[與會學者與講題介紹]
1. Anatomy and neurophysiology of the primate visual system
This lecture will be a tutorial on the visual system of the monkey, from an anatomical (visual areas, retinotopic maps, visual hierarchy, partial separation of visual function) and physiological point of view (tuning, magno/parvo cellular paths, the laminar organization of feedforward/feedback pathways, higher-order stimulus representations).
2. Attentional modulation of visual processing in the primate
This lectures will give an overview of studies of spatial attention in the monkey, including studies that have examined how spatial attention modulates sensory processing in the visual cortices, as well as work looking at areas that modulate visual processing (LIP, the microstimulation studies in FEF of Moore and Fallah, perhaps something on the pulvinar). The modulation of sensory processing by spatial attention has several parallels to contrast-dependent response modulation, so I can describe how one can think of the attention results in the context of models that have been used to explain contrast-dependent response modulation.
3. Object-based competition in attention and rivalry
This lecture will discuss aspects of vision/attention that are hard to model using the standard tools in the physiologist's tool box, including some recent work that we have been doing, looking at object-based attention both in psychophysics and physiology.
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A
brief overview of topics that will be important for discussing work on
attention and visually guided action. The first two sections address "preattentive"
processes whereas the processes in the third section on action are motor
activities usually (with the exception of blindsight) accompanied by
focused attention.
a) Measurement of the image. In the retina: cones and rods, fovea
and periphery, opponent color and non-opponent luminance. In the cortex:
orientation and size tuning, low-level motion, binocular disparity,
spatial layout, shape and face recognition.
b) Inference from image data. Recovering surfaces, light, shadow,
material properties, and object size.
c) Action. Eye movements, saccades, smooth pursuit, grasping and
blindsight
II.
Acuity of attention: Limits of spatial and temporal selection.
The ability
to select items and events in space and time is quite limited. Items
spaced too close to each other cannot be individuated and selected for
further analysis. Similarly, events too close together in time are
unavailable for scrutiny as individual events. These limits place the
upper bound on our visually guided performance and they are far coarser
than the limits on visual resolution. We will review evidence for these
limits on attention from crowding tasks, flanker tasks, and RSVP tasks.
This evidence will be placed in the framework of possible mechanisms and
models for selection.
III.
The tracking function of attention.
The role of
attention is not only to select relevant targets as they appear in the
scene, but also to follow them if they move. Whether it is a ball and
the players during a game or children crossing a busy street, we often
are required to maintain attention on one or more targets over extended
periods of time. How does attention keeping track of targets as they
change and move through these cluttered environments. What are the
properties are available from a tracked object? We will combine evidence
from multiple item tracking tasks, high-level motion, and apparent
motion and look at studies in children, patients, and normals.
Steven
Yantis :
1. Visual attention: Domains of selection and modes of control
This lecture will provide a tutorial overview of voluntary and stimulus-driven attentional control (primarily behavioral evidence), including domains of selection: locations, features, objects, sensory modalities, modes of control: goal-directed/top-down vs. stimulus-driven/bottom-up, using the biased competition framework for understanding these various phenomena.
2.
Control of
voluntary attention in human cortex
A great deal
of evidenceconcerning the attentional modulation of cortical acitivty
provides an account of the behavioral effects of attention. Recent
work has begun to explore how these modulations are controlled.
This lecture will review evidence concerning the cortical mechanisms of
voluntary attentional control, including data from human neuroimaging
and patient studies.
3. Cortical mechanisms of stimulus-driven attentional control
Salient sensory events (e.g., a loud noise) can capture attention
involuntarily.This lecture will review issues related to visual salience
and attention,including attentional capture by abrupt onsets, and
contingent attentional capture, focusing primarily on human behavioral
and neuroimaging data.
