Attention and Social Attention Flashcards
What is Covert Attention?
attention without an eye movement
What is Overt Attention?
attention with a shift of eyes and gaze
What is Overt Attention?
attention with a shift of eyes and gaze
What was the first study of Covert Attention?
Herman von Helmholtz (1894)
- Screen with random array of letters
- Electrical spark to illuminate screen
- Screen too large to view without making eye movements
- If he held gaze at centre of screen he could choose where to attend
Helmholtz argued that attention is essential for visual perception
What is Visual attention?
Our visual environment is crowded with multiple objects, but at any one time we tend to only be aware of a limited part of this array of information
The attended object – appears to receive more processing and is represented in perception
Posner’s Classic Study ?
Simple model task in which human subjects are asked to commit attention to a position in visual space other than fixation
RT’s faster when target at valid cued location
In an attention experiment the RT (reaction time) is the response time following a target onset
- Participants are presented with a central fixation dot flanked by two squares
- The task is to make a key press as quickly as possible when a target item appears inside one of the squares
- This target event is preceded by a cue e.g., the flashing of one of the squares or the appearance of a central arrow pointing toward one of the squares
- The finding is that the target is detected faster when it appears in the cued square than when it appears in the uncued square
The brain processes attended items more quickly than unattended items.
Concluding that, target detection time is speeded because attention has been committed to the square that was cued.
Two different ways that attention is manipulated in the cuing task:
- One way is to flash one of the squares (attention is directed to the cued square that flashed – exogenous
- Second way is to present a central arrow pointed toward (attention is directed to the cued square that the arrow is pointed toward)
Exogenous vs Endogenous:
Exogenous (automatic) – people are faster to detect a target in the cued square even when the flashing does not predict where the target will be
Endogenous (voluntary) – attention can be allocated voluntarily
- Exogenous cues induce faster and more transient effects than endogenous orienting
Examples of exogenous and endogenous
Exogenous cues – external (flashing lights)
Endogenous cues – internal (arrows)
Spotlight theory of visual attention Posner (1980)
According to the spotlight theory of visual attention, people can attend to only one region of space at a time
This theory assumes that the attentional spotlight cannot be divided across multiple locations.
If more than one object must be attended to at a given time for instance football opponents coming in for the tackle – then attention must serially shift from one location to another.
Theory that spatial attention cannot be divided – decision to shift attention to a new spatial location (Disengage – Move – Engage)
Functional anatomy of human attention Posner & Peterson, (1990)
Three fundamental propositions:
- The attentional system is separate from the ‘data processing’ system (but interacts with other systems)
- Attention is carried out by a network of anatomical areas
- These areas carry out different functions that can be specified in cognitive terms
Three major functions:
- Orienting
Dorsal system (top-down visuospatial) – shifts of attention
Ventral system (bottom-up reorienting) – respond to external salient events (interruption)
- Detection (for conscious processing)
Two networks:
Frontoparietal- relating to task switching and implementing task instructions
Cingulate (ACC) – ‘task-set’, maintenance of task, error monitoring
- Maintaining a vigilant for alert state
Alerting/vigilance
Norepinephrine (NE) system
Norepinephrine, also known as noradrenaline, is both a neurotransmitter and a hormone.
It plays a significant role in your body’s “flight or fight” response
It is used to increase and maintain blood pressure
- Warning signal increases activity in locus coeruleus which produces norepinephrine
- Diffuse connections including frontal areas
- Right hemisphere dominance, but both hemispheres may have a role
- Tonic or phasic alerting
Zoom Lens Model (LaBerge, 1983)
LaBerge (1983) proposed that the attentional focus can vary in size
Attention is directed to a particular region of visual field
The area however can be increased or decreased depending on the requirements
LaBerge (1983) participants were either asked to categorise 5 letter words (attention sped over entire word) or to categorise the middle letter of a word
Attention can be narrowly focused or widely distributed
Yarbus (1967) Picture scanning (Overt Attention)
Yarbus argued that changing the information that an observer is asked to obtain from an image drastically changes his pattern of eye movements
Eye-gaze and arrow cues Kuhn and Kingstone, 2009
- Eye gaze can elicit an automatic shift of attention (c.f. Driver et al. 1999)
- Similar effects for arrow-cues – (Kuhn & Kingstone, 2009)
- Assumption is that they may both produce an automatic reflexive shift of attention
Brain responses to eyes and arrows Tipper et al, (2008)
- Participants periodically told it’s an eye, or arrow.
- Made manual responses to a target appearing to left or right.
- Told direction of eye/arrow not predictive of target location
- Responses (RT’s) faster in cued direction with ‘eyes’ and arrows
Eye gaze and arrow cues engaged a similar neural network of dorsal and ventral fronto-parietal regions
Larger response in some frontal lobe regions for eye gaze cues
Social cues do not involve a unique brain network
