[vslist] PhD studentship - Aston University, Birmingham, UK

[Mark Georgeson]

POSTGRADUATE STUDENTSHIP --- CALL FOR APPLICATIONS

ASTON UNIVERSITY, BIRMINGHAM (UK) ---  NEUROSCIENCES RESEARCH INSTITUTE

"Mechanisms of shading and texture analysis in the perception of 3-D surface=
s"

1. About the studentship
1.1 Background
Applications are invited for a PhD studentship that is funded by, and 
forms part of, an EPSRC research project held jointly by Professor 
Mark Georgeson (Aston University) and Dr Andrew Schofield (University 
of Birmingham).

The post-graduate studentship will be based at Aston University in 
Birmingham, supervised by Mark Georgeson, but will involve close 
collaboration with Dr Schofield and his post-doctoral fellow at the 
University of Birmingham. The stipend is =A38092 per year, and all 
tuition fees will be paid up to the level charged for a UK student.

The student will be registered for the Ph.D. degree, subject to 
satisfactory progress in the first year.

Start date is negotiable between 1st April 2003 and 1st October 2003 
at the latest.

Candidates should hold (or expect to hold) a good Honours degree 
(first, or good 2.1) in a relevant discipline (e.g. Psychology, 
Optometry, Physiology, Physics, Computer Science), and should have an 
interest in the analysis of visual processes through psychophysical 
experiments and computational modelling. Mathematical and computing 
skills, including some programming experience, will be especially 
advantageous.

Applicants should provide a clear statement about their research 
interests, either on the application form or in an attached letter or 
CV.  Applicants should also include contact details of at at least 
two (and preferably three) academic referees who can be contacted.


Informal enquiries to Mark Georgeson by email:   m.a.georgeson@aston.ac.uk

=46or application form write to
Victoria Heath, Neurosciences Research Institute,
Aston University, Birmingham B4 7ET, U.K., or:
Email:   v.e.heath@aston.ac.uk,      Tel: 0121 359 3611 ext.5173



1.2 The research
The project is about human perception of 3-D surfaces. The research 
will consider possible interactions between shading (luminance, first 
order) and contrast (second order) signals as 'pictorial' cues to 
support the perception of surface shape, and depth. We have 
previously noted that while luminance (LM) and contrast (CM) cues do 
not interact at detection threshold (Schofield and Georgeson, 1999) 
they do combine to form very different percepts when presented in and 
out of phase with one another. When added to a noise texture, 
sinusoidal luminance variations produce the percept of shape from 
shading. When contrast modulations are imposed on the noise in-phase 
with the luminance signal (high contrast pairs up with high 
luminance) then the shape from shading percept is enhanced and the 
contrast modulations seem to disappear. When out of phase with the 
luminance signal, the contrast modulations are quite visible and seem 
to disrupt the shape from shading percept. It is as if the contrast 
modulations serve to key the shading percept.

We propose to investigate these interactions using a range of 
psychophysical and perceptual measures.
1) Depth probe mapping:
2) Visual - haptic surface matching:
3) Facilitation and masking at threshold:
4) Cross-over adaptation:
5) Cue combination of shading, texture and disparity cues above threshold:

  It is expected that the student will focus on studies 3 and 4 at 
Aston, but will have the opportunity to collaborate on studies 1,2 
and 5 at Birmingham.

  Further details available on request, from    m.a.georgeson@aston.ac.uk



2. Contact & useful websites

Aston University:   http://www.aston.ac.uk
School of Life & Health Sciences: http://www.aston.ac.uk/lhs/research/
Vision Research Group: http://www.aston.ac.uk/lhs/research/nri/vrg/

Birmingham University: http://www.bham.ac.uk
The Vision Laboratory at Birmingham: http://web.bham.ac.uk/visionlab

Midlands Vision Group: http://www.bham.ac.uk/mvg

=46ind out more about the city of Birmingham: http://www.birmingham.org.uk/

Informal enquiries to Mark Georgeson by email:   m.a.georgeson@aston.ac.uk



3. Some recent publications by the grant-holders

Georgeson M A, Hammett S T  (2002)  Seeing blur: 'motion sharpening' 
without motion. Proc Roy Soc B  269, 1429-1434.
Georgeson M A, Schofield A J (2003).   Shading & Texture: separate 
information channels with a common adaptation mechanism? Spatial 
Vision. (in press)
Georgeson M A, Scott-Samuel N E (2000)  Spatial resolution and 
receptive field height of motion sensors in human vision. Vision 
Research. 40, 745-758.
Schofield A J, Georgeson M A (2000).  The temporal properties of 
first- and second-order vision. Vision Research.  40, 2475-2487.
Schofield A J, Georgeson M A (2002). Sensitivity to contrast 
modulation: the spatial frequency dependence of second order 
vision.Vision Research.  (in press).
Schofield A.J., & Georgeson, M.A. (1999) Sensitivity to modulations 
of luminance and contrast in visual white noise: separate mechanisms 
with similar behaviour, Vision Research, 39, 2697-2716.
Webster M A, Georgeson M A, Webster S M (2002) Neural adjustment to 
image blur.  Nature Neuroscience, 5(9), 839-840.

=46or a broad introduction to vision research, see:
Bruce V, Green P R, Georgeson M A (1996)  Visual Perception: 
Physiology, Psychology and Ecology, 3rd edition. Hove & London: 
Psychology Press. pp.448.

=A7=A7=A7=A7=A7=A7=A7=A7=A7=A7=A7=A7=A7=A7=A7=A7=A7=A7=A7=A7=A7=A7=A7=A7=A7=
=A7=A7=A7=A7=A7

-- 

=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D
Mark Georgeson, Professor of Vision Sciences
Neurosciences Research Institute
Aston University
Birmingham B4 7ET, U.K.

Phone: +44 (0)121 359 3611 ext.5419
=46ax:   +44 (0)121 333 4220
Email: m.a.georgeson@aston.ac.uk
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D