Spotlight on dream recall. The ages of dreams

Brain and sleep maturation covary across different stages of life. At the same time, dream generation and dream recall are intrinsically dependent on the development of neural systems. The aim of this paper is to review the existing studies about dreaming in infancy, adulthood, and the elderly stage of life, assessing whether dream mentation may reflect changes of the underlying cerebral activity and cognitive processes. It should be mentioned that some evidence from childhood investigations, albeit still weak and contrasting, revealed a certain correlation between cognitive skills and specific features of dream reports. In this respect, infantile amnesia, confabulatory reports, dream-reality discerning, and limitation in language production and emotional comprehension should be considered as important confounding factors. Differently, growing evidence in adults suggests that the neurophysiological mechanisms underlying the encoding and retrieval of episodic memories may remain the same across different states of consciousness. More directly, some studies on adults point to shared neural mechanisms between waking cognition and corresponding dream features. A general decline in the dream recall frequency is commonly reported in the elderly, and it is explained in terms of a diminished interest in dreaming and in its emotional salience. Although empirical evidence is not yet available, an alternative hypothesis associates this reduction to an age-related cognitive decline. The state of the art of the existing knowledge is partially due to the variety of methods used to investigate dream experience. Very few studies in elderly and no investigations in childhood have been performed to understand whether dream recall is related to specific electrophysiological pattern at different ages. Most of all, the lack of longitudinal psychophysiological studies seems to be the main issue. As a main message, we suggest that future longitudinal studies should collect dream reports upon awakening from different sleep states and include neurobiological measures with cognitive performance

Mental sleep activity and disturbing dreams in the lifespan

Sleep significantly changes across the lifespan, and several studies underline its crucial role in cognitive functioning. Similarly, mental activity during sleep tends to covary with age. This review aims to analyze the characteristics of dreaming and disturbing dreams at dierent age brackets. On the one hand, dreams may be considered an expression of brain maturation and cognitive development, showing relations with memory and visuo-spatial abilities. Some investigations reveal that specific electrophysiological patterns, such as frontal theta oscillations, underlie dreams during sleep, as well as episodic memories in the waking state, both in young and older adults. On the other hand, considering the role of dreaming in emotional processing and regulation, the available literature suggests that mental sleep activity could have a beneficial role when stressful events occur at dierent age ranges. We highlight that nightmares and bad dreams might represent an attempt to cope the adverse events, and the degrees of cognitive-brain maturation could impact on these mechanisms across the lifespan. Future investigations are necessary to clarify these relations. Clinical protocols could be designed to improve cognitive functioning and emotional regulation by modifying the dream contents or the ability to recall/non-recall them

La costruzione dello storytelling. La logica della pratica dietro alla logica della rappresentazione nella comunicazione organizzativa.

Il presente studio vuole descrivere come la logica della pratica e la logica della teoria interagiscano per arrivare a definire la logica della rappresentazione. L\u2019opportunit\ue0 per descrivere questa relazione, viene dalla pratica dello storytelling. Lo storytelling in quanto tale non \ue8, quindi, il focus di questo lavoro, ma ne rappresenta una cornice, una sorta di contestualizzazione. Questo lavoro mira piuttosto ad illustrare come le rappresentazioni narrative siano costruite nella pratica. Empiricamente, questo elaborato \ue8 il frutto di tre anni di lavoro e di osservazione all\u2019interno di un contesto organizzativo. Perci\uf2, esso vuole prima fornire una riflessione e un\u2019analisi della particolare condizione all\u2019interno del sito studiato, che \ue8 definita facendo riferimento al concetto di liminalit\ue0 (Czarniawska e Mazza, 2013). In effetti, questa condizione ha determinato e influenzato la conduzione e l\u2019oggetto finale di questo lavoro di ricerca e non pu\uf2, pertanto, non essere presa in considerazione nella descrizione dei fenomeni osservati. Questo elaborato prende in considerazione le rappresentazioni narrative dell\u2019organizzazione studiata e ne descrive il processo di costruzione. In questo modo, vuole pervenire alla costruzione di una teoria locale valida per il contesto specifico (Czarniawska, 2001). In particolare, questo lavoro vuole dunque essere uno studio praxiografico (Mol, 2002): partendo dai prodotti del lavoro in impresa e, attraverso un\u2019analisi fondata sull\u2019osservazione, l\u2019auto-osservazione e l\u2019osservazione retrospettiva, ricostruisce i processi organizzativi che sono stati necessari alla loro realizzazione prima, e alla loro diffusione poi. Avendo svolto tali attivit\ue0 di comunicazione partecipando al lavoro in due contesti estremamente diversi appartenenti alla stessa organizzazione, l\u2019ufficio comunicazione e quello di ricerca per l\u2019innovazione, in questo lavoro sono contemplati e messi a confronto diversi tipi di rappresentazioni e diversi processi di costruzione delle narrazioni. Questo elaborato presenta quattro delle narrazioni sviluppate nei due diversi contesti e ne ricostruisce i processi di costruzione e di diffusione. La scelta \ue8 ricaduta sulle rappresentazioni narrative che potessero essere pi\uf9 significative, sia da un punto di vista dei temi descritti e rappresentati, sia per l\u2019importanza rivestita dalle stesse all\u2019interno del contesto organizzativo di riferimento. L\u2019elaborato procede poi tracciando un modello che sintetizzi e includa gli step attraverso cui si perviene alla costruzione di una rappresentazione narrativa nel sito di studio. Si tratta quindi di un modello e dunque di una generalizzazione, ma che ha valenza locale, perch\ue9 appunto relativo al mio "sito". Da questo modello, in seconda istanza, emergono dei temi e delle riflessioni di portata pi\uf9 ampia, che acquistano valore alla luce del confronto con la letteratura e le pratiche osservate

The functional role of dreaming in emotional processes

Dream experience (DE) represents a fascinating condition linked to emotional processes and the human inner world. Although the overlap between REM sleep and dreaming has been overcome, several studies point out that emotional and perceptually vivid contents are more frequent when reported upon awakenings from this sleep stage. Actually, it is well-known that REM sleep plays a pivotal role in the processing of salient and emotional waking-life experiences, strongly contributing to the emotional memory consolidation. In this vein, we highlighted that, to some extent, neuroimaging studies showed that the processes that regulate dreaming and emotional salience in sleep mentation share similar neural substrates of those controlling emotions during wakefulness. Furthermore, the research on EEG correlates of the presence/absence of DE and the results on EEG pattern related to the incorporated memories converged to assign a crucial role of REM theta oscillations in emotional re-processing. In particular, the theta activity is involved in memory processes during REM sleep as well as during the waking state, in line with the continuity hypothesis. Also, the gamma activity seems to be related to emotional processes and dream recall as well as to lucid dreams. Interestingly, similar EEG correlates of DE have been found in clinical samples when nightmares or dreams occur. Research on clinical samples revealed that promoting the rehearsal of frightening contents aimed to change them is a promising method to treat nightmares, and that lucid dreams are associated with an attenuation of nightmares. In this view, DE can defuse emotional traumatic memories when the emotional regulation and the fear extinction mechanisms are compromised by traumatic and frightening events. Finally, dreams could represent a sort of simulation of reality, providing the possibility to create a new scenario with emotional mastery elements to cope with dysphoric items included in nightmares. In addition, it could be hypothesized that the insertion of bizarre items besides traumatic memories might be functional to “impoverish” the negative charge of the experiences

Oscillatory EEG activity during REM sleep in elderly people predicts subsequent dream recall after awakenings

Several findings underlined that the electrophysiological (EEG) background of the last segment of sleep before awakenings may predict the presence/absence of dream recall (DR) in young subjects. However, little is known about the EEG correlates of DR in elderly people. Only an investigation found differences between recall and non-recall conditions during NREM sleep EEG in older adults, while—surprisingly—no EEG predictor of DR was found for what concerns REMsleep. Considering REMsleep as a privileged scenario to produce mental sleep activity related to cognitive processes, our study aimed to investigate whether specific EEG topography and frequency changes during REM sleep in elderly people may predict a subsequent recall of mental sleep activity. Twenty-one healthy older volunteers (mean age 69.2 ± 6.07 SD) and 20 young adults (mean age 23.4 ± 2.76 SD) were recorded for one night from19 scalp derivations. Dreams were collected upon morning awakenings from REM sleep. EEG signals of the last 5min were analyzed by the Better OSCillation algorithm to detect the peaks of oscillatory activity in both groups. Statistical comparisons revealed that older as well as young individuals recall their dream experience when the last segment of REM sleep is characterized by frontal theta oscillations. No Recall (Recall vs. Non-Recall) × Age (Young vs. Older) interaction was found. This result replicated the previous evidence in healthy young subjects, as shown in within- and between-subjects design. The findings are completely original for older individuals, demonstrating that theta oscillations are crucial for the retrieval of dreaming also in this population. Furthermore, our results did not confirm a greater presence of the theta activity in healthy aging. Conversely, we found a greater amount of rhythmic theta and alpha activity in young than older participants. It is worth noting that the theta oscillations detected are related to cognitive functioning. We emphasize the notion that the oscillatory theta activity should be distinguished from the non-rhythmic theta activity identified in relation to other phenomena such as (a) sleepiness and hypoarousal conditions during the waking state and (b) cortical slowing, considered as an EEG alteration in clinical samples

The spatiotemporal pattern of the human electroencephalogram at sleep onset after a period of prolonged wakefulness

During the sleep onset (SO) process, the human electroencephalogram (EEG) is characterized by an orchestrated pattern of spatiotemporal changes. Sleep deprivation (SD) strongly affects both wake and sleep EEG, but a description of the topographical EEG power spectra and oscillatory activity during the wake-sleep transition after a period of prolonged wakefulness is still missing. The increased homeostatic sleep pressure should induce an earlier onset of sleep-related EEG oscillations. The aim of the present study was to assess the spatiotemporal EEG pattern at SO following SD. A dataset of a previous study was analyzed. We assessed the spatiotemporal EEG changes (19 cortical derivations) during the SO (5 min before vs. 5 min after the first epoch of Stage 2) of a recovery night after 40 h of SD in 39 healthy subjects, analyzing the EEG power spectra (fast Fourier transform) and the oscillatory activity [better oscillation (BOSC) detection method]. The spatiotemporal pattern of the EEG power spectra mostly confirmed the changes previously observed during the wake-sleep transition at baseline. The comparison between baseline and recovery showed a wide increase of the post- vs. pre-SO ratio during the recovery night in the frequency bins 10 Hz. We found a predominant alpha oscillatory rhythm in the pre-SO period, while after SO the theta oscillatory activity was prevalent. The oscillatory peaks showed a generalized increase in all frequency bands from delta to sigma with different predominance, while beta activity increased only in the fronto-central midline derivations. Overall, the analysis of the EEG power replicated the topographical pattern observed during a baseline night of sleep but with a stronger intensity of the SO-induced changes in the frequencies 10 Hz, and the detection of the rhythmic activity showed the rise of several oscillations at SO after SD that was not observed during the wake-sleep transition at baseline (e.g., alpha and frontal theta in correspondence of their frequency peaks). Beyond confirming the local nature of the EEG pattern at SO, our results show that SD has an impact on the spatiotemporal modulation of cortical activity during the falling-asleep process, inducing the earlier emergence of sleep-related EEG oscillations

Electrophysiological correlates of dream recall during REM sleep: evidence from multiple awakenings and within-subjects design

Purpose: In the current study, we aimed to investigate the EEG correlates of dream recall (DR) monitoring both the homeostatic and state-trait like factors. We assessed the influence of the time of night on the EEG correlates of DR from REM sleep. Specifically, we tested the continuity-hypothesis (on the theta EEG band) and the activation-hypothesis (on the delta and beta bands). Methods: Twenty-seven subjects underwent polysomnography with multiple provoked awakenings during REM sleep. Only the subjects showing combinations of dream recall (REC) and non-REC (NREC) conditions in both first (1st– 2nd sleep cycle) and second (3rd– 4th sleep cycle) part of the night were included in the analyses. The final sample was composed of 10 subjects (mean age 24± 0.70). EEG power spectra of the 5-min of REM sleep preceding each awakening were computed by a fast Fourier transform. The following frequency bands were considered: delta (0.50– 4.75 Hz), theta (5.00– 7.75 Hz), and beta (16.00– 24.75 Hz). We also calculated the delta/beta power ratio as an integrated EEG index of activation. Results: The 2× 2 within-subjects ANOVA recall × time revealed: a) no significant effect for time and no interaction; b) significant differences over the occipital area in the beta band; c) significant differences over the parietal area for the activation index values. Overall, the results indicated that DR is associated with higher activation regardless of homeostatic pressure across the night of sleep. Conclusion: In line with recent findings, we have shown that DR is predicted by desynchronized EEG activity during REM sleep, providing clear evidence in favor of the activation-hypothesis. We have also confirmed that the EEG pattern of DR can be ascribed to state-like factors. Further studies should assess whether homeostatic modulation may interact with some dream features and the related EEG predictors

Dorsomorphin reverses the mesenchymal phenotype of breast cancer initiating cells by inhibition of bone morphogenetic protein signaling

Increasing evidence supports the theory that tumor growth, homeostasis, and recurrence are dependent on a small subset of cells with stem cell properties, redefined cancer initiating cells (CICs) or cancer stem cells. Bone morphogenetic proteins (BMPs) are involved in cell-fate specification during embryogenesis, in the maintenance of developmental potency in adult stem cells and may contribute to sustain CIC populations in breast carcinoma. Using the mouse A17 cell model previously related to mesenchymal cancer stem cells and displaying properties of CICs, we investigated the role of BMPs in the control of breast cancer cell plasticity. We showed that an autocrine activation of BMP signaling is crucial for the maintenance of mesenchymal stem cell phenotype and tumorigenic potential of A17 cells. Pharmacological inhibition of BMP signaling cascade by Dorsomorphin resulted in the acquisition of epithelial-like traits by A17 cells, including expression of Citokeratin-18 and E-cadherin, through downregulation of Snail and Slug transcriptional factors and Cyclooxygenase-2 (COX2) expression, and in the loss of their stem-features and self-renewal ability. This phenotypic switch compromised A17 cell motility, invasiveness and in vitro tumor growth. These results reveal that BMPs are key molecules at the crossroad between stemness and cancer

La valutazione della sonnolenza e delle abilita’ di guida nella terza eta’

L’eccessiva sonnolenza diurna (EDS) è una condizione patologica che interferisce con le attività quotidiane, causando un calo dei livelli di vigilanza che incide sulle capacità di concentrazione e di valutazione del tempo di reazione al pericolo. Tali aspetti sono particolarmente rilevanti nella valutazione delle performance di guida, che richiedono l’integrità di varie funzioni cognitive, fra cui le capacità attentive, percettive di valutazione del rischio nel traffico. Il normale invecchiamento fisiologico determina un aumento dei livelli di sonnolenza diurna, contestualmente a una frammentazione del sonno che diventa meno profondo e più frammentato. Al riguardo, alcuni studi hanno rilevato nelle persone anziane una prevalenza di EDS e una maggior vulnerabilità al rischio di incidenti stradali. Tuttavia, i dati relativi alle conseguenze di questi aspetti sulla quotidianità non sono stati sufficientemente indagati e i risultati disponibili non consentono di raccogliere informazioni esaustive. Peraltro, risulta mancante una validazione delle misure della sonnolenza nell’anziano sano alla guida. Lo studio si propone, quindi, di indagare la relazione tra qualità del sonno, sonnolenza diurna e performance di guida nella terza età. Metodo: 40 soggetti anziani (età 58-80) e 40 giovani (età 20-35) abilitati alla guida hanno effettuato una valutazione con i seguenti strumenti: Psychomotor Vigilance Task-PVT per la sonnolenza oggettiva comportamentale; Karolinska Sleepiness Scale-KSS ed Epworth Sleepiness Scale-ESS per la sonnolenza soggettiva; Pittsburgh Sleep Quality Index-PSQI per la qualità del sonno percepita; Cognitrone-COG/S11, Adaptive Tachistoscopic Traffic Perception Test-ATAVT e Vienna Risk-Taking Test Traffic-WRBTV (test della batteria Vienna Test System TRAFFIC) per la valutazione dell’attenzione selettiva alla guida, della percezione tachistoscopica e dell’assunzione del rischio nel traffico. Risultati e Conclusioni: Il confronto statistico effettuato per mezzo di un’ANOVA 2x2 between subjects (Età x Genere) ha mostrato: (1) una minor efficienza del sonno negli anziani rispetto ai giovani e delle tendenze a commettere un maggior numero di errori al PVT, con rallentamenti nel segmento dei tempi di reazione più rapidi; (2) un inatteso risultato relativo a maggior sonnolenza di stato da parte dei giovani; (3) delle robuste differenze legate all’età per quanto riguarda le variabili di guida, mostrando tempi di lavoro più lunghi, scarse performance attentive e percettive ma maggior prudenza nell’assunzione del rischio da parte degli anziani rispetto ai giovani. Un approccio previsionale condotto per mezzo di regressioni multiple ha dimostrato che fra le misure di qualità del sonno e sonnolenza soggettiva considerate, solamente il PSQI risulta in grado di predire la prestazione comportamentale al PVT. Infine, l’indagine condotta per mezzo di regressioni multiple, in merito alla predittività del comportamento di guida -da parte delle variabili relative ad età, qualità del sonno e sonnolenza comportamentale e soggettiva- ha mostrato, in primo luogo, un robusto valore predittivo dal parte dell’età mentre, in secondo luogo, è emersa una tendenza da parte del KSS e del PVT nel predire la prestazione rispetto ai tempi totali di lavoro e alla rapidità con cui vengono rifiutati gli stimoli distrattori nel compito di attenzione selettiva alla guida. I dati in merito a una minor efficienza del sonno nell’anziano risulterebbero coerenti con la letteratura di riferimento, sebbene tale aspetto non si rifletta in chiare differenze nelle performance al PVT. Al contrario, i giovani riportano maggior sonnolenza soggettiva di stato: tale inatteso risultato necessita di ulteriori chiarimenti e potrebbe rendere conto dell’assenza di specifiche differenziazioni prestazionali rispetto agli anziani. Infatti, rappresentando un limite intrinseco allo studio, potrebbe indebolire la successiva logica previsionale, volta specialmente all’individuazione della capacità del set delle misure soggettive e oggettive del sonno e della sonnolenza di predire le prestazioni nel comportamento di guida. D’altra parte, dagli approcci previsionali considerati a tale scopo, emerge il fattore età come unico e robusto predittore, mentre viene rilevata solo una tendenza da parte delle misure soggettive e oggettive della sonnolenza di prevedere la prestazione nei compiti di attenzione selettiva alla guida, confermando solo in maniera parziale le ipotesi di partenza

Approccio neurobiologico allo studio del sonno

Il capitolo presenta una completa e estesa panoramica degli studi sugli aspetti neurobiollogici dell'esperienza oniric