1. Consciousness and Awareness
There is a great number of definitions of consciousness that differ in almost any conceivable aspect, from theoretical background to experimental implications. However, many of them share the assumption that consciousness is affiliated or equated with awareness (Dennett, 1996) . This conception has been supported by European philosophers including Descartes and Locke, but has been developed and promoted mainly by Freud and the psychodynamically oriented school of psychologists (Freud, 1981) .
The supporters of this approach consider consciousness as varying along a perpendicular continuum, in which the upper end is defined as consciousness, representing ordinary consciousness, with its highly valued quality of awareness, enhanced by affiliated terms, such as clarity, logical thinking, reason, control of drives, emotional regulation, realism and volition. The lower end represents unconsciousness, the state in which repressed contents, mostly of sexual or aggressive nature (Freud, 1981) , or archetypal themes (Jung, 1981) are kept. The manifestations of this state are all lumped together under the label of low or minimal awareness. Since the term altered states of consciousness has been coined by Ludwig (1966) and adopted by Tart (1975) , there has been an unclear tendency to refer to the label altered states of consciousness in the plural. But there has been no clear evidence that these are actually states of consciousness that differ from each other in major characteristics.
2. State or States of Consciousness?
A survey of the rich literature concerning states of consciousness readily reveals that the major distinctions drawn among them are in terms of the external stimuli or triggers responsible for their evocation. These may be classified into three major groups: (a) conditions under which the states characteristically occur (e.g., mental disorders, oxygen deprivation, sleep deprivation, fasting, sensory deprivation, accidents involving the brain, high fever, infections, epilepsy); (b) techniques used for inducing particular states (e.g., meditation, hypnosis, shamanistic practices, music, dancing), and (c) chemical or other substances applied as triggers (e.g., psychoactive drugs, alcohol, stimulants, opioids, psychedelics, dissociatives and delirants).
Identifying trigger conditions provides merely a starting point for characterizing the differences between these conditions. There have been several proposals of dimensions for characterizing consciousness phenomena. One of the best known is the continuum from the outer being to the inner being (Gooch, 1972; Lilly, 1972) , which represents the axes of the subjective-objective, the personal- impersonal, the illusory-absolutely true, the material-spiritual, and the temporary-constant. Further examples are the two orthogonal dimensions of irrationality and of the ability to hallucinate (Tart, 1975) and the two dimensions of perception-hallucination and perception-meditation (Fischer, 1978) . The most extensive proposal refers to ten parameters based on empirical data representing interviews, surveys and preliminary psychological investigations (Kreitler, 2009) : Salience and status of the self; sense of control and ability to control; clarity of thought; precision of perception in regard to external reality and environment; precision of perception in regard to internal reality and environment; emotional involvement; arousal; kind of cognitive processes activated; accessibility and inhibition of certain kinds of information (kinds of and amount).
The described variables enable characterizing major experiential aspects of at least some of the states of consciousness (Kreitler, 2009) . These and similar results, for example, about the emotional effects of certain drugs (Aldridge & Fechner, 2006) imply that what has been referred to as “the unconscious” represents in fact a cluster of different states of consciousness. Overlooking the differences among them is unjustified theoretically and empirically. Studying empirically the differences between the states of consciousness requires analyzing manifestations of the different states by means of experimental procedures. In the present context cognition has been chosen as a starting point.
3. Consciousness, Cognition and Meaning
There is a lot of evidence about the close relations of consciousness with cognition. Cognition has been considered as the antecedent condition for consciousness (Mandler, 1984) , as its function (Baars, 1988: chap. 10) , or as a factor contributing to cognitive performance (Hardcastle, 1995; Barber, Spanos, & Chaves, 1974) . On the basis of these approaches it was assumed that it may be possible to change consciousness by changing specific aspects of cognition. Previous studies fully supported this assumption. The findings showed that specific changes in consciousness were attained by cognitive changes affected by manipulating meaning processes. For example, strengthening meanings involved in personal- subjective meaning were related to changes in scores of the Rorschach test in normal and schizophrenic patients (Kreitler, Kreitler, & Wanounou, 1987-1988) . The rationale for these findings was a body of data that showed correspondences between performance in particular cognitive tasks, such as planning or creativity and scores in variables that were identified as reflecting processes constituting meaning assignment, for example, stating the function or structure or sensory features of a stimulus to which meaning is assigned (Kreitler & Casakin, 2009; Kreitler & Kreitler, 1986a; 1990b) . These and other variables used in meaning assignment form part of the system of meaning (Kreitler, 2014) .
On the basis of a large body of data and empirical studies (Kreitler & Kreitler, 1988, 1990a, 1993; Kreitler, 2013b) meaning was defined as a referent-centered pattern of cognitive contents, whereby referent is the input, the carrier of meaning, which can be a word, an object, a situation, an event, or even a whole period, and meaning values are cognitive contents assigned to the referent for the purpose of expressing or communicating its meaning. The referent and the meaning value together form a meaning unit (e.g., computer-serves communication), which is characterized in terms of five sets of meaning variables referring to the contents, structure, and form or expression of the unit components (Table 1 presents the full list of variables). The five sets constitute the system of meaning which may be applied for characterizing stimuli of different kinds, meaning assignment tendencies of individuals (by means of the Meanings Test), and processes involved in cognitive acts and different personality traits and predispositions (Kreitler & Kreitler, 1985, 1986b, 1990a; Kreitler, 2010, 2012, 2013a) .
The role that meaning fulfills in regard to cognition indicates that meaning
Table 1. Major variables of the meaning system: the meaning variables.
Note. The table does not include the meta-meaning variables. aModes of meaning: Lexical mode: TR1+TR2; Personal mode: TR3+TR4; bClose SR: 1 + 3 + 9 + 12 Medium SR: 2 + 4 + 5 + 10 + 11 Distant SR: 6 + 7 + 8 + 13; cThis meaning dimension includes a listing of subcategories of the different senses/sensations: [for special purposes they may also be grouped into “external sensations” and “internal sensations”] e.g., color, form, taste, sound, smell, pain, humidity and various internal sensations.
functions as the infrastructure of cognition, providing the contents and pro- cesses for the performance of cognitive acts and other tasks in which cognition is involved. The close relations between cognition and meaning enable changing the functioning of cognition by changing certain aspects of meaning. The changes of meaning may be limited, as in priming of a specific meaning variable. In other cases they may involve a greater number of meaning variables, which consists in placing specific clusters of meaning variables in focal positions so that they have an organizational primacy and a functional advantage for elicitation and involvement in cognitive activities, while the other meaning variables are in the background in different states of inactivation (Kreitler, 1999, 2001, 2002, 2009; Rotstein, Maimon, & Kreitler, 2013) .
We suggest to consider comprehensive changes in cognition, originating in the meaning system, as equivalent to states of consciousness. Accordingly, consciousness is the state of cognition at any given time defined in terms of the organization of the meaning system at that time, whereas any major changes in the state of cognition, brought about by specific changes in meaning, may be considered as different states of consciousness.
Examples of states of consciousness produced experimentally are states dominated by personal-subjective meaning or by interpersonally-shared meaning. The former consists in placing in focal positions the meaning variables repre- senting personal meaning (based on promoting the exemplifying-illustrative and metaphoric-symbolic types of relation), the latter depends on inducing interpersonally-shared meaning (based on promoting the attributive and comparative types of relation). As compared to the induction of the interpersonally- shared meaning mode, the induction of the personal-subjective mode of meaning resulted in better performance on visual memory tasks, identifying embedded figures, recounting of bizarre experiences, creativity tests assessing fluency, flexibility and originality, and the production of more associations; but worse performance on judging the validity of logical syllogisms and reality testing and emotional control in the Rorschach test (Kreitler, 2013a; Kreitler, Kreitler, & Wanounou, 1987-1988) .
4. Objectives of the Study
The subjects were 82 undergraduates (41 women, 41 men) in the age range of 23 - 31 years who volunteered to participate for credits in the course of their study.
The two procedures were identical in the number and kinds of meaning variables that were promoted but differed in the specific meaning variables. The training procedures were presented on tablets or paper (depending on the subject’s choice) and lasted 18 - 20 minutes. The training of each variable consisted of three sequential phases. The first phase was devoted to extending the range of values exemplifying the meaning variable by examples from different domains, partly presented as examples, and partly requiring the subject to select the right ones out of presented lists (e.g., for Size and Dimensions the presented examples included big, small, bidimensional, gigantic, large, huge, tiny, short, tall, high). The second phase consisted of elaborating the meaning of each variable, e.g., for sensory qualities―their function, the emotions they evoke; for the conjunctive form of relation―results, structure. The third phase consisted of performing cognitive tasks in which the trained variable is involved, e.g., for locational qualities―planning routes; for results―classifying them according to some principle, e.g., emotional or financial.
In each group of subjects the members got first the manipulation procedure and then the six tasks in random order. There was a 1 - 2 minutes break between any two tasks. The experiment was carried out in small groups of 2 - 5 participants, in the presence of an experimenter. Rliability tests based on Cronbach’s alpha were applied.
The statistical procedures applied for analyzing the findings were Pearson correlations and independent mean comparisons by t-test. Reliability checks were done by using Cronbach’s alpha coefficients.
Preliminary analyses showed that the four tasks of logical reasoning, labels, verbal memory and visual memory were correlated with one another positively and significantly (in the range of 0.28, p < 0.05 to .33, p < 0.01). The sorting test was correlated only with logical reasoning (−0.31, p < 0.01). Reliability checks were done for the reasoning test, labels test and the MBAS (Cronbach’s alpha coefficients were in the range of 0.70 - 0.82).
aThe scores for the two types of photos were combined because they did not differ significantly in either of the two groups.
The findings concerning the sorting test, labels provision, visual memory and the actional-dynamic and sensory aspects of the self image are significant also in view of the Bonferroni criteria.