Sleep quality is an important clinical construct since it is increasingly common for people to complain about poor sleep quality and its impact on daytime functioning. Moreover, poor sleep quality can be an important symptom of many sleep and medical disorders. However, objective measures of sleep quality, such as polysomnography, are not readily available to most clinicians in their daily routine, and are expensive, time-consuming, and impractical for epidemiological and research studies., Several self-report questionnaires have, however, been developed. The present review aims to address their psychometric properties, construct validity, and factorial structure while presenting, comparing, and discussing the measurement properties of these sleep quality questionnaires. A systematic literature search, from 2008 to 2020, was performed using the electronic databases PubMed and Scopus, with predefined search terms. In total, 49 articles were analyzed from the 5734 articles found. The psychometric properties and factor structure of the following are reported: Pittsburgh Sleep Quality Index (PSQI), Athens Insomnia Scale (AIS), Insomnia Severity Index (ISI), Mini-Sleep Questionnaire (MSQ), Jenkins Sleep Scale (JSS), Leeds Sleep Evaluation Questionnaire (LSEQ), SLEEP-50 Questionnaire, and Epworth Sleepiness Scale (ESS). As the most frequently used subjective measurement of sleep quality, the PSQI reported good internal reliability and validity; however, different factorial structures were found in a variety of samples, casting doubt on the usefulness of total score in detecting poor and good sleepers. The sleep disorder scales (AIS, ISI, MSQ, JSS, LSEQ and SLEEP-50) reported good psychometric properties; nevertheless, AIS and ISI reported a variety of factorial models whereas LSEQ and SLEEP-50 appeared to be less useful for epidemiological and research settings due to the length of the questionnaires and their scoring. The MSQ and JSS seemed to be inexpensive and easy to administer, complete, and score, but further validation studies are needed. Finally, the ESS had good internal consistency and construct validity, while the main challenges were in its factorial structure, known-group difference and estimation of reliable cut-offs. Overall, the self-report questionnaires assessing sleep quality from different perspectives have good psychometric properties, with high internal consistency and test-retest reliability, as well as convergent/divergent validity with sleep, psychological, and socio-demographic variables. However, a clear definition of the factor model underlying the tools is recommended and reliable cut-off values should be indicated in order for clinicians to discriminate poor and good sleepers.

The space-time interaction suggests a left-to-right directionality in the mind’s representation of elapsing time. However, studies showing a possible vertical time representation are scarce and contradictory. In Experiment 1, 32 participants had to judge the duration (200, 300, 500 or 600 milliseconds) of the target stimulus that appeared at the top, centre, or bottom of the screen, compared to a reference stimulus (400 milliseconds) always appeared in the centre of the screen. In Experiment 2, 32 participants were administered with the same procedure, but the reference stimulus appeared at the top, centre, or bottom of the screen and the target stimulus was fixed in the centre location. In both experiments, a space-time interaction was found with an association between short durations and bottom response key as well as between long durations and top key. The evidence of a vertical mental timeline was further confirmed by the distance effect with a lower level of performance for durations close to that of the reference stimulus. The results suggest a bottom-to-top mapping of time representation, more in line with the metaphor “more is up”.

The abstract concept of time is mentally represented as a spatially oriented line, with the past associated with the left space and the future associated with the right. Although the line is supposed to be continuous, most available evidence is also consistent with a categorical representation that only discriminates between past and future. The aim of the present study was to test the continuous or categorical nature of the mental timeline. Italian participants judged the temporal reference of 20 temporal expressions by pressing keys on either the left or the right. In Experiment 1 (N = 32), all words were presented at the center of the screen. In Experiment 2 (N = 32), each word was presented on the screen in a central, left, or right position. In Experiment 3 (N = 32), all text was mirror-reversed. In all experiments, participants were asked to place the 20 temporal expressions on a 10-cm line. The results showed a clear Spatial–TEmporal Association of Response Codes (STEARC) effect which did not vary in strength depending on the location of the temporal expressions on the line. However, there was also a clear Distance effect: latencies were slower for words that were closer to the present than further away. We conclude that the mental timeline is a continuous representation that can be used in a categorical way when an explicit past vs. future discrimination is required by the task.

Time is represented along a horizontal mental line with an association between the past (or short duration) and left space as well as between the future (or long duration) and right space. A possible vertical time representation is also supposed to exist, even if results are contradictory depending on the stimuli and response keys used. The aim of the present study was to test the presence of a vertical representation of temporal expressions, overcoming possible methodological limits. In Experiment 1, 167 Italian students had to categorize 20 Italian temporal expressions that appeared at the center of the screen with two analogous vertical response keys ("down" and "up" arrows of a regular keyboard). Specifically, in Experiment 1A participants pressed the down arrow with their left hand and the up arrow with their right hand, whereas in Experiment 1B the key-hand assignment was reversed. In Experiment 2, 25 participants underwent the same procedure using a vertically positioned response box. The same participants also performed a Time-to-Position task, in which they located temporal expressions along a vertical line. In both experiments, a space-time interaction was found, with an association between past expressions and the bottom (or down arrow) response key as well as between future expressions and the top (or up arrow) key. The results suggest a bottom-to-top mapping of time representation, according to the "more-is-up" metaphor. Public Significance StatementThe present study suggests that a vertical mental timeline representation exists, showing a space--time association from bottom to top. This mental representation is probably influenced by the daily life experience of verticality in the physical world, such as the construction of a building from the ground floor to the attic, according to the "more-is-up" metaphor. The results were confirmed using both an analogous and a literal concept of verticality in a temporal judgment task, and this bottomto-top representation of time was not influenced by the hand used to press the response button. Moreover, we confirmed not only that the past was associated with the bottom space and the future was associated with the top space, but also that the temporal expressions used in this study showed an ordinal pattern when participants performed a Time-to-Position task. Therefore, we can conclude that, even if temporal expressions do not refer to fixed moments in time, they occupy a specific position on the mental timeline with a "specific order."

Recent studies have shown that making accurate passage of time judgments (POTJs) for long‐time intervals is an important cognitive ability. Different temporal domains, such as circadian typology (biological time) and time perspective (psychological time), could have an effect on subjective POTJs, but few studies have investigated the reciprocal influences among these temporal domains. The present study is the first systematic attempt to fill this gap. A sample of 222 participants (53.20% females; 19–60 years) filled in the Zimbardo Time Perspective Inventory for the measurement of time perspective, the reduced version of the Morningness‐Eveningness Questionnaire (rMEQ) for chronotypes, and an ad‐hoc questionnaire assessing sleep habits during weekdays and the weekend (for social jetlag). The POTJ was measured using a modified version of a pictorial timeline presented at five different moments. Also, participants judged how different temporal expressions were related to the past, present, and future along a 7‐point Likert scale. After confirming the association between eveningness and present‐hedonism orientation and morningness and future‐orientation, we found that evening‐types produced higher scores for future expressions. The subjective POTJ expressed in minutes was predicted by Deviation from Balanced Time (DBTP), present‐fatalism orientation, and social jetlag. Finally, the rMEQ score, past‐positive orientation, and DBTP predicted the difference between subjective and objective POT. The results are discussed offering an explanation in terms of the interconnections between circadian typology, individual time perspective, and the sense of the POT, suggesting the multicomponent nature of the concept of time.

Insomnia disorder is considered a public health problem and additional studies should investigate predisposing and perpetuating factors. This study examined the relationship between Big Five personality traits, time perspective, and insomnia. In a cross-sectional study, 400 participants (227 women; age range 18–74 years) were administered the Big Five Inventory—10 items, the Zimbardo Time Perspective Inventory, and the Insomnia Severity Index (ISI). A measure of chronotype was also included for control purposes. The results show that insomniacs reported lower scores for conscientiousness and extraversion, and for past-positive (PP) and future (F) perspectives, whereas they obtained higher scores for past-negative (PN) perspectives and deviation from a balanced time perspective. The correlations confirmed these findings, but negative correlations between present-hedonistic (PH) perspective and ISI score, and between emotional stability and ISI score, were also found. The mediation analyses showed that F played an indirect role in the relationship between consciousness and ISI score, PN had an indirect effect on the relationship between emotional stability and ISI or between extraversion and insomnia, and PH had an indirect effect on the relationship between extraversion and ISI score. The current outcomes shed light on the mechanisms which serve to mediate the relationship between insomnia and personality traits.

It has been suggested that the Theory of Mind (ToM) may rely on more basic processes of social cognition, such as action control (e.g., joint action), even if little is known about this relationship. The relationship between ToM and joint action can be studied in patients with Parkinson's disease (PD), because they are characterized not only by a deficit in ToM (and in its cognitive and affective subcomponents) but also by a deficit in the inhibition of competing responses. Sixty PD patients and 60 matched healthy controls (HCs) performed a go/no-go Flanker task in both joint and individual conditions. Cognitive (Advanced Test or AT) and affective (Emotion Attribution Task or EAT) ToM also were measured. Thirty-five PD patients and matched HCs also performed the standard Flanker task, as a control measure. In patients, only individuals with high AT scores exhibited a joint Flanker effect, whereas in HCs the joint effect was found irrespectively of AT score. Patients with low EAT scores showed a greater interference effect than patients with high scores, whereas the opposite pattern was found for HCs. In regression analysis AT and EAT scores predicted the Flanker effect in the joint condition only. In the standard task, both groups showed a Flanker effect. The role of different fronto-striatal circuits, especially in PD patients, could explain the different involvement of cognitive and affective ToM in joint tasks. The Flanker effect is discussed considering the referential coding account and the attention-focus account as possible candidates to explain joint action effects.

Research on joint action has demonstrated that individuals are sensitive to a coactor’s attentional relation to jointly attend stimuli. It has also been suggested that some features are necessary to resolve the discrimination problem (i.e., self-own and other-own actions). In the present study, we aimed to test whether the gender composition of interacting pairs modulated the joint action effect. Same- (female-female or male-male) and mixed- (female-male) gender pairs performed a joint version of flanker tasks in Experiment 1 (90 participants, 50% males), while in Experiment 2 (154 participants, 50% males) Navon tasks were performed. In Experiment 1, a higher joint flanker effect in same-gender pairs than in mixed-gender pairs, and this joint effect was similar to the classical flanker effect reported by males and females in a classical procedure of the task (70 participants, 50% males). In Experiment 2, the same-gender pairs reported a joint Navon effect, which was reversed in mixed-gender pairs. In conclusion, our findings support how the gender composition of interacting pairs plays a role in joint attentional tasks.