The temporal extent of holistic processing

1
1
The temporal extent of holistic processing Jed
Singer and David Sheinberg
2
2
What is a composition?
Some things?
An arrangement of things?
A new thing unto itself?
3
3
The Composite Face Effect (CFE)
It is more difficult to identify one half of a
face when the other half has a different identity
This phenomenon is reduced when the pieces are
separated or the face is inverted
4
4
Classical results (RT differences)
Inversion eliminates interference from
properly-aligned bottom half in recognition task
(Young et al. 1987)
5
5
The CFE as an indicator of holistic processing?
One line of reasoning The composite face effect
shows that we can not disregard distracting parts
of a face when they are presented in a normal
configuration with the attended parts of a face
because we see faces as immediate and
undifferentiated wholes. An alternative The
percept of a particular face identity at a
particular location arises from an accumulation
of evidence (for and against) this accumulation
might even span spatial or temporal disjunction.
6
6
Gauthier, Tanaka, Brown (submitted)
Subjects study only one of two dissociated face
halves Yet, test response (same/different) is
delayed in aligned trials when the ignored half
would indicate a different response than the
studied half
7
7
Does the CFE survive temporal discontinuity?
Four faces each of Clinton and Kerry, for 32
chimeras 8 originals Original images repeated
four times each orientation 11 SOAs, upright and
inverted 1408 total trials Noise matches average
spatial spectrum of faces
8
8
Does the CFE survive temporal discontinuity?
Subjects report identity of interior face,
instructed to focus on accuracy we expect to see
a composite face effect at 0 SOA, but will we see
it for asynchronous presentations?
real-time example
slow example
9
9
Splitting faces across time is no big deal
whole faces
split faces
upright
inverted
upright chimeric
inverted chimeric
10
10
Our CFE measure (correct reaction times)
-
interference
-
interference when inverted
-
CFE magnitude
11
11
Zero-lag (classical) CFE replicated
-
229 ms
764 ms
-
535 ms
-
155 ms
819 ms
664 ms
74 ms
12
12
CFE results!
CFE magnitude (ms)
permutation test p-values
.05
.01
N 11
.001
exterior-interior SOA (ms)
13
13
In conclusion
Replicate classical composite face effect Effect
is even stronger when distracter part follows Are
well-known faces processed more holistically
when their parts are presented sequentially? Hol
istic processing is a complicated issue!