A technique for the bilateral activation of neural nets that leads to a functional asymmetry of two simulated "cerebral hemispheres" is described. The simulation is designed to perform object recognition, while exhibiting characteristics typical of human consciousness-specifically, the unitary nature of conscious attention, together with a dual awareness corresponding to the "nucleus" and...
Even though various investigations found a preponderance of negative emotions in dreams, the conclusion that human dream life is, in general, negatively toned is limited by several methodological issues. The present study made use of three different approaches to measure dream emotions: dream intensity rated by the dreamer, intensity rated by a judge, and scoring of explicitly mentioned...
This paper offers a framework for consciousness of internal reality. Recent PET experiments are reviewed, showing partial overlap of cortical activation during self-produced actions and actions observed from other people. This overlap suggests that representations for actions may be shared by several individuals, a situation which creates a potential problem for correctly attributing an action...
An exploration is given of neural network features now being uncovered in cortical processing which begins to go a little way to help bridge the "Explanatory Gap" between phenomenal consciousness and correlated brain activity. A survey of properties suggested as being possessed by phenomenal consciousness leads to a set of criteria to be required of the correlated neural activity. Various...
J. G. Taylor advances an empirically testable local neural network model to understand the neural correlates of phenomenal experience. Taylor's model is better able to explain the presence (i.e., persistence, latency, and seamlessness) and unity of phenomenal consciousness which support the idea that consciousness is coherent, undivided, and centered. However, Taylor fails to offer a...
The nature and time course of sleep onset (hypnagogic) mentation was studied in the home environment using the Nightcap, a reliable, cost-effective, and relatively noninvasive sleep monitor. The Nightcap, linked to a personal computer, reliably identified sleep onset according to changes in perceived sleepiness and the appearance of hypnagogic dream features. Awakenings were performed by the...
Excitation at widely dispersed loci in the cerebral cortex may represent a neural correlate of consciousness. Accordingly, each unique combination of excited neurons would determine the content of a conscious moment. This conceptualization would be strengthened if we could identify what orchestrates the various combinations of excited neurons. In the present paper, cholinergic afferents to the...
Thirty-eight "practiced" dreamers (Study 1) and 50 "novice" dreamers (Study 2) completed questionnaires assessing the cognitive, metacognitive, and emotional qualities of recent waking and dreaming experiences. The present findings suggest that dreaming cognition is more similar to waking cognition than previously assumed and that the differences between dreaming and waking cognition are more...
It is argued that theoretical models cannot use qualia as explanatory tools, and cannot explain them either; thus, there is no way to make qualia do any useful work at all, at least in a theory. However, qualia do occur in both imagery and perception, and this article presents some ways of thinking about qualia from a functional perspective. Imagery differs from perception in its function. It...
Experiences of qualia, subjective sensory-like aspects of stimuli, are central to imagistic representation. Following Raffman (1993), qualia are considered to reflect experiential knowledge distinct from descriptive, abstract, and propositional knowledge; following Jackendoff (1987), objective neural activity is distinguished from subjective experience. It is argued that descriptive physical...
Claparède's report of a case of amnesic syndrome is an early example of the cognitive neuropsychology paradigm, by which studies of brain-damaged patients are used to shed light on the nature of normal mental processes. The case illustrates the selective impairment of episodic memory, with procedural and semantic memory remaining intact. Moreover, the several demonstrations of preserved...
Subjective consciousness suggests a unity of the sensing and perceiving self that is difficult to reconcile with the multiplicity of sensory analyzers and the absence of a convergence zone in the brain. This has led--on the one hand--to the dead-end assumption of a unifying sentient homunculus and--on the other--to a denial of conscious unity. The sketchpad model presented here avoids this...
As part of his rediscovery of consciousness, Searle has recently provided an interpretation of Freud's account of consciousness, including the relation of consciousness to nonconscious mental occurrences [i.e., preconscious mental occurrences and unconscious (repressed) mental occurrences]. Regrettably, Searle's interpretation is based on a single paragraph from The Unconscious and serves to...
Since the discovery that the characteristics of dreaming sleep are far stronger in Stage 1 rapid eye movement (REM) sleep than in any other biological state, investigators have attempted to determine the relative responsibility of the tonic versus the phasic properties of REM sleep for the different characteristics of dreaming--features such as the amount of information in the dream report, the...
A tacit assumption since the 19th Century has been that the neocortex serves as the "seat of consciousness." An unexpected challenge to that assumption arose in 1949 with the discovery that high-frequency EEG activation associated with an alert state requires the intactness of the brainstem reticular formation. This discovery became the impetus for nearly three decades of research on what came...
The evidence can therefore be summarized as follows: (1) RF, nRt, and ILN activity seem to be necessary but not sufficient for conscious experience. (2) Stimulus representation in primary sensory projection areas also seems to be necessary but not sufficient for conscious perceptual experience (Weiskrantz, 1980). The simplest hypothesis is that both components are necessary and sufficient to...
The main idea in this series of essays is that subjective awareness (more precisely, what I call C) depends upon the intralaminar nuclei of each thalamus (hereafter, ILN). This implies that the internal structure and external relations of ILN make subjective awareness possible. An array of material relevant to this proposal was briefly reviewed in Part I (Bogen, 1995). This Part II considers in...
How certain neural mechanisms (Mc) momentarily endow with subjective awareness (C) percepts and affects represented elsewhere is more likely to be clarified when structures essential to Mc are identified. The loss of C with bilateral thalamic lesions involving the intralaminar nuclei (ILN) contrasts with retention of C after large cortical ablations depriving C of specific contents. A role of...