Vincenzo Natale

Sex Difference in Sleep‐Time Preference and Sleep Need: A Cross‐Sectional Survey among Italian Pre‐Adolescents, Adolescents, and Adults

The aim of this study was to examine sex differences in sleep‐time preference by age among Italian pre‐adolescents, adolescents, and adults. The final sample consisted of 8,972 participants (5,367 females and 3,605 males) from 10 to 87 yrs of age. To assess preferred sleep habits, we considered the answers to the open‐ended questions of the Morningness‐Eveningness Questionnaire (MEQ). In agreement with previous studies, we found that sleep‐time preference started to shift toward eveningness from the age of 13 yrs. Females reached their peak in eveningness earlier (about 17 yrs of age) than males (about 21 yrs of age). Thereafter, the ideal sleep‐time preference advanced in men and women with increasing age. Females presented a more significant advanced sleep phase than males only during the years when sexual hormones are typically active. Moreover, females reported a longer ideal sleep duration than males across all age groups examined, except in over 55 yrs one. (Author correspondence: vincenzo.natale@unibo.it)

Transcultural Properties of the Composite Scale of Morningness: The Relevance of the “Morning Affect” Factor

Morningness scales have been translated into several languages, but a lack of normative data and methodological differences make cross‐cultural comparisons difficult. This study examines the psychometric properties and factor structure of the Composite Scale of Morningness (CSM) in samples from five countries: France (n=627), Italy (n=702), Spain (n=391), Thailand (n=503), and Australia (n=654). Strong national differences are identified. A quadratic relationship between age and CSM total score was apparent in the Australian data with a downward trend after age 35 yrs. There was no age effect in any sample in the range from 18 to 29 yrs. Factor analysis identified a three‐factor solution in all groups for both men and women. Tuckers congruence coefficients indicate that: (1) this solution is highly congruent between sexes in each culture, and (2) a morning affect factor is highly congruent between cultures. These results indicate there are national differences in factorial structure and that cut‐off scores used to categorize participants as morning‐ and evening‐types should be established for different cultural and age groups.

RELATIONSHIP BETWEEN CIRCADIAN TYPOLOGY AND FUNCTIONAL AND DYSFUNCTIONAL IMPULSIVITY

The present study explores the relationships between functional and dysfunctional impulsivity factors, circadian typology, and sex. A sample of 850 university students (396 men) aged between 18 and 33 yrs of age completed the Dickmans Impulsivity Inventory (DII) and reduced morningness–eveningness questionnaire (rMEQ). Factorial analysis showed a dimensional clustering with satisfactory item saturation for both dimensions of impulsivity, especially in men and evening-type. Men presented higher values than women for functional and dysfunctional impulsivity, while morning-type subjects obtained lower scores in dysfunctional impulsivity than the neither- and evening-types. An interactive effect between circadian typology and sex was obtained for dysfunctional impulsivity. Higher scores in men for dysfunctional impulsivity were found in neither- and evening-types, while no significant differences were obtained between men and women in the morning-type group. The morning-type typology can be considered a protective factor for impulse control disorders, especially in men, but further research is needed on the clinical and neurobiological implications of our results. (Author correspondence: aadan@ub.edu).

The effect of tibolone versus continuous combined norethisterone acetate and oestradiol on memory, libido and mood of postmenopausal women: a pilot study

OBJECTIVEnSeveral studies have shown a positive effect of oestrogen on memory, mood and well-being but these data are controversial and focus particularly on the effect of oestrogen alone. In this pilot study we have investigated the effect of a continuous combination of norethisterone acetate 1 mg and oestradiol valerate 2 mg (Kliogest) versus tibolone (Livial) on memory, sexuality and mood.nnnMETHODSnTwenty-two postmenopausal women, age range 51-57, were randomised to a 6 months single blind interventional study treatment with either continuous combined oestradiol plus norethisterone acetate, or tibolone. Computerised psychological test of memory, mood and libido were administered both before and at the end of the 6 months treatment.nnnRESULTSnFourteen patients completed the study; eight on Livial and six on Kliogest. Recognition memory was improved by Kliogest but not by Livial (P<0.05) while either drug equally improved both the reaction time (P<0.01) and accuracy of performance (P<0.001) of categorical semantic memory. Both the treatments improved libido significantly (P<0.05), while the mood did not change with either.nnnCONCLUSIONnThe results suggest that both these forms of hormonal replacement therapy improve the efficiency of memory performance and libido. However, a combination of oestradiol and norethisterone acetate seems to be marginally more effective on improving cognitive processes.

Relationship between preterm birth and circadian typology in adolescence

A possible relationship between preterm birth and circadian typology was investigated in two pilot survey studies involving 13-year-old teen-agers. Two different questionnaires were used: the Junior Morningness-Eveningness Questionnaire (MEQ) (administered to 55 preterm and 210 fullterm subjects) and the Junior Composite Scale (CS) (administered to 40 preterm and 318 fullterm subjects). In both surveys, preterm groups presented significantly higher total scores, indicating a higher propensity to morningness. Indeed in the preterm samples no evening types were found. The results are discussed in relation to recent models of circadian regulation of the sleep-wake cycle.

Season of birth and personality in healthy young adults

The purpose of this study was to explore a possible season of birth effect on big five personality traits, taking into account also gender and circadian typology variables. A sample of 419 healthy young adults (249 females and 170 males) was administered the self-report version of the Big Five Observer (BFO) and the Morningness -- Eveningness Questionnaire (MEQ) to determine, respectively, personality features and circadian preference. Participants were subdivided into four season groups, according to their birth date. No significant season of birth effect was observed as regards personality traits even if summer-born participants tended to score lower on the conscientiousness dimension. In regard to the conscientiousness domain, there was a significant interaction between gender and season of birth. Males presented greater conscientiousness variation with summer born participants scoring lower. On the basis of a multiple regression analysis, MEQ score proved to be a better predictor of conscientiousness than gender, age, and season of birth. The results provide no clear evidence for a season of birth effect on the big five personality traits. It is possible that circadian preference may modulate the season of birth effect on personality traits.

Season of birth modulates mood seasonality in humans

We investigate whether mood seasonality is modulated by season of birth. A sample of 1682 university students were administered the Seasonal Pattern Assessment Questionnaire. We found that subjects born during spring or summer months had significantly higher Global Seasonality scores than those born during autumn or winter months.

Circadian motor asymmetries before and after prolonged wakefulness in humans

It was hypothesized that the relative superiority of the non-dominant hand movements during late evening could arise from a more pronounced homeostatic deactivation of the left hemisphere. We tested such hypothesis collecting motor activity before and after prolonged wakefulness. Fifty-one right-handed subjects wore actigraphs on both left and right wrist for three consecutive days (baseline-sleep deprivation-sleep recovery). We replicated higher motor activity in left hand respect to the right hand at 22:00 and 23:00 h, but only in baseline condition. The results provide the evidence that circadian motor asymmetries do not seem to express homeostatic processes.

Bizarreness of size and shape in dream images

Bizarreness in dreams is defined as an unusual combination of features in the phenomenal unified consciousness, that is, an incoherent simulation of the waking world. The present study investigated the specific mechanisms underlying dream image production and the phenomenal unity of consciousness by focusing on size and shape bizarreness. Data were derived from a Dream Data Bank of experimental dream studies. Analyses revealed that feature distortion was quite infrequent. Results are discussed in terms of cognitive processes proposed in a dream production model. Theoretical cognitive constructs, such as Kosslyns imagery model, memory systems functioning, and binding, were used to speculate about these two specific types of bizarreness.

Prospective time estimation over a night without sleep

Abstract The aim of the present study was to investigate the time of night effect on prospective time estimation efficiency. Fifty-four participants took part in six consecutive experimental sessions from 10:00 p.m. to 8:00 a.m. at intervals of 2 h, during which they had to carry out two kinds of tasks (simple reaction time and prospective time estimation), give an evaluation of their subjective alertness, and record body temperature. In agreement with previous data on body temperature, subjective alertness and performance in simple reaction time showed a significant decrease during the night, while performance in prospective time estimation did not change over the night. Taking into account circadian typology we found that morning-types tended to produce significantly shorter time intervals and less time estimation accuracy than evening-types. With reference to recent cognitive timing models and data derived from free-running conditions, it is hypothesised that internal pace-makers pulse at different rates between the extreme chronotypes.