The functional basis of visual attention

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The functional basis of visual attention

• Ute Leonards

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The functional basis of visual attention
BACKGROUND
On attention itself, it is needless to discourse
at length its nature and conditions are familiar
to every thoughtful student (Munsell, 1873)
Everyone knows what attention is (James, 1890)

• No one knows what attention is, and there may
  even not be an it there to be known about
  (Pashler, 1998)

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The functional basis of visual attention VISUAL
ATTENTION in SCENE EXPLORATION
Pieter Brueghel
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The functional basis of visual attention
OVERVIEW
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The functional basis of visual attention
THEORETICAL BACKGROUND
a) Functional mechanism of visual attention
dichotomy or continuum?
SERIAL SEARCH
PARALLEL SEARCH
Treisman Gelade, 1980
Treisman Gormican, 1988
Treisman, 1991
Corbetta et al., 1995
spatial shifts of attention
INEFFICIENT PARALLEL SEARCH
EFFICIENT PARALLEL SEARCH
Townsend, 1990
Fahle, 1990
Cheal Lyon, 1992
Bravo Nakayama, 1992
Wolfe, Yee Friedman-Hill, 1992
continuous up-modulation of
- attention
- computational complexity
- spatial resolution
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The functional basis of visual attention VISUAL
SEARCH and fMRI
Leonards, Sunaert, VanHecke Orban (2000)
Journal of Cognitive Neuroscience, 12, Suppl. 2,
61-75
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The functional basis of visual attention VISUAL
ATTENTION and fMRI
R
L
1,g) DIPSM 2) DIPSL 3,5,d) DIPSA 4,8) SFS
6,e,7,f) MIPS/VIPS 9) Ant.Cing a) SEF b,c)
FEF
Leonards, Sunaert, VanHecke Orban (2000)
Journal of Cognitive Neuroscience, 12, Suppl. 2,
61-75
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The functional basis of visual attention VISUAL
SEARCH and ERPs
N2pc component
ERP- mapping Feature Conjunction Search
FS5
N2pc
CS5
no N2pc
Leonards, Palix, Michel, Ibanez (in press) J.
Cognitive Neuroscience
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The functional basis of visual attention
PERCEPTUAL LEARNING
Some inefficient search can become efficient by
training.
Inefficient search ltgt inefficient search
Leonards, Rettenbach, Nase Sireteanu (2002)
Vision Research, 42, 2193-2204
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The functional basis of visual attention IMAGING
of OCULOMOTOR LEARNING
FAMILIAR - NEW
NEW - FAMILIAR
Grosbras, Leonards, Lobel et al. (2001) Cerebral
Cortex 11, 936-945
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The functional basis of visual attention
PERCEPTUAL LEARNING of eccentric reading
Sommerhalder et al. (2003) Vision Research, 43,
269-283
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The functional basis of visual attention
BACKGROUND SCHIZOPHRENIA
after Green, 1998
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The functional basis of visual attention
BACKGROUND SCHIZOPHRENIASchizophrenia and
Attention

• Subjects with schizophrenia suffer from attention
  and from oculomotor deficits
• Which attentional subprocesses are affected in
  which schizophrenia subtype?
• How are these subprocesses related to
  oculomotor deficits

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The functional basis of visual attention
QUESTIONSVisual Scene Exploration in Early
Psychosis
Do scan path abnormalities in subjects with
first-episode psychosis depend on the stimulus
material used? (i.e. face exploration is
disturbed due to social withdrawal, while
landscapes are explored normally) Work in
progress Compared to healthy volunteers, are
subjects with first episode psychosis
differentially attracted by the most salient
parts of the images? (analysis based on saliency
model of Parkhurst, Law, and Niebur, 2002)
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The functional basis of visual attention SCENE
EXPLORATION in EARLY PSYCHOSIS
Control SK
Patient CS
Patient PW
Patient RD
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The functional basis of visual attention SCENE
EXPLORATION in EARLY PSYCHOSIS
FACES
LANDSCAPES
CS
AR
CS
AR
GG
PW
GG
PW
SK
RD
SK
RD
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The functional basis of visual attention
SUMMARY
VISUAL ATTENTION and VISUAL SCENE EXPLORATION

• complex cortical network(s)

• network modulating parameters (e.g. saliency,
  complexity, familiarity)

• sensitive to learning mechanisms, cortical
  plasticity

• not isolated processes but close interaction
  with other brain mechanisms

• understanding of these networks helps to solve
  clinical questions

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The functional basis of visual attention
OUTLOOK
Studying the brain from all sides and inside
needs interdisciplinary collaboration