perception week 9 day 2 activity

broadbent's (early selection) filter theory

proposes that attention only allows stimuli whose physical characteristics match our goals to be processed to the point of extracting meaning

deutsch & deutsch (late selection) filter theory

proposes that attention allows many or all stimuli to be processed to the point of extracting meaning, and then attention operates at the level of decision making to influence what information is available

treisman's attenuation theory of attentional selection

psychological theory that proposes that attention allows items that match our goals to be fully represented. other items are still represented, but are reduced in strength.

desimone & duncan's biased competition theory

neuroscientific theory that proposes that all available items compete for representation. attention enhances signals associated with the attended item at all levels of representation and diminishes signals associated with other items at all levels of competition.

treisman's feature integration theory

proposes that attention is a stage of processing. prior to attention, all perceptual features are represented, but they are not bound together into coherent objects. after attention processes an item, its features are bound together.

goal-driven/top-down/endogeneous scenario

a posner cueing task uses a cue at central visual fixation (like an arrow or a color) to indicate that the target will be in a particular location. this cue is 90% valid-that is, it is telling the truth on 9 out of 10 trials, but the target is actually elsewhere on 1 out of 10 trials.

bottom-up/salience-driven/exogenous scenario

a posner cueing task uses a cue in one of the potential target locations (like a brief flash) to indicate that the target will be in that location. this cue has chance validity (that is, for two potential target locations, the cue is telling the truth half of the time and lying half of the time).

value-drive/selection history scenario

a two stage task starts out by having participants report something about an item with a particular color. the important color changes from trial to trial, and participants are told at the start of each trial what the important color is on that trial and how much they will be rewarded for correct performance. in a second stage, color is no longer relevant at all-but colors that were previously strongly rewarded are more distracting than colors that were previously less or unrewarded.

value-drive/selection history scenario

your favorite breakfast cereal that you buy every time you go to the grocery store, Frosted Flakes, has always come in a blue box. However, the manufacturer has changed the packaging to an orange bag. The next time you go to the grocery store, you go to buy Frosted Flakes as usual. You know the packaging has changed, but you keep finding yourself looking at the blue boxes of Blueberry Cheerios even though you want to find the Frosted Flakes in their new package.

goal-driven/top-down/endogeneous scenario

you, a novice birdwatcher, go for a walk in the woods with your binoculars, your experienced birdwatcher friend, and the goal of spotting a rare wood thrush. you and your friend find a nice spot to wait and watch for birds. your friend notices you looking up at the trees but tells you that the wood thrush is more often found on the ground, so you start watching the ground instead of the trees.

bottom-up/salience-driven/exogenous

you are driving down a rural road. there are cattle ranches as far as the eye can see-cows everywhere. you unexpectedly see a giraffe among the cattle. it distracts you and you nearly drive off the road!

a ________ process happens one item at a time; an example is writing down notes, one word at a time.

serial

a _______ process happens a few items at a time; an example is eating blueberries by putting three or four in your mouth at a time.

limited-capacity parallel

a ________ process can handle as many items as are available, all at once; an example is listening to music, where you can hear as many instruments as are playing at once-whether it is a single instrument or a whole orchestra.

unlimited-capacity parallel

with respect to visual search: in a _______ search, the number of distractors does not matter and the search is said to be efficient.

feature

with respect to visual search: in a _______, the more distractors there are, the slower the search; such a search is said to be ______.

conjunction; inefficient

a reichardt detector is a circuit model of a motion-sensitive cell that

explains sensitivity to motion speed, includes two receptive fields, includes a delay, explains sensitivity to motion direction, and explains apparent motion

motion opponent (motion contrast) cell

receives input from two reichardt detectors such that it increases its firing rate for one direction of motion and decreases its firing rate for the opposite direction of motion.

real motion cell

responds to motion of objects in the world, but does not respond to motion of objects as projected on the retina if that motion stems from eye movements.

mirror neuron

responds both to watching someone else perform an action and you performing the action yourself

bimodal neuron

can have a hand-centered visual receptive field

saccade

a rapid eye movement jumping from one point to another

smooth pursuit

a slow eye movement following a moving object

area MT

brain structure that seems to lead to our awareness of motion

indicators of biological motion

having no obvious external cause for changes in motion, piecewise rigidity, sudden changes in motion/direction