Flashcards in Sensation and Perception Deck (18)
What is sensation?
Registering stimulation of the senses
What is perception?
Processing and interpreting sensory information
This is where consciousness begins
What is cognition?
Using perceived information to learn, classify and comprehend
Why is studying sensation and perception important?
Racing - need to perceive when to start running
Shooting and aiming
Aid someone's life by understanding sense
Tells us about the brain
Each external change in the body has a different receptor associated with it, and a different part of the brain
What is bottom up processing?
Perception starts with physical characteristics of stimuli and basic sensory processes - features
Don't need other information to understand what is going on
Direct processing - Gibson - information from sensory receptors is enough for perception to happen. Complex thought isn't required. the environment contains sufficient cues to provide context to aid perception ie. texture indicates depth
What is top down processing?
The perceiver constructs their understanding of external knowledge based on past experience and knowledge
dynamic search for the best interpretation of available data
Despite ambiguous stimuli, you can still make inferences about what is going on eg. hearing lyrics when there are none - filling in gaps
What are the methods of investigating sensation and perception?
Single cell recordings
Optical imaging/near infra red spectroscopy
Event related potential from EEG
Animal - by knife or neurotoxins, ethics - studying faulty system, brain will change
Neuropsychology - damage due to stroke, trauma, boxing etc
Damage can be diffuse, individual variation in damage
TMS - send pulses of magnetic energy which disrupts activity in the brain for a short period of time (temporary lesion) - used to investigate sensation and perception
eg. TMS on posterior superior temporal sulcus - disrupts biological motion, shows there is a specific part of the brain responsible for motion
Quantifying the relationship between physical stimuli and sensation and perception
Threshold - change from one experience to anther
Absolute threshold - smallest stimuli intensity needed for detection
Differential - smallest difference between stimuli can be detected
Psychophysics has found distrusted biological motion in children with autism
How to measure thresholds?
Method of adjustment - change intensity of a stimulus until can no longer detect it
Take dead brain tissue, apply stains, depending on chemical properties, it will stain in different ways (can see structures, layers etc)
Measure activity that is going on in the brain
Shine light on skulll and sense how much blood is going through
Event related potential
Electrodes on head, look at visual stimuli
No depth cues lead to ambiguity
introspection is a valid way to ask about sensation and perception, consider investigating it systematically