Adaptation Properties of Macaque

MT Neurons

Adam Kohn

Matt A. Smith

Najib Majaj

J. Anthony Movshon

Questions

• Change in direction tuning– Direction specificity

• Transfer of adaptation in RF– Spatial specificity

Dragoi et al. (2000)

Specificity of V1 Adaptation Effects

•Spatial Frequency-Movshon and Lennie (1978)-Saul and Cynader (1989)

•Temporal Frequency- Saul and Cynader (1989)

•Orientation-Muller et al. (1999)

-Dragoi et al. (2000)

TestTest Adapt

Pre

ferr

edF

lan

kN

ull

Response=Rmaxcn/(cn+c50n)+base

TestAdaptTest

Pro

po

rtio

n o

f C

ells

Ratio of Contrast Sensitivities

Different Patch Same Patch

0.5

0.25

Ratio of Contrast Sensitivities

Pro

po

rtio

n o

f C

ells

0.5

0.25

Different Patch Same Patch

Conclusions

Adaptation in MT

•causes a change in contrast gain

•transfers across directions within the tuning curve

•does not transfer across positions within the RF