Exam 2
Where is the receptive field located relating to the retinal ganglion cells?
Depends on what cells are communicating with it.
Synaptogensis
Formation of synapses
Name at least three cutaneous (skin) receptors
Free nerve endings, Merkel's disks, Ruffini endings
This theory explains why psychological experience of pain is often suppressed until after a threat has passed
Gate control theory
Cochlea
Hearing/audition
Cranial Nerve VIII
Hearing/audition
What are the three general principles of sensory system organization
Hierarchical organization, functional segregation, parallel processing
Example of each general principle of sensory system organization (at least two different senses)
Hierarchical organization: auditory cortex has a core region (primary auditory cortex), and a belt surrounding the core region (secondary auditory cortex). Primates have 10 distinct secondary auditory cortical areas. They also interact with the visual system, some neurons in the posterior parietal cortex have responding receptive fields for sight and hearing, making them it an association cortex. Functional Segregation: In vision, there's a functional area for ocular dominance (favoring left or right eye) and orientation columns. Each are on the same level of hierarchy but have different functions. Parallel processing: M channels (perception) and P channels (color and detail) with vision
List the cells of the retina in order from the back of the retina to the front of the retina
Photoreceptors (cones and rods), horizontal cells, bipolar cells, amacrine cells, ganglion cells
This cortical gyrus contains a somatotopic arrangement of neurons responsive to stimulation of cutaneous and proprioceptive inputs
Postcentral gyrus
Projections from visual cortex to this region of association cortex are involved in locating objects in space for guidance of movement
Posterior parietal cortex
Cortical myelination parallels functional development, with this region not fully myelinated until late adolescence
Prefrontal cortex
The anterior auditory pathway to this region of association cortex is involved in identifying specific patterns of sounds
Prefrontal cortex
Summarize the anterior auditory pathway
Prefrontal cortex, involved in identifying specific patterns of sound (what)
Summarize the ventral stream of visual association
Projection from VI to inferior temporal lobe, involved in object recognition
Summarize the dorsal stream of visual association
Projection from VI to posterior parietal cortex, involved in location of objects in space for guiding movement
Following the formation of the neural tube, a rapid increase in the number of cells
Proliferation
Golgi tendon organs and stretch receptors in the muscles are receptors of this somatic system
Proprioceptive (kinesthetic senses)
This neurological condition is also known as face blindness
Prosopagnosia
Explain scotopic visual system
RODS, 100 million in human retina, outside fovea (peripheral retina), 1 photopigment, high sensitivity, low acuity (detail)
Explain Opponent-process theory
There are three receptor complexes operating in opponent fashion to yield a perception of color and brightness. Evidence of this are negative afterimages.
Cranial Nerve I
olfaction
Medial dorsal nucleus
olfaction
Olfactory epithelium
olfaction
Piriform cortex
olfaction
Neurotrophins
promote growth and survival, guide axons, and stimulate synaptogenesis
Lateral Geniculate nucleus
vision
Retina
vision
Rods and Cones
vision
Striate cortex/area 17
vision
Explain magnocellular layer of the LGN
large cells, ventral 2 layers, low spectral sensitivity, high contrast sensitivity, low spatial resolution, high temporal resolution
Summarize the posterior auditory pathway
Parietal cortex, involved in locating sounds (where)
Electrical stimulation of this midbrain structure produces analgesia
Periacqueductal gray
The experience of painful sensations from an amputated limb
Phantom pain
Migration
- Radial migration (moving out): usually by moving along radial glial cells - Tangential migration (moving up)
Examples of neurotrophins in development
- Nerve growth factor (NGF) - Brain Derived Neurotrophic Factor (BDNF) - Glial Derived Neurotrophic Factor (GDNF)
Where are gustatory receptors?
Papillae (tongue)
The auditory receptors are located in this structure within the cochlea: A) Organ of Corti B) tympanic canal C) Reissner's membrane D) oval window E) round window
A) Organ of Corti
Functional brain imaging studies have shown that early music training increases the size of the A) auditory cortex B) visual cortex C) motor cortex D) brain stem E) cerebellum
A) auditory cortex
Which of the following body parts is represented in more lateral regions of the somatosensory cortex than all the others in this list? A) face B) arms C) trunk D) legs E) toes
A) face
This midbrain structure is part of the descending pain control circuit. A) periaqueductal gray B) superior colliculus C) inferior colliculus D) red nucleus E) substantia nigra
A) periaqueductal gray
The ANTERIOR auditory pathway from auditory cortex to ______________ cortex is involved in ______________. A) prefrontal, sound recognition B) posterior parietal, sound recognition C) prefrontal, sound localization D) posterior parietal, sound localization E) inferior temporal, sound recognition
A) prefrontal, sound recognition
A receptive field for neurons in the visual system is: A) the region of the visual field where light must fall to stimulate a particular visual neuron. B) specialized receptors that detect and respond to environmental stimuli. C) the conversion of physical energy into a neural signal. D) a specific pattern of neural activity that contains information about environmental stimuli
A) the region of the visual field where light must fall to stimulate a particular visual neuron.
Define blindsight
Ability to respond to visual stimuli in a scotoma with no conscious awareness of them.
Oliver Sacks wrote "The Case of the Color Blind Painter" about a man who experiences this neurological impairment following brain injury
Achromatopsia
Aggregation
After migration, cells align themselves with others cells and form structures
What are three physical characteristics of sound waves and their corresponding perceptual dimensions?
Amplitude --> Loudness Frequency --> Pitch Complexity --> Timbre
Sensory nerves from nociceptors innervate neurons in the spinal cord, which project along these tracts to the opposite side of the ventral posterior thalamus
Anterolateral spinothalamic tract
Up to 50% of neurons die off during the course of normal brain development as a result of this process of pre=programmed cell death
Apoptosis
A failure to recognize one's own body parts is typically unilateral and associated with extensive right posterior parietal damage
Asomatognosia
This somatosensory impairment is characterized by an inability to recognize objects through active touch
Astereognosia
This embryonic layer develops into the nervous system. A) Endoderm B) Ectoderm C) Mesoderm
B) Ectoderm
Cortical areas that receive and integrate inputs from more than one sensory area are called: A) tertiary sensory cortex B) association cortex C) relational cortex D) primary sensory cortex E) secondary sensory cortex
B) association cortex
During postnatal brain development, myelination progresses in this order. A) from front to back with myelination of the brain stem regions last B) from back to front with myelination of the prefrontal cortex last C) from inside out with myelination of the cerebral cortex last D) from outside in with myelination of the cerebral cortex first
B) from back to front with myelination of the prefrontal cortex last
The ventral stream of visual association cortex projects from the primary visual cortex to the __________ cortex and is involved in ____________. A) inferior temporal; movement perception B) inferior temporal; object recognition C) inferior temporal; color perception D) posterior parietal; perception of object location E) posterior parietal: object recognition
B) inferior temporal; object recognition
Unlike the anatomical projections of most other sensory systems, the projections of the gustatory system are primarily A) contralateral. B) ipsilateral. C) unilateral. D) bilateral. E) descending
B) ipsilateral.
The chemosensory receptors for olfaction (smell) are found in the: A) cochlea B) olfactory bulb C) semicircular canals D) retina E) papillae
B) olfactory bulb
This region of cerebral cortex contains neurons in a somatopic arrangement of neurons sensitive to touch and proprioception. A) posterior occipital lobe B) postcentral gyrus in parietal lobe C) cingulate gyrus D) superior temporal gyrus E) inferior temporal gyrus
B) postcentral gyrus in parietal lobe
The last part of the human brain to reach full maturity is the A) hippocampus B) prefrontal cortex C) amygdala D) occipital cortex E) hypothalamus
B) prefrontal cortex
Phototranduction occurs in these cells. A) retinal ganglion cells B) rods and cones C) horizontal cells D) bipolar cells E) amacrine cells
B) rods and cones
For barn owls, this specialized sensory function is attributed to their facial ruffs and to the asymmetrical positioning of their ear canals on each side of the head. A) frequency coding B) sound localization C) tone discrimination D) sound recognition E) keen listening skills
B) sound localization
Which statement depicts a difference between rods and cones in the retina? A) Cones have a higher convergence than rods onto retinal ganglion cells. B) Rods are heavily concentrated in the fovea and cones are more widely dispersed in the peripheral retina. C) Rods are more sensitive than cones in dim light. D) All of the above E) None of the above
C) Rods are more sensitive than cones in dim light.
This neurological disorder is characterized by a deficit in acknowledging or recognizing one's own body parts and is often a component of contralateral neglect. A) anosmia B) prosopagnosia C) asomatognosia D) anosognosia E) astereognosia
C) asomatognosia
This neurological condition is characterized by an inability to recognize objects through active touch. A) anosmia B) prosopagnosia C) astereognosia D) anosognosia E) asomatognosia
C) astereognosia
The primary gustatory cortex is located in the insula, hidden within the: A) longitudinal fissure. B) central fissure. C) lateral fissure. D) parietal lobe. E) temporal lobe
C) lateral fissure.
During embryological development of the nervous system, new neurons move outward from the ventricular zone. This stage of development is called: A) proliferation B) apoptosis C) migration D) aggregation E) synaptogenesis
C) migration
The proprioceptive system detects: A) mechanical stimuli on the skin B) thermal and nociceptive stimuli C) muscle stretch and position of limbs D) All of the above E) A and B only
C) muscle stretch and position of limbs
The axons of these neurons form the optic nerve: A) bipolar cells B) horizontal cells C) retinal ganglion cells D) P cells E) M cells
C) retinal ganglion cells
The conscious perception of odors is mediated by activation of this pathway. A) amygdala B) piriform cortex C) thalamic-orbitofrontal cortex D) all of the above E) A and B only
C) thalamic-orbitofrontal cortex
Explain photopic visual system
CONES, 4 million in human retina, mainly in fovea, 3 photopigments (color), low sensitivity, high acuity (detail)
What can damage to association cortex do?
Can cause issues on different specializations because it integrates the sensory systems
Roger Sperry's classic eye-rotation and regeneration experiments remain a classic example of evidence in support of this hypothesis
Chemoaffinity hypothesis
This cortical area is presumable linked to the emotional experience of pain
Cingulate cortex
Explain Young-Helmholtz theory
Color perceptions come from a pattern of stimulation of 3 sets of color receptors in the retina. Evidence supporting this is there being 3 cone types.
Color vision and visual acuity rely on the transduction properties of these photoreceptors and their low convergence ratio with retinal ganglion cells
Cones
This refers to deficits in visual perception following damage to the striate cortex
Cortical blindness (blindsight)
What are the three divisions of the somatosensory system?
Cutaneous, kinesthetic, and organic
These cranial nerves transmit gustatory (taste) inputs to the brain. A) Facial (VII) B) Glossopharyngeal (IX) C) Vagus (X) D) All of the above E) A and B only
D) All of the above
These somatic receptors are proprioceptors. A) Pacinian Corpuscles B) Meissner's Corpuscles C) Merkel's disks D) Golgi tendon organs E) All of the above
D) Golgi tendon organs
The auditory nerve from the cochlea is part of this cranial nerve. A) IX (nine) B) X (ten) C) VII (seven) D) VIII (eight) E) III (three)
D) VIII (eight)
This neurological disorder is characterized by an impairment in visual perception of moving objects. A) prosopagnosia B) astereognosia C) asomotagnosia D) akinetopsia E) achromatopsia
D) akinetopsia
In comparison to the cortices of rats that had been reared in enriched environments, the cortices of rats that had been reared in isolation A) were thinner. B) had less dendritic development. C) had fewer synapses per neuron. D) all of the above E) none of the above
D) all of the above
The human brain grows after birth due to: A) synaptogenesis B) myelination C) increased dendritic branching D) all of the above E) none of the above
D) all of the above
Which organizational features do the visual, auditory, and somatosensory systems have in common? A) functionally distinct columns of cells in primary sensory cortex B) topographic representations in primary sensory areas C) parallel pathways from receptors to thalamus to cortex D) all of the above E) A and C only
D) all of the above
When light is absorbed by photoreceptors in the retina, they A) increase their rate of firing action potentials. B) decrease their rate of firing action potentials. C) are depolarized due to the opening of Na+ channels. D) are hyperpolarized due to the closing of Na+ channels. E) are hyperpolarized due to the opening of Cl- channels.
D) are hyperpolarized due to the closing of Na+ channels.
In a classic experiment, Roe and colleagues (1990) caused the developing axons of ferret retinal ganglion cells of the visual system to synapse in the medial geniculate nuclei of the auditory system. Once the ferrets matured, their A) auditory cortex responded to visual stimuli. B) auditory cortex was laid out retinotopically. C) auditory cortex had totally degenerated. D) both A and B E) both A and C
D) both A and B
The four dorsal layers of the lateral geniculate nucleus (LGN) containing small cells are called the: A) ocular dominance columns B) orientation columns C) magnocellular layers D) parvocellular layers E) minicellular layers
D) parvocellular layers
This form of visual agnosia is also known as "face blindness". A) asomatagonosia B) astereognosia C) contralateral neglect D) prosopagnosia E) blindsight
D) prosopagnosia
This somatosensory pathway provides information about fine touch and proprioception and crosses to the opposite side at the level of the medulla
Dorsal column medial lemniscus (DCML)
The exteroceptive system detects: A) mechanical stimuli on the skin B) thermal and nociceptive stimuli C) muscle stretch and position of limbs D) all of the above E) A and B only
E) A and B only
The dorsal column medial lemiscal pathway transmits this type of somatosensory information. A) fine (discriminative) touch B) proprioception C) pain and temperature D) all of the above E) A and B, but not C
E) A and B, but not C
Neurons in the magnocellular layers of the lateral geniculate nucleus (LGN) exhibit: A) low spatial resolution B) high temporal resolution C) low spectral sensitivity D) high contrast sensitivity E) all of the above
E) all of the above
In mammals, adult neurogenesis occurs in the A) hippocampus. B) olfactory bulb. C) amygdala. D) all of the above E) both A and B
E) both A and B
In a classic study, the area of right somatosensory cortex receiving input from the left hand was found to be larger in: A) percussionists. B) tennis players. C) piano players. D) gymnasts. E) musicians who fingered stringed instruments with the left hand.
E) musicians who fingered stringed instruments with the left hand.
These neuropeptides suppress incoming signals from afferent pain pathways
Endorphins
Pacinian corpuscles, Merkel's disks, Meissner's corpuscles, and Ruffini endings are all receptors of this somatic system
Exteroceptive (cutaneous senses)
Define prosopagnosia
Face blindness. Can be acquired either during development or as a result of brain injury.
Explain a clear and articulate summary of each of the three principles of sensory system organization
Hierarchical organization: specificity and complexity increases with each level, includes sensation (detecting a stimulus) and perception (understanding the stimulus). Primary, secondary, association. Functional segregation: distinct functional areas within a level Parallel processing: simultaneous analysis of signals along different pathways
The membrane potential change when rods are exposed to light
Hyperpolarization
Define achromatopsia
Inability to discriminate among different hues as a result of cortical damage
Define akinetopsia
Inability to perceive movement caused by damage to area V5 of the visual association cortex
Abbreviated names for the anatomically and functionally segregated layers of the LGN
M and P cells
What are the three ossicles of the middle ear?
Malleus, incus, stapes
This thalamic nucleus is part of the auditory pathway
Medial geniculate nucleus
What is the process of sound transduction by the auditory receptors?
Movement of fluid against the basilar membrane causes the inner hair cells to bend.
Proliferation
Neurogensis
The overproduction of synapses in the in the young brain may contribute to a greater capacity for
Neuroplasticity
These life preserving factors promote the growth and survival of neurons, guide axons, and stimulate synaptogensis
Neurotrophins
Primary visual cortex is organized with alternating columns of cells exhibiting a pattern of this type of dominance
Ocular dominance
Monocular deprivation just a few days early in life impairs the development of visual acuity in that eye and the normal development of these in the visual cortex
Ocular dominance columns
Where are olfactory receptors?
Olfactory bulb
This structure inside the cochlea contains the inner hair cells responsible for the transduction of mechanical stimulation into neural signals
Organ of corti
These three bones in the middle ear focus and amplify air pressure changes into movements of the fluid contained within the cochlea
Ossicles: incus, malleus, stapes
What is the primary visual pathway?
Retina to cortex
The three-word name for the primary visual pathway
Retina-Ganiculate-Striate
The axons of these neurons form the second cranial nerve (CN II)
Retinal Ganglion Cells
Adult musicians who play instruments fingered by the left hand have an enlarged representation of that hand in this region
Right somatosensory cortex
Located at the back of the retina, these cells are responsible for phototranduction
Rods and cones (photoreceptors)
Pacinian corpuscles
Somatosenses
A barn owl's facial ruff and large ear canals positioned at slightly different heights on each side of its head contribute to this specialized auditory function
Sound localization
This brain stem structure responds to differences in arrival and amplitude and contributes to sound localization
Superior olivary nuclei (superior olives)
Human brain volume quadruples between birth and adulthood due to these three developmental processes
Synaptogensis, myelination, dendritic branching
Briefly distinguish the chemical senses from other senses
The projections are predominantly ipsilateral rather than contralateral (same side projections), chemical is a chemical process (chemical binding to receptor)
What are two neurological explanations for blindsight?
The striate cortex is not completely destroyed and the remaining islands of functional cells are capable of mediating some visual abilities. Visual pathways that ascend directly to the secondary visual cortex from subcortical w/o passing primary cortex are capable.
What is the role in hearing of the three ossicles of the middle ear?
Their movements helps to focus and amplify the air pressure changes that constitute sound waves from the ear canal into movements of the fluid contained within the cochlea.
Axons growing from one topographic surface to another are guided to specific targets arranged on the terminal surface in the same way the axon's cell bodies are arranged on the original cell surface
Topographic gradient hypothesis
This hypothesis was proposed to account for axonal migration from one topographically organized structure to another, such as the retinal projections to the optic tectum
Topographic gradient hypothesis
This theory of color vision is supported by the existence of three cone populations in the human retina
Trichromatic theory
What are the cranial nerves that provide gustatory information to the brain?
VII (7), IX (9), X (10)
What are the cranial nerves that provide olfactory information to the brain?
VIII (8)
Cranial Nerve II
Vision
Relate a perception disorder with one of three principles of sensory system organization
Visual agnosia: inability to identify, recognize, or name objects presented visually despite normal visual acuity and object identification by other senses is otherwise normal. May be caused by damage within the visual association cortex even though the primary visual pathway in intact.
Cranial Nerves VII, IX, X
gustation
Insula
gustation
Orbitofrontal cortex
gustation
Papillae
gustation
Medial geniculate nucleus
hearing/audition
Organ of corti
hearing/audition
Superior temporal gyrus
hearing/audition
Explain parvocellular layer of the LGN
small cells, dorsal 4 layers, high spectral sensitivity, low contrast sensitivity, high spatial resolution, low temporal resolution
Anterolateral spinothalamic tract
somatosenses
Dorsal column medial lemniscus
somatosenses
Free nerve endings
somatosenses
Golgi tendon organs
somatosenses
Meissners corpuscles
somatosenses
Merkels disks
somatosenses
Postcentral gyrus (or Brodmann's areas 3a, 3b, 1, 2)
somatosenses
Ruffini endings
somatosenses
Ventral posterior nucleus
somatosenses
Define receptive field
the region of the visual field (retina) where light must fall to stimulate the neuron.
