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Locating perceptual learning within the hierarchy of visual
areas
Geoff GhoseUniversity of Minnesota
Departments of Neuroscience and PsychologyCenter for Magnetic Resonance Research
Macaque Visual Cortex
(Felleman and Van Essen 1991)
Visual Cortex Hierarchy
V1
7a
PIT
CIT
AIT
TEO
VP
V4
MT
DP
V2
V4
MST
VIP
LIP
Low HighPreferred Stimulus Complexity
Receptive Field Size
Learning in V1?
• somatosensory and auditory map changes with training
• adult plasticity seen with retinal lesioning
• psychophysical experiments in which training effects were retinotopically specific
Training History
Orie
nta
tio
n C
ha
ng
e (
de
g)
Naive Humans
J Neurophysiology 2002
Trained
Trained
Opticnerve
Opticchiasm
Optictract
Opticradiation
LGN
V1
Control
V1 Hypotheses
Example Cell
V1 Expansion
45
Orientation
Preferred Orientation Distribution
Preferred Orientation (deg)
Trained
Location (N=139)
Untrained
Location (N=180)
0 45 90 1350
0.1
0.2
Pro
port
ion o
f C
ells
0 45 90 1350
0.1
0.2
V1 Refinement
45
Orientation
Orientation Bandwidth
0 45 90 1351800
50
Bandw
idth
(deg)
0 45 90 1351800
50
Trained Location
N=139
Preferred Orientation (deg)
Untrained Location
N=180
Orientation4545
Resp
onse
V1 V2Expansion no no
Preferred Orientation no no
Visuotopic Magnification no no
RefinementOrientation Bandwidth no no
Maximum Response no no
Tuning Amplitude no no
Response Variance no no
Receptive Field Size no no
Preferred Spatial Frequency no no
Orientation Relative to Preferred
No
rma
lize
d R
esp
on
se
0
1
-90° -45° 0° 45° 90°
Fig 16
Trained
(N=266)
Untrained
(N=215)
Orientation Discrimination Training in V4
(Yang and Maunsell 2004)
Perceptual learning in V1?Electrophysiology
Task Receptive Field Effect
Crist et al. (2001) Line Bisection Surround Only
Schoups et al. (2001)
Orientation Discrimination Orientation Tuning
Ghose et al. (2002)
Orientation Discrimination
Decrease in trained stimulus representation
Perceptual learning in V1?fMRI
Task Signal from Trained Stimuli
Schwartz et al. (2002) Texture Detection Increase
Furmanski et al. (2004)
Orientation Detection Increase
Sigman et al. (2005) Visual Search Increase
Kourtzi et al. (2005) Shape Detection Increase, No effect
(Kourtzi, Betts, Sarkheil, Welchman 2005)
Shape Analysis after LearningLow Salience
High Salience
Visual Hierarchy and Spatial Attention
V1
0.5
0.0
TEOMTV4V3AV3V2
Atte
ntio
n M
odul
atio
nIn
dex
(O’Connor, Fukui, Pinsk, Kaster 1989)
(Kourtzi, Betts, Sarkheil, Welchman 2005)
Shape Analysis after Learning
(Kourtzi, Betts, Sarkheil, Welchman 2005)
Positive Correlation between V1 Activity and Performance
Negative Correlation between V1 Activity and Performance
(Sigman et al. 2005)
Task Specific Orientation Learning
0 45 90 135 180
10
20
30
40
50
Discrimination Response Pooling
50%
100%
75%
Perf
orm
ance
Orientation (deg)Orienta
tion D
iffe
rence (
deg)
0 45 90 135 180
10
20
30
40
50
Behavior
0 45 90 135 180
10
20
30
40
50
Discrimination Detector Pooling
0 45 90 135 180
10
20
30
40
50
Stimulus Classification Response Pooling
Language as a representational hierarchy
?reisae yna siht sI
Visual Cortex Hierarchy
V1
7a
PIT
CIT
AIT
TEO
VP
V4
MT
DP
V2
V4
MST
VIP
LIP
Low High
Preferred Stimulus Complexity
Representation Plasticity
Attentional Modulation
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