Sensation and Perception Flashcards Preview

Cognitive Psychology > Sensation and Perception > Flashcards

Flashcards in Sensation and Perception Deck (18)
Loading flashcards...

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


Important concepts

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
fMRI scanning
Optical imaging/near infra red spectroscopy
Event related potential from EEG
Computational modelling


Lesion studies

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


Virtual lesions

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


Optical imaging

Shine light on skulll and sense how much blood is going through


Event related potential

Electrodes on head, look at visual stimuli


Virtual illusions

No depth cues lead to ambiguity
introspection is a valid way to ask about sensation and perception, consider investigating it systematically


Single cell recordings

Put a microelectrode inserted close to cell, action potentials are then recorded
Cortical recordings require section of skull to be removed, only on humans if medical operation (epilepsy)
Identifies selective cells - for certain faces
Evidence - epileptic patients implanted with depth electrodes, presented with photos, text name of people and spoken name. Selective neutrons in medial temporal lobe respond to individuals in multiple sensory modalities