Exam 3

Question 1

What is Sensation?

Answer 1

The aquisition of sensory information; exterior stimulation detected and transferred by sensory system.

Question 2

What is Perception

Answer 2

The interpretation of sensory information; the interpretation of these sensations after they have been processed by the brain

Question 3

Sensory Neurons

Answer 3

Specialized neurons that carry information from sensory receptors into the central nervous system

Question 4

Sensory receptors

Answer 4

Specialized structures that respond to physical stimuli by producing electrical impulses in sensory neurons

Question 5

Transduction

Answer 5

The transformation of a physical stimulus into a neural signal

Question 6

Physical versus perceived qualities of sensory stimuli (e.g., frequency-> pitch amplitude -> loudness)

Answer 6

Physical qualities of sound stimuli such as frequency and amplitude (intensity) are converted into the perceived qualities of pitch and loudness. Frequency corresponds to the rate of vibration and is perceived as pitch, while amplitude, or the height of a wave, corresponds to the perceived intensity of the sound, also known as loudness

Question 7

How does sound differ?

Answer 7

1. Frequency: the number of cycles or waves of alternating compression and decompression of the vibrating medium per second
2. Pitch: our psychological perception of the frequency of a sound- more waves per secound correspond to higher percieved pitch
3. Intensity: term for the physical energy in a sound; loudness is the term for our perception of a sound’s intensity
4. Pure tone: with only one frequency; a complex sound mixes different frequencies

Question 8

Mechanics and physiology of auditory system, from sound waves to perception: The Outer and Middle Ear

Answer 8

Pinna is the flap that graces the side of your head, it filters and then amplifies it slightly by funneling it from the larger area of the pinna to the smaller area of the auditory canal.
The seperation between the outer and middle ear is the eardrum (tympanic membrane), a very thin membrane stretched across the end of the auditory canal; its vibrations transmits sound energy to the three middle ear bones (or ossicles).
The second part of the middle ear is the ossicles, tiny bones that operate in lever fashion to tranfer vibration from the tympanic membrane to the cochlea.
Eustchian tube, connecting the middle ear to the back of your mouth, which equalizes the air pressure of the middle ear with the outside world.

Question 9

Mechanics and physiology of auditory system, from sound waves to perception: The Inner Ear

Answer 9

The snail-shaped structure is the cochlea, where the ear’s sound-analyzing structures are located. The vestibular canal is the point of entry of sound energy into the cochlea and it connects to the tympanic canal at the far end of the cochlea through an opening called helicotrema. They both bathe the cochlear canal, where the auditory receptors are located, in vibration.
The vibration passess to the organ of Corti, the sound-analyzing structure that rests on the basilar membrane and consists of 4 rows of a specialized cells called hair cells, their supporting cells, and the tectorial membrane above the hair cells.
The inner hair cells are the sensory cells; they recieve 90% to 95% of the auditory neurons, and they provide most of the information about auditory stimulation. The outer hair cells increase the cochlea’s sensistivity, both by amplyfying its output and by sharpening the frequency tuning at the location of peak vibration.

Question 10

Mechanics and physiology of auditory system, from sound waves to perception: Pathway to the Auditory Cortex

Answer 10

The auditory cortex is tonotopically organized, which means that neuron from adjacent receptor locations project to adjacent cells and they convey similar frequencies. The human primary cortex has a secondary area surrounding it, but auditory info also travels beyond the auditory areas, following the dorsal or the ventral stream.

Question 11

Primary auditory cortex

Answer 11

The first brain region to recieve and process auditory information, playing a crucial role in identifying fundamental sound elements like pitch and loudne, and is involved in speech and language processing.

Question 12

Topographical map

Answer 12

A systematic, organized representation of sensory or motor information within the brain. It shows how neurons in specific areas of the nervous system are spatially arranged to correspond to certain features of sensory inputs or motor outputs

Question 13

Volley theory

Answer 13

A hypothesis of auditory frequency analysis that states that groups of neurons follow the frequency of a sound when the frequency exceeds the firing rate capability of a single neuron. Some frequencies are too high for a single neuron to fire that quickly so instead, a series of neuron work togther to send an orchestrated “volley” of signals instead.

Question 14

Contralateral organization of sensory and motor systems

Answer 14

Auditory information from the cochlea ascends through many brain areas before arriving at the auditory cortex. Most auditory information crosses to the opposite (contralateral) hemisphere between the cochlea nucleus and trapezoid body, but some stays on the same side (ipsilateral) as the cochlea.

Question 15

Disorders of Speech: Broca’s aphasia

Answer 15

Involved in speech production. Able to understand most but can’t create grammatical speech. Symptoms include nonfluent speech, anomia, difficulty with articulation, agrammatic.
Brain areas involved includes Broca’s area of frontal lobe

Question 16

Disorders of Speech: agraphia

Answer 16

Symptoms include inability to write due to impaired language center output to motor systems.
Brain areas involved include Angular gyrus

Question 17

Disorders of Speech: Wernicke’s Aphasia

Answer 17

Involved in speech production. Impaired understanding, can create grammatical sentences with no meaning. Symptoms inculde Articulate, yet agrammatic (meaningless “word salad”)
Brain areas involved, Wernicke’s area of temporal lobe

Question 18

Disorders of Speech: Alexia

Answer 18

Symptoms include inability to read due to impaired visual input to language centers.
Brain area involved, Angular gyrus

Question 19

Disorders of Speech: Dyslexia

Answer 19

Symptoms include impaired reading due to imbalanced visual inputs.
Brain area involved, Planum temporale equal or larger on right side. Neurons lack orderly arrangement.

Question 20

Mechanics of physiology of language, including brain regions, structural anatomy, etc.

Answer 20

Language: a structural system of communication with a common set of grammatical lexical, and organizational rules.
Verbal input arrives in the auditory cortex and then travels to Wernicke’s area for interpretation. Written input arrives there via the visual cortex and angular gyrus. If a verbal response is required, Wernicke’s area sends output to Broca’s area for articulation of the response, and the facial area of the motor cortex produces the speech.

Question 21

Mirror neurons and their connection to language

Answer 21

Mirror neurons are neurons that fire both when we engage in a specific act and while observing the same act in others. They are believed to be the precursor to the development of human language, providing the foundation for understanding and imitating actions and gestures, which could have evolved into spoken language. They were first found in monkeys and later discovered them in a similar region in humans. The role of mirror neurons in language deveopment is supposedly in the imitation of gestures and mouth actions.

Question 22

Visible light (humans) and the electromagnetic spectrum

Answer 22

Visible light is a part of the electromagnetic spectrum. The electromagnetic spectrum includes a variety of energy forms, ranging from gamma rays at one extreme of frequency to the radiations of alternating current circuits at another.

Question 23

Photoreceptors and the physiology of the retina

Answer 23

Photoreceptorsare specialized light-detecting cells. Light energy is transduced by two types of photoreceptors cells in the retina, rods and cones, that ultimately trigger action potentials in neurons that form the optic nerve.
rods: focus on contrast and motion (120,000,000 per eye)
cones: focus on detail and color (7,000,000 per eye)

Question 24

Mechanics and physiology of the visual system from light to perception

Answer 24

Read the textbook 316-319

Question 25

Lateral inhibition

Answer 25

Where each neurons activity inhibits the activity of its neighbors and in turn they inhibit its activity, to enhance the contrast in brightness that defines an object's edge.

Question 26

Mach band illusion

Answer 26

Each bar in the Mach band image is consistent in brightness across its width, but it looks a bit darker on the left and a bit lighter on the right than it does in the middle. This is because the illusion suggest subtle shadowing on the left side of each bar. Exaggeration of brightness contrast at edges helps us see the boundries of objects.

Question 27

Hermann grid Illusion

Answer 27

In the Hermman grid illusion, lateral inhibition causes you to see, grayish blotches at the intersections of the large squares.

Question 28

Simple verses complex cells

Answer 28

Simple cells: a simple cell responds to a line or an edge that is at a specific orientation and at a specific place on the retina Complex cells: a complex cell continues to respond when a line or an edge move to a different location, as long as it is not too far from the original site.

Question 29

Magnocellular versus parvocellular system

Answer 29

Parvocellular ganglion cells are smaller than magnocellular cells, account for the large majority of ganglion cells, and are most numerous in the fovea. They have circular receptive fields that are small and color opponent, which suits them for the specialties of the parvocellular system, the discrimination of fine detail and color. Magnocellular ganglion cells have large circular receptive fields that are brightness opponent and respond rapidly but only briefly to stimulation. Resulting, the magnocellular system being specialized for brightness contrast and for movement.

Question 30

Dorsal verses ventral system in magnocellular and parvocellular systems

Answer 30

The parvocellular system dominates the ventral stream, which flows from the visual cortex into the temporal lobes, and the magnocellular system dominates the dorsal stream from the visual cortex to the parietal lobes. ventral= "what" of visual processing dorsal= "where" of visual processing

Question 31

Disorders in Vision: Visual agnosia

Answer 31

inability to identify objects (oject agnosia). Caused by damage to the inferior temporal cortex

Question 32

Disorders in Vision: Prosopagnosia

Answer 32

inability to recognize faces. Variety of causes including stroke, carbon monoxide poisoning, and Alzheimer's disease. Damage ususally impairs ability to recognize both objects (visual agnosia) and faces.

Question 33

Disorders in Vision: Blindsight

Answer 33

can respond to visual stimuli but cannot consciously experience/no true perception. Depends on pathways passing hrough the superior colliculus directly to extrastriate areas.

Question 34

Disorders of Vision: Color agnosia

Answer 34

inability to see or identify color (also called achromotopsia).

Question 35

Disorders of Vision: Movement agnosia

Answer 35

inability to detect and follow motion (also called akinetopsia).

Question 36

Disorders of Vision: Visual neglect

Answer 36

inability to perceive half of visual field. Neglect is twice as likely following right-hemisphere stroke, occuring in 40% of cases compared to 20% of left-hemisphere stroke. Aka: contralateral neglect, hemispatial neglect, visuospatial neglect, spatial neglect

Question 37

Disorders of Vision: Synethesia

Answer 37

crossing of sensory modalities (e.g., seeing sounds or smells; color-associating)

Question 38

Disorders in Vision: Color blindness (Color vision deficiency)

Answer 38

Occurs when an individual has a poor or absent response from one or more cone types, leading to difficulty distinguishing certain colors.

Question 39

Color constancy

Answer 39

The ability to recognize the so-called natural color of an object despite variations in brightness and wavelength of illumination.

Question 40

Synesthesia

Answer 40

A condition in which stimulation in one sense triggers an experience in another sense or a concept evokes an unrealted sensory experience.

Question 41

Proprioception

Answer 41

(Latin proprius "belonging to one's self") Is the sense that informs us about the position and movement of our limbs, body, and head.

Question 42

Skin receptors and their functions

Answer 42

Two general types of receptors, *free nerve endings* are simply processes at the ends of neuronal dendrites; they detect warmth, cold, and pain. All the other receptors are *encapsulated receptors,* which are more complex structures enclosed in a membrane; their role it to detect touch.

Question 43

Somatosensation including touch/skin senses

Answer 43

Somatosensation includes a wide range of tactile experiences, from light touch and pressure to vibration and the perception of texture. These sensations are primarily received by specialized receptors in the skin and other tissues.

Question 44

Somatosensation including temperature perception

Answer 44

The somatosensory system allows us to perceive changes in temperature, whether it's heat, cold, or a gradual transition between them. This information helps us regulate our body temperature and avoid potentially harmful temperatures.

Question 45

Somatosensation including pain perception

Answer 45

Somatosensation also includes pain perception, which is a crucial warning system that helps us avoid injury. Pain signals are sent to the brain when tissue damage is detected, triggering a response to protect the body.

Question 46

Vestibular system

Answer 46

Helps us maintain balance, and provides information about head position and movement. * Contributes to spatial orientation & coordination of movement * Located with the auditory sensory organs, but is more closely linked with visual processing * Discrepancies between vestibular and visual information results in “motion sickness”  Evolutionary reflex to purge ingested neurotoxins * Vector motion – false feeling of motion due to visual movement (e.g., when a neighboring car moves)

Question 47

Dermatomes

Answer 47

The body is divided into segments called deratomes, each served by a spinal nerve or cranial nerve. The labels identify the nerve; letters indicate the part of the spinal cord where the nerve is located, and the numbers indicate the nerve's position within that secretion.

Question 48

Feature detectors

Answer 48

the mechanisms the brain uses to identify and process faces, allowing us to recognize individuals and understand their expressions and social cues.

Question 49

Gate control theory of pain

Answer 49

They hypothesized that pressure signals arriving in the brain triggers an inhibitory message that travels back down the spinal cord, where it closes a neural "gate" in the pain pathways.

Question 50

Periaqueductal gray

Answer 50

Pain causes the relase of endophins in the periaqueductal gray, a brain stem structure surrounding the cerebal ventricles with a large number of endophin synapses.

Question 51

Muscles

Answer 51

* Skeletal muscles: which move the body and limbs but can fatigue if overused * Smooth musces: produce rhythmic contractions in the internal organs * Cardiac muscles: are non-fatiguing muscles that make up the heart * antagonistic muscle: that produce opposite movement at a joint

Question 52

Tendons

Answer 52

Skeletal muscles are anchored to bones across a joint by tendons, which are tough fiberous bands of connective tissues.

Question 53

Movement

Answer 53

Muscles are able to operate the the limbs like levers to produce movement by pulling against their attachments. Muscles can only contract; a limb is both flexed and extended by pulling on the joint from one side or the other.

Question 54

Anatomy of the basal ganglia

Answer 54

The basal ganglia include the caudate nucleus, putamen, globus pallidus, and the substantia nigra.

Question 55

How does the basal ganglia relate to movement/body senses

Answer 55

It uses information from the primary and secondary motor areas and the somatosensory cortex to intergrate and smooth movements. It sends output directly to the primary motor cortex and supplementary motor area and to the premotor cortex via the thalamus. It is also active during complex sequences of movements.

Question 56

Disorders of the body senses: Muscular dystrophy

Answer 56

Characterized by muscle degeneration; sex-linked disorder (mostly males)

Question 57

Disorders of the body senses: Myasthenia gravis

Answer 57

Is a disorder of muscular weakness caused by reduced numbers or sensitivity of acetylocholine receptors. Autoimmune: antibodies bind to the nicotinic ACh receptor  muscle weakness.

Question 58

Disorders of the body senses: Polio

Answer 58

Contagious virus, targets and destroys spinal alpha motor neurons  Muscle weakness and paralysis, usually of the legs

Question 59

Disorders of body senses: Amyotrophic Lateral Sclerosis (ALS)

Answer 59

Also known as Lou Gehrig’s Disease. Degeneration of the ACH motor neurons in the spinal cord and brain stem

Question 60

Disorders of the body senses: Huntington's disease

Answer 60

Dominant mutation in the huntingtin gene. Degenerative disorder of the motor system involving cell loss in the striatum and cortex. Unlike Parkinson's disease, cognitive and emotional deficits are a universal characteristic of Huntington's disease.

Question 61

Disorders of the body senses: Multiple Sclerosis (MS)

Answer 61

Is a motor disorder with many varied symptoms, caused by deterioration of myelin (demyelination) and neuron loss in the central nervous system. In later stages the person experiences muscular weakness, tremor, pain, impaired coordination, urinary incontinence, and visual problem

Question 62

Disorders of the body senses: Parkingson's disease

Answer 62

Symptoms include motor tremors, rigidity, loss of balance & coordination, and difference in moving, especially in initating movements. * Progressive difference in all movements, muscle tremors, and frozen facial expressions * DA neurons of the substantia nigra degenerate  L-DOPA (remember: L-DOPA converted to DA in brain) medications can be helpful, in addition to: 1. DA agonists 2. MAO-B inhibitors 3. Anticholinergic medications

Question 63

Pay attention to which neurotransmitter are involved in various processes in these chapters!

Answer 63

*Glutamate* plays a crucial role in the retina, where it is the primary exitatory neurontransmitter in visual processing and auditory processing in the cochlea. *Dopamine* maye be realted to auditory issues. *GABA*, maintains accurate temporal coding sounds. *Acetylcholine* trigger muscle contractions and essential for voluntary movements. *Dopamine* is crucial for initating and coordinating movements.

Question 64

How do neurons communicate through voltage-gated channels?

Answer 64

They communicate by transmitting electrical signals, aka action potentials, along the cell membrane.