Attention and scene perception
All senses receive more input than we can handle.
Attention = name we give to a family of mechanisms that restrict or bias processing in various ways.
Attention = any of the large set of selective processes in the brain. To deal w/ the impossibility of
handling all inputs at once, the nervous system has evolved mechanisms that are able to bias processing
to a subset of things, places, ideas, or moments in time.
Can be external (stim in the world) or internal (attend to one line of thoughts as opposed to another;
select one response over another).
Can be overt (directing a sense organ at a stimulus: fixating the eyes e.g.) or covert (point eyes on the
page but attend to a person of interest on the left).
Divided attention: read & be aware of the music at the same time.
Watching the pot to note the moment when water begins to boil = vigilance task requiring sustained
attention.
Here: focus on selective attention (= ability to pick one (or a few) out of many stimuli).
Selective attention = form of attention involved when processing = restricted to a subset of the possible
stimuli.
Selection in space
Reaction time (RT) = measure of time from the onset of a stim to a response.
Cue = stim that might indicate where/what a subsequent stim will be. Cues can be valid (giving correct
info), invalid (incorrect) or neutral (uninformative).
Exogenous cue = in directing attention, an exogenous cue = located out at the desired final location of
attention.
Endogenous cue = located in or near the current location of attention.
Stimulus onset asynchrony (SOA) = time btwn onset of one stim & onset of another.
Inhibition of return = relative difficulty in getting attention (/the eyes) to move back to a recently
attended (/fixated) location.
The “spotlight” of attention
Visual search
Visual search = search for a target in a display containing distracting elements.
Target = goal of a visual search.
Distractor = any stim other than the target.
Set size = number of items in a visual display.
Feature searches are efficient
Feature search = search for a target defined by a single attribute, such as a salient colour or orientation.
Salience = vividness of a stim relative to its neighbours.
Parallel search = search in which multiple stim are processed at the same time.
Many searches are inefficient
Serial self-terminating search = search from item to item, ending when a target is found.
All senses receive more input than we can handle.
Attention = name we give to a family of mechanisms that restrict or bias processing in various ways.
Attention = any of the large set of selective processes in the brain. To deal w/ the impossibility of
handling all inputs at once, the nervous system has evolved mechanisms that are able to bias processing
to a subset of things, places, ideas, or moments in time.
Can be external (stim in the world) or internal (attend to one line of thoughts as opposed to another;
select one response over another).
Can be overt (directing a sense organ at a stimulus: fixating the eyes e.g.) or covert (point eyes on the
page but attend to a person of interest on the left).
Divided attention: read & be aware of the music at the same time.
Watching the pot to note the moment when water begins to boil = vigilance task requiring sustained
attention.
Here: focus on selective attention (= ability to pick one (or a few) out of many stimuli).
Selective attention = form of attention involved when processing = restricted to a subset of the possible
stimuli.
Selection in space
Reaction time (RT) = measure of time from the onset of a stim to a response.
Cue = stim that might indicate where/what a subsequent stim will be. Cues can be valid (giving correct
info), invalid (incorrect) or neutral (uninformative).
Exogenous cue = in directing attention, an exogenous cue = located out at the desired final location of
attention.
Endogenous cue = located in or near the current location of attention.
Stimulus onset asynchrony (SOA) = time btwn onset of one stim & onset of another.
Inhibition of return = relative difficulty in getting attention (/the eyes) to move back to a recently
attended (/fixated) location.
The “spotlight” of attention
Visual search
Visual search = search for a target in a display containing distracting elements.
Target = goal of a visual search.
Distractor = any stim other than the target.
Set size = number of items in a visual display.
Feature searches are efficient
Feature search = search for a target defined by a single attribute, such as a salient colour or orientation.
Salience = vividness of a stim relative to its neighbours.
Parallel search = search in which multiple stim are processed at the same time.
Many searches are inefficient
Serial self-terminating search = search from item to item, ending when a target is found.
