Sensation and perception 2 Wk 6 Flashcards
properties of sound
sound is caused by vibrations (wave frequency is 1 second
wave frequency (Hz) = pitch wave amplitude (dB) = loudness wave complexity = timbre
what is our audible spectrum
the human ear is sensitive to me mechanical vibration from about 20 to 20 000Hz
auditory perception
different tones excite different areas of the basilar membrane and primary auditory cortex (tonotopic organisation)
describe the place theory
for high pitch, hairs in specific areas of the basilar membrane activate specific regions in the primary auditory cortex
describe the frequency
for low pitch, the rate of action potentials signals frequency of sound wave (up to 100 Hz)•
what is conductive hearing loss
problems in outer/middle ear : - amplification of sound (hearing aid) can be helpful
what is Sensorineural hearing loss
Problems in inner ear, auditory nerve and auditory cortex can be more complex–Cochlear implant
causes of hearing loss
genetic/congenital disease/injury noise induced medication substances age
what is olfaction ?
smell
what is gustation?
taste
what do olfaction and gustation do?
they work together to enhance the liking or disliking of foods
describe olfaction
olfactory receptors code for one odour (lock and key analogy)
humans can identify 2000-4000 odours
we can adapt rapidly to smell
describe gustation
sweet, sour, bitter, salty and now (umami)
olfactory and gustatory, is apart of what system?
limbic system (orbitofrontal cortex, amygdala)
strong connections to emotion smell and tastes
describe somatosensory system
Specialised receptors within the skin detect physical stimuli from the external environment
what are the three classes of skin receptors?
1) pressure (mechanoreceptors)
2) temperature (thermoreceptors)
3) pain (nociceptors)
what is the tongue map myth
that certain parts of the tongue are responsible for different types of flavour
what is the phantom limb illusion? (Prac where we had the hand)
Phantom limb pain of amputees can be relieved with a mirror box
what is congenital pain insensitivity?
Isaac brown was born with a congenital insensitivity to pain
Isaac’s parents had to teach him to identify injuries
what are proprioception?
proprioceptors are located in the joints, muscles and tendons providing feedback for the brain
what is vestibular control?
-balance
inner ear
info sent to brain stem and cerebellum to coordinate/adjust eye, head and body movements
what is perception?
organisation of sensation into meaningful units that can be interpreted in the brain
an action process by which the brain selects, organises and interprets sensory information
Principles of perceptual organisation
Top-down and bottom up processing •Perceptual sets / context –Perceptual constancy –Gestalt principles –Motion perception –Depth or distance perception
3 steps of top down processing
1) use prior knowledge and experience to organise and interpret sensations
2) select specific features and meet expectations about stimulus
3) form perception
3 steps of bottom up processing
1) detect features of sensory data
2) analyse specific features and combine component pairs into more complex forms
3) form perception
what is perceptual constancy
to perceive objects as perceptually stable despite variation in stimulation of sensory receptors
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 is gestalt principles?
Gestalt principles’, or rules describe how visual elements are organised into groups or unified wholes.
Whole is greater than the sum of parts
what is motion perception?
Visual system is organised to detect motion
–Some cells in the retina are sensitive to motion
–Neurons (feature detectors) in visual cortex respond to motion
two ways of detecting movement (motion perception)
- A: eye is stationary as object moves on the retina
–B: eye moves to maintain object at same place on the retina
what is depth (distance) perception?
the organisation of perceptions into three dimensions
what are the two visual cues that enable us to judge depth and distance?
Binocularcues: visual input from two eyes
•Monocular cues: only one eye provides visual input
what are some binocular cues?
Primary cues for distance/depth perception
- Binocular/Retinal disparity (aka stereopsis)–degree of overlap of image between the retinas in each eye
- Convergence–eyes converge at small distances
what is perceptual interpretation?
generating meeting from stable percepts
depth perception - molecular cues
Secondary distance cues (monocular) •Relative size •Texture gradient •Height in plane •Motion parallax •Linear perspective•Interposition •Shading
what is synaesthesia ?
it is experience of cross modal sensations (hearing, tasting shapes)
Different perceptual experiences can be produced 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
- Can have a brief, short-term impact on behaviours and attitudes
- Effect disappears when people are aware of or suspect subliminal influences
what is subliminal PERSUASION
Fairly unlikely to produce large-scale or enduring attitudes or decisional changes
- Subliminal self-help tapes have been shown to be ineffective (the illusory placebo effect)
- Reversed subliminal messages also ineffect
what is extrasensory perception? (ESP)
The perception of events outside the known channels of sensation (people don’t find positive effects for ESP)
What are the three major types of ESP
1) precognition
2) telepathy
3) Clairvoyance
blindspot?
point of no cells where information enters the brain
myopia?
nearsightedness. focus point is before retina
