Consciousness and Cognition
December 1, 2004
A strategy for identifying neural correlates of consciousness is proposed, based on a state space approach from dynamical systems theory. The article focuses on phenomenal awareness, a constituent of consciousness, and suggests several rudimentary requirements for identifying its neural correlates. These requirements are related to empirical data on selective attention, completely intrinsic selection, and globally unconscious states. As an example, neuroscientific findings on synchronized gamma activity are categorized according to these requirements, illustrating how the strategy might be applied.
Consciousness and Cognition
September 1, 2004
Dennis J L G Schutter, Jack Van Honk
Consciousness is thought to involve temporary connections in thalamo-cortico-cortical networks, with connectivity levels determining conscious state. This study investigated whether emotional compared to neutral facial expressions, presented either unconsciously (masked) or consciously (unmasked), would differently modulate EEG coherence—a measure of neural connectivity. EEG coherence was measured between frontal, parietal, and midline scalp sites. Objective checks confirmed that masked expressions were not consciously identified. Results showed reductions in EEG coherence in the lower frequency range for masked versus unmasked neutral expressions. Crucially, this decline did not occur for emotional expressions. The level of EEG coherence varied with awareness, but not when emotion was involved, suggesting that unconscious emotional processes modulate EEG coherence, extending views on the global workspace architecture of consciousness.
Consciousness and Cognition
March 1, 2003
Josef Perner, Zoltan Dienes
Children likely become consciously aware of events in the world between 12 and 15 months of age, with a possible range of plus or minus 3 months. This conclusion emerges from evaluating five strategies: three look for signs of verbal communication, executive control, or explicit memory—activities that require conscious awareness in adults; two consider when children can engage in the minimal higher-order thought needed for access consciousness and phenomenal consciousness. The answer is tentative, based on converging evidence from these different approaches.
Consciousness and Cognition
June 1, 2002
Wim Van de Grind
The debate over Benjamin Libet's findings on the timing of conscious experiences reflects deeper assumptions about how the nervous system handles time. The nervous system recombines and recodes sensory messages; ignoring these processes can lead to theories requiring subjective back-referral. Many neuroscientists assume a neural correlate of consciousness (NCC) that compares activity patterns only if they arrive simultaneously, prompting searches for synchrony or latency compensation. Alternatively, symbolic representations of time and space could be encoded as tags multiplexed with sensory qualities. The hidden issue is whether the NCC is uniquely smart—solving timing and location problems on its own—or whether such information is coded symbolically early in processing. The author sides with the latter, distributed-smartness view.
Consciousness and Cognition
March 1, 2002
Paul Skokowski
Some philosophical theories claim that zombies—beings identical to humans in every physical respect but lacking conscious experience—are possible, arguing that qualia (the subjective qualities of experience) are nonphysical properties. This article argues instead that qualia are physical properties. It demonstrates how, through a posteriori identification of qualia with physical properties, a reasoned choice can be made between competing theories, ultimately favoring materialism and rejecting the possibility of zombies.
Consciousness and Cognition
March 1, 2002
David Kahn, Edward F Pace-Schott, J Allan Hobson
Emotions felt during dreams are almost always triggered by the characters that appear, and people frequently use those emotions to identify who the characters are. Affection and joy are commonly linked with known characters, even when those emotional associations contradict how the person feels about the same individual while awake. These patterns align with brain activity differences between dreaming and waking states: the dorsolateral prefrontal cortex, which supports short-term memory, is less active during dreaming, while limbic areas involved in emotion are more active and receive minimal input from the prefrontal cortex.
Consciousness and Cognition
December 1, 2001
M Schredl, A T Funkhouser, C M Cornu et al.
Dream recall and dream length are stable over time, but dream characteristics like bizarreness and emotional tone fluctuate greatly within individuals. Analyzing a series of 20 dreams from healthy elderly persons obtained through weekly telephone interviews, internal consistency and retest reliability after 4 or 22 weeks were computed. To obtain reliable measures of these fluctuating dream variables for correlational studies with waking-life traits, researchers need to collect as many dreams as possible (about 20) within a very short time period. Further research is needed to extend these findings to diary and laboratory dreams.
Consciousness and Cognition
March 1, 2001
P C Cicogna, M Bosinelli
Dreaming involves two aspects of consciousness: awareness and strategic control. Awareness has three types: phenomenal experience of objects/events, meta-awareness (awareness of mental life), and self-awareness (awareness of being oneself). Phenomenal experience and self-awareness are usually present during dreaming, but meta-awareness is typically absent except in lucid dreaming. Strategic control can also occur in dreams. A cognitive model proposes that dreams result from three interacting components: bottom-up activation of memories, top-down interpretative processes, and monitoring of phenomenal experience. A feedback loop among these components generates the dream plot, guided by both unconscious and conscious processes.
Consciousness and Cognition
December 1, 2000
R Lange, M A Thalbourne, J Houran et al.
A revised 17-item Transliminality Scale (RTS) corrects age and gender biases in the original 29-item version, is unidimensional by a Rasch criterion, and has a reliability of 0.82. The scale defines a probabilistic hierarchy of items addressing magical ideation, mystical experience, absorption, hyperaesthesia, manic experience, dream interpretation, and fantasy proneness. These findings validate William James's and Thalbourne's suggestions that some mental phenomena share a common underlying dimension with selected sensory experiences. Low scores correlate with "tough mindedness," "self-control," and "rule consciousness" on the Cattell 16PF test, while high scores associate with "abstractedness" and "openness to change." An independent validation study confirmed predictions implied by the definition of transliminality.
Consciousness and Cognition
June 1, 2000
J Prinz
Visual consciousness depends on mental representations at an intermediate level of processing, a hypothesis supported by neuropsychological evidence. Attention, which can be guided by high-level representations, is also necessary for consciousness. This theory challenges higher-order thought accounts, the multiple drafts account, and the belief that sensation precedes perception. It also illustrates a methodology that bridges functionalist approaches that ignore the brain and neural reductionists who reject functionalism.
Consciousness and Cognition
June 1, 2000
D M Rosenthal
Metacognition, or having mental access to one's own cognitive states, and consciousness are closely linked. The ability to access information from non-conscious mental states supports the theory that a mental state becomes conscious when we have a noninferential higher-order thought about it. This higher-order-thought hypothesis explains why confabulatory mental states—states that do not actually occur—can appear to consciousness. This account aligns with and refines the 'No-Magic Hypothesis' proposed by Nelson and Narens in 1990.
Consciousness and Cognition
September 1, 1999
J A Cheyne, S D Rueffer, I R Newby-Clark
Sleep paralysis often involves vivid hypnagogic and hypnopompic experiences (HHEs) that closely resemble supernatural assault narratives across cultures. A three-factor structural model explains these experiences through REM neurophysiology. The Intruder factor involves sensed presence, fear, and hallucinations from midbrain hypervigilance. The Incubus factor includes chest pressure and breathing difficulties from motoneuron hyperpolarization affecting respiration perception. Both imply an alien 'other' consistent with occult narratives. The Unusual Bodily Experiences factor involves floating, out-of-body sensations, and bliss from conflicts between endogenous and exogenous activation related to body position. These findings connect to hallucinations in hypnosis and schizophrenia.
Consciousness and Cognition
September 1, 1999
S Franklin, A Graesser
A software agent called Conscious Mattie (CMattie) implements Baars' global workspace theory of consciousness. CMattie operates within a UNIX system in a clerical domain, sending and interpreting natural-language messages to organize university seminars. The implementation integrates contemporary cognitive science and artificial intelligence architectures to create a detailed computational model. The article discusses how CMattie's design accounts for the psychological facts that Baars argues any complete theory of consciousness must explain, and evaluates the extent to which it successfully implements global workspace theory.
Consciousness and Cognition
September 1, 1995
J Antrobus, T Kondo, R Reinsel et al.
Dreaming is more intense during REM sleep than other sleep stages, but it remains unclear whether the brief, phasic events of REM or its sustained, tonic background activation are responsible for features like visual vividness, narrative shifts, and incongruities. This experiment sampled reports of imagery and thought during spontaneous variations within the REM-NREM cycle and across the 24-hour diurnal rhythm, manipulating sleep and wake times to separate their effects. Results suggest that the main driver of vivid visual imagery and enhanced cognitive activity during sleep is a pattern of subcortical and cortical activation common to both the REM phase and the activated (waking) phase of the diurnal cycle.