Chapter 4 Flashcards
what is sensations
the process of receiving energy from stimuli in our internal or external environment and transforming this energy into action potentials
what 3 things do all sensory systems have in common
- specialized receptor cells
- transduction
- multiple subsystems
what is transduction
- when receptor cells register a stimulus, transduction occurs which is the conversion of energy into an action potential that relays information about the stimulus through the nervous system to the brain
what is perception
- the process of organizing and interpreting sensory information so that it makes sense
i.e. receptor cells in our eyes record, a silver object in the sky, but they don’t recognize it as a plane (our perception does that)
what is the difference between sensation and perception
sensation is the raw materials of experience (light, sound, touch)
perception is how our brain processes and makes sense of that information
- you can think of it as the brains way of interpreting the sensory input to give it meaning
what is bottom-up processing
sensory receptors register information about the external environment and send it up to the brain for interpretation
- so you are taking in information and trying to make sense of it
what is top-down processing
it starts with cognitive processing in the brain
- we begin with some sense of what’s happening (we use what we already know) and interpret incoming details instead of just reacting to new information
example of bottom-up and top-down processing
experiencing a song:
- the first time you listen to a snog, you listen carefully to analyze rhythm, lyrics, etc.
- this is bottom-up processing, as you initially receive sensory signals (external audio) and then you can perceive/interpret it as music
- after hearing the song multiple times, you have expectations of what lyrics and melody will come next, and sometimes you find yourself thinking about the song and start playing it in your head: HUMMING
what are sensory receptors
specialized cells that detect stimulus information and transmit it to sensory (afferent) nerves in the brain
- sensory nerves bring information from the world into the brain
- sensory receptors are the opening through which the brain and nervous system experience the world
what are the 3 categories of energy sense organs + receptors can detect
1) photoreception: detection of light (sight)
2) mechanoreception: detection of pressure, vibration, and movement (touch, hearing, equilibrium)
3) chemoreception: detection of chemical stimuli (smell and taste)
examples of sense confusion
- synaesthesia
- mirror-touch synaesthesia
- phantom limb pain
where do most of sensory signals go to?
- THALAMUS
- the brains relay station
- they are then routed to the sensory areas of the cerebral cortex
which areas in the cerebral cortex are responsible for each sense
Occipital Lobe= visual information
Temporal Lobe=hearing
Parietal Lobe=pain and touch
what does psychophysics examine
interactions between sensory signals and perception to answer questions
i.e. “how much of a stimulus is necessary for you to see, hear, taste, smell, or feel smth?”
and “what was the lowest amount of stimulation that will still be detected?”
what is the absolute threshold
- minimum amount of stimulus energy that a person can detect
- so if energy falls below this threshold, we CANNOT detect its presence but if its falls above the absolute threshold we CAN detect the stimulus
how did scientists detect what the absolute threshold
- the point at which the individual detect the stimulus 50% of the time
what is the difference threshold?
- the difference between 2 stimuli before the difference is detected
- “just noticeable difference” (also 50% of the time)
what is weber’s law
the principle that 2 stimuli must differ by a constant proportion to be perceived as different
e.g.: mentioned candle example
what is subliminal perception
- the detection of information below the level of conscious awareness
i.e. participants in a study were exposed to either words to do with thirst or normal words, the ones who got the words w/ thirst, drank more
couldnt actually see the flashed word
what is the signal detection theory
focuses on the decision making about stimuli under conditions of uncertainty
- the detection of sensory stimuli depends on many factors beside the physical intensity of the stimulus and the sensory abilities of the observer
- it provides a way to detect and account for subjects’ biases
what is an example of the signal detection theory
- if you are expecting an important phone call, you’re overly responsive and can shift your tendency towards more “YES” responses
- if the stimulus is present (phone ringing) you can respond either “YES” (answering call) or “NO” (failing to notice the call)
- if the stimulus is absent (phone isn’t ringing), you can respond either “YES” (answering call but nobody is calling) or “NO” (correctly identify that nobody is calling)
what are the two main components of decision making in the signal detection theory
1) information acquisition
2) criterion
what is information acquisition
- the gathering of relevant indicators, e.g. noticing the signal whether the phone is ringing or not
what does criterion refer to in the signal detection theory
- the standards used to make a decision
e.g. if its an important call, you may set low criterion and interpret any sound as the phone ringing
- if its not an important call, you’ll set high criterion and only respond if you’re sure the phone is ringing
what is attention
focusing awareness on a narrow aspect of the environment
what is selective attention
focusing on a specific aspect of experience while ignoring others
Stroop Effect
psychological phenomenon that describes how people have a longer reaction time when naming the color of a word if it’s different from the color of the word. For example, if the word “red” is printed in blue ink, it takes longer to say “blue” than if the word “red” were printed in red ink.
what are features of stimuli that draw attention to them
novelty
size
colour
movement
emotional stimuli
inattention blindness
cant detect external stimuli if we are engrossed with a task
what is a perceptual set
reflects top-down influences on perception
- its the predisposition/readiness to perceive something in a particular way
sensory adaptation
getting used to a stimulus/lack thereof
what are the parts of the eye you can see
sclera: white, outer part of the eye that maintains its shape
iris: coloured part of the eye
pupil: appears black, opening in centre of iris, has muscles that control the size of the pupil and amount of light entering the eye
retina: light-sensitive surface that record EM energy and converts it into neutral impulses for the brain
important part of retina=foveaL a tiny area in the centre of the retina that lets us see details
how do we focus on an image
- we use the cornea (a clear membrane in front of the lens) and the lend (transparent, filled with gelatinous material)
- they bend the light falling on the surface of the eye to focus it at the back
- the cornea bends while the lens fine-tunes things
what is the retina
- multilayered structure at the back of the eye that takes incoming light an converts it into neutral impulses for processing in the brain
- primary mechanism of sight
( light —- action potentials ; uses receptor cells)
what are the 2 kinds of visual receptor cells
rods (receptors in retina sensitive to light) and cones (receptors for colour and small details)
feature detectors
individual neurons or groups of neurons in the brain’s visual system that respond to particular features of a stimulus
parallel processing
simultaneous distribution and management of information across different neural pathways
binding
integration of what is processed by different pathways or cells
trichromatic theory
- proposed by Thomas Young and Hermann von Helmholtz
- colour perception is produced by 3 cone receptors (red, green, blue)
BUT
Ewald Hering found that this theory could not adequately explain afterimages, sensations that remain after a stimulus is removed
his view: opponent-process theory
- cells in the visual system respond to red-green and blue-yellow colours, and a given cell might be excited by one and inhibited by another (red-green and yellow-blue)
red and yellow=excited
green and blue=inhibited
figure-ground relationship
- organize the perceptual field into stimuli that stand out and those that are left over
place theory
each frequency produces vibrations at a particular spot on basilar membrane (inner ear)
frequency theory
identifies these other factors by stating that the perception of a sound’s frequency depends on how often the auditory nerve fires
volley principle
states that a cluster of nerve cells can fire neutral impulses in rapid succession
kinesthetic senses
vestibular sense
semicircular canals
vestibular sacs
kinesthetic: provide info about movement, posture, and orientation
vestibular: provides info about balance and movement
semicircular: inner ear, contains the sensory receptors that detect head motion
vestibular sacs: detect changes in head pistons
sociocognitive theory
dissociation model
sociocognitive theory - explaining hypnosis based on peoples beliefs and social expectations
dissociation model- approach to explaining hypnosis based on separation of the parts of the personality responsible for planning from the part that controls memories
idiosyncratic intoxication
state in which small amounts of alcohol produce dramatic behavioural changes
DTs
delirium tremens
- disorientation, confusion, visual, hallucination, memory problems resulting from alcohol withdrawal, may be fatal w/o proper care
Ivan Pavlov
BF Skinner
William Sargent
MKULTRA
Stanley Milgram
Robert Heath
Ivan PavlovStudied classical conditioning with dogs.
B.F. Skinner – Developed operant conditioning. (reinforcement through reward and punishment)
William Sargent – Researched brainwashing and conditioning.
MKULTRA – CIA’s secret mind control experiments.
Stanley Milgram – Studied obedience to authority.
Robert Heath – Experimented with brain stimulation.
