Attention Flashcards
What is attention?
The limited-capacity process that allows the preferential processing of certain sensory or imaged info at the expense of other available stimuli.
What is the most basic level of attention?
Alertness and arousal - it lowers when sleepy
What are higher levels of attentional processing? (5)
- Focused attention
- Sustained attention (vigilance)
- Selective attention
- Alternating attention
- Divided attention
What is focused attention?
The inhibition and redirection of attention - the ability to respond discretely to visual, auditory or tactile stimuli
What is sustained attention?
The ability to maintain a consistent behavioural response during continuous and repetitive activity.
What is selective attention?
The ability to maintain a behavioural or cognitive set in the face of distracting stimuli.
What is alternating attention?
The capacity for mental flexibility that allows for a shift in attention and focus between tasks that have different cognitive requirements.
What is divided attention?
The ability to respond simultaneously to multiple tasks.
What is multiple resource theory?
A limited set of distinct resource pools exist, each of which can only be applied to certain types of processes.
What is forward span attention and what is backward span attention?
- Concentration
- Working memory
What structures are involved in attention?
RAS, superior colliculus, thalamus, posterior parietal lobe, frontal lobe and cingulate cortex.
How is the Reticular Activation System involved in arousal?
It regulates cortical activation for overall arousal - the sensory input charges the RAS. It’s involved in controlling sleep wake cycles. It also has diffuse connections to most regions of the cortex, meaning it can modulate for arousal throughout the brain.
What is the RAS dorsal route to the cortex?
RAS - thalamus - cortex
What is the ventral route to the cortex?
RAS - hypothalamus - basal forebrain - cortex
What network is involved in sustained attention?
RIGHT FRONTO-PARIETAL-THALAMIC NEURAL NETWORK:
- Frontal lobe: directs attentional resources
- Posterier parietal love: focuses conscious attention, overall allocation of attentional resources to stimulus
- Thalamus - relay station
Two kinds of selective attention:
- Bottom up - a bright light.
2. Top-down - looking for a yellow flower.
Selective attention: early selection vs late selection
- Early selection: before the items are identified
- Late selection: after the items have been identified and categorised.
Two assumptions of feature integration theory:
- Rudimentary perceptual features of objects are coded in parallel and prior to attention
- Attention is the glue that binds the features together
Brain areas involved in selective attention: (5)
- Superior colliculus: bottom up process, orientating to visual stimuli.
- Inferior colliculus: orienting to auditory stimuli
- Thalamus: filtering function, LGN input from eyes and pulvinar filters distractions.
- Parietal lobe: overall allocation of attentional resources.
- Medial and Lateral prefrontal cortex: Selection of appropriate motor responses, top-down attention control
What is the stroop test?
Colours written in different colours - proved the role of the cingulate cortex in response selection.
4 main parts of the attentional system:
- Arousal system
- Orienting system
- Perceptual system
- Executive system
3 network models of attention:
- Mesulam, 1981 - anatomical model of spatial attention and unilateral spatial neglect
- Posner and Rothbart, 2007 - anterior and posterior attention model
- Corbetta and Shulman, 2002 - controls of goal directed and stimulus driven attention in the brain
Mesulam 1981 - anatomical model of spatial attention and unilateral spatial neglect
Neural network:
- Frontal eye fields modulates and coordinates motor programmes
- Parietal generates sensory maps
- Cingulate cortex regulates motivation and emotional significance
- RAS deals with vigilance and arousal
The networks overlap to orient attention
Implication of Mesulam’s model: (3)
- It implies that a lesion confined to one brain region may affect not only attention, but other behaviours
- Because the model is strictly localizationist, damage to attention can be caused by damage to other regions
- The most severe disruption of a complex function will occur after damage to more than one region.
Posner and Rothbart, 2007.
Attention has 3 major functions:
- Achieving and maintaining an alert state
- Orientating to events
- Orchestrating voluntary actions
P&R: Alerting network
Mobilizes and sustains alertness for processing high priority targets - involves RAS, thalamus, parietal regions and right frontal cortex area
P&R: Orienting system
Visual orienting - involves parietal lobes, temporoparietal junction, lateral pulvinar nucleus and superior colliculus. May be modulated by acetylcholine
P&R: Executive system
Anterior system that control and coordinates other brain regions for voluntary attention - lateral prefrontal cortex (W.M.), basal ganglia and anterior cingulate (error detection); dopamine involved.
How is the hierarchy of attentional processing structured?
Anterior to posterior
Corbetta and Shulman, 2002
Two partially segregated networks carry our different attentional functions:
- A dorsal subsystem that works top-down
- A ventral subsystem that works bottom-up
What is the default mode network?
A group of areas that are typically more active during rest than during an active task performance.
What is hemineglect?
Loss of conscious awareness of an aspect of space despite adequately functioning sensory and motor systems.
How does hemineglect manifest?
- When asked to point out the midpoint, the right hand side is favored
- Colliding with objects and people on the left side
- Reading and drawing is restricted to the right hand side
- Ignorance to the space contralateral to the lesion
How does hemineglect differ from hemianopsia?
Hemianopsia entails blindness over half the field, hemineglect does not have a lack of sensory input, just a lack of attention
Theories on hemineglect
- Individuals lack an internal mental representation of the neglected side of space
- Competition between hemispheres
Treatment for hemineglect
Top-down and bottom-up approaches - visual scanning training and manipulating sensory input to the brain.
What is the right hemisphere more important for?
Overall arousal and attention
What is the gradient of attentional neglect?
The further an item is into the neglected visual field, the less attention it gets
How does the Gradient of Attentional Allocation differ between hemispheres?
The left eye has a steeper gradient with concern to attention paid to the contralateral side.
