Exam 3 Review Flashcards
Long Cone
wavelength light excites “red” cones and the red-green ganglion cell, to give the sensation of red. Or the “L” cone
Trichromatic Theory
states that just three color processes account for all the colors we are able to distinguish. Red, green, and blue
Medium Cone
wavelength light excites the “green” cones and inhibits the red-green cell, reducing its firing rate below its spontaneous level and signaling green to the brain. The “M” cone
Small Cone
wavelength light excites “blue” cones and inhibits the yellow-blue ganglion cell, leading to a sensation of blue. The “S” cone
Opponent process theory
attempts to explain color vision in terms of opposing neural processes. yellow, black, and green flag is the negative color after effect
red/green receptor is broken down by red light and regenerates in the presence of green light
The chemical in the yellow/blue receptor is broken down in the presence of yellow light and regenerates in the presence of blue light.
This arrangement was proposed to explain the phenomenon of complementary colors, colors that cancel each other out to produce a neutral gray or white.
Ventral or “what” Visual pathway from the occipital to the temporal lobe
ventral stream flows from the visual cortex into the temporal lobes,
Which is the parvocellular system (Parvocellular ganglion cells are located mostly in the fovea and Involve discrimination of fine detail (visual acuity) and color.)
The Dorsal or “where/how” Visual Pathway from the occipital to the parietal lobe
dorsal stream from the visual cortex to the parietal lobes.
magnocellular system which Magnocellular ganglion cells are located mostly in the periphery and are specialized for brightness contrast and for movement.
Blindsight
They can locate and track the movement of objects and they can discriminate colors, all the while claiming to be guessing.
The posterior parietal lobe is the back up signal that can still detect movements of the object but cannot actually see the object
Object agnosia
Object agnosia is the impaired ability to recognize objects.
caused by damage to the inferior temporal cortex
Prosopagnosia
Prosopagnosia is the inability to visually recognize familiar faces.
fusiform gyrus on the underside of the temporal lobe is so important to face recognition that it is referred to as the fusiform face area.
Color agnosia
Color agnosia is the loss of the ability to perceive colors, due to brain damage
Movement agnosia
Movement agnosia is the inability to perceive movement.
Vision neglect
patient ignores visual, touch, and auditory stimulation on the side opposite the injury.
Neglect is not due to any defect in visual processing, but rather to a deficit in attention.
The auditory cortex pathway
The neurons pass through brain stem nuclei to the inferior colliculi, to the medial geniculate nucleus of the thalamus, and finally to the auditory cortex in each temporal lobe
Visual Pathway
The two optic nerves run to a point just in front of the pituitary, where they join for a short distance at the optic chiasm before separating again and traveling to their first synapse in the lateral geniculate nuclei of the thalamus. Where axons synapse from the optic nerve to the thalamus then neurons are sent to the striate cortex in the occipital lobe.
The auditory cortex is on the superior (upper) gyrus of the temporal lobe of each hemisphere. How is it organized?
The area is topographically organized, which means that neurons from adjacent receptor locations project to adjacent cells in the cortex.
In this case, the projections form a sort of map of the unrolled basilar membrane.
Broca’s or expressive aphasia
Broca’s aphasia is language impairment caused by damage to Broca’s area and surrounding cortical and subcortical areas.
Limited to one or two syllables and located on the left side of the primary motor cortex kind of in the premotor cortex. Planning of response
Language
Language is not limited to speech, but includes the generation and understanding of written, spoken, and gestural communication.
Wernicke’s or receptive aphasia
Wernicke’s aphasia the person has difficulty understanding and producing spoken and written language. Word Salad.
Located in the posterior portion of the left temporal lobe. Comprehension
Wernicke-Geschwind model
Answering a Spoken Question:
AUDITORY CORTEX ➞ WERNICKE’S AREA ➞ BROCA’S AREA
Broca’s area then communicates with the facial area of the motor cortex to produce speech.
Alexia, an angular gyrus disruption
Alexia is the inability to read.
Agraphia, an angular gyrus disruption
Agraphia is the inability to write.
Dyslexia
Dyslexia, an impairment of reading. In most people the planum temporale, where Wernicke’s area is located, is larger in the left than in the right.
mirror neurons
respond both when we engage in specific acts and while observing the same act in others. Located in angular gyrus, wernicke’s area, and Broca’s area.
Somatosenses
Proprioception, the sense that informs us about the position and movement of our limbs and body
the skin senses, which tell us about conditions at the surface of our body
the interoceptive system, concerned with sensations in our internal organs
Vestibular System
The vestibular sense helps us maintain balance, and it provides information about head position and movement.
The vestibular organs, in the inner ear, are the semicircular canals, the utricle, and the saccule.
The vestibular system sends projections to the cerebellum and the brain stem and to posterior parietal cortex
Primary Somatosensory Cortex
Spinal cord to thalamus then swaps info with secondary somatosensory to posterior parietal lobe. Most of the neurons cross from one side of the body to the other side of the brain, so the touch of an object held in the right hand is registered mostly in the left hemisphere.
secondary somatosensory cortex
The secondary somatosensory cortex receives input from the left and the right primary somatosensory cortices, so it combines information from both sides of the body.
posterior parietal cortex
The posterior parietal cortex is an association area that brings together the body senses, vision, and audition.
What are the “somatosenses”?
The somatosenses include:
1) Proprioception - the sense that informs us about the position and movement of our limbs and body.
2) The skin senses - touch, warmth, cold, and pain
3) The interoceptive system - that which is concerned with sensations in our internal organs.
Identify the pathway of a neural impulse from a simple touch. For example, how does sensory information travel through the body (identify the path taken).
Receptors (can be from the cranial nerves or peripheral nerves) –> spinal cord –> brainstem –> thalamus –> primary sensory cortical areas –> nonprimary sensory cortical areas.
What is “apraxia”?
Apraxia is an impairment in the ability to carry out the complex movements, even though there is no muscle paralysis. This can be caused by a stroke or other damage to the premotor cortex.
If sensory input occurs on the right side of the body, which hemisphere is responsible for processing this information?
The left hemisphere.
The primary somatosensory cortex projects to the ___________ cortex, as well as to the secondary somatosensory cortex.
Posterior parietal cortex.
Amputees often report the perception of sensations in their missing limbs due to activity in the _____________ cortex.
Posterior parietal cortex. This part of the brain is responsible for determining the body’s orientation in space, the location of the limbs, and the location in space of objects detected by touch, sight, and sound.
____________ is when a patient ignores visual input and stimulation on the side OPPOSITE the injury (which is usually on the left side).
Visual neglect
Pain is transmitted from the periphery to the brain by the following pathway:
Sensory input –> spinal cord –> medulla –> ___________ –> midbrain (periaqueductal grey area) –> thalamus –> ___________ cortex.
1) pons
2) cingulate cortex
A healthy human ear can hear sounds from _____ Hz to _____ Hz.
20Hz to 20,000Hz (or, 20kHz).
_______ agnosia is the impaired ability to recognise objects.
Object agnosia. This is caused by damage to the inferior temporal cortex.
The loss of the ability to perceive colours due to brain damage (V4 area) is called __________.
Colour agnosia.
The inability to perceive movement is called ___________.
Movement agnosia; caused by damage to the V5 area.
When visual input is received, the _______ stream determines WHAT you are looking at (also, is part of the parvocellular system), while the _______ stream determines WHERE/HOW you are looking at something.
1) Ventral stream
2) Dorsal stream
The _____________ and limbic system structures are the seat of emotions.
Hypothalamus
The amygdala is involved in _________ emotions.
Negative emotions (fear, pain, anger, etc).
Stimulation of the septal nuclei produces _______.
Pleasure
The _________ cortex is necessary for making judgements about behaviour and its consequences… never leave home without it!
Prefrontal cortex
Define “stress”.
Stress is a condition in the environment that make unusual demands on the organism (such as a threat, failure, or bereavement).
The hypothalamic-pituitary-adrenal axis is a group of structures that help the body cope with _______.
Stress
Form vision is the detection of an object’s __________.
Boundaries.
What is the “cocktail party effect”?
The cocktail party effect is the ability to sort out meaningful auditory messages from a complex background of noises.
_______ cues help us to locate the source of a sound.
Binaural cues.
