Foto del docente

Vincenzo Natale

Full Professor

Department of Psychology "Renzo Canestrari"

Academic discipline: M-PSI/01 General Psychology


Keywords: memory actigraphy chronopsychology dream sleep circadian typology

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.