Electrophysiological pattern of dream experience

Dreaming is a common human experience investigated from multiple perspectives over the centuries. Recently, this phenomenon has stimulated scientific interest, becoming a peculiar context to study memory processes and consciousne

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

The efficacy of transcranial current stimulation techniques to modulate resting-state EEG, to affect vigilance and to promote sleepiness

Transcranial Current Stimulations (tCSs) are non-invasive brain stimulation techniques which modulate cortical excitability and spontaneous brain activity by the application of weak electric currents through the scalp, in a safe, economic, and well-tolerated manner. The direction of the cortical effects mainly depend on the polarity and the waveform of the applied current. The aim of the present work is to provide a broad overview of recent studies in which tCS has been applied to modulate sleepiness, sleep, and vigilance, evaluating the efficacy of different stimulation techniques and protocols. In recent years, there has been renewed interest in these stimulations and their ability to affect arousal and sleep dynamics. Furthermore, we critically review works that, by means of stimulating sleep/vigilance patterns, in the sense of enhancing or disrupting them, intended to ameliorate several clinical conditions. The examined literature shows the efficacy of tCSs in modulating sleep and arousal pattern, likely acting on the top-down pathway of sleep regulation. Finally, we discuss the potential application in clinical settings of this neuromodulatory technique as a therapeutic tool for pathological conditions characterized by alterations in sleep and arousal domains and for sleep disorders per se

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

Olive oils protected by the EU geographical indications: creation and distribution of the value-adding within supply chains

The world olive oil market is characterized by a growing price competition on the supply side. Economy of scales and low production costs from both traditional and more recent producing Countries determine an increasing pressure on European Union (EU) olive farmers that suffer lower revenues. Product differentiation, driven by higher quality and consumer expectations, is one of the most powerful competitive strategies that EU farmers may adopt to face this challenge. Geographical indications established by the EU (PDO and PGI) can be successful marketing levers to ensure olive oil differentiation based on high quality standards and geographical origin of production. These EU quality certification schemes were designed to respond to consumer demand, to ensure intellectual property protection for the most qualifying products, and to provide farmers with a fair share of the added value. There is a wide literature about the PDOs’ economic and social impacts, but only few studies analyze their benefits and costs along the supply chain. By investigating the added value generation process within an Italian PDO olive-oil supply chain (“Terra di Bari” PDO), this work aims to evaluate the effectiveness of PDO certification schemes in improving farm’s profitability. The study was performed directly interviewing a sample of the most representative farmers, manufacturers and stakeholders of the PDO olive oil supply chain localized in the Province of Bari (Puglia, Italy).olive oil, protected designation of origin, supply chain, value-chain., Agricultural and Food Policy,

Sleep in the aging brain

We have entered an era of a steep increase in the absolute and relative number of older people. This well-come phenomenon represents a major challenge for health care. However, maturational changes in sleep associated with aging do not easily appear as main factors, even though sleep alterations in the aging process lead to many detrimental consequences. In this editorial paper, we summarize the present knowledge about the main aging-related sleep modifications and their relevance for health problems and cognitive decline. Then, we present the papers published in the Special Issue “Disturbances of Sleep Among Older People”

THE EFFECTS OF THE CAP REFORM PROCESS ON ITALIAN OLIVE TREE FARMING

The decoupling process of direct payments is affecting the Italian olive oil sector’s economic structure and competitiveness. The implementation of the SPS regional model, as proposed by European Commission with the Health check proposals, might further affect this sector and treat the survival of the olive-growing farms in marginal areas. This work aims to analyse the effects of the ongoing CAP reform process on olive growers’ behaviour and economic performance in southern Italy. In particular, the object area is the Apulia region that is one of the most important in Italy. To analyse the economic impact of CAP reform on olive growers, we adopt a simulation scheme of the farm economic balance based on the definition and characterization of Representative Olive-growing Farms (ROFs) that are able to represent regional olive sector. The analysis shows a general income reduction for the olive-growing farms, which is higher in the so-called “complete approximation of entitlements” scenario and for the medium-size holdings.decoupling, CAP reform, olive tree farming, Representative Olive-growing Farms, economic performance., Agricultural and Food Policy, Q18,

Insights from human sleep research on neural mechanisms of Alzheimer’s disease

The current research in the field of sleep and AD is increasing in importance, denoting a possible innovative future in terms of non-invasive and early interventions and prevention strategies. The above-mentioned results on sleep electroencephalogram in relation with AD have to be considered as preliminary reports, because other confirmations are needed. Future researches should propose complex and integrated experimental protocols, in order to provide concurrent electrophysiological, behavioral, anatomical and neuropsychological data. At this purpose, longitudinal studies that follow the entire course of the pathology, since the preclinical stage of the disease are needed. Further investigations on the role of specific NREM sleep components are also required, with the aim of confirming the original and promising existing evidence

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

Enhancing human cognition with cocoa flavonoids

Enhancing cognitive abilities has become a fascinating scientific challenge, recently driven by the interest in preventing age-related cognitive decline and sustaining normal cogni-tive performance in response to cognitively demanding environments. In recent years, cocoa and cocoa-derived products, as a rich source of flavonoids, mainly the flavanols sub-class, have been clearly shown to exert cardiovascular benefits. More recently, neuromodulation and neuroprotective actions have been also suggested. Here, we dis-cuss human studies specifically aimed at investigating the effects of acute and chronic administration of cocoa flavanols on different cognitive domains, such as executive func-tions, attention and memory. Through a variety of direct and indirect biological actions, in part still speculative, cocoa and cocoa-derived food have been suggested to possess the potential to counteract cognitive decline and sustain cognitive abilities, particularly among patients at risk. Although still at a preliminary stage, research investigating the relations between cocoa and cognition shows dose-dependent improvements in general cognition, attention, processing speed, and working memory. Moreover, cocoa flavanols administration could also enhance normal cognitive functioning and exert a protective role on cognitive performance and cardiovascular function specifically impaired by sleep loss, in healthy subjects. Together, these findings converge at pointing to cocoa as a new interesting nutraceutical tool to protect human cognition and counteract different types of cognitive decline, thus encouraging further investigations. Future research should include complex experimental designs combining neuroimaging techniques with physiological and behavioral measures to better elucidate cocoa neuromodulatory properties and directly compare immediate versus long-lasting cognitive effects