Foundational Concept 6A! Flashcards
Sensory Processing, Vision, Hearing, Other Senses, Perception
MCAT Behavioural Sciences - Sensory Processing
A weight lifter is just able to tell the difference between 100 and 125 pounds. According to Weber’s law, the lifter would notice a difference between:
1. 125 and 150 pounds
2. 5 and 6 pounds
3. 25 and 35 pounds
4. 225 and 275 pounds
Why?
3) 25 and 35 pounds
Weber’s law posits that thresholds are proportional. 100 to 125 pounds is a 25% increase. 25 and 35 pounds is a 40% increase while the rest are under 25%
MCAT Behavioural Sciences - Sensory Processing
A man is at a party with his wife. There is loud music in the background and the location is crowded. While listening to the music he hears what he believes to be his wife’s laughter and turns around to investigate. The man is exhibiting:
1. Feature detection
2. Bottom-up processing
3. Vestibular sense
4. Signal Detection
4) Signal Detection
Signal detection is the ability to discern a specific noise within a field of many noises.
MCAT Behavioural Sciences - Sensory Processing
A woman is at a restaurant and orders a spicy entrée. After the first bite, she experiences burning in her mouth and becomes concerned that her food is too hot for her. The next few bites are similarly uncomfortable, but after a while the spiciness seems to subside somewhat, and by the end of the meal, she doesn’t notice the spice level. The end of the meal experience is best described as:
1. Adaptation
2. Signal detection
3. A difference threshold
4. Pain perception
Why?
1) Adaptation
Experiencing the stimulus multiple times renders the stimulus barely perceptable - adaptation.
MCAT Behavioural Sciences - Sensory Processing
Which sensory receptors send signals in respond to tissue damage?
1. Chemoreceptors
2. Nociceptors
3. Osmoreceptors
4. Photoreceptors
What are each of the sensory receptors responsible for?
2) Nociceptors
Chemoreceptors respond to chemicals - volatile, aerolised, and dissolved. Nociceptors respond to pain. Osmoreceptors respond to changes in blood osmolarity. Photoreceptors respond to light.
MCAT Behavioural Sciences - Sensory Processing
Which part of the eye is responsible for gathering and focusing light?
1. Cornea
2. Pupil
3. Iris
4. Retina
What are the responsibilites of the other options?
1) Cornea
The iris and pupil are responsible for regulating the amount of light coming into the eye but not in focusing it. The retina tranduces light into electrical signals.
MCAT Behavioural Sciences - Sensory Processing
A man is looking for change to do laundry. He decides to look under the seats of his car. He uses a flashlight but is still unable to get more than an obscured look at the space below. There are various items such as wrappers and papers, but the man sees the glint of silver from an object laying flat and determines it to be a coin. To make this determination, this man used:
1. Signal detection
2. Sensory adaptation
3. Feature detection
4. Kinesthetic sense
3) Feature Detection
MCAT Behavioural Sciences - Sensory Processing
Upon which part of the eye are images projected and transduced into electrical signals?
1. Cornea
2. Pupil
3. Retina
4. Lens
4) Retina
MCAT Behavioural Sciences - Sensory Processing
The ability to sense stimuli against one’s own skin is known as:
1. Somatosensation
2. Kinesthetic sense
3. Vestibular sense
4. Chemoreception
Define the other options
1) Somatosensation
Kinesthetic sense is the ability to tell where one’s body is in space. Vestibular sense is the detection of linear and rotational acceleration in the middle ear. Chemoreception is the sensing of chemicals in the environment
MCAT Behavioural Sciences - Sensory Processing
Which of the following is not a taste modality?
1. Sweet
2. Floral
3. Savory
4. Bitter
2) Floral
MCAT Behavioural Sciences - Sensory Processing
Which of the following best describes the difference between endolymph and perilymph?
1. Endolymph is found in the vestibule, while perilymph is found in the cochlea
2. Endolymph is found in the cochlea, while perilymph is found in the vestibule
3. Endolymph is found in the membranous labyrinth, while perilymph is found in the bony labyrinth
4. Endolymph is found in the bony labyrinth, while perilymph is found in the membranous labyrinth
What are endolymph and perilymph?
3) Endolymph is found in the membranous labyrinth, while perilymph is found in the bony labyrinth
Endolymph is the potassium-rich fluid that bathes the hair cells of the inner ear, which are found in within the membranous labyrinth. Perilymph is found in the space between the membranous labyrinth and the bony labyrinth
MCAT Behavioural Sciences - Sensory Processing
Chemicals that compel behaviour after binding with chemoreceptors are known as:
1. Pheromones
2. Olfactory Receptors
3. Somatostimuli
4. Papillae
1) Pheromones
Pheremones are volatile chemicales given off by organisms that bind with olfactory chemoreceptors and influence behaviour.
MCAT Behavioural Sciences - Sensory Processing
Prolonged vitamin B deficiency can be associated with the subacute combined degeneration of the spinal cord. Patients with this disease have difficulty walking because they lose the ability to feel where their feet are in space. This represents a loss of:
1. Vestibular sense
2. Kinesthetic sense
3. Parallel processing
4. Feature detection
2) Kinesthetic Sense
Proprioception refers to the ability to tell where body parts are in three-dimensional. The sensors for which are found predominantly om the muscles and joints. Loss of vestibular sense would also cause difficulty walking but this would be due to a sense of dizziness or vertigo, not an inability to feel one’s feet.
MCAT Behavioural Sciences - Sensory Processing
A person proofreading a paper reads over a long, misspelled word in which an “e” is replaced with an “o”. The person does not recognise the error and reads the word as correct. Which of the following could explain why the proofreader read the word as a correct?
1. Parallel processing
2. Feature detection
3. Top-down processing
4. Bottom-up processing
3) Top-down processing
The proofreader used expectations and recognition, which led to missing a detail.
MCAT Behavioural Sciences - Sensory Processing
A corporate logo uses five unconnected angles equally spaced in a circular fashion. When viewed, it appears to be a star. Which of the following is the logo artist using to create a complete pattern to viewers?
1. Bottom-up processing
2. Top-down processing
3. Gate theory
4. Gesalt principles
4) Gesalt Principles
Geslat principles are the basis for many optical illusions and include the tendancy of people to see continuity even when lines are connected. Specifically, this logo appears to rely on the law of closure to create one complete star from five non-touching angles.
MCAT Behavioural Sciences - Sensory Processing
A patient comes in with a tumour of the pituitary gland, which grows upwards into the optic chiasm and causes a visual field defect. The most likely defect from compression of the optic chiasm is:
1. Complete blindness in one eye
2. Loss of the upper visual fields in both eyes
3. Loss of the nasal visual fields in both eyes
4. Loss of the temporal visual fields in both eyes
How does the lens play into this?
4) Loss of the temporal visual fields in both eyes
The optic chiasm houses the crossing fibers from each optic nerve. Specificallt, the fibers coming from the nasal half of the retina in each eye cross in the chiasm to join the optic chiasm to join the optic tract on the opposite side. The lens of the eye causes inversion, so images on the nasal half of the retina actually originate in the temporal visual field.
MCAT Behavioural Sciences - Sensory Processing
Define Sensation
What is the more appropriate term?
The conversion of information from the internal and external environment into electrical signals in the nervous system.
Transduction
MCAT Behavioural Sciences - Sensory Processing
Define Perception
The processing of sensory information to make sense of its significance
MCAT Behavioural Sciences - Sensory Processing
Define Sensory Receptor
List seven common sensory receptors
Nerves that respond to stimuli and trigger electrical signals
Photoreceptors, hair cells, nociceptors, thermoreceptors, osmoreceptors, olfactory receptors, and taste receptors
MCAT Behavioural Sciences - Sensory Processing
Definition and Function: Sensory Ganglia
Collections of cell bodies outside of the CNS that synaptically relay signals between neurons
MCAT Behavioural Sciences - Sensory Processing
Define Projection Areas
Areas of the brain that further analyse specific sensory signals
MCAT Behavioural Sciences - Sensory Processing
Define Threshold
Name three key threshold levels
The minimum stimulus that is needed to cause a change in signal transfuction
Absolute threshold, threshold of conscious perception, difference threshold
MCAT Behavioural Sciences - Sensory Processing
Define Absolute Threshold
The minimum of stimulus energy that is needed to activate a sensory system
MCAT Behavioural Sciences - Sensory Processing
Define Threshold of Conscious Perception
The minimum of stimulus energy that will create a signal large enough in size and duration to be brought to awareness
MCAT Behavioural Sciences - Sensory Processing
Define Difference Threshold
What is the alternative name?
The minimum difference in magnitude between two stimuli before one can percieve the difference
Just-noticiable difference (jnd)
MCAT Behavioural Sciences - Sensory Processing
Define Weber’s Law
The jnd for a stimulus is proportional to the magnitude of the stimulus, and that this proportion is constant over most of the range of possible stimuli
MCAT Behavioural Sciences - Sensory Processing
Define Signal Detection Theory
How does this relate to response bias?
The effects of nonsensory factors, such as experiences, motives, and expectations, on the perception of stimuli
In a signal detection experiment, a stimulus may or may not be given, and the subject is asked to state whether or not the stimulus was given. There are four possible outcomes: hits, misses, false alarms, or correct negatives.
MCAT Behavioural Sciences - Sensory Processing
Define Adaptation
The decrease in response to a stimulus over time
MCAT Behavioural Sciences - Sensory Processing
Function: Cornea
Gathers and filters incoming light
MCAT Behavioural Sciences - Sensory Processing
Function and Mechanism: Iris
Divides the front of the eye into the anterior and posterior chamber. Contains two muscles, the dilator and constrictor pupillae, which open and close the pupil.
MCAT Behavioural Sciences - Sensory Processing
Function and Mechanism: Lens
Refracts incoming light to focus it on the retina and is held in place by suspensory ligaments connected to ciliary muscle
MCAT Behavioural Sciences - Sensory Processing
Function and Mechanism: Ciliary Body
Produce aqueous humour (supplies nutrition and gives the eye its shape), which drains through the canal if Schlemm
MCAT Behavioural Sciences - Sensory Processing
Function and Mechanism: Retina
Contains rods (light/dark) and cones (colour). Cones are mostly found in thr maculus and the center is the fovea, which only contains cones
MCAT Behavioural Sciences - Sensory Processing
Synapses involving rods and cones
Rods and cones synapse on bipolar cells, which synapse on ganglion cells. Integration of the sifnals from ganglion cells and edge-sharpening is performed by horizontal and amacrine cells.
MCAT Behavioural Sciences - Sensory Processing
Which three objects support the eye?
Vitreous, sclera, and choroid
MCAT Behavioural Sciences - Sensory Processing
Outline the visual pathway
Function of each object
eye -> optic nerves -> optic chiasm -> optic tracts -> lateral geneticulate nucleus (thalamus) -(visual radiations)> visual cortex (occipital lobe)
Eye recieves visual information. Optic nerves are responsible for transmitting optical signals. Optic chiasm contains fibers crossing from the temporal visual fields of both eyes. LGN is the primary visual cortex. Visual radiations run through the temporal and parietal lobes to the visual cortex in the occipital lobe.
MCAT Behavioural Sciences - Sensory Processing
Define Parallel Processing
What cells are involved in parallel processing?
The ability to simultaneously analyse and combine information regarding colour, shape, and motion.
Colour is detected by cones. Shape is detected by parvocellular cells (high spatial resolution, low temporal resolution). Motion is detected by magnocellular cells (low spatial resolution, high temporal resolution).
MCAT Behavioural Sciences - Sensory Processing
Components (3) of the outer ear
What are their functions?
Pinna (auricle), external auditory canal, and tympanic membrane
MCAT Behavioural Sciences - Sensory Processing
Components (5) of the middle ear
What are their functions?
Ossicles (malleus, incus, stapes), oval window, eustachian tube
MCAT Behavioural Sciences - Sensory Processing
Components (10) of the inner ear
What are their functions?
Bony labyrinth, membranous labyrinth, perilymph, endolymph, cochlea, utricle, succule, and three semicircular canals
MCAT Behavioural Sciences - Sensory Processing
Outline the auditory pathway
Cochlea -> vestibulocochlear nerve -> medial geniculate nucleus (thalamus) -> auditory cortex (temporal lobe)
MCAT Behavioural Sciences - Sensory Processing
What are the superior olive and inferior colliculus each involved in?
The superior olive localises sound and the inferior colliculus is involved in the startle reflex
MCAT Behavioural Sciences - Sensory Processing
Outline the olfactory pathway
What is smell?
Olfactory chemoreceptors/nerves (olfactory epithelum) -> olfactory bulb -> olfactory tract -> higher-order brain areas e.g., limbic system.
MCAT Behavioural Sciences - Sensory Processing
Define taste and its mechanism
Define its five modalities
The detection of dissolved by taste buds in the papillae
Sweet, sour, salty, bitter, and umami (savory)
MCAT Behavioural Sciences - Sensory Processing
Definition of somatosensation and its four modalities
The combination of four touch modalities: pressure, vibration, pain, and temperature
MCAT Behavioural Sciences - Sensory Processing
Define Two-Point Threshold
The minimum distance necessary between two points of stimulation on the skin such that the points will be felt as two distinct stimuli
MCAT Behavioural Sciences - Sensory Processing
Define Physiological Zero
The normal temperature of skin to which objects are compared to determine if they feel ‘cold’ or ‘warm’.
MCAT Behavioural Sciences - Sensory Processing
Define Gate Theory of Pain
Pain sensation is reduced when other somatosensory signals are present
MCAT Behavioural Sciences - Sensory Processing
Define Proprioception
The ability to tell where one’s body is in three-dimensional space, also known as kinesthetic sense.
MCAT Behavioural Sciences - Sensory Processing
Define Data-Driven (Bottom-Up) Processing
Name an advantage and a drawback
Recognition of objects by parallel processing and feature detection
It is less prone to mistakes but is slower.
MCAT Behavioural Sciences - Sensory Processing
Define Conceptually Driven (Top-Down) Processing
Name an advantage and a drawback
Recognition of objects by memories and expectations, with little attention to detail
It is faster but more prone to mistakes
MCAT Behavioural Sciences - Sensory Processing
Define Perceptual Organisation
List four key perceptions
The synthesis of stimuli to make sense of the world
Depth, form, motion, and constancy
MCAT Behavioural Sciences - Sensory Processing
Define Gesalt Principles
Define six key Gesalt principles
The ways that the brain can infer missing parts of a picture when a picture is incomplete
Law of proximity, similarity, good continuation, closure, pragnanz, and subjective contours
