Chapter 7 Flashcards
Arousal vs Selective Attention
- Arousal attention
- Wakefulness
- — Inattentiveness (drowsiness, relaxed states)
- — Attentiveness (alert states)
- Sleep
- — Different sleep stages
- Selective attention
- Attention to one thing while ignoring other things
Properties of Selective Attention
- Prioritize some “things” for cognitive processing while deprioritizing or ignoring other things
- Don’t have the bandwidth to process every single thing we see
- Voluntary (top-down) vs reflexive (bottom-up) attention
- Voluntary: choosing to pay attention to something
- — Endogenous ”to come from within”
- Reflexive: something draws our attention to it
- — Exogenous
- Overt vs covert attention
- Overt
- — Shift in attention that is obvious from the outside
- — Someone turns their head away from you in the middle of a conversation
- Covert
- — Shift in attention is not obvious from the outside
- — You keep your head turned to the person speaking but are paying attention auditorily to a conversation happening behind you
The Spotlight Metaphor
- You can shift your attention around, you are aware of the things in the center of the attention, not as aware the farther you get away from center
Benefits and Costs of Spatial Attention Spatial Cuing Paradigm
- If we are paying attention to a location and something happens there, we are faster to respond than we would be otherwise
- (valid trials)
- benefits
- If we are paying attention to a location and something happens outside of the location, we are slower to respond
- (invalid trials)
- Cost
Selective Auditory Attention: The Cocktail Party Effect
In a room full of a lot of conversation, somehow we are able to selectively focus on one conversation and ignore the others
Selective Auditory Attention: Intrusion
- When you really want to pay attention to one conversation, but something salient draws your attention away i.e. your name, a curse word
- Attention gets pulled away reflexively
Dichotic Listening Task
- Ask the participant to attend to stimuli from one ear
- Tested through shadowing
- People could remember what they were listening to in the attended ear and not the ignored input (maybe could tell you something the gender of voice) unless intrusion occurs
Early vs Late Selection Debate
- Early selection
– In the early stages of analyzing the information - Late selection
– Attentional selection does not effect the process early on
– All things are perceptually analyzed the same
At the semantic level is where selection occurs
(Where is the bottleneck
Where does attention do selection
When the question was first posed it was considered absolute
A more nuanced version is what if it happens in more than one stage and does it have to be absolute in ear selection
Problems were the belief that selection was all or none (intrusion disproves this))
Descending Auditory Pathways May Modulate Very Early Auditory Processing
The act of paying attention effects how the sound is transduced in the ear
Otoacoustic Emissions and Attention
When someone is paying attention to what they are listening to there is change on the otoacoustic emissions
ERP in Dichotic Listening Task
- If the person is not paying attention to the sound you get a smaller n1 response
- If the person is paying attention to the sound you get a larger n1 response
- Suggests earlier selection?
Magnetic Event-Related Fields Associated with Auditory Attention
- 20-50 ms
- Better spatial resolution than ERP
- We know attention is effecting 20-50 ms and where it is effecting it
- Primary auditory cortex
- Not possible that paying attention at the level of the retina because there are no descending pathways
ERP’s in a Spatial Attention Task
- Valid trials
- Positive P1 response
- The p1 response is larger
- Invalid trials
- The p1 response is smaller
Spatial Attention Effects in the LGN and Cortex
- Ask to attend to the left visual cortex
- Greater activity in the right hemisphere thalamus and visual regions
- Retina vs cochlea
- The first place that attentional selection can affect processing is the thalamus
- This effects all of the processing downstream
- Earlier selection in the thalamus effects the activation in later pathways like the visual cortex
- Or is it possible that the visual cortex independent of the thalamus has its own attentional selection?
Bestmann et al
- Testing if the visual cortex has its own mechanism for attentional selection
- B and D are virtual targets
- Tms is put on one of the hemispheres
visual cortex is stimulated - You see something in the contralateral vision field
- It starts in the visual cortex bypassing the usual flow of information
Bestmann et al Conclusion
- The act of paying attention allows people to respond quicker
- When they aren’t attending people are slower to respond
- Does the same thing apply to virtual stimuli?
- The thalamus does not effect the virtual stimulus
- When it was a valid trial you did not have to turn the magnet up high
- When it was an invalid trial you had to turn the magnet up stronger
- It is important what you are paying attention to even if it bypasses the thalamus
- ATTENTION MODULATES VISUAL PROCESSING, EVEN IF THE STIMULUS BYPASSES THE THALAMUS
- Probably sites throughout the process
Balint’s Syndrome
- Signs
- Optic ataxia
- Oculomotor apraxia
- — Difficulty controlling voluntary eye movements
- Simultanagnosia
- — Difficulty seeing more than one part of a scene at once
- — Introducing more than one object causes the patient to only be able to see one of the objects, focus on one of the objects
- — Patient can perceive the comb but not the spoon
- — Attention gets lost on an object and has trouble disengaging
- — Suggests that something in healthy individuals allow us to quickly engage and disengage
- Bilateral brain damage causes it, typically parietal/occipital
Neglect
- Leaves patients with a baffling syndrome, that makes it appear as if half their world has disappeared
- Copies only half of drawings
- Damage to the attentional system not the eyes
Neglect Patients and Copying Tasks
- If you aren’t paying attention to stimulus its as if it doesn’t exist
- You aren’t even considering what you are missing
- Not attending to what you are missing
- Why is almost always left neglect?
- Damage to the right hemisphere causes left neglect
- Right neglect is pretty rare
- Deficit in ability to fully scan the object
- Theory; right hemisphere can compensate for damage to left easier
Neglect Patient Recovering from a Stroke
- Unilateral special neglect
- Neglecting half of the canvas
- Neglecting half of his face
- Inflammation of the brain rather than cell death
- Plasticity
- Prism glasses that move everything to the right
Neglect in Mental Imagery
- Patient who grew up in Mulan is asked to describe a famous piazza
- He leaves out the buildings that would have been on the left side of the piazza
- Then ask him to describes the piazza from the opposite side and he still neglects the left side of the piazza (i.e. he recounts the buildings that he could not the first time)
- We are using attention to explore imagery and to move around the spotlight
Line Cancellation Task
- Patients are asked to cancel each line through the center of it
- Extrapersonal and object centered neglect
Extrapersonal space neglect
- Where things are located relative to the person
- Left side neglect
Object-centered neglect
- Right vs the left side of the object regardless of position relative to the viewer
- Neglects the left side of the objects