Task 6
MCADAMS
& MAUNSELL
REYNOLDS
Research question
Can attention alter tuning curves?
Increase sensitivity?
Change in width
Methods
and materials
Recordings
Monkey V1 & V4
delayed match-to-sample task
shift attention
required
Sample stimuli
Gaussian & Gabor
Attended
inside RF
Unattended
outside RF
Instruction cue
(attention to one)
orientation task
colour task
release lever
for match
Results
Behavioural states
same stimuli, different tasks
Gabors
(optimalised)
Gaussians
RF mapped
bar moving
Isolation units
AP > 3x noise
Hypthesis
Narrowing uncommon in stimulus-stimulus interactions
Data analysis
Orientation tuning curves
Undriven activity
While fixating (before)
Four parameters
amplitude, width (SD), asymptote, mean
Goodness of fit
Quality of fit within Gaussian
Histology
Population-tuning curves
aligned at pref orientation
75% Guassian fit
16% Gaussian fit attention only
All neurons
One neuron:
43% increase amplitude (sig)
rest no sig changes
Population (75%):
amplitude (med 1.26, sig, 20%)
widt (med 1.0, not sig, 9%)
symptote (med 1.0, skewed right, sig, 13%)
preferred orientation (no sig, 8%)
Population tuning curves:
22% increase amplitude
13% increase asymptote
Population tuning curves:
31% increase amplitude
13% increase asymptote
no change width
increase amplitude
no increase width
Multiplicative scaling
slope = 1.32, 32% increase
proportional (r = 1.00)
Discussion
Time course
enhancement increased
during time course stimulus
Baseline activity
attention effect only after stimulus (no sig diff baseline)
Increase firing rate
No change sensitivity
(no change width)
Multiplicative
scaling
Interaction stimulus
attributes
Undriven not changed
by attention (baseline)