Reviews evidence which suggests that there may be little or no direct introspective access to higher order cognitive processes. Ss are sometimes unaware of the existence of a stimulus that importantly influenced a response, unaware of the existence of the response, and unaware that the stimulus has affected the response. It is proposed that when people attempt to report on their cognitive processes, that is, on the processes mediating the effects of a stimulus on a response, they do not do (...) so on the basis of any true introspection. Instead, their reports are based on a priori, implicit causal theories, or judgments about the extent to which a particular stimulus is a plausible cause of a given response. This suggests that though people may not be able to observe directly their cognitive processes, they will sometimes be able to report accurately about them. Accurate reports will occur when influential stimuli are salient and are plausible causes of the responses they produce, and will not occur when stimuli are not salient or are not plausible causes. (shrink)

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. Key Words: consciousness; dreaming; neuroimaging; neuromodulation; NREM; phenomenology; qualia; REM; sleep. (shrink)

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. Key Words: consciousness; dreaming; neuroimaging; neuromodulation; NREM; phenomenology; qualia; REM; sleep. (shrink)

Metacognition refers to any knowledge or cognitive process that monitors or controls cognition. We highlight similarities between metacognitive and executive control functions, and ask how these processes might be implemented in the human brain. A review of brain imaging studies reveals a circuitry of attentional networks involved in these control processes, with its source located in midfrontal areas. These areas are active during conflict resolution, error correction, and emotional regulation. A developmental approach to the organization of the anatomy involved in (...) executive control provides an added perspective on how these mechanisms are influenced by maturation and learning, and how they relate to metacognitive activity. (shrink)

Empirical studies largely support the continuity hypothesis of dreaming. Despite of previous research efforts, the exact formulation of the continuity hypothesis remains vague. The present paper focuses on two aspects: the differential incorporation rate of different waking-life activities and the magnitude of which interindividual differences in waking-life activities are reflected in corresponding differences in dream content. Using a correlational design, a positive, non-zero correlation coefficient will support the continuity hypothesis. Although many researchers stress the importance of emotional involvement on the (...) incorporation rate of waking-life experiences into dreams, Hartmann formulated the hypothesis that highly focused cognitive processes such as reading, writing, etc. are rarely found in dreams due to the cholinergic activation of the brain during dreaming. The present findings based on dream diaries and the exact measurement of waking activities replicated two recent questionnaire studies. These findings indicate that it will be necessary to specify the continuity hypothesis more fully and include factors which modulate the incorporation rate of waking-life experiences into dreams. Whether the cholinergic state of the brain during REM sleep or other alterations of brain physiology are the underlying factors of the rare occurrence of highly focused cognitive processes in dreaming remains an open question. Although continuity between waking life and dreaming has been demonstrated, i.e., interindividual differences in the amount of time spent with specific waking-life activities are reflected in dream content, methodological issues have limited the capacity for detecting substantial relationships in all areas. Nevertheless, it might be concluded that the continuity hypothesis in its present general form is not valid and should be elaborated and tested in a more specific way. (shrink)

Evidence of reflective awareness and metacognitive monitoring during REM sleep dreaming poses a significant challenge to the commonly held view of dream cognition as necessarily deficient relative to waking cognition. To date, dream metacognition has not received the theoretical or experimental attention it deserves. As a result, discussions of dream cognition have been underrepresented in theoretical accounts of consciousness. This paper argues for using a converging measures approach to investigate the range and limits of cognition and metacognition across the sleep–wakefulness (...) cycle. The paradigm developed by LaBerge and his colleagues to study "lucid-control" dreaming offers one such framework for relating phenomenological, cognitive, and physiological measures. In a lucid-control dream, the dreamer is both aware that the experimental context is a dream and has the ability to intentionally regulate aspects of the dream . Subjects can make patterns of deliberate eye movements to signal from the dream and thus index significant events such as the time of lucidity onset and the completion of previously agreed-upon tasks in the dream. Lucid dreaming and other examples of reflective awareness during dreaming have important implications for models of human cognition. The existence of these phenomena raises fundamental questions about current assumptions regarding "state" constraints on consciousness and cognition. (shrink)