A Functional Architecture of the Brain for Vision

The primary objective of this research programme is to develop a new functional
architecture of the visual brain, based on two concepts: necessity and the
theoretical framework of cortical networks.

In the last decades, electrophysiological and neuroimaging studies have
identified more than 40 separate maps in the brain that are selectively tuned
to specific visual features, such colour or motion. Brain-behaviour
relationships based electrophysiology and functional neuroimaging are per
definition correlational. We need neuropsychological research with patients who
suffered focal brain damage to show us which brain structures are necessary
(e.g. Catani & Stuss, 2012). A structure is deemed necessary when a lesion in
that structure has a selective detrimental effect on the execution of that
function.

Next, the proposed research programme will investigate how these necessary maps
are linked together. As a theoretical perspective, this programme adopts a
critical position towards the *what and where pathways* model developed by
Goodale & Milner (1992), the current gold standard. Goodale & Milner postulated
two major pathways; one for processing visuospatial information for motor
programming, and one for visual recognition and memory. Recently, De Haan and
Cowey (2011) suggested an alternative model in which the maps are thought to be
organised in multiple overlapping networks.

This research programme represents one of the most comprehensive
neuropsychological programmes ever proposed for the investigation of the visual
domain. The lesion study entails a large-scale, cohort-study involving four
academic medical centres in the Netherlands. The Netherlands is uniquely placed
for such a programme with four excellent teaching hospitals in close vicinity
and a high density of high-field neuroimaging facilities. The ERC grant will
furnish the resources to carry out the proposed studies and to set up a
collaborative network that will remain an asset for future large-scale
neuropsychological investigations.

Catani, M. & Stuss, D.T. (2012) Cortex, 48, 1-6.
De Haan, E.H.F. and Cowey, A. (2011) Trends in Cognitive Sciences, 15, 460-466.
Goodale, M.A. & Milner, A.D. (1992) Trends in Neuroscience, 15, 20-25.

The primary objective of this research programme is to develop a new functional
architecture of the visual brain based on two concepts: the methodology to
establish necessity and the theoretical framework of cortical networks. In
addition, this project will investigate the frequency and severity of (visual)
cognitive impairments following ischemic stroke and their effect on long-term
outcome.

We propose a large-scale cohort study in a series of consecutive patients who
suffered from ischemic stroke. This study will be implemented in four academic
medical centres in the Netherlands.
Participation involves 1) an intake including a neuropsychological screening (1
- max. 1.5 hours), b) MRI scan (45 minutes + 15 minutes preparation), and c)
computerised tests of specific visual abilities (visual test battery; 1.5
hours). Testing can take place from the sub-acute phase until several months
after stroke, as long as the behavioural testing and the neuroimaging coincide
in time. Single cases with selective deficits will be studied in depth using ad
hoc developed testing procedures to explore the constellation of impaired and
spared abilities.
A control group of 200 participants will be collected as a reference sample for
the experimental tests and for a subgroup also MRI.

The proposed project is an observational study with no known health risks. The
participant may experience discomfort during the MRI session, or during the
neuropsychological examination as this might be tiring. To minimize these
discomforts a) we will provide extensive information on MRI scanning; b) the
participant will have the possibility to pause the neuropsychological
assessment at any time or complete it on another day if necessary.