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
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 lowfrequency 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 lowfrequency 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