Lecture 2 Flashcards
Discuss the process of sensation to perception
Stimulus energy (light/sound) - Sensory receptors (eyes/ears) - Neural impulses - Brain (visual/auditory areas)
Discuss perception to cognition
Separating sensation/perception/cognition is largely artificial but provides useful starting points
How much of the world do we encode
Agreement that there is a sensory memory store that holds information from the lead environment until we perceive, or attend to it.
Discuss the multi-store models of memory
Information goes into sensory store and either decays or is giving more attention. If attention is given, it is stored in the short-term store and either displaced, or rehearsed. Should information be rehearsed, it is stored in the long-term store, and only gets lost with interference
Discuss sensory memory in terms of vision
Information is held in the sensory registers until it is perceived (or payed attention to).
What is the evidence for the visual sensory memory
Sperling (1960) - visual sensory memory: iconic memory. Investigated visual store by presenting participants with a fixation point. Then presented a visual array containing 3 rows of 4 letters each for 50ms. Then presented the fixation point again and asked participants to recall as many letters as they could. This would give an indication of the span/capacity, of a sensory memory system and begin to answer the question of how much of the world we encode. Found that participants reported an average of 4.5 letters, and concluded that not all information was stored in the sensory memory
Discuss the twist in Sperling’s full report procedure
In another condition, participants were cued to recall letters from only one row. A tone way played after the display had disappeared. Participants had to recall the letters from the row that corresponded to the tone. Found that participants could recall 3 out of 4 of the letters on the cued row however participants did not know which row they were going to have to recall beforehand. THUS sperling concluded that sensory memory retained almost all of the stimulus information but only for a short time
Summarise sensory memory
Sensory memory holds more information than we can process. We need to attend to certain items in order to remember them because information is lost rapidly from sensory memory
Discuss perceptual thresholds
Imagine an experiment where we sit a participant in a dark room and shine a spot of light on the wall in front of them. Do we register stimuli in all or nothing fashion (we either see it or we don’t) OR is it best described as a continuous curve? - our thresholds are determined by subjective factors
Discuss the signal detection theory
This theory tries to disentangle perceptual effects arising from sensory processes - signal? AND those arising from decisional processes - response? This framework has been used to try and describe/model behaviour is applied settings. Choosing behaviour in police line ups, memory performance in EWT, remembering childhood traumas
Once something has entered the sensory memory and we have registered a stimulus, what happens next?
The eye and inverted image - one old theory: the picture theory: argued that the world is represented literally as a picture in the brain. But where does perception actually occur
Discuss 2 additional problems (other than perception) with the picture theory
Implies that perception is a literal copy of info in the world. AND it relies entirely on incoming information - but this is not always random - it can be structured in meaningful ways that mean it requires less interpretation
Discuss was J.J.Gibson proposed about meaningless light
Ecological Optics - perception depends on the structure of the light picked up by the observer, not simply on stimulation of the observer by the light. We are not just passive recipients of sensory energy
Discuss why during the 2nd world war efforts to improve pilots ability to land plans didn’t work well
Happy landings seemed to depend as much on the richness of the cues in the environment as on pilot’s ability. Thus, structure in the light or optic array seems to be as important as structure in the head - this is why landing strips are lit so well
Discuss the Gibsonian speed control on roads
Works by changing the structure of the perceived world not be appealing to the internal perceptual or cognitive mechanisms with a reduce speed now sign
What forms does the structure of light take
Texture gradients. Horizon ratio - objects which are the same size but different distances away from the observer, whereas objects of different sizes at the same distance away have different horizon ratios
Discuss perceptual invariants
It is unchanging aspects of the environment from the observers viewpoint. Texture gradients and horizon ratios are examples of this. But we are not static and passive perceiver’s of out environment - we move through it. Motion results int he flow of optic information around the perceiver
Discuss the Gestalt principles
Prior to Gestalt psychology the classical associationist approach suggested that we break down the perceived world into a number of separate sensations. These are then associated together in order to perceive integrated objects. Thus we build up a picture of the whole from the available parts = reductionist
Name a problem with the Gestalt principles
Things are often perceived as being similar even though they consist of different parts
How do we deal with the problems with the Gestalt principles
Gestalt psychologists turned the traditional argument on its head and claimed that perception of the whole, not the parts, came first = holistic. Thus the saying “the whole is greater than the sum of its constituent parts”
Discuss the process of bottom up processing
Stimuli input - stimulus processing - perception
Discuss similarities between Gibson (direct perception) and Gestalt (principles)
Both remind us of the rich structure inherent in the world. Neither accounts sufficiently for how this information is processed or perceived. Some description is needed for how different animals pick out the structures they need to see. Because if all the information was “out there” int he environment then humans stickleback fish and frogs should not differ in their perceptual abilities - but they do
Discuss whether perception = interpretation
Understanding neurophysiology and structure of light on its own it not enough, we need psychological explanation too. TOP DOWN process is relevant here. Because our experience leads us to see things in a certain way
Discuss the process of top-down processing
Perception of knowledge, belief and expectation, as well as stimuli input both lead to stimulus processing
What are illusions a classic case of
Top-down/concept driven processing. Because it is involved in perception - sometimes our perception is faulty
Discuss some real-life examples of the Muller-Lyer effect
Goal-keepers: estimated 24cm taller when arms up. Swim suits = longer legs.
Discuss cultural differences in perception
They differ in the extent to which they are susceptible to the Muller-Lyer illusion
