Grouping of brain rhythms in corticothalamic systems

The interest in the systematic study of the circadian typology (CT) is relatively recent and has developed rapidly in the two last decades. All the existing data suggest that this individual difference affects our biological and psychological functioning, not only in health, but also in disease. In the present study, we review the current literature concerning the psychometric properties and validity of CT measures as well as individual, environmental and genetic factors that influence the CT. We present a brief overview of the biological markers that are used to define differences between CT groups (sleep-wake cycle, body temperature, cortisol and melatonin), and we assess the implications for CT and adjustment to shiftwork and jet lag. We also review the differences between CT in terms of cognitive abilities, personality traits and the incidence of psychiatric disorders. When necessary, we have emphasized the methodological limitations that exist today and suggested some future avenues of work in order to overcome these. This is a new field of interest to professionals in many different areas (research, labor, academic and clinical), and this review provides a state of the art discussion to allow professionals to integrate chronobiological aspects of human behavior into their daily practice.

Circadian typology: a comprehensive review.

Sleep researchers in different disciplines disagree about how fully dreaming can be explained in terms of brain physiology. Debate has focused on whether REM sleep dreaming is qualitatively different from nonREM (NREM) sleep and waking. A review of psychophysiological studies shows clear quantitative differences between REM and NREM mentation and between REM and waking mentation. Recent neuroimaging and neurophysiological studies also differentiate REM, NREM, and waking in features with phenomenological implications. Both evidence and theory suggest that there are isomorphisms between the phenomenology and the physiology of dreams. We present a three-dimensional model with specific examples from normally and abnormally changing conscious states.

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Dreaming and the brain: toward a cognitive neuroscience of conscious states

The nature and origins of new ideas are examined, focusing particularly on how existing knowledge shapes those ideas and on cognitive processes by which people access and use their knowledge.The paradoxical role of knowledge – of both generating and inhibiting creativity – is discussed in conjunction with a creative cognitive approach, which offers the theoretical background for understanding the thought process. This approach considers creative ideas to be the natural result of applying basic mental functions to existing knowledge structures. The origin of an idea can be determined through a variety of processes accessing knowledge, such as conceptual combination, analogy, and problem formulation. Conceptual combination analysis suggests that when two previously separate concepts or images are combined into a single new unit, new properties can arise that were not present in the separate components.Analogy, or the mapping of knowledge, considered central to creative development in art, science, and literature can also be applied to entrepreneurship.Problem formulation has to do with one's approaches to problem-solving; knowing whether one's goal is more or less new can help to determine the most productive approach. The study cites empirical research on fundamental processes, making suggestions throughout on how to translate this work into entrepreneurial applications.Careful application of a number of various basic processes can put knowledge to an effective use and improve entrepreneurial creativity. (CBS)

Cognition, Creativity, and Entrepreneurship

Cognition, creativity, and entrepreneurship

Morningness-eveningness dimension: is it really a continuum?

Fifty volunteers slept two nonconsecutive nights in a sleep laboratory under electropolygraphic control. They were awakened for one report per night. Awakenings were made, in counterbalanced order, from slow wave sleep (SWS--stage 3-4 and stage 4) and rapid eye movement (REM) sleep. Following dream reporting, subjects were asked to identify memory sources of their dream imagery. Two independent judges reliably rated mentation reports for temporal units and for several content and structural dimensions. The same judges also categorized memory sources as autobiographical episodes, abstract self-references, or semantic knowledge. We found that REM reports were significantly longer than SWS reports. Minor content SWS-REM differences were also detected. Moreover, semantic knowledge was more frequently mentioned as a dream source for REM than for SWS dream reports. These findings are interpreted as supporting the hypothesis that dreaming is a continuous process that is not unique to REM sleep. Different levels of engagement of the cognitive system are responsible for the few SWS-REM differences that have been detected.

Piercarla Cicogna

Papers

Morningness-eveningness dimension: is it really a continuum?

Slow wave sleep dreaming.

Cognitive efficiency and circadian typologies: a diurnal study

Circadian regulation of subjective alertness in morning and evening ‘types’

Consciousness during dreams.