Flashcards in Week 6 - Sensation & Perception 2 Deck (59):
What is sound caused by?
Wave frequency =
Wave amplitude =
Wave complexity =
The human ear is sensitive to mechanical vibration from what frequency (Hz)?
Explain the Place Theory of pitch perception
Our perception of sound depends on where each component frequency produces vibrations along the basilar membrane.
For high pitch, hairs in specific areas of the basilar membrane activate specific regions in the primary auditory cortex
Explain the Frequency Theory of pitch perception
The frequency of the nerve impulses corresponds to the frequency of a tone, which allows us to detect its pitch.
For low pitch, the rate of action potentials signals frequency of sound wave (up to 100Hz)
Explain the Volley Theory of pitch perception
Groups of neurons of the auditory system respond to a sound by firing action potentials slightly out of phase with one another so that when combined, a greater frequency of sound can be encoded
Combinations of action potentials slightly de-synchronised collectively signal the frequency of sound wave/
What is Conductive hearing loss?
Problems in the outer/middle ear
What is Sensorineural hearing loss?
Problems in the inner ear, auditory nerve and auditory cortex
3 causes of hearing loss
What is the relationship between olfaction and gustation?
They work together to enhance liking or disliking some foods
Olfaction is what?
Gustation is what?
Olfaction is like the lock and key analogy, why?
Because olfactory receptors code for one odour
How many odours can humans identify?
What types/groups of people are considered to have better olfaction? (3)
What are the 4 main gustations? and what is the extra 5th one that has recently been added?
Smell and taste converge on parts of what system?
limbic (orbitofrontal cortex, amygdala)
What is the Somatosensory System?
Specialised receptors within the skin detect physical stimuli from the external environment eg temp and pain
What are the 3 classes of skin receptors?
Pressure - "mechanoreceptors"
Temperature - "thermoreceptors"
Pain - "nociceptors"
What is the Phantom Limb illusion?
A vivid sensation that a missing limb is still present
How can Phantom Limb pain be relieved?
With a mirror box
What is Congenital Pain Insensitivity?
The inability to feel pain
What are the 5 body senses?
Touch, Pain, Temperature, Body position, balance
What is proprioception?
Perception or awareness of the position and movement of the body (body position)
- Kinaesthetic sense
Where are proprioceptors (stretch and force) located?
The joints, muscles and tendons which provide feedback to the brain
What is the Vestibular System?
Sensory system that provides the leading contribution to the sense of balance and spatial orientation for the purpose of coordinating movement with balance (balance)
How does the Vestibular System work?
Information is sent to the brainstem and cerebellum to co-ordinate/adjust eye, head and body movements
Inner ear balance is supported by what (2) things?
Semicircular canals and otoliths
What is the role of perception?
Organisation of sensations into meaningful units that can then be interpreted by the brain
What is perception?
An active process by which the brain selects, organises and interprets sensory information
What are the 6 principles of perceptual organisation?
top-down and bottom-up processing
depth or distance perception
What is bottom-up processing?
Detecting and analysing specific features and combining the parts into more complex form
eg you recognise the parts that make up a dog (fur, tail) and then recognise the object as a dog
What is top-down processing?
Using prior knowledge to organise and interpret sensations
Select specific features that meet the expectations about a stimulus (you recognise the parts of a dog because you have first recognised the dog as a whole)
What is Perceptual Constancy?
Tendency to perceive objects as perceptually stable despite variation in stimulation of sensory receptors
For example, you recognise that small brownish dog in the distance as your neighbour's large golden retriever, so you aren't surprised by the great increase in size (size constancy) or the appearance of the yellow colour (colour constancy) when he comes bounding up. And in spite of the changes in the appearance of the dog moving toward you from a distance, you still perceive the shape as that of a dog (shape constancy) no matter the angle from which it is viewed.
What are the 2 compartments of Perceptual constancy?
Shape: We recognise an object as having the same shape when viewed from a different angle
Size: Objects do not differ in size when viewed from different distances
What do Gestalt Principles describe?
How visual elements are organised into groups or unified wholes
What is the common Gestalt rule?
Whole is greater than the sum of its parts
7 Principles of Gestalt
Simplicity: Our mind perceives everything in its simplest form.
Proximity: Objects and shapes that are close to one another start to form groups. Even if they are very different. We perceive elements as belonging to the same group if they are laid out close together.
Similarity: We perceive elements as belonging to the same group if they look like each other.
Continuation: Elements are visually associated if they are aligned with each other. (xmas tree pencil sharpener)
Closure - We automatically fill in gaps between elements to perceive a complete image
Symmetry: Symmetrical elements are perceived as part of the same group
Figure-Ground: The “figure” is the element in focus, while the “ground” is the background behind the figure.
The visual system is organised to do what?
What are the two ways to detect movement?
Eye is stationary as object moves on the retina
Eye moves to maintain object as same place on the retina
What is depth perception?
The organisation of perception into three dimensions
What are the 2 visual cues that enable us to judge depth and distance?
Binocular: Visual input from two eyes
Monocular: Visual input from one eye
Which cue is primary and which is secondary for distance/depth perception?
Binocular and Monocular
Binocular/retinal disparity is also known as?
What is binocular/retinal disparity?
The degree of overlap between the retina in each eye
Eyes converge at what size distance?
Monocular cues involve things such as (4)?
Height in plane
Explain Perceptual Interpretation
Form, depth, motion perception and constancy explain how sensation is organised into stable recognisable forms
Perceptual interpretation is generating meaning from the stable percepts
Examples of where perception has deceived
rubber-hand illusion, Synaethesia, Phantom limb pain
What is Synaethesia?
Joining or merging of senses that aren't normally connected.
eg hearing colour, seeing sound
What is Synaethesia caused by (brain)?
By cross-modal processing (cross-talk between brain areas) or overlap in brain areas
What is Subliminal Perception?
Processing of sensory information that occurs below the level of conscious awareness
Occurs when a stimulus is too weak to be perceived yet a person is influenced by it
What can Subliminal Perception do?
Can have a brief short-term impact on behaviours
Can effects of Subliminal Perception disappear? When?
Yes, when people are made aware of or suspect subliminal influence
What is Extrasensory Perception (ESP)
The perception of events outside the known channels of sensation