After at least two months of treatment, they looked more alert, more youthful and more attractive than when their sleep was still notably disturbed [ 23 ]. Being a clinical group though, it is hard to ascertain whether it was just better sleep that caused the difference or whether other health factors came into play. It has also been shown that women with chronic poor sleep rate themselves as less attractive than women with normal sleep [ 24 ], but again, it is unclear whether reduced sleep is actually the main cause, and whether this self-evaluated attractiveness is related to how others perceive them.
Taking this exploration one step further, we wanted to know whether a decreased willingness to socialize with sleepy people might be based on their being less attractive and looking less healthy, or possibly less trustworthy.
A secondary purpose was to replicate the findings that a tired appearance is related to looking less healthy and less attractive [ 5 ]. Two sets of participants took part in this study, those who were photographed subjects and those who rated the photos raters.
Other exclusion criteria were smoking, shift work during the previous three weeks and excessive coffee intake more than five cups per day and problems abstaining.
Subjects received financial compensation for their time. In order to participate, raters had to be between the ages of 18 and 65 and not a student of psychology. They received a movie ticket for their participation. These visits were in a counterbalanced order, at least one week apart.
To verify adherence to the sleep protocol, subjects used actigraphs Camntech, AW4, Cambridge, UK , clock-sized units which measure activity and give good estimates of sleep timing [ 26 ]. Subjects were instructed to go to bed between Subjects were photographed at the same time of day on both occasions Subjects wore the same dark grey T-shirt at both times, had their hair pulled back, and wore no make-up and minimal jewellery.
They were told to sit comfortably, look straight into the camera and relax their face. A minimum of six photos were taken during each condition. The most representative photo, i. Directly following the photo session, subjects rated their sleepiness on the Karolinska Sleepiness Scale KSS , ranging from 1 extremely alert to 9 very sleepy [ 27 ].
Subjects were not informed about the purpose of the study or the photos prior to being photographed. Fifty facial photos two of each subject, one from each condition were displayed one by one on a inch computer screen in a pseudo-randomized order. The same photo could be displayed more than once, but the same subject was never shown twice in a row. The faces were rated on seven-point scales pertaining to sociability How much would you like to socialize with this person?
Not at all —Very much , trustworthiness How trustworthy is this person? Very untrustworthy—Very trustworthy , attractiveness How attractive is this person? Very unattractive—Very attractive , health How is this person's health? Very poor—Very good and sleepiness How sleepy is this person?
Very sleepy—Extremely alert. The questions were presented in blocks, so that all faces were rated on one question at a time in the above order.
In order to take into account random variations in levels between both subjects and raters, the ratings were analysed using multi-level mixed effects linear regression with two crossed independent random effects. The random effects concern the extent to which the subjects and raters differ from the average subject and rater. The p -level was set to 0.
The strength and significance of mediated effects were calculated through bootstrapped samples, using the boot [ 28 ] package in R.
Data from seven raters were lost because of equipment malfunction. The sleepiness scale initially ranged from 1—extremely alert to 7—very sleepy , similar to the commonly used KSS [ 27 ].
Therefore, the responses of the first 40 raters all raters prior to reversal of the scale have been excluded regarding sleepiness, leaving 75 raters in the analyses of this particular factor. Ratings on other scales were retained. Raters were also excluded on the basis of low variability in ratings, i. Such a limited use of the scale may indicate low motivation to adhere to the instructions of the task.
This led to nine raters being removed for sociability, 19 for trustworthiness, seven for attractiveness, nine for health and two for sleepiness. Raters were less willing to socialize with a subject who was sleep restricted table 1. Sleep-restricted subjects were also rated as less attractive, less healthy and more sleepy compared with their well-rested selves table 1. There was no significant difference in ratings of trustworthiness between the two conditions table 1. Effects of two nights of sleep restriction on rated appearance.
The average rating of the average face after normal sleep intercept and the fixed effect b of sleep restriction on these ratings. Scales ranged from 1 to 7 for willingness to socialize Not at all — Very much , attractiveness Very unattractive — Very attractive , health Very unhealthy — Very healthy , sleepiness Very sleepy — Very alert , reverse scored and trustworthiness Very untrustworthy — Very trustworthy.
Each increment on the sleepiness scale thus corresponds to a 0. Relationship between willingness to socialize and perceived sleepiness a , health b , attractiveness c and trustworthiness d. The dots are based on raw data, with each dot representing one rating.
Jitter was applied to better illustrate the distribution of the ratings. Regression lines are from the linear mixed models, with random effects of both subject and rater.
The replication analyses of the relationships between looking sleepy, attractive and healthy [ 5 ] were all significant.
Relationship between attractiveness and perceived sleepiness a , health and sleepiness b and attractiveness and health c. The average level of willingness to socialize was 0. When adjusting for the other mediators, through including all of them simultaneously, together with sleep restriction, as predictors of willingness to socialize in a multivariate model, 7.
As subjects were allowed to regulate their own bed- and wake-times, 19 out of 25 chose to rise earlier in the morning during the sleep restriction days. As time awake is a factor in sleepiness [ 30 , 31 ], additional analyses were performed in order to rule out the possibility that this was the driving factor behind the results.
When subjects had been sleep restricted before being photographed, raters were less willing to socialize with them compared with when they had gotten two nights of good sleep. Interestingly, the decreased willingness to socialize with sleep-restricted subjects was not solely due to their looking less attractive, less healthy, more sleepy or less trustworthy.
These four factors mediated about one-third of the effect of sleep restriction on other's willingness to socialize with the sleep-restricted person. This suggests that sleep loss affects facial cues over and above those presently measured.
For a social animal, being left out of a group can have dire effects. Since sleep deprivation is implied in making people more emotionally reactive [ 35 , 36 ], as well as more aggressively inclined [ 37 ], these affective and behavioural responses to exclusion may be amplified in a person who has not slept, even if their immediate distress response is unaffected [ 38 ].
Whether the indicated decrease in motivation to socialize with someone who is sleep deprived actually results in overt ostracism remains to be studied. On the other hand, it may be adaptive that the cues which sleep-deprived individuals give off [ 4 ] enable them to be left alone in order to recover from their current state.
Someone who is driven by the motivation to sleep could thus have less interest in socializing with other people, alternatively be less attentive to their social surroundings and as such may be less negatively affected by being undesired and excluded. If this is true, it is likely that the social effects of sleep loss found here would be stronger in real life, with both parties less motivated to socialize.
Adding to previous research on appearance after sleep loss [ 5 ], partial sleep deprivation, like total sleep deprivation, made participants appear less attractive and less healthy. Also in line with findings on how sleep apnoea and chronically poor sleep affects attractiveness [ 23 ], this is the third study to connect poor sleep to a less attractive and less healthy appearance. One possible mechanism for this change in looks is a difference in skin blood coloration.
A healthy, attractive face is characterized by a certain degree of redness, which in turn is indicative of increased vasodilation and vascularization [ 2 ]. Blood flow to the skin is strongly promoted by sleep and this vasodilation may be a way for the body to facilitate the distribution of endogenous defence agents [ 39 ].
With a lack of sleep, blood flow to the skin is reduced [ 40 ], and according to raters faces look more pale after not sleeping [ 4 ]. The subjects also looked more sleepy after two nights of restricted sleep, adding to the earlier findings of people looking more tired and fatigued after a night of total sleep deprivation following a night of sleep restriction [ 4 , 5 ].
It is possible that the participants rating the photos would only make a distinction between sleepiness and tiredness if they were concurrently evaluated, as the two are often used as synonyms in everyday language [ 41 ]. Regardless, people seem to be able to tell when someone needs more sleep, and are more inclined to leave them alone in that case. This appears to be true even though the subjects were not perceived to be very sleepy, regardless of condition.
This study showed pictures of strangers' faces to people and asked them to indicate their willingness to socialize with the person in the picture. They had no background information about personality or interests or other factors that may affect how we perceive people.
The effect of sleep restriction might be different if the raters were instead friends or family members of the photographed individual. A shift in focus might also affect ratings of trustworthiness, as the context affects how different dimensions are valued [ 44 ]. In this study, there were no differences in the appearance of trustworthiness after two nights of sleep restriction, but perhaps in a different context trustworthiness would be more salient and thus more harshly judged.
The effects of sleep deprivation on others' willingness to socialize, and the appearance of sleepiness, attractiveness and health, were arguably quite small; ranging from 0.
This is not surprising, considering the multitude of things that affect one's appearance see e. But the fact that this has been repeatedly found, despite different scales and sleep-loss paradigms [ 5 , 23 ], and with high power due to the total number of raters, supports these as being true effects. As with all studies where photographs are evaluated, it is hard to say whether the effects would be amplified or disguised in a real social setting.
For example, one might expect a sleepy person to yawn, blink more slowly [ 46 ], have a less expressive face [ 11 ] and more monotonic speech [ 47 ]. Such multi-sensory information is generally more effective than unimodal signalling, especially when stimuli are weak [ 48 ], which speaks for detection of sleep loss being facilitated when, for example, auditory, postural and facial cues can be evaluated together.
Furthermore, sleep loss in everyday life is often comorbid with stress [ 49 ] and other health issues [ 50 ], which may exacerbate the negative effects on appearance. But on the other hand, the sleep-deprived person might have put on make-up, ingested a lot of coffee and made an effort to appear more alert, which could reduce such effects. There were no visible injuries. No broken bones, no internal bleeding. Afterward, she considered herself lucky, and remained deployed with her company.
Nevertheless, the attack would change her life in dramatic ways. Physically, as she would later discover, she had permanent, painful joint and nerve damage in her left shoulder, elbow, and wrist. But the worst injuries were harder to identify.
Upon returning home to Montana, she enrolled in college, only to be quickly put on academic probation. Therapy for her post-traumatic stress disorder PTSD and resulting depression and anxiety helped Jourdan heal in essential ways, but she still had symptoms she could not categorize, symptoms that disrupted her academic course work and daily life.
Simply running errands was frustrating and overwhelming. When I had outbursts of tears, I thought I was weak. When I was put on academic suspension in college due to my poor grades, I internalized it as a fact that I was too dumb for college. My family and friends tried to be supportive of me, but not having a full diagnosis and the words to articulate what I was struggling with ultimately caused major rifts in my relationships. I felt completely alone in my daily struggles and thought I was inherently flawed.
In , during a checkup with her neurologist about residual problems resulting from her other injuries, Casey was referred for a neuropsychological evaluation to screen for a concussion.
All subjects were right-handed, and had normal or corrected-to-normal vision. The experiment was approved by a local Institutional Review Board, and informed consent was obtained from each participant. The congruent stimuli consisted of the three color words in Chinese red, yellow, blue written in the same color in which the stimulus was presented e.
The incongruent stimuli consisted of the same three words with display colors that do not match the word meaning e. Each incongruent stimulus appeared in either of the two colors that does not match its meaning. In the neutral condition, two no-color words ball, watch were presented in one of the three colors. Subjects were instructed to rest their right middle three fingers on the left three keys of the E-prime response box, and each finger represents one color.
They were told that a gray cross would always appear first in the center of the screen serving as a fixation point, and then one word written in different colors would appear. The order is as follows: the fixation point appeared for ms, the word appeared for ms, and then the empty screen appeared for ms. Subjects were asked to identify the color in which the stimulus was written as fast and accurately as possible and responded by pressing the button of the corresponding color.
The experiment was divided into a practice phase and a test phase. The test phase was about 3 min. The formal test consisted of three blocks of 90 trials 30 congruent stimuli, 30 neutral stimuli, 30 incongruent stimuli , each block was around 15 min. Participants were instructed to avoid blinking and eye movement of any sort and to keep their eyes fixated on the monitor rather than looking down at their fingers during task performance.
Participants rested briefly after finishing one block. Before and after training, all subjects performed a Stroop word-color task while their brain activity was measured using a high-density electroencephalography system. Integrative body-mind training involves body relaxation, mental imagery and mindfulness training, accompanied by selected music background. Cooperation between the body and the mind is emphasized in facilitating and achieving a meditative state Tang et al.
The trainees concentrated on achieving a balanced state of body and mind guided by an IBMT coach. The method stresses no effort to control thoughts, but instead a brain state of restful alertness that allows a high degree of awareness of body, mind, and external instructions. RT involves the relaxing of different muscle groups over the face, head, shoulders, arms, legs, chest, back, and abdomen, guided by a qualified tutor.
With eyes closed and in a sequential pattern, one is forced to concentrate on the sensation of relaxation, such as the feelings of warmth and heaviness. This progressive training helps the participant achieve a physical and mental relaxation and calmness Tang et al. Eighteen subjects had 10 consecutive IBMT sessions with about 30 min per day 5 h in total , 17 subjects were given the same amount of RT.
These two training sessions were conducted in parallel. The reference electrode was placed on the FCz, while ground was linked to the AFz. Vertical and horizontal electro-oculograms EOG were recorded by electrodes situated supra-and infra-orbital of the left eye and external canthi of both eyes, respectively. The EEG was digitally low-pass filtered at 20 Hz, and transformed to an average reference. The averaged epoch for ERP was ms, and the first ms before stimulus presentation served as baseline.
Only segments with correct responses were averaged, and at least 52 trials were available for each subject and condition incongruent, congruent, and neural. Grand averages were computed to identify components and time windows for statistical analysis.
The P2, N2, and P3 peak amplitudes, which were detected from individual ERPs, were measured within time windows of — ms, — ms, and — ms, respectively. The peak amplitude and peak latency data of each component were compared between two groups using between-group, repeated measure ANOVA with Greenhouse—Geisser correction.
Conflict scores refer to the difference between congruent and incongruent conditions. The pre vs. For accuracy analysis at pre-session, Congruent Incongruent This suggested that the superior performance on Stroop reaction times at post-training was not due to participants responding less carefully. Comparison of Reaction Time in Stroop task between two groups after training. To examine the training effects on brain activity, we then computed differences in ERP components between the two groups at the post-training session.
Four midline sites along the anterior-posterior axis Fz, FCz, Cz, and Pz were selected based on previous research findings that showed frontopolar, frontocentral, central, and parietal scalp regions have Stroop-related changes Liotti et al. The letters F, C, P, and O stand for frontal, central, and parietal lobes, respectively. There was no significant difference between two groups for the N2 latency, and the effect is mainly observed in the amplitude of the component.
Inspection of the topographical voltage map for N2 component in the incongruent condition indicated that group differences were mainly over frontal midline and left temporo-parietal scalp regions. The time window is — ms. The letters P, S, A stand for posterior, superior, and anterior view of brain portion, respectively. LV, left view; RV, right view. The warm colors mean increased activity and cold colors represent decreased activity.
Using the classic Stroop task, 5 h of IBMT improved the ability to resolve conflict compared to an active relaxation control. This result supported our previous findings using the attention network test to measure conflict resolution Tang et al. A series of behavioral and imaging studies have established that IBMT can improve attention and self-control after only 2 h of practice through increased activation in the ACC accompanied by improved connectivity to the parasympathetic system Tang et al.
These measures were obtained at rest and thus reflect a change in brain state Tang et al. This change in brain state is not achieved by RT which served as a control condition in these studies Tang et al. In the current study, we found significant differences between two groups in brain electrical activity over frontal midline ACC regions after training. The P3 amplitude is thought to reflect the amounts of attentional resources employed in a given task Polich, Our study is consistent with the idea that meditation practice affects attentional resource allocation and increases the efficiency of conflict resolution Cahn and Polich, ; Sarang and Telles, ; Slagter et al.
These findings provide a likely account of how a change in brain state influences the ability to resolve conflict. Posterior brain potentials did not differ between two groups but the frontal midline N2, which has often been related to the effort to monitor conflict, was greatly reduced in the IBMT, especially in the more dorsal part of the ACC.
Thus, the smaller N2 may suggest less effort needed to monitor conflict after meditation training and quicker resolution as shown by both reaction time and P3 latency.
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