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.
