Cognitive Neuroscience: 2000 Admission Exams
English is the language preferred by the Commission.
Italian may be used if absolutely necessary. Please write clearly.
Please answer a total of 3 questions, which must consist of Question #1 and any two selected from Questions #2-15.
(1) Tell us about a publication in any scientific field
that has had a major influence on you.
The publication you choose need not necessarily be in cognitive neuroscience.
Use the following format for your answer:
(a) title and authors (accuracy not required);
(b) the problem addressed in the paper;
(c) what was known about the problem before;
(d) the methods used to approach the problem;
(e) the main results;
(f) the authors' interpretation of the results;
(g) how this publication changed your way of thinking.
Alternatively, you may do the same exercise for a lecture that
you have attended.
(2) Take any cognitive domain and discuss the consistencies and the
contrasts between any two of
(i) brain imaging findings;
(ii) neuropsychological findings from brain-damaged patients;
(iii) cognitive psychological evidence.
(3) Take a model of any cognitive function and describe how
you would go about testing model-based predictions that have not yet been
considered, using a single case approach.
(4) Take any one neurological syndrome. Describe its
characteristics and discuss its theoretical significance for our understanding
of how the normal mind-brain works.
(5) Are symbolic and connectionist models of cognitive
functions incompatible? Take any one area of cognition and assess which type
of model, or neither or both is most effective in explaining findings from
both the effects of neurological impairment and normal experiments.
(6) Briefly describe the
mechanisms and factors controlling synaptic plasticity.
(7) Discuss the proposal that neurotrophic factors are involved in neuronal
survival and neuronal differentiation.
(8) Design an experiment to test the possibility that a
predefined brain region is involved in visual form recognition, in monkeys.
Also describe the training schedule, if training is needed.
(9) Is there a "supervisor" in the flow of sensory information which
orients a motor act towards a sensory stimulus? Which experimental evidence
might support or deny either possibility?
(10) A 1 mm-diameter column of cerebral cortical tissue
contains about 10,000 neurons, arranged in layers, forming something like 1
billion synapses.What are some of the basic
operations carried out by a cortical column? Localization of function is a
fundamental principle of cerebral cortex. Are the functional diffferences
between cortical regions due to differences in the operation of the columnar
units that comprise them? Alternatively, if the columnar units function in a
similar manner, what might account for cortical functional specializations?
Give concrete examples.
(11) You are asked to provide some of the hyperlinks for the
new Dictionary of Cognitive Neuroscience on CD-rom. Specify 3 nouns to which
you would like to associate the adjective "associative", and provide brief
descriptions (e.g., 100 words) of how the adjective qualifies each of the
nouns.
(12) Your lab happens to have at its disposal a 100-channel recording
systems, which can be used with electrodes of any configuration, and the
intent is to record from as many neurons as possible in a brain region in
which they are tightly packed. If you use 100 distant electrodes, each of them
will be able to record from 1 or at most 2 nearby cells, but the signal from
more distant cells will be below the noise level. If you use electrodes
spatially closer, instead, several of them may pick up the signal from the
same cells, enabling better separation of faint signals; but if they are too
close they will all sample the same few cells. Regarding electrodes as
point-like and disregarding considerations of tissue damage, write how you
would go about formalizing your dilemma as a mathematical optimization problem.
(13) Briefly describe an experiment to
investigate whether, at birth, the functional properties of the cortex in
human infants are organized like those of adults.
(14) It is already late on the sixth
day of Creation, and the Almighty decides to provide behemas, a
mammalian species, with a rudimentary sound communication system, to help them
face the threat posed by the newly created human race. The Almighty reckons
that if behemas are to use P distinct phonemes, it will take
them a time of order of the square root of P msec to
produce each of them in a way that cospecifics will tell it apart from the
other phonemes. How many phonemes should behemas be endowed with, for
optimal speed of communication? And if a fraction q of phoneme pairs
can be uttered consecutively in a time 25 percent less than twice the time to
utter them separately, for which values of q (as a function of
P) would it be convenient for behemas to use such dipthongs
instead of the original phonemes?(Please note
that the Almighty had already formulated a mathematical theory of
communication on day 4, although it was reinvented independently by Claude
Shannon 5708 years later).
(15) People suffering from motor neuron disease or spinal cord
injury would benefit from a technology that would utilize brain signals to
control external devices, such as a joystick. Suppose that you have access to
neuronal activity recorded at 100 electrodes, implanted chronically in the
hand/arm region of primary motor cortex. Describe how you would
"decode" this neural activity to control an external device in
realtime.