Week Eleven - Attention Flashcards
What is arousal/alertness?
Global state of attention
What is arousal regulated by?
The RAS
What is vigilance/sustained attention?
Maintenance of attention for infrequent events over long periods of time
What is Selective Attention?
Attending to some stimuli while ignoring others
What is Divided Attention?
Ability to allocate central attentional resources to perform more than one task at a time
Selective attention can be what 2 things?
Voluntary: Intentional, top-down, goal-directed & endogenous
Reflexive: Stimulus driven, attentional capture, exogenous, bottom-up
What is Overt Attention?
When we might move our eyes, head, body towards a region of interest
What is Covert Attention?
Attention to spatial locations independent of eye gaze ie. cocktail party effect
What two concepts indicate our selective attention?
cocktail party
dichotic listening
Explain Broadbent’s Bottleneck Theory of Attention
There is a selective filter that switches between competing sensory inputs so that only one input gains access to STM.
Explain the late selection models of attention
Suggest that all sensory inputs receive some low level of analysis which then reach a stage of semantic encoding
What is the Attenuation Theory?
All information receives some processing, allowing our information to be directed if it considered important
What is Unilateral Spatial Neglect?
Failure to attend to space at the opposite side of the region following unilateral damage to cortical areas.
ie. not eating food on certain side of plate
What occurs in space-based neglect?
What occurs in object neglect?
Patients don’t attend to objects in left hand side of space
Patients attend to object on left but only half of the objects
There is a double dissociation between what two forms of neglect?
Perceptual (external) and representational (imaginal) neglect
What is Extinction?
A failure to perceive or act on stimuli contralateral to lesion when simultaneously presented with stimuli ipsilateral to lesion
impairs the ability to perceive multiple stimuli of the same type simultaneously.
What is Balint’s Syndrome?
Inability to perceive more than one object at a time
Inability to reach in direction of an object under visual guidance
Inability to voluntarily shift gaze to new visual stimuli
What is the Feature Integration Theory?
Suggests features are registered early, automatically and in parallel while objects and identified separately and at a later stage in processing
Single Feature: parallel - single feature maps (colour etc) in extra striate areas
Conjunction: Serial - spotlight of attention deployed sequentially to integrate feature maps onto master map of location
Selective attention can be directed to where, resulting in what?
Selective attention can be directed to spatial locations, features or objects resulting in enhanced processing in modality specific sensory/perceptual areas of the brain
Explain the Attentional Network Model
There are 3 functionally and structurally separate networks involved in attention
1) Alerting: Associated with general level of arousal/vigilance
2) Orienting: Directing of attention to prioritise external information
3) Executive Control: Higher level regulation of information from other systems
Alerting Network?
An automatic arousal base network which originates in the Locus coeruleus which are norepinephrine projections from the midbrain to the cortex and this is part of the reticular activating system
2 types of alerting -
Tonic Alerting: General level of vigilance (vigilance tasks)
Phasic Altering: Cued to the fact that something is about to happen (warning)
Orienting Network
The orienting network helps us to prioritise sensory information by selecting certain locations or features or modalities or objects and this network can be either automatic or voluntary
Dorsal System: which is comprised of parts of the frontal eye fields and also parts of the parietal lobe and this is involved in top-down visuospatial orienting (voluntary)
Ventral System: which includes the parts of the ventral frontal cortex and this system is important for bottom-up reorienting
Mediated by acetylcholine
Executive Control Network
Important for top-down control over the other systems, it helps to prioritise that information that is important for current goals and also the voluntary control over the current focus of attention
Fronto-Parietal: which is important for moment-to-moment aspects of completing a task so like starting or stopping
Cingulo-Percular: which helps in terms of task set maintenance
Mediated by Dopamine
What are frontal eye fields important for?
Voluntary eye movements, gaze shifts, and covert visuospatial attention
Participate in the top-down guidance of attention
Ventral Attention Network and Dorsal Network difference in involvement
The dorsal network is primarily involved in that voluntary control of spatial attention
The ventral network which is involved in stimulus-driven attention and in particular detecting novelty and attentional reorienting
What is the Superior Colliculus important for?
Detecting and shifting attention to salient locations via reflexive eye movements
What is the Pulvinar of the thalamus important for?
Covert and overt engagement of spatial attention, and filtering distracting information
greater activation in the Pulvinar when distraction is high
What does the injection of GABA do to the Pulvinar?
Disrupts shifting of covert attention
