Attention Flashcards
Main take away from covert direction of attention: fixate on central point?
Attention not sensory, change what brain is aware of.
Donder’s Mental Chronometry
RT simple - RT complex = mental operation
overly simplistic, but on the right track
Reaction time process
Retina –> LGN –> V1 (primary visual) –> V2/V4 –> inferior temporal/prefrontal cortex –> premotor cortex –> primary motor cortex – >spinal cord –> output
Ventral stream
V2/V4, visual to temporal lobe
OBJECT RECOGNITION
Dorsal Stream
SPATIAL
V2 –> Secondary somatosensory cortex of parietal lobe –> prefrontal
Prefrontal cortex
plans sequence of movement
Basal ganglia/cerebellum
modulate movement, strength, timing, and accuracy
How do you measure voluntary (top-down, Endogenously)
Symbolic cuing, faster RT if cue actually symbolic
Slower, but maintained longer
How do you measure reflexive (bottom-up, exogenously)
Peripheral cuing, shows inhibition of return with longer delays around ~300ms
Faster, moves quickly
Treisman and Gelade
Feature search (1) and conjunction search (2+) Conjunction is longer RT function of # object in the array
Temporal resolution: How
EEG
Spatial resolution: Where
fMRI
ERP: remember…
negative is ABOVE the line
N1
negative ~100ms
selectively attended stimuli
P3
positive ~300-500ms
higher order AUDITORY processing and late selective attention
P1
positive, ~70-100ms
VISUAL input
invalid trials in symbolic cuing: no P1 effect
P1 reduced during inhibition of return
Early ERP signals
bottom-up (Spatial cues)
Late ERP signals
top-down (arrow)
Visual search where green square in middle and red line on the side
N2pc
Shows seeking/attending to visual stimulus augments activity of CONTRALATERAL visual areas
Visual search with green square and red line on side
Pd- distractor positivity
needed to ignore distractors
fMRI Spatial cuing task:
2 locations? 2 areas light up
Superior colliculi/LGN
attentional selection, likes motion
If impaired, worse inhibition of return
Fusiform face area
faces
Parahippocampal
places
The 3 ways attention can change rate of neuron firing
- increase rate of firing
- Tuning sharpened
- tuning shifted
Desimone and Moran’s monkey
measure neuron firing, high when red bar, moves to green, decreased.
ATTENTION SHIFTING could be DECREASE in neural activity.
What did experiment with neuron receptive field in visual cortex with Dimond and circle show?
Cell’s receptive field retuned by attentional processes.
Attentional shifting = tuning and decrease in receptive field
___ drives attention shifting/filters distractors
Pulvinar
GABA agonist = worse covert attention
GABA antagonist= enhances covert attention
Cognitive control over attention
Dorsal frontoparietal
Intraparietal sulcus (IPS) in humans
controls voluntary top-down attention
Such as LIP in monkeys, which has priority map, and ventral lip for direction attention/dorsal LIP for eye movement planning
Frontal Eye fields
directs eye gaze to cognitive goals
Temporoparietal junction
Shifts attention to new location AFTER target onset
ALTERTING SIGNAL (for unexpected)
involuntary attention more to the
right
connections between TPJ and IPS provide means for
novel stimuli to interrupt and reorganize attentional priorities
Hemispatial neglect is here? Why?
similar damage to attention areas
right inferior parietal lesion- can’t see double nature of simuli
Baliant’s syndrome and the symptoms
- Oculomotor apraxia-difficulty voluntarily steering visual gaze to target
- Optic Ataxia- spatial disorientation, patient can’t reach for object with visual guidance
- Simultagnosia- restriction of attention, limited to single feature
Diminished conciousness
reduced activity of frontoparietal network
Claustrum
not seat of consciousness, but a lot of reciprocal connections, stimulating it cuts it off, part of circuit
Free will/awareness of your actions
just before pressing, button, you decide what to do before hand. Brain is predictor
Hierarchal cognitive control
ability to direct short term activities while keeping longer term goals in mind
Dysexecutive
DORSOLATERAL
poor judgment, planning, insight, temporal organization, cognitive persistence, motor defects, diminished self-care
Disinhibited
ORBITOFRONTAL
stimulus driven behavior, diminished social insight, distractability
Apathetic
MEDIOFRONTAL
diminished spontaneity, diminished verbal output/motor, increase response latency, spontaneous activity,
Cool areas without damaging: Delay to match sample
Delay to match sample: sample, delay, sample/novel. Longer delay, worse you do.
Prefrontal cooled? do a lot worse, parietal is fine
Cool areas without damaging: Delay response
spatial- same letter, pick one that occurs in the same spot
still prefrontal
Tests for attention: Stroop
Color words
INHIBITORY CONTROL
Tests for attention: Wisconsin Card sort
Rule change
FRONTAL LESIONS= Struggle in task shift
Tests for attention: Tower of London
planning and strategizing
Norman and Shalice model
Habitual, but also interference from executive.
Mostly habitual, way that executive interacts is through GABA/inhibitory connections
