Effects of the perceived temporal distance of events on mental time travel and on its underlying brain circuits.

Mental Time Travel (MTT) allows us to remember past events and imagine future ones. According to previous literature, the Temporal Distance of events affects MTT: our ability to order events worsens for close, compared to far, events. However, those studies established distances a-priori, albeit the way we perceive events' temporal distance may subjectively differ from their objective distance. Thus, in the current study, we aimed to investigate the effects of Perceived Temporal Distance (PTD) on the MTT ability and the brain areas mediating this process. Thirty-three healthy volunteers took part in an fMRI MTT task. Participants were asked to project themselves into the past, present, or future, and to judge a series of events as relative-past or relative-future, in relation to the adopted time location. Outside the scanner, participants provided PTD estimates for each stimulus of the MTT task. Participants' performance and functional activity were analyzed as a function of these estimations. At the behavioural level, PTD predicts the modulation of the performance for relative-past and relative-future. Bilateral angular gyrus, retrosplenial cortex, temporo-parietal region and medial, middle and superior frontal gyri mediate the PTD effect. In addition to these areas, the closer the relative-future events are perceived, the higher the involvement of left parahippocampal and lingual gyri and right cerebellum. Thus, perceived proximity of events activates frontal and posterior parietal areas, which therefore might mediate the processing of PTD in the cognitive spatial representation of time. Future proximity also activates cerebellum and medial temporal areas, known to be involved in imaginative and constructive cognitive functions.

Spatial attention modulation of the brain network involved in mental time travel.

OBJECTIVES: The ability to mental time travel (MTT) consists in moving along a cognitive and spatially oriented representation of time, that is, an ideal mental time line, where past and future events are, respectively, located on the left and on the right portion of such a line. A shift of spatial attention by prismatic adaptation (PA) influences this spatial coding of time, thus affecting MTT. Here, we investigated the neural correlates of such a spatial modulation on MTT in a functional Magnetic Resonance Imaging protocol. METHOD: To study MTT ability, participants were asked to indicate if a series of events took place before or after (Self-Reference component) an imagined self-location in time (Past, Present or Future; Self-Projection component), where they had to project themselves. The MTT task was performed before and after PA inducing a leftward shift of spatial attention, which is supposed to move toward the left portion of mental time line (MTL), where Past is represented. RESULTS: Following PA, we observed a facilitation in responding to past as compared to future events when participants projected themselves to the Past projection. As a functional counterpart of this behavioral finding, we propose a model of the brain activity modulations following the PA effects on MTT. CONCLUSIONS: As a result of the shift of spatial attention toward the left, the facilitation in having access to past events is associated with the inhibition of superior frontal gyrus in the left hemisphere, whereas the facilitation in projecting toward the Past may result from the activity modulation in right and left inferior parietal lobule. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

"When You're Smiling": How Posed Facial Expressions Affect Visual Recognition of Emotions.

Facial imitation occurs automatically during the perception of an emotional facial expression, and preventing it may interfere with the accuracy of emotion recognition. In the present fMRI study, we evaluated the effect of posing a facial expression on the recognition of ambiguous facial expressions. Since facial activity is affected by various factors, such as empathic aptitudes, the Interpersonal Reactivity Index (IRI) questionnaire was administered and scores were correlated with brain activity. Twenty-six healthy female subjects took part in the experiment. The volunteers were asked to pose a facial expression (happy, disgusted, neutral), then to watch an ambiguous emotional face, finally to indicate whether the emotion perceived was happiness or disgust. As stimuli, blends of happy and disgusted faces were used. Behavioral results showed that posing an emotional face increased the percentage of congruence with the perceived emotion. When participants posed a facial expression and perceived a non-congruent emotion, a neural network comprising bilateral anterior insula was activated. Brain activity was also correlated with empathic traits, particularly with empathic concern, fantasy and personal distress. Our findings support the idea that facial mimicry plays a crucial role in identifying emotions, and that empathic emotional abilities can modulate the brain circuits involved in this process.

Class inclusion versus quantifiers comprehension tasks: an experimental study with school-aged children.

Literature in developmental psychology pays special attention to the difficulties met by preschool children when confronted with (universal vs. existential) quantified sentences. According to the pivotal Piagetian view, the difficulties exhibited in quantifier comprehension during the preoperational period (age 2-6) derive from the same limitations in logical reasoning that cause bad performance outcomes in class inclusion problems. Nevertheless, as far as we know, a direct comparison between the two tasks has never been produced. In this research we tested the logical hypotheses concerning the failure in quantifier comprehension of preschool children by administering a sentence-picture matching task to two groups of children (5-6 vs. 7-8 years old). Pictures, obtained by partially pairing two entity sets, one of which outnumbers the other, were presented to participants. After each picture, children were asked to answer questions involving quantified versus class inclusion contents. Main findings showed that younger children performed the quantifier task worse than older children and their performance in that task was also worse with respect to the class inclusion task. This difference was not observed with older children who obtained better results than younger children in both tasks. These findings suggest that the specific abilities involved in solving the two problems evolve independently from each other during cognitive development. The results have been discussed in the light of the recent developmental theories.

Accurate Determination of the Cold Detection Threshold with High-Speed Cooling of the Skin.

OBJECTIVE: This study used high-speed cooling of the skin and exact control of stimulus duration to measure the cold detection threshold in healthy participants. The objective was to compare the method of limits, in which the temperature is slowly and gradually increased/decreased until the subject perceives the stimulation, and the method of levels, in which the subject must detect brief thermal stimulations close to the threshold of perception. METHODS: Twenty healthy volunteers (nine women, 11 men) aged 20-30 years participated in the study. The method of limits and method of levels were performed in all subjects in a counterbalanced order. Four cold detection thresholds were measured with the method of levels, with a temperature ramp of 300°C/sec and stimulus durations of 50 ms, 100 ms, 300 ms, and 500 ms. Three thresholds were measured with the method of limits, with temperature ramps of 1°C/sec, 2°C/sec, and 4°C/sec. RESULTS: On average, the cold detection thresholds were -0.47°C below skin temperature with the method of levels and -1.67°C the method of limits. Interindividual variability was significantly lower with the method of levels than with the method of limits. CONCLUSIONS: These results suggest that the method of levels is more accurate than the method of limits for measuring cold detection threshold. The improvement of cold detection threshold measurement may provide new perspectives to more precisely assess the function of A-delta fibers and the spino-thalamic pathway.

Effects of thermosensory aging well demonstrated by cold stimulations with high temporal resolution.

INTRODUCTION: The method of limits (MLi) is the most commonly used paradigm to measure the threshold of thermal stimuli. However, the threshold measured by MLi is dependent on reaction time (RT). Because RT in adults increases with age, the inclusion of RT in the MLi paradigm may result in an overestimation of thermal threshold in the older individuals. METHODS: A device with a very rapid cooling rate (300°C/s) was employed to measure cool thresholds by using the method of levels (MLe), a method independent of RT, in 11 older patients and 14 younger adults. RESULTS: Compared with the MLi, the MLe resulted in a greater than 2°C gain in threshold measurement accuracy in older patients. DISCUSSION: The MLe confirmed that cool perception threshold is dependent on age. The use of MLe provides new opportunities for the study of mechanisms underlying age-associated alterations in thermal perception. Muscle Nerve 60: 141-146, 2019.

Seizure metaphors in children with epilepsy: A study based on a multiple-choice self-report questionnaire.

The advantages of metaphorical representation are pointed out in many fields of clinical research (e.g. cancer, HIV, psychogenic nonepileptic seizures). This study aimed at offering a novel contribution showing how children with epilepsy describe the symptomatology of their seizure experiences by means of particular kinds of cognitive metaphors. Twenty-three children with idiopathic generalized epilepsy and thirty-one healthy children were recruited for this study and interviewed with a multiple-choice questionnaire asking them to describe their epileptic seizures by means of suitable metaphors. A psychologist blinded to medical diagnosis assessed and categorized all metaphors. By considering the 89 metaphors produced by the children with epilepsy and the 147 ones by the healthy controls, Agent/Force was the primary metaphor assessed by children with epilepsy, followed by Event/Situation as the second preference. Moreover, comparing the results of the control group with those of the subjects with epilepsy, it was found that controls were oriented towards selecting exogenous forces, while subjects with epilepsy tended to select endogenous forces. In particular, children with epilepsy showed a peculiar preference for an endogenous force resembling the waggle metaphor, which is similar to the effect of a quake's shaking (earthquake or seaquake). The metaphors identified by this research are a useful resource to better understand the seizure experiences of patients with epilepsy, helping to improve clinical treatment.

Parenting stress evaluation and behavioral syndromes in a group of pediatric patients with epilepsy.

The aim of the present work was to measure the amount of stress in parents of children with epilepsy and to determine whether and how parenting stress is linked to behavioral symptoms of the children. Parenting stress was measured with the Parenting Stress Index (PSI) and behavioral symptoms with the Child Behavior Checklist (CBCL). Data obtained from 26 parents of children with epilepsy were compared with those obtained from 31 parents of healthy children. Children with epilepsy obtained higher scores in all the subscales of PSI and in almost all the subscales of CBCL compared with healthy children. Epilepsy caused a high level of parenting stress and of problematic behaviors since the behavioral symptoms predicting the degree of parenting stress significantly differed between healthy children and children with epilepsy. Therefore, parents of children with epilepsy should be offered psychological support to cope with parenting stress and to improve the relationship with their children.

Spiral implants bearing full-arch rehabilitation: analysis of clinical outcome.

A spiral implant (SPI) is a conical internal helix implant with a variable thread design which confers the characteristic of self drilling, self tapping, and self bone condensing. The effectiveness of this type of implant has been reported in several clinical situations. However, because there are no reports that specifically focus on one of the biggest challenges in oral rehabilitation, that is, full arch rehabilitation, it was decided to perform a retrospective study. The study population was composed of 23 patients (12 women and 11 men, median age 57 years) for evaluation and implant treatment between January 2005 and June 2009. Two-hundred six spiral family implants (SFIs) were inserted with a mean postloading follow-up of 23 months. Several variables were investigated: demographic (age and gender), anatomic (maxilla and mandible, tooth site), implant (type, length, and diameter), surgical (surgeon, postextractive, flapless technique, grafts), and prosthetic (implant/crown ratio, dentition in the antagonist arch, type of loading, and computerized tomography [CT] planning) variables. Implant loss and peri-implant bone resorption were evaluated. Univariate and multivariate tests were performed. Survival and success rates were 97.1% and 82.5%, respectively. Only implant length and implant/crown ratio showed statistical significance in determining a better clinical outcome. In conclusion, SFIs are a reliable tool for the most difficult cases of oral rehabilitation. No differences were detected among implant type. Length and implant/crown ratio can influence the crestal bone resorption with better result for longer fixtures and a higher implant/crown ratio. In addition, banked bone derived from living donors can be used to restore alveolar ridge augmentation without adverse effects. Finally, flapless and CT-planned surgery did not significantly increase the clinical outcome in most complex rehabilitation.

Implant rehabilitation in grafted and native bone in patients affected by ectodermal dysplasia: evaluation of 78 implants inserted in 8 patients.

OBJECTIVES: Ectodermal dysplasia (ED) is a congenital syndrome characterized chiefly by abnormalities of tissues of ectodermal origin, namely skin, nails, hair, and teeth. Dental treatment of patients with ED is necessary, because it affords the opportunity to develop normal forms of speech, chewing, swallowing, and normal facial support. Because there are few reports focusing on implants inserted in bone grafted in patients affected by ED. This is a retrospective study of 78 implants inserted in 8 patients to detect those variables acting on survival and crestal bone remodeling around the implant neck in such subjects. MATERIALS: Seventy-eight fixtures were analyzed. Several patient-related (age and gender), anatomical (maxilla and mandible, tooth site), implant (type, length, and diameter), surgical (sites and types of grafts), and prosthetic (type of loading and implant/crow ratio) variables were investigated. Implant failure and peri-implant bone resorption were considered as predictors of clinical outcome. Kaplan-Meier algorithm and Cox regression were then performed to detect those variables statistically associated with the clinical outcome. RESULTS: Implant length and diameter ranged from 11.5 to 18 mm and from 3.5 to 6.0 mm, respectively. Implants were inserted to replace 19 incisors, 19 cuspids, 21 premolars, and 19 molars. One implant was lost. On the contrary, implant' length, grafted sites, and type of loading have an impact on univariate analysis, but this datum was not confirmed by multivariate algorithm. CONCLUSION: The use of dental implants and bone grafts to orally rehabilitate patients affected by ED is a valuable service with no difference in the results compared with unaffected patients, at least in adults.