chapter 7-attention and scene perception Flashcards
attention
any of the very large set of selective processes in the brain
to deal with the impossibility of handing all inputs at once, nervous system has evolved mechanisms that are able to ___ processing to a subset of things, places, ideas, or moments in time
restrict
selective attention
form of attention involved when processing is restricted to subset of possible stimuli; process some things but not others
what guides selective attention
whats important to you; endogenous, exogenous
endogenous
internal, symbolic
exogenous
external, peripheral
overt
directing sense organ at simulus
covert
focus eyes on one point while directing attention elsewhere
acuity variation
due to variation in receptive field size and cone density, usually what we are fixating on is what dominates our attention and brain processing
receptive field size and cone density; ___ resolution for things we look at ____
high, directly
top down processing
endogenous; thoughts, goals, knowledge; higher cognition
effects of top down processing
intentional control of switching, influenced by prior knowledge (initial impression wont switch unless you know about both)
necker cube
designed to look like a cube, no shading to say whats the front or whats the back
perceptual state
high level vision
bottom up processing
exogenous; local receptive fields, neural activation; low level and middle vision
bottom up influence
local mutual inhibition (visual system makes choice for you), neural adaptation (1st view strength decreases over time)
is attention spatially constrained or object oriented
both
spatial attention
move around a spotlight that involves greater processing of a location in space, even other than what you are looking at; other nearby things get attention
object based attention
you are processing something of interest, even if it moves; object properties will be given attention
ambiguous stimuli
show effects of top top processing and include bottom up influence
reaction time
measure of the time from the onset of a stimulus to a response
cue
a stimulus that might indicate where (or what) a subsequent stimulus will be
cues can be valid (__ info), invalid (__ info), or neutral (__)
correct, incorrect, uninformative
RT decreases with __ cue
valid
RT increases with __ cue
invalid
posner cuing paradigm
measure reaction time to stimuli;
stimulus onset asynchrony (soa)
time between onset of 1 stimulus and onset of another
inhibition of return
relative difficulty in getting attention to move back to recently attended location
behavioral cuing results
faster and more accurate for cued location;
physiological cuing results
ERP, shows different magnitude responses depending on contralateral and ipsilateral brain locations
example of object based attention
multiple object tracking
with multiple object tracking
can distribute attention to different objects
constraints of multiple object tracking
limited number of objects that you can accurately track, temporal limit-the faster they move the less you can track
visual search
looking for a target in a display containing distracting elements
target
goal of a visual search
distractor
in visual search, any stimulus other than the target
set size
number of items in a visual search display (iv, RT is dv)
feature search
parallel search; independent of distractors, low level; efficient, salience; RT doesn’t change with set size
conjunction search
serial search; as number of distractors increase, takes longer to find; need top down unification or local vision attention to combine the factors; presence of 2 or more attributes
spatial configuration search
arrangement of elements in 3D space
how does attention work in terms of neural activity
response enhancement, sharper tuning, altered tuning
response enhancement
orientation tuning of neuron, prefer 1 over the other, change in threshold and response in single neuron; bigger response
sharper tuning
focus on some orientations and less than others, change in interaction between neurons, more mutual inhibition; more precise response
altered tuning
changed preference of orientation, change in receptive field input or different pattern of mutual inhibition
attention to specific part of the visual field causes neurons coding those locations to have __ activity
increased
increased activation detected using
fMRI (good spatial resolution); enhance/increase in what you pay attention to
single cell recording shows attention effects where
LGN
how could attention alter tuning of a receptive field
receptive fields of neurons are not completely fixed and can change in response to attentional demands
how do we perceive and understand scenes
selective and non-selective pathways
nonselective pathway processes what
scene gist and layout
spatial layout
description of the structure of a scene without reference to the identity of specific objects in a scene (openness and expansion), attention bottleneck
memory for objects and scenes is
good and bad
brady et al. performed task with subjects looking at 2500 objects in the training phase and then chose which of two they had seen in test phase
different types of categories - 92%
different examples within category- 88%
same object, different states- 87%
unintended memory
change blindness
failure to notice change between 2 scenes; if the change doesn not change gist of the scene probably wont notice
mask present
treat as 2 different images, huge transient signal
mask abent
local motion signal, local transient signal
inattentional blindness
failure to notice, or at least report, stimulus that would be reportable if attended
