Supplementary Figure
1
Mean change in performance caused by microstimulation
of
each face patch.
Dark gray bars for same identity trials, light gray bars for different identity trials, error bars show the standard erro
r of the mean. The
results of individual sessions are shown as circles, filled circles show session in which the effect size was significant wit
h p <= 0.01. As
shown in Figure 3, effect size per session correlates with the face selectivity of each stimulat
ion site, explaining the sessions with
smaller effect sizes.
Nature Neuroscience: doi:10.1038/nn.4527
Nature Neuroscience: doi:10.1038/nn.4527
Supplementary Figure
2
The dependence of effect magnitude for faces on stimulation current strength.
(
a, b
) Behavioral performance on same
-
and different
-
i
dentity trials, with and without microstimulation, for stimulation strength
magnitude of 100 μA (a) and 300 μA (b), with stimulation performed in the same session (AM, M1). (
c, d
) Another session, comparing
effect on behavior of face patch stimulation at 1
00 μA and 300 μA (AM, M1). (
e, f
) Effect of face patch stimulation at 100 μA and 200 μA
during the same session (AM, M2). (
g, h
) Effect of face patch stimulation at 100 μA and 200 μA during the same session (AM, M2). (
i, j,
k
) Effect of face patch stimulat
ion at 100 μA, 200 μA, and 300 μA during the same session (ML, M2). Gray bars denote trials without,
red bars trials with electrical micro
-
stimulation; Darker bars show the performance for same identity trials, lighter bars for different
identity trials. *
: P < 0.05; **: P < 0.01; ***: P < 0.005; Fisher’s exact test
(see
Supplementary Table 3
for exact
P
-
values
)
. The lower
plot in each panel shows the change in percentage points caused by electrical stimulation for same identity trials in dark gr
ay and for
the different identity trials in light gray.
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Supplementary Figure
3
The dependence of effect magnitude for round objects on stimulation current strength and electrode position
,
for subject M1 for three
different sessio
ns.
(
a
) Low stimulation current (50 μA) inside face patch AM. (
b
) Intermediate stimulation current (100 μA) inside face patch AM. (
c
) Large
stimulation current (200 μA) outside the face patches. Top row: Behavioral performance on same and different trials
, with and without
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microstimulation, for stimulation in face patch AM of monkey M1, for faces, apples, citrus fruits, teapots, and clocks. 2
nd
row: Size of
stimulation effect in percentage points for the same five categories. 3
rd
row: Behavioral performanc
e on same and different identity trials
of the face identification task of the same session. 4
th
row: Size of stimulation effect for the face identification task. Conventions as in
Suppl. Fig. 2.
*: P < 0.05; **: P < 0.01; ***: P < 0.005; Fisher’s exact te
st
(see
Supplementary Table 3
for exact
P
-
values
)
.
Nature Neuroscience: doi:10.1038/nn.4527
Nature Neuroscience: doi:10.1038/nn.4527
Supplementary Figure
4
The dependence of effect magnitude on proximity of the stimulation site to the center of the face patch
,
for the five different object
categorie
s from Experiment 3.
Same conventions as in Figure 3a. Pooled data for 14 sessions (M1: 9, M2: 5) showing how the magnitude of electrical
microstimulation effect on same (left column) and different identity trials (right column) correlates with the face s
electivity of the target
location as measured by fMRI. Out of the five object categories (faces (
a
), apples (
b
), citrus fruit (
c
), pots (
d
) and clocks (
e
)), only for
faces was there a significant correlation (same identity trials: p: 0.044706, correlation
coefficient r =
-
0.54319, r
2
= 0.2951; different
identity trials: p: 0.0053008, correlation coefficient r = 0.70014, r
2
= 0.4902).
Nature Neuroscience: doi:10.1038/nn.4527
Supplementary Figure
5
Experiment 2:
effect
of stimulation inside face patch AM on
the
perception of non
round objects.
Conventions as in Fig. 2. (
a
) Effect of AM stimulation on non
-
round object perception in monkey M1. Performance was significantly
worse on microstimulation “same” trials (reduction by 7.77 percentage points). (
c
) Performan
ce change in percentage points caused by
electrical microstimulation for same
-
(dark gray bar) and different
-
identity trials (light gray bar) (
b
) Same as (a) and (
d
) same as (c), for
stimulation in monkey M2. Stimulation current was 300 μA.
*: P < 0.05; Fi
sher’s exact test
(see
Supplementary Table 3
for exact
P
-
values
)
.
Nature Neuroscience: doi:10.1038/nn.4527
Supplementary Figure
6
Experiment 4b:
effect
of stimulation inside face patch AM on perception of non
-
face objects II in M2
.
(
a
) Effect of face patch s
timulation on perception of house line drawings, house cartoons, house silhouettes, Mooney faces, and upside
down Mooney faces. (
b
) Effect obtained in same experimental session, for face stimuli of Experiment 1. (
c
) Performance change in
percentage points
caused by electrical microstimulation for same
-
(dark gray bar) and different
-
identity trials (light gray bar) for each of
the five categories of non
-
face objects II, and (
d
) for the faces of Experiment 1. Stimulation current was 200 μA. Conventions as in
Fig.
4.
*: P < 0.05; **: P < 0.01; ***: P < 0.005; Fisher’s exact test
(see
Supplementary Table 3
for exact
P
-
values
)
.
Nature Neuroscience: doi:10.1038/nn.4527
Supplementary Figure
7
Electrode position for M1 showing that
,
for the data presented in
Fig
ure
7
,
the electrode tip was located inside face patch AM
.
Scale bar (top left) = 1 cm.
Nature Neuroscience: doi:10.1038/nn.4527
Nature Neuroscience: doi:10.1038/nn.4527
Supplementary Figure
8
Activation to fac
es, cartoon houses, real houses
and real objects.
(
a
) Coronal slices showing fMRI activation to
the contrast faces > objects. Face patches are indicated by arrows. (
b, c
) Slices from the
same animal as (a), showing activation to the contrast cartoon houses > objects (b), and real houses > objects (c). (
d
) Flat maps of the
left and right hemisphere v
isual cortex, showing the same data as (a
-
c). Face patches are indicated by green outlines. Notice overlap
between face patches ML and PL and cartoon house activation (middle two panels), which is absent for real house activation (r
ight two
panels). Face p
atches indicated by green outlines in middle and right panels. (
e
) Beta values for faces, cartoon houses, real houses,
and real objects, from PL/ML, showing strong activation to faces and to cartoon houses.
Box
-
and
-
whisker plot
indicates the median
value
(
red line)
, the 25
–
75
th
percentiles (box) and +/
-
2.7 sigma (whiskers)
.
Nature Neuroscience: doi:10.1038/nn.4527
Nature Neuroscience: doi:10.1038/nn.4527
Supplementary Figure
9
Experiment 5:
d
ependence
of effect magnitude on stimulation timing.
Behavioral performance for same
-
and different
-
identity
trials, across four different stimulation conditions: no stimulation (gray bars),
stimulation during cue 1 and cue 2 (yellow bars), stimulation during cue 1 (green bars), stimulation during cue 2 (red bars).
Plots on the
right show the change in percentag
e points caused by electrical stimulation (electrical stimulation during cue1: green; during cue2: red;
during both cues: yellow). Darker bars denote same
-
identity trials, lighter bars different
-
identity trials. *: P < 0.05; **: P < 0.01; ***: P <
0.005; F
isher’s exact test
(see
Supplementary Table 3
for exact
P
-
values
)
. (
a
): ML, M1, (
b
): AM M1, (
c
): AM M2. (
d
): AM M1:
Stimulation experiment in M1, with stimulation trains of 50 ms duration (images were presented for 200 ms each), instead of 2
00 ms
(b). All
trains were delayed by 75 ms relative to visual stimulation to account for the typical response latency of anterior temporal
cortex.
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Supplementary Figure
10
Analysis of data in
Supplementary Figure 9
, separating data
for each of 32 different cue
2 identities.
Nature Neuroscience: doi:10.1038/nn.4527
(
a
,
b
) Analysis of data in panels (a), (b) of Supplementary Figure 9, respectively. Numbers below each bar indicate number of
contributing trials
,
*: P < 0.05; **: P < 0.01; ***: P < 0.005; Fisher’s exact test
(s
ee
Supplementary Table 5
for exact
P
-
values
)
.
A 3
-
way
ANOVA examining main effects and interactions of identity, trial type (same/different) and microstimulation (yes/no) showed s
ignificant
main effects for trial (same/different) and stimulation condition,
but not for identity, and a significant interaction between trial and
stimulation. The results do not support the idea that effect of stimulation depended on the specific identity of the face: th
is would show
up as a two
-
way interaction between stimulatio
n and identity or three
-
way interaction between stimulation, trial type, and identity.
M1
(a
), trial type F(1, 92) = 401.58, p < 0.0001; stimulation F(3, 92) = 110.74, p < 0.0001; identity F(31, 92) = 1.51, p = 0.0666
;
trial*stimulation F(3, 92) = 39.75, p
< 0.0001; trial*identity F(31, 92) = 1.51, p = 0.0665, stimulation*identity F(93, 92) =
0.94, p = 0.6137;
M2 (b
), trial type F(1, 92) = 150.51, p < 0.0001; stimulation F(3, 92) = 57.88, p < 0.0001; identity F(31, 92) = 1.15, p = 0.2937;
trial*stimulation
F(3, 92) = 10.22, p < 0.0001; trial*identity F(31, 92) = 1.16, p = 0.2846, stimulation*identity F(93, 92) = 0.83, p = 0.8079
.
Nature Neuroscience: doi:10.1038/nn.4527