Psychology Unit Three Test
Briefly describe the roles of the prefrontal cortex, the premotor cortex, and the motor cortex in movement.
Prefrontal cortex: plans movements, Premotor cortex: organizes movement sequences, Motor cortex: produces specific movements.
Know that (blank) connect to (blank) via (blank). Know that (axons) of the (blank) form the (blank).
(Photoreceptors) (Retinal ganglion cells) (Three cell types) (axons) (retinal ganglion cells) (optic nerve)
Know that (blank) connect to one type of (blank) and that these retinal ganglion cells connect to one portion of the (blank) (the "visual thalamus"), and that cones connect to another type of (blank) and that theses retinal ganglion cells connect to another portion of the (blank). What are M and P cells? You don't have to know the names of the LGN regions or the numbers of the LGN layers to which M and P cells connect.
(rods) (retinal ganglion cell) (lateral geniculate nucleus) (cones) (retinal ganglion cells) (lateral geniculate nucleus) M cells: rods, P cells: cones.
List important characteristics of the corticospinal tracts.
Motor cortex and spinal cord.
What are sensory receptors?
Specialized cells that transduce sensory energy into neural activity.
What is a receptive field? What are some characteristics of receptive fields? What functions do receptive fields make possible?
A specific part of the world to which a receptor cell or a sensory-receptor organ responds. Receptive fields sample unique information, Receptive fields sample overlapping information. Enable brain to identify information, Enable brain to contrast the information coming from different receptive fields, Enable brain to locate sensory events in space, Enable the brain to produce cortical patterns and maps.
What functions might the basal ganglia have in movement?
Because damage causes twitches, the basal ganglia controls involuntary movements. Makes sure all movements are voluntary.
Why can't retinal ganglion cells detect shape? How does shape perception arise?
Because their receptive fields are miniscule dots. Each retinal ganglion cells only responds to presence or absence of light in its receptive field, not the shape.
What kinds of information remain segregated in V1 and V2?
Color, form and motion stay segregated throughout the V1 and V2.
What are neural relays? What are some characteristics of neural relays? What is the major functional consequence of having neural relays?
Connection of receptors to cortex via intervening neurons. They allow sensory information to interact. They organize our movements hierarchally.
Characterize visual function in the dorsal and ventral streams.
Dorsal stream: form, motion. Ventral stream: dynamic form and color form.
Describe the general features of the somatosensory pathways to the brain.
Dorsal-root ganglion neurons respond to fine touch and pressure, it crosses the spinal cord, it ascends to the brain, to the ventrolateral area of the thalamus and the information arrives into the somatosensory cortex.
List behaviors controlled by the brainstem.
Eating, drinking, sexual behavior, eating non-food objects, grooming, sequential behavior that everyone does, posture, standing upright, coordinating the movement of limbs, swimming, walking, making nests.
List the major components of our motor system.
Frontal lobe, spinal cord, motor neurons, sensory receptors, basal ganglia, sensory cortex.
What are some effects of damage to the somatosensory cortex?
Impairs the ability to make even simple sensory discriminations and movements. It impairs sensory thresholds, proprioception, and hapsis.
How does the nervous system encode different aspects of sensations?
Increase or decrease in discharge rate of neurons, Amount of increase or decrease in discharge rate of neurons, Activity in different neurons, Representation in different secondary areas of the cortex, Processed in distinct neural systems, associated with certain kinds of reflex movements, Topographic maps in primary cortical areas.
What do somatosensory neurons do in addition to conveying sensation to the brain?
It is also the structure for perception.
According to Kaas, how is somatosensory information represented in the cortex?
It is separated into four homunculi: 3a, 3b, 1, 2. Information is passed to 2, which is responsive to combined somatosensory information.
How might the cerebellum be involved in movement?
It is the plan for the movement. It is the center of hand-eye coordination.
What kinds of information does the somatosensory system provide?
Movement.
How is somatosensory perception hierarchically constructed?
Muscles and skin(slow), to skin(fast), all to joints, pressure
List important characteristics of dorsal-root ganglion neurons.
Neurons, myelinated axons, it has to deal with fine touch.
List and briefly define the three types of somatosensory perception.
Nociception: pain, temperature, itch, slow adaptation. Hapsis: fine touch and pressure, rapid and slow adaptation. Proprioception: body awareness, rapid adaptation.
Describe on-center and off-center cells.
On center: when lights hits the center of the cell, it creates an excitatory effect, when it hits around the center region, it creates an inhibitory effect, whenever light is over the entire cell, the cells firing rate only increases slightly. Off center: does the opposite, in the center, inhibitory, on the outer ring, excitatory, on the entire cell, slightly inhibitory.
List common features of sensory systems
Organized on a similar, hierarchical plan, Sensory receptors, Neural relays (between the receptor and the neocortex), Sensory coding and representation, Perception.
What is the motor cortex homunculus? What is its most striking feature?
Representation of the human body in the sensory or motor cortex; also any topographical representation of the body by a neural area. The disproportionate relative sixes of its body parts compared with the relative sizes of actual parts of the human body.
What are some common properties of our range of sensory receptors?
Respond to a narrow band of energy, Filter the sensory world to produce a unique representation of reality, Responsible for important individual and species differences.
What are the two types of photoreceptors, to what kinds of light are they sensitive, and for what aspects of vision are they responsible?
Rods, dim light, night vision. S-cones, bright light, color vision, fine detail. M-cones, bright light, color vision, fine detail. L-cones, color vision, fine detail.
What are simple and complex cells? Describe the receptive fields of these cells.
Simple cells have an on-off arrangement in rectangles. Complex cells are maximally excited by bars of light moving in a particular direction through the visual field.
How do on-center and off-center ganglion cells provide information about shape?
The ganglion cell is able to tell the brain about the amount of light hitting a certain spot on the retina compared with the average amount of light falling on the surrounding retinal region.
List important features of the control of muscles by motor neurons.
The extensor and the flexor to both contract and relax. They work in pairs for more control.
Describe the pathways by which information from the right and the left visual fields enter the brain, including crossing the optic chiasm. Describe the Geniculostriate system and the Tectopulvinar system.
The left half of each eye process the information on the right, the right half of each eye processes the information on the left.
In a sentence, describe the role of neuronal activity in the dorsal stream.
The neuronal activity has to do with movement, therefore, when you are unconscious, these cells do not respond because it is an unneeded function.
What are motor neurons? Describe important features of the connections between fibers of the corticospinal tract and neurons in the spinal cord.
The neurons in the spinal cord that connects to the muscles in the ventrolateral part of the spinal cord.
How does V1 construct bars from retinal ganglion cell input?
The on cells are laid in a row, so when a par of light hits all, or most of the cells, it is in a row because of how the on receptors are laid out in the cell.
What are primary visual cortex and extrastriate cortex?
The primary visual cortex is the V1 section of the occipital lobe. The extrastriate cortex is the rest of the regions in the occipital lobe; V2, V3, V3a, V4 and V5.
Define perception.
The process of organizing and interpreting sensory information, enabling us to recognize meaningful objects and events.
What are the functions of the superior colliculus, and what kind of information does the pulvinar send to the parietal and temporal lobes?
The superior colliculus sends connections to the region of the thalamus known as the pulvinar. It sends the "where" function which is important in the "what" and "how" visual stream.
What are dorsal and ventral streams? Later in the chapter the authors will say the dorsal stream is involved in using visual information to control movement ("how" function), and the ventral stream is involved in identifying what a stimulus is ("what" function).
They are the two pathways that create visual knowledge. Milner and Goodale came up with the "what-how" distinction. Saying that one of the pathways accounts for the "what" in processing visual information, and the other pathway accounts for the "how" when processing visual information. The pathway to the temporal lobe is ventricle stream and the pathway to the parietal lobe is the dorsal stream.
List some important features of TE neuron function.
They maximally excite by complex things, like faces, they are very specific to their responsiveness, they require complex features for their activation, like orientation, size, color and texture, all the neurons are excited by slightly different things, not one neuron can comprehend an object, these neurons are grouped together in a column, and the information is sent to the brain.
In a couple sentences, summarize what happens to motor abilities when sensory nerves are damaged.
They still continue to work, but you don't have awareness of them. You can move your hands around objects, but you can't feel when you are holding the objects.
What affect does damage to the secondary somatosensory cortex have on movement?
We would not feel our movements, they would just happen but there would be no confirmation of a complete movement.
