1. HISTORICAL BACKGROUND

Lev Vygotsky created his "cultural-historical" psychology in twenties and early thirties of the 20th century. After his early death in 1934

Vygotsky's theory disappeared from open scientific discussions for a few decades due to political reasons (van der Veer & Valsiner, 1991). From fifties Vygotsky's works appeared again on a scientific arena, first in Russian and then also in English and other languages. Since the publication of the abridged version of Vygotsky's "Thought and Language" in 1962, Vygotsky step-by-step became one of the acknowledged theoreticians in "mainstream" Anglo-American psychology. Vygotsky wrote more than ten books and hundreds of articles in almost every field of psychology -- he wrote on normal and abnormal mental development, comparative psychology, cultural psychology, education, neuropsychology, structure of cognition etc. Surprisingly a very few of his ideas, however, have had an impact on recent psychological thinking. The ideas associated usually with Vygotsky's theory are the social origin of individual mental functioning, the role of culture in human development, the developmental method, and some very specific issues like a "zone of proximal development" and "egocentric speech" (see Wertsch & Tulviste, 1992, for a recent review). Such selected pieces seem not to fit together.

Even though there have been attempts to synthesize Vygotsky's contribution into a coherent theoretical whole, such attempts have remained unsuccessful (e.g., van der Veer & Valsiner, 1991).

2. THREE LEVELS OF ANALYSIS IN CULTURAL-HISTORICAL PSYCHOLOGY

In my dissertation it is argued that cultural-historical psychology would benefit from understanding that Vygotsky's theory can not fully been understood when taken as a complex of ideas at one level of analysis. Three hierarchical levels of analysis should be differentiated in his theory. The first and most general level of analysis can be called a theory of functional systems. The second level of analysis concerns general principles of the emergence and development of the human mind. According to cultural-historical psychology specifically human attributes of mind result from the emergence of semiotically mediated mental processes. Semiotically mediated processes, in turn, develop in the social interaction of individual minds. Finally, at the third, most specific level of analysis two issues are studied. First, according to Vygotsky, semiotic systems develop. To understand semiotically mediated mind it must be understood how

signs, especially their meaning, develop. And second, it must be understood how semiotically mediated processes emerge with the synthesis of nonmediated, "natural", mental processes. I argue that the three levels of analysis are in hierarchical relationships. It means that rules of every higher (more general) level of analysis apply to every lower (more specific) level of analysis. At the same time, every lower level of analysis is defined by additional constraints and rules, which do not apply to the more general levels (see Baldwin, 1906, for the thorough analysis of the idea of hierarchy). In the analysis of cultural-historical psychology it means that the general principles of the theory of functional systems must always kept in mind when more specific levels of analysis are studied. On the other hand, however, that general level of analysis is insufficient for understanding psyche (or whatever other phenomenon studied in science). There are no

general rules that would explain specific structures and processes. In addition to general rules every specific object or phenomenon follows it's own rules specific to it (see, again, Baldwin, 1906).

2.1. The Theory of Functional Systems

The basic principles of the theory of functional systems, necessary to take

into account in the study of mind, are described in more details in Papers

II and VII. Briefly, the concept of "functional systems" (or "gestalts", or

"structures") is of central importance in understanding cultural-historical

psychology. Vygotsky, supporting gestalt theory (cf. (Koffka, 1935; Köhler,

1947), viewed mental functions not as unitary abilities but as complex

processes which are made up of more basic skills. According to him,

specific combinations of such basic skills constitute "functional systems"

of psychic processes. According to the theory of functional systems, to

understand mind it is necessary to answer three questions (e.g., Vygotsky,

1994): First, which are the components of the mental system; second, how

those components are related to each other; and third, from where and how

the system emerged, i.e., how it developed.

Application of the theory of functional systems may have important

consequences in the scientific research. On the one hand, the theory may be

a powerful tool in directing attention to interesting aspects of studies

worthy of further elaboration. On the other hand, the theory of functional

systems is useful for discovering shortcomings in existing theories and

interpretations of empirical facts. Both of these applications can be

exemplified by papers which constitute this dissertation.

In Paper I we described results of a study of cognitive

functioning of children with early lateralized brain damage. Cognitive

performance of children with right-sided hemiparesis (damage to the left

hemisphere) was compared with the performance of healthy participants. We

found several differences in average performance levels of different

cognitive tasks which suggested that the left hemisphere of a brain may

congenitally be disposed for the acquisition of verbal skills and

abilities. There was one very interesting result we did not even notice

then. There is one principle in the theory of functional systems that led

me back to this study. The theory predicts that novel components of a

system emerge in the process of differentiation of the existing system (see

also Werner, 1978, on the orthogenetic principle). In general, it can be

predicted that the more developed the system the more it is differentiated

into distinguishable components. In our study we described performance of

children by 12 different cognitive measures (see Table 2 in Paper I). In

healthy children only one of the 66 pairwise correlations between cognitive

measures was statistically significant. In children with brain damage,

however, fifty-six of the correlations between the same measures were

statistically significant. Average correlation between measures was only

0.09 in healthy participants and 0.81 in children with left brain damage.

These results suggest that mind of brain damaged children may be much less

differentiated when compared to the healthy children. Further studies are

needed to clarify this issue.

Results of a study of memory performance in adults with Traumatic

Brain Injury, described in Paper X, also support the idea of

differentiation in development. In this study, however, evidence for

dedifferentiation can be found. We presented differently organized lists of

words and a list of nonwords for a free recall to participants. The type of

a list organization significantly influenced memory performance in

participants. That effect, however, was more marked in healthy

participants. Memory performance decreased more with lists which

organization-principle is a relatively late development in ontogenesis and

decreased less with lists which organization could be understood relatively

early. When development proceeds in the direction of differentiation then

in this study the results suggest that after brain damage regression in

memory performance can be found. That regression is characterized by

dedifferentiation of the influence of list organization.

In Paper IV a novel way for describing the development of drawing

of a cube and a cylinder was proposed. Following the suggestions of the

reviewers the theoretical background with the explanation why exactly these

stages in the development of drawing were differentiated, was left out. It

was found in this study that the development of drawing can be

characterized by four successive stages. After Scribbles children begin to

draw Single Units. Next Differentiated Figures appear which, in turn, are

followed by Integrated Wholes. This developmental sequence can be used as

an example of the orthogenetic principle -- single unit differentiates into

parts which can be synthesized into a more complex whole in the final

developmental stage. Of course it is not sufficient for understanding

exactly why and how this differentiation-synthesis sequence happens in

development. But, as every lower-level phenomenon must follow the rules of

the more general level of analysis, findings of this study suggest that the

search proceeds in a right direction.

The principle that development proceeds hierarchically is also

well supported by the findings of Paper IV. If the development is

hierarchical then every next stage may develop only after the theoretically

earlier stage has been reached. In this study the theoretically later stage

always appeared at a later age than a theoretically earlier stage of

development.

The principle of hierarchy also applies to the development of

culture. In Paper VII results of cross-cultural research are discussed.

Even though many researchers have explicitly denied that different cultures

can be classified into developmentally different levels, the analysis in

that paper revealed that the existing empirical evidence is in full

concordance with the idea of hierarchy in the development of cultures. Some

cultures are "less developed" than the others.

The theory of functional systems is a useful tool for discovering

shortcomings of existing theories as well. In Paper VI it is pointed out

that for understanding a system all of it's components must be taken

simultaneously into account. Every component of a system has a specific

role in the whole. If a researcher wants to understand what roles a

specific component has in a system then all components must be described.

When one or more components are left out of the analysis it is possible

that characteristics of the missing component are attributed to a wrong

component. It does not follow, of course, that we always know which are the

components of a system. But the theory of functional systems predicts that

when a new component of a system is discovered then all the previous

evidence and theory must be reanalysed because knew knowledge may lead to

reinterpretation of findings.

In Paper IX we direct memory researchers' attention to the idea

that the usual way of differentiation components in working memory may be

inappropriate. In studies of working memory it is assumed that when two

processes interfere with one another they share processing resources. We

pointed to the possibility that such an interference may emerge not because

the processes have to share a common limited resource -- a component in

terms of the functional systems theory -- but rather because the two

components may inhibit each other. Thus, a similar result, interference

between two tasks, may be a consequence of not one but two different

mechanisms. One possibility, indeed, is that one and the same component of

a system is involved in the two tasks. The other possibility, however, is

that the interference emerges because of a specific -- inhibitory -- type

of the relationship between two different components of a system. Thus, the

analysis of a system into components and the relationships between those

components reveals complementary information. According to the theory of

functional systems the emphasis on only components in the analysis may be

misleading.

In Paper V I commented upon a theory that knowledge may be

represented in perceptual terms. Some of my comments have direct relevance

to general theoretical issues discussed here. First, the author of the

target article did not describe how information is selected for creating a

representation. I proposed that the selection process may be guided by

efferent control of activity. The target theory did not consider the

possibility that efferent mental systems may be important for the theory.

In general terms it means a possible component of a representation system

was left out from the analysis. And, correspondingly, the system could not

be fully understood. Second, the target theory did not consider the

possibility that qualitatively novel formations emerge with the

hierarchical synthesis of existing components. The target theory did not

have an explanation how novel information is created by a mind. I proposed,

following Lotman's theory of semiotics, that novel information (like every

novel quality of mind) may emerge only with the synthesis of existing

distinguishable components of a system into a more complex whole. In the

human mind those components may be sensory-perceptual and

amodal-linguistic. (The creation of qualitatively novel knowledge in human

mind is analysed in more details in Papers II, III and VII). That idea,

again, is directly related to the theory of functional systems.

Finally, in Paper VIII an empirical study of putative components

of a drawing system is described. That study was designed with the idea

that all components of a system must be simultaneously taken into account

for understanding it. The results of that study confirm that all

theoretically differentiated components are distinguishable and relevant

for understanding mental mechanisms of drawing. In principle, the results

of the study also suggest that for understanding mental mechanisms of

drawing in future studies always all of the differentiated components

should be simultaneously "controlled" to understand what specific roles

every of the components has. The theory of functional systems predicts that

studies which focus on only one or some of the differentiated components

can never lead to unambiguous interpretation of empirical findings.

In sum, all theoretical claims and interpretations of empirical

findings in papers which constitute this dissertation, can benefit when

analysed in terms of the theory of functional systems. Thus, it is possible

that that general theory should be important to consider seriously in very

different fields of psychology if not in all field of science (cf. von

Bertalanffy, 1968, for a support to the latter claim).

2.2. Culture and the Emergence of Semiotically Mediated Thought

Next level of cultural-historical psychology studies principles of the

genesis of the human mind. According to the Vygotsky's theory the

distinguishing characteristic of the human mind is it's semiotically

mediated character (e.g., Vygotsky, 1994, 1996; Vygotsky & Luria, 1930,

1994). At that level of analysis all principles of the theory of functional

systems -- the next more general level of analysis -- must be applied. In

Papers II, III, and VII it is analysed how and why semiotic mediation may

make human minds special when compared to the minds of other animals.

Briefly, it is argued that semiotically mediated thought emerges when two

components of the differentiated system of mind, that of sensory-based

information-processing and that of sign utilization are united into one

higher level system. With that synthesis humans acquire the ability to

construct qualitatively new king of information, information about a world

beyond the reach of senses. It is also argued that this synthesis becomes

possible only and only through the process of social co-operation.

Theoretically, novelty in minds emerges only when two different

information-processing systems are united into a higher level system.

Sensory-based information processing relies on the mechanism which

processes information in one way. Signs, usually words, are not processed

by the same mechanism. Even though in the process of acquisition of first

words these just reflect knowledge already processed by sensory perception,

in the process of social co-operations words differentiate from sensory

reality and it becomes possible to connect them according to the rules

different from the rules according to which referents of words are

connected. So a new information-processing mechanism differentiates. The

ability to use signs for communication is necessary but not sufficient for

the emergence of ability to construct novel information. That ability is

acquired when already differentiated mechanisms are united into a higher

level whole, into a semiotically mediated system of mind.

The emergence of semiotically mediated mind, in turn, allows to bring new

meanings into a system of socially shared meanings. That socially shared

system of meaning constitutes "culture". In the aforementioned papers that

notion of culture is analyzed in details. Perhaps one of the most important

ideas in that discussion is the idea why it is feasible to define culture

in that specific way, why it is feasible to choose that definition from a

pool of more than three hundred different definitions of culture used in

different fields of human studies and by different scholars. It is

suggested that this specific definition differentiates a qualitatively

specific aspect of the (human) environment which is necessary to understand

for understanding psyche, especially the genesis of semiotically mediated mind.

In Paper II it is also pointed out that it is easy to

misunderstand Vygotsky's ideas when principles of the theory of functional

systems, he explicitly analysed in several works, are ignored. For example,

many scholars have suggested that Vygotsky contrasted natural and cultural

processes of development in a dualistic way. Such an interpretation of

Vygotsky's ideas would probably be correct if to assume that Vygotsky wrote

every new paper as totally independent of other papers he wrote before. As

far as we know Vygotsky did not have memory problems. Thus, it is more

reasonable to assume that Vygotsky' followed the principles of the theory

of functional systems even when he did not repeat it in every single piece

he wrote. If that is the case then most of the critics against Vygotsky's

ideas just does not hold. Relevant examples, how critics against Vygotsky's

cultural-historical psychology may be a misrepresentation of his ideas, can

be found in Papers II and VII.

Paper VI discusses yet another aspect of cultural-historical

psychology. In early thirties Vygotsky's school of thought began to

disintegrate. One product of that process was a new school of psychology

known as "activity theory". It is shown in this paper that activity theory

ignores the basic principles of the theory of functional systems, and, for

that reason, can not lead us to understanding or explanation of mind or any

specific psychological function. (It might be interesting to note that most

of the critics against Vygotsky's ideas comes from scholars who support

activity theory. In a way it is surprising that these critics blame

Vygotsky in Cartesian thinking they follow themselves. On the other hand,

would it be true that Vygotsky's thinking was Cartesian, much of the

critics would be justified.)

2.3. Studies of Word Meaning and Semiotically Mediated Processes

The most specific level of analysis in cultural-historical psychology

studies specific mental processes in details. It is not sufficient to claim

that human mind is characterized by mediated thought because sign meaning

develops. Even when the basic structure of mediated mind is established,

the development may proceed in the direction of utilization of structurally

more and more developed signs. Thus, for understanding mind it is

necessary to study how sign meaning develops and, next, how mind changes

when more complex signs are involved in mediated thought.

In Paper VII evidence for hierarchically different levels of

mediated thought is discussed. It is proposed that cultures can be

classified into different stages of cultural development. At every next

higher level of cultural development a new way for semiotic

information-processing is acquired. That new level does not replace the

previous, less developed ways of thinking. Rather, a pool a different ways

for organizing information increases with every new stage. A new level is

not directly in one-to-one correspondence with some subjective value, it is

not necessarily "better" in every respect. A new and higher level of

development is defined only in terms of system development. A higher level

is structurally more complex. Vygotsky differentiated three successive

levels of word (sign) meaning development: Syncretic, Complexes, and

Scientific concepts (e.g., Vygotsky, 1996). The available evidence allows

to differentiate cultures where only thinking with "complexes" is present

and cultures where both "complexes" and "scientific concepts" are found.

Paper X gives some evidence that "vertical" and "horizontal"

relationships between words can be dissociated in traumatic brain injury.

In vertical relations links are made between items at different

hierarchical levels (e.g., "pets" -- dog, parrot); in horizontal relations

links between items at the same level of taxonomic hierarchy are

represented (e.g., dog-cow). In traumatic brain injury free recall of

vertically organized word lists declines significantly more than the recall

of horizontally related item lists. It is noteworthy that, according to

Vygotsky, "complexes" are characterized among other characteristics, with

horizontal relationships between items and "scientific concepts" with

vertical relationships between items. Thus, complexes and scientific

concepts can be dissociated neuropsychologically.

Finally, in Paper VIII results of a study of drawing system are

described. It was hypothesised that mental system of drawing includes in

addition to sensory-perceptual and motor components also verbal components.

In other words, it was studied whether drawing is an example of

semiotically mediated system or not. The results of two studies are in

agreement with the idea that drawing is a semiotically mediated system.

3. CONCLUSIONS

It is argued in this dissertation that cultural-historical psychology

should be analysed simultaneously at three different levels of analysis.

The most general level of analysis, the theory of functional systems,

defines general principles which should apply to all phenomena under study.

Scientific method should search for the components of a system, describe

relationships between those components, and genesis of systems. Application

of the theory of functional systems is useful for finding new areas of

research as well as for analysing existing theories and interpretations of

empirical findings.

Next level of analysis differentiates mental characteristics

specific to the human mind. According to Vygotsky's theory only human

mental operations are semiotically mediated. Semiotic mediation allows to

construct knowledge about the universe beyond reach of senses.

Finally, mind can not be understood by applying general principles

of the theory of functional systems and/or semiotic mediation. Every

phenomenon, including mental phenomena, must be studied in their own rights

as well. Even though principles that characterize general level of analysis

must apply to all more specific levels of analysis, every specific level of

analysis is characterized by additional principles and constraints specific

to that level. These principles can be understood only through the analysis

of the "real mind" in the "real world".