Psychophisiology of sleep and dream, chronobiology and
chronopsychology, individual differences in circadian rhtyhms,
validation of instruments to assess circadian typology, motor
asymmetries.
The purpose of the
present research project aims to investigate individual differences
in the circadian system functioning. We refer to the framework of
two processes (circadian and homeostatic) model relating to the
sleep-wake cycle regulation. On one hand we will investigate the
relationship between homeostatic process and genetic polymorphisms,
on the other hand we will investigate a possible relationship
between circadian rhythms and hemispheric dominance.
As regards the
first research topic we will adopt a sleep deprivation paradigm.
200 healthy subjects will be sleep deprived for a whole night.
Electrophysiological measurements (theta and alpha, slow eyes
movements and eye blink frequencies) and cognitive performance
(speed and accuracy on simplex and complex tasks) are recorded. The
cognitive tasks will be performed in a specific temporal window: at
08:30/09:00. On the base of electrophysiological and cognitive
measurements, the subjects will be divided into "more sensitive"
and "less sensitive" groups. For these different groups, the
polymorphisms PERIOD-3 and 5-HTTLPR will be determined. The genetic
aspects could indicate the polymorphism roles respect to an higher
or lower susceptibility to homeostatic process.
To address the
second research objective, we will plan two main phases. In the
first phase, a wide survey will be performed in young adults (age
range 18-30) with a casual sampling method. Two questionnaires (The
Edinburgh Inventory; the reduced version of Morningness-Eveningness
Questionnaire, rMEQ) will be administered, in order to investigate
the relationship between laterality and individual differences in
circadian rhythms (circadian typology).
The survey can
allow us to obtain 40 experimental subjects (20 males and 20
females), divided in 4 groups according to their handedness and
chronotype.
In the second
phase, the experimental sample will perform four computerized
tasks, involving the left or right hemisphere's superiority for
information processing. The experimental group will be tested at
two different times of day: at 10:00/11:00 and at 22:00/23:00, with
one week between 2 recording sessions. Indeed it seems that in
right-hand subjects there is an higher motor activity in left hand
(non dominant hand, right hemisphere) respect to the right hand
(dominant hand, left hemisphere) at 22:00/23:00, while the reversed
superiority was found at 10:00/11:00. Moreover, our subjects will
be invited to wear actigraphs on both wrists for a week. In that
way, we will can analyse the hypothesised relationship between
circadian motor asymmetries and hemispheric asymmetries in
cognitive functioning.
