Cocktail Effect concentration at its best

Cocktail Effect concentration at its best - Transcript

1Dr. Steve Shimozaki
Office: 333b MSB
Email: ss373@le.ac.uk
Offi hce ours:
10 am to 12 pm, Tuesdays
10 am to 12 pm, Thursdays
Main website
http://www.le.ac.uk/pc/ss373/syllabus_3019.html
Lectures slides and notes will appear on website.
I’ll also bring copies to class.
Main text
Banich, M.T. (2004). Cognitive Neuroscience and
Neuropsychology, 2nd Edition. Boston, Houghton Mifflin.
Website with multiple-choice practice questions
http://college.hmco.com/psychology/banich/cognitive/2e/student
s/ace.html
Additional readings (2-3 weekly)
Not technically ‘essential,’ but will enhance
knowledge of the topic. ‘Recommended.’
To be distributed through blackboard (starting the end of this week
(contact me if you want access sooner):
To get to the articles:
1. Log into the blackboard site (https://blackboard.le.ac.uk)
with your CFS account.
2. Find the course listed as
'COGNITIVE AND CLINICAL NEUROPSYCHOLOGY.'
3. Go to 'Course Documents.'
4. You should find folders for each week's readings.
Weekly overview
Week 2 (08/10/07, lectures 1 and 2)
Disorders of attention – Chapter 8
Week 3 (15/10/07, lectures 3 and 4)
Di d f l Ch t 9sor ers o anguage – ap er
Week 4 (22/10/07, lectures 5 and 6)
Disorders of executive function – Chapter 11
Week 5 (29/10/07, lectures 7 and 8)
Development and ageing – Chapter 13
Week 2 (lectures 1 and 2)
Disorders of attention – Chapter 8
Additional readings –
Rafal, R. D. (1994). Neglect. Current Opinion in
Neurobiology, 4, 231-236.
Posner, M. I., Walker, J. A., Friedrich, F. J., & Rafal, R. D.
(1984). Effects of parietal injury on covert orienting of attention.
The Journal of Neuroscience, 4, 1863-1874.
Behrmann, M., & Tipper, S. P. (1999). Attention accesses
multiple reference frames: evidence from visual neglect.
Journal of Experimental Psychology: Human Perception and
Performance, 25, 83-101.
General types of attention
Alertness and Arousal: sleepiness, coma
Vigilance (sustained attention): In a lecture
Selective Attention:
2What is selective
attention?
It is the mental process
h ll lt at a ows us to se ect
information from a stream
of information
The Cocktail Party effect (Cherry, 1953)
The Cocktail Party effect (Cherry, 1953) The Cocktail Party effect (Cherry, 1953)
The Cocktail Party effect (Cherry, 1953) The Cocktail Party effect (Cherry, 1953)
Attending one auditory stimulus (out of many)
3The Cocktail Party effect (Cherry, 1953)
Switching attention
‘Bill Gates is a
...’
The Cocktail Party effect (Cherry, 1953)
Switching attention
Your car in
the parking lot?
Chimney in
a landscape?
What is selective visual
attention?
Areas of the brain associated with attention
Reticular Activating System (RAS) - arousal
Medulla and Pons (brainstem)
Reticular Activating System (RAS)
Medulla and Pons
Basic alerting and arousal
Connected to most parts of the brain
Sleep cycles (circadian rhythms)
Respiration, cardiac rhythms
Damage: coma (chronic vegetative state)
Possible links to : Alzheimer’s, ADHD
4Superior Colliculus – selective attention
midbrain
Reflexive selective visual attention, eye
movements, movement of selective attention
Cone and rod distribution
more cones = good vision
central area (fovea) = more cones (red)
Overt visual attention
Eye movements
Superior Colliculus (midbrain)
Reflexive selective visual attention, eye
movements, movement of selective attention
5Superior Colliculus (midbrain)
Reflexive selective visual attention, eye
movements, movement of selective attention
Ocular motor output
Direct visual input from the retina
Superficial layers: mostly visual (some auditory)
responses
Deep layers: diffuse motor and sensory
connections (visual, auditory, somatosensory)
Organised by direction and amplitude of
saccades
Pulvinar (thalamus) (diencephalon)
Pulvinar of the thalamus (diencephalon)
– selective attention, possible ‘gate’ or ‘filter’.
Engagement of attention.
Broadbent (1958) – attention is a ‘filter’ on
perception
Early perceptual
processes
(sensory register)
attention
Later perceptual
processes
Treisman (1960) – attention is an ‘attenuator’ on
perception
Early perceptual
processes
(sensory register)
attention
Later perceptual
processes
Parietal Lobe: selective (covert) attention
6Covert visual attention
Separable from eye movements
Ventral (what, vision for recognition, Parvocellular + magno)
LGN -> V1 – V2 – V4 – IT
Dorsal (where, ‘vision for action’, Magnocellular )
LGN -> V1 – V2 – V3 – MT – MST – Posterior Parietal
Anterior Cingulate Cortex
Response selection
Anterior Cingulate Cortex
Response selection
Novel (new) responses
Inhibiting automatic (overlearned) responses
The ‘Stroop’ task:
Task: name the colour of the words
Ball
Telephone
Speaker
Book
Pencil
Computer
7Ball
Telephone
Speaker
Red
Green
Blue
The ‘Stroop’ task:
Task: name the colour of the words
Book
Pencil
Computer
Black
Yellow
Red
Frontal lobes (Frontal Eye Fields)
Voluntary selective visual attention, voluntary
eye movements
Frontal lobes (Prefrontal cortex)
Executive function (later)
Dorsal (where, ‘vision for action’, Magnocellular )
LGN -> V1 – V2 – V3 – MT – MST – Posterior Parietal
Hemineglect
Patient ignores one side of space
Caused by unilateral lesions, usually right parietal
Considered an attentional loss
Not a pure visual deficit
Different from visual field loss (hemianopia)
Play movie
Types of neglect
Visual
Auditory
Tactile
Hemispheric Asymmetry
Ri ht L ftg > e
Multiple Areas
Parietal
Frontal cortex (dorsolateral)
Thalamus
Basal ganglia
8Recovery from Neglect
Usually spontaneous
Up to a year
Rapid initially
Specific training – directed eye movements
Recovery from Neglect
Usually spontaneous
Up to a year
Rapid initially
Specific training – directed eye movements
Release from Neglect (Temporary)
vestibular stimulation
optokinetic stimulation
transcutaneous stimulation
ExtinctionAssessment CancellationAssessment
Line Bisection
Assessment
‘Attention’ to visual memories/representations
Drawing (daisy, clock, house)
Assessment
9‘Attention’ to visual memories/representations
Piazzas (Bisiach and Luzzatti, 1978)
‘Imagine you’re in a familiar piazza (square)
from one location. What would you see?’
‘Attention’ to visual memories/representations
Piazzas (Bisiach and Luzzatti, 1978)
‘Imagine you’re in a familiar piazza (square)
from one location. What would you see?’
‘Attention’ to visual memories/representations
Piazzas (Bisiach and Luzzatti, 1978)
‘Now imagine you’re on the other side of the
piazza. What would you see?’
‘Attention’ to visual memories/representations
Piazzas (Bisiach and Luzzatti, 1978)
‘Now imagine you’re on the other side of the
piazza. What would you see?’
Frames of reference
Global
Local
Object-oriented? (Behrmann and Tipper)
10
Behrmann and Tipper, 1999
Neglect patients
Blue and red
barbells
Detect white spot
2/3 trials
In squares
Or in circles
Behrmann and Tipper, 1999
Neglect patients
Blue and red
barbells
Detect white spot
2/3 trials
In squares
Or in circles
Behrmann and Tipper, 1999
Neglect patients
Blue and red
barbells
Detect white spot
stationary

2/3 trials
In squares
Or in circles
moving
Behrmann and Tipper, 1999
Neglect patients
Blue and red
barbells
Detect white spot
stationary

2/3 trials
In squares
Or in circles
moving
Behrmann and Tipper, 1999
Neglect patients
Blue and red
barbells
Detect white spot
stationary

2/3 trials
In squares
Or in circles
moving
11
Behrmann and Tipper, 1999
Neglect patients
Blue and red
barbells
Detect white spot
stationary

2/3 trials
In squares
Or in circles
moving
Behrmann and Tipper, 1999, results for neglect
Squares :
Static : Left longer than Right
‘Moving’ : Left longer than Right (but squares did
not move)
R
es
po
ns
e
Ti
m
e
(m
s)
Left Right
Moving
Static
Behrmann and Tipper, 1999, results for neglect
Circles :
Static : Left longer than Right
Moving : Left shorter than Right
Moving
R
es
po
ns
e
Ti
m
e
(m
s)
Left Right
Static
The Cueing Task (Posner, 1980)
- Used extensively in visual attention research, and also
in clinical neuroscience settings. (Posner, et al., 1984)
80%
20%
50%
Cue validity (cueing) effect –
valid cues lead to better performance
Response time or accuracy
12
Neuroimaging (MRI) Studies
Anatomical Maps
Functional MRI – measure brain activity
Oxygenated
blood
Deoxygenated
blood
More brain activity -> more oxygen used by neurons
-> more blood flow
Deoxygenated blood (hemoglobin) has different magnetic
properties than oxygenated blood.
fMRI measures

Oxygenated
blood
BOLD activations
fMRI Studies
task task
rest rest
Timecourse for one voxel
BOLD effects - Blood Oxygenation Level Dependent
Deoxygenated
blood
BOLD activation
Corbetta, et al., 2000 – cueing task
Cue validity = 73%
Cueing effect: response times, valid = 380ms
invalid = 426ms
Corbetta, et al., 2000 – cueing task, evidence of
parietal lobe
Serial attention : a common view of visual
attention
Attention moves from place to place
(first to the cued location)
Versions
-Spotlight of attention (Treisman & Gelade, 1980)
-Enhancement (Posner, 1980)
Spotlight of attention:
serial processing
to the cued location, then to the
uncued location
13
Spotlight of attention:
serial processing
Posner’s theory (1984)
1. Disengage
2. Move
3. Engage
Spotlight of attention:
serial processing
Engaged
Spotlight of attention:
serial processing
Disengage from centre
Spotlight of attention:
serial processing
Move to cued location
Spotlight of attention:
serial processing
Engage at cued location
Spotlight of attention:
serial processing
Valid trial
14
Spotlight of attention:
serial processing
Invalid trial
Spotlight of attention:
serial processing
Disengage from cued location
Spotlight of attention:
serial processing
Move to uncued location
Spotlight of attention:
serial processing
Engage at uncued location
Spotlight of attention:
serial processing
1. Disengage - Parietal
2. Move – Superior Colliculus
3. Engage - Pulvinar
Parietal injury (Neglect) and the cueing task
(Posner, et al., 1984, 6 Right, 7 Left)
Signal on left Signal on right
Cue on
left
* *
Cue on
right
Invalid-right
Invalid-left Valid-right
Valid-left
* *
15
Parietal injury (Neglect) and the cueing task
(Posner, et al., 1984, 6 Right, 7 Left)
Signal on left Signal on right
Cue on
left
* *
Delay when
target
appeared on
side
contralateral
Cue on
right
Invalid-right
Invalid-left Valid-right
Valid-left
* *
to parietal
lesion
(assume
lesion on
right side in
this case),
invalid trials
only
Superior Colliculus and the cueing task
(progressive supranuclear palsy, Rafal, et al., 1988)
8 patients, 8 Parksinson’s controls
Two types of cues
a brightening peripheral box (50/50)
an arrow in the center (80/20)
Two conditions
L/R
Up/Down
Signal on top Signal on bottom
Cue on
top
Superior Colliculus and the cueing task
(progressive supranuclear palsy, Rafal, et al., 1988)
*
Cue on
bottom
Invalid-bottom
Invalid-top Valid-bottom
Valid-top
*
*
*
Signal on top Signal on bottom
Cue on
top
Superior Colliculus and the cueing task
(progressive supranuclear palsy, Rafal, et al., 1988)
*
Cue on
bottom
Invalid-bottom
Invalid-top Valid-bottom
Valid-top
*
*
*
Signal on top Signal on bottom
Cue on
top
Superior Colliculus and the cueing task
(progressive supranuclear palsy, Rafal, et al., 1988)
*
Needed
longer time
between
Cue on
bottom
Invalid-bottom
Invalid-top Valid-bottom
Valid-top
*
*
*
cue and
target for
cue to be
effective
(350ms
instead of
50ms)
Signal on left Signal on right
Cue on
left
The pulvinar and the cueing task
(Rafal & Posner, 1987, 3 thalamic patients)
* *
Cue on
right
Invalid-right
Invalid-left Valid-right
Valid-left
* *
16
Signal on left Signal on right
Cue on
left
The pulvinar and the cueing task
(Rafal & Posner, 1987, 3 thalamic patients)
* *
Delay when
target
appeared on
side
contralateral
Cue on
right
Invalid-right
Invalid-left Valid-right
Valid-left
* *
to thalamic
lesion
(assume
lesion on
right side in
this case),
both valid
and invalid
Time course of selective attention (ERP’s)
Cortical Basis
Potential at scalp
Synapse
location
ElectroEncephaloGraph (EEG) Studies
Axon Axon
„ Reflect
post-synaptic
activity
Pyramidal Cells
ERPs: Recording EEG
_
e
ERP’s: Event-Related Potentials
Time
+
Vo
lta
g
EEG
ERPs: Signal Averaging
EEG
epochs
Time Series: Interpretation
Electrophysiological Studies
Sensory
Processing
Feature
Extraction
Discrimination Recognition Decision
17
Covert visual attention
Time course
Covert visual attention
Time course
75 - 100 ms
P1