on left side using top down processes • simply tell them to pay attention, look left, or feel something with left hand • crossing left and right hands increases awareness of left side • very difficult to attend to two items presented closely together
James W. Kalat Biological Psychology, 8th Edition Chapter 7: The Other Sensory Systems and Attention 50 of 52 Attention-Deficit Hyperactivity Disorder (ADHD) • ADHD symptoms include distractibility, hyperactivity, impulsivity, mood swings, short temper, vulnerability to stress and difficulty planning • affects school performance and social behavior lifelong • 3-10% of children (and fewer adults) diagnosed with ADHD, 2-3 times more often in males • very difficult to make reliable diagnosis
James W. Kalat Biological Psychology, 8th Edition Chapter 7: The Other Sensory Systems and Attention 51 of 52 Attention-Deficit Hyperactivity Disorder (ADHD) cont. • Measured characteristics of person with ADHD • less likely to delay gratification when given opportunity of greater reward later • difficulty inhibiting behavior if decision is required quickly • more difficulty shifting attention quickly • Causes • higher incidence in families, suggesting high heritability • 95% of normal brain volume with smaller right prefrontal cortex and cerebellum
James W. Kalat Biological Psychology, 8th Edition Chapter 7: The Other Sensory Systems and Attention 52 of 52 Attention-Deficit Hyperactivity Disorder (ADHD) cont. • Most common treatment is stimulant drugs Ritalin or amphetamine • increases attentiveness, school performance and social relationships and decreases impulsiveness • helps adults pay better attention to driving, avoid tickets and reduce irritability toward other drivers • increases availability of dopamine for about three hours • also increases attention span of so-called normal children