Attention Flashcards
(29 cards)
Selective attention
Our ability to focus processing on a particular thing and ignore everything else
Divided attention
Our ability to process multiple things at the same time
Attention capture
a failure of selective attention, due to a sudden salient visual event
Theeuwes et al 1999
wanted to see if something flashy or colorful could capture your eyes automatically, even if you were trying to ignore it.
If a bright, colorful thing appeared suddenly, people’s eyes would move towards it even if they were trying to focus on something else
The study consisted of a fixation and pre-cues, target, and onset distractors
The fixation is the starting point
The precue is the hint (right or wrong)
The target is what you are supposed to find
The onset distractor is the distractor that captures your attention.
Attention Deficit Disorder
An abnormal inability to maintain focus on a selected item or event
Vigilance
Our ability to hold focus on an item over time
The Spatial Cueing paradigm Posner 1980
Studied 3 types of hints
valid cue- a hint that correctly points to where the target will appear
neutral- there is no useful hint
invalid cue- trick hint
The study showed that your attention is like a spotlight, and your brain moves it around based on hints
Attention to a location in space speeds the processing of information at that location
The Attentional enhancment effect Carrasco et al
When two gratings have identical contrast, the contrast of the attended grating appears higher
Inattentional blindness
When you are engaged in an attention-demanding task, you often fail to notice irrelevant salient visual stimuli
Mack and Rock 1998 inattentional blindness
had participants deduce whether a plus sign symbol had a longer vertical or horizontal line, at the same time, random shapes were added to the photos and subjects were asked if they remember the shape, many of them did not.
Simons and Chabris inattentional blindness 1999
Gorilla suit walking scene
Neural mechanism of selective attention (Moran and desimone 1985)
When a preferred stimulus and a non-preferred stimulus are presented at the same time, it creates an average reaction of the neuron
When attention is focused on a preferred stimulus, neuronal firing rapidly fires as if the non-preferred stimulus is not there.
When attention is focused on a non-preferred stimulus, neuronal firing is very low as if the preferred stimulus is not there.
Attending to a stimulus functionally restricts a neuron’s receptive field to that stimulus.
The neural basis of attention colby et al
Attention enhances firing rate in neurons. When focused, your brain’s neurons fire rapidly regardless of stimuli Neurons in the parietal cortex respond more when attention is directed to light
sheinberg and logothetis 2001
trained monkeys to respond to specific objects in a location
found that neurons in the IT responded to each object when it was in the RF
When these objects were then placed into scenes, the same neurons responded. This did not happen unless the monkey noticed the object.
The zoom lens theory of attention LaBerge and Brown 1989
Attention can be distributed broadly and narrowly, but there is a tradeoff between focus and processing speed
Broad dist of attention, slow processing of objects within this focus
Narrow dist of attention = Fast processing of objects within focus
Divided attention consists of 2 parts being…
Parallel Processing and serial processing
Parallel processing
An operation that can be performed on many objects simultaneously
Analysis of orientation and other basic features occurs simultaneously across the entire visual field in parallel.
serial processing
An operation that can be performed on only one object at a time
Visual scanning of a scene is a serial process, one object is processed, then another, etc.
Yarbus 1967
Your eyes jump from spot to spot, called saccades, focusing on 1 detail at a time
a specified task changes how you pay attention to things ex. How old is this person?
Visual search Triesman and Gelade 1980
Subjects are asked to find a target among non-
target “distractors”
Parallel process
Does adding distractors make the search harder? No, not really. Set size is largely irrelevant to this task.
Is ‘absent’ search harder than ‘present’ search?
No, not really. Present and absent judgments are
about equally difficult.
The flat search time x set
size functions indicate
That search difficulty is
not affected by the
number of distractors in
the display
serial process
Does adding distractors make the search harder?
Yes, search gets harder as set size increases.
Is ‘absent’ search harder than ‘present’ search?
Yes, target absent judgments typically take longer than
target present judgments
the set size effect (visual search)
Search times increase
With the number of
objects, known as the
set size effect.
The set size effect is
larger for target absent
search than target
present search (target x
set size interaction);
adding items slows target
absent search more than
target present search
serial search means that..
Serial search means that more individual shifts of
Attention would be needed for larger set sizes.
The more objects in the display,
The more shifts of attention and the longer the total search time.
Target absent search is assumed
to be exhaustive, meaning that
each object is visited by attention
(the display is exhaustively
inspected)
Why are slopes typically less steep when the target is present?
Visual search treisman
When a target is present you need to search
through only half of the objects, on average
