The most important characteristic distinguishing human beings from other organisms is that human behaviour follows from long-term goals having no genetic basis. A naive theory of goal-directed processes shared by many scientists suggests that an individual first forms a goal and then searches for or creates the means to attain it. Accordingly, a separation is made between goals and means. Two examples from problem solving suggest that this postulate is incorrect. It is hypothesized that the brain always synthesizes goals and means in the process of self-organization. Theoretical foundations of this idea include the analysis of neuroscientific data and an evolutionary principle. A model of how the brain constructs, performs, and completes goal-directed processes is described in this target article. Some consequences for various disciplines such as Artificial Intelligence and personality psychology are considered.
Qualified professional biobehavioral, neural or cognitive
scientists are hereby invited to submit Open Peer Commentary on
this target article. Please email or consult the websites below for
Instructions if you are not familiar with format or acceptance
criteria for PSYCOLOQUY commentaries (all submissions are
refereed).
To submit articles and commentaries or to seek information:
EMAIL: psyc@pucc.princeton.edu
URL: http://www.princeton.edu/~harnad/psyc.html
http://www.cogsci.soton.ac.uk/psyc
1. Comparisons between various human societies reveal remarkable differences in social, cultural, technical, scientific and moral characteristics. Obviously, such differences arise from the fact that some aspects of the organization of human societies have genetic prerequisites; however, these are not sufficient to explain most of the interactions which take place among humans. Technical and economical interactions, for example, have no genetic basis. One cannot explain the occurrence of space flights and communism as a consequence of a mutation in the human genome that occurred a century ago.
2. From our viewpoint, people are not constrained by genetic limitations because unlike other organisms, the human brain is able to construct and pursue long-term goals which have no genetic basis, but result from interactions among human beings. This brain property, rather than the faculty of language, defines human beings as intellectual organisms. Language is only a mediator in information exchanges, hence, if the goal-directed processes of organisms lie within genetic limitations, their language or other cognitive systems are also restricted, regardless of the flexibility of their mechanisms. On the other hand, if organisms are capable of constructing goals beyond genetic limitations, a flexible language is a very useful instrument for creating such goals.
3. Nevertheless, there is no satisfactory theory of how people construct and pursue goals (Austin & Vancouver 1996). Common sense offers some insight into this problem: the formation of a goal is a more or less conscious response to external influences (e.g., the commands and actions of other people and different situations, and to internal influences such as diseases, emotions, and other goals and needs. Once a goal is set up, the individual should construct or select some means by which to pursue it. If the method of achieving the goal fails, it is necessary to alter the means, through observation of the method and its result. Then, the goal can be converted into another goal or a hierarchy of goals, and previous methods can be applied where appropriate.
4. Our experience, then, teaches us that a goal can be achieved through various means or methods. The property of goals to be achieved through multiple methods and regardless of initial state is called equifinality (Austin & Vancouver 1996, Heckhausen 1980). This implies that a method can be applied to reach absolutely different goals. Hence a hypothetical system responsible for goals is separated from a system responsible for means and vice versa. The idea of an absolute separation between goals and means, the postulate of separation, underlies a naive view of purposeful processes as basic theories of purposeful behaviour (Leontiev 1975, Miller, Galanter & Pribram 1960; Powers 1973).
5. There are some facts which are inconsistent with this postulate. For example, the overload on short-term memory caused by the pursuit of a goal can eliminate the goal itself from memory (Reason 1990). The ability to form and maintain long-term goals and means maturates in adolescence (Mussen et al 1984), which suggests that this postulate is not likely to be valid with regard to children. Serious disturbances in some brain structures, especially in the prefrontal lobes can heavily impair not only the establishment of goals, but also the process of searching for means (Luria 1966).
6. These examples seem to be rare exceptions which only prove the rule. A more usual situation in which goals interact with means is when, in order to establish a goal, an individual estimates the various relations between possible goals and means and selects an appropriate combination. However, in this case, establishing a goal is simply a hierarchical goal-directed process itself, whose phases are likely to comply with the postulate. The postulate of separation is considered to be absolutely valid. For example, a fundamental review by Austin and Vancouver (Austin & Vancouver 1996), which is devoted to goal construction in psychology, and covers a broad range of domains from Artificial Intelligence to personality psychology (and includes around 600 Citations), is implicitly based on the postulate of separation and does not attempt to challenge it.
7. It appears, however, that the difficulties of solving some problems reveal a weakness in the postulate. Consider the following riddle borrowed from a well-known textbook: "How can one construct four equilateral triangles out of six matches, where each side of a triangle is equal in length to the length of the matches?" (Johnson-Laird & Wason 1977, p.17). This simple problem is difficult to solve, because most people try to construct triangles lying flat on the table, and even after many attempts it is not easy to find the right solution: a tetrahedron. The usual explanation for this difficulty is that past experience of playing with matches on table tops leads us in the wrong direction for solving the riddle.
8. This does not explain why this approach is preferable, nor why observation of the solution process does not reveal that the direction is wrong. Most people have some knowledge of three-dimensional objects such as pyramids and neither special skills nor a special working memory are necessary for solving this riddle.
9. In another explanation for this effect, one assumes that in accordance with the condition of the riddle and past experience, the brain synthesizes a goal and the requisite means of achieving it. The criterion for this synthesis is that the brain minimizes the resources needed to construct a goal and means.
10. The goal synthesized by the brain can be formulated as follows: the above source condition, plus the words "the triangles should lie flat". Simultaneously the brain retrieves information on triangles, which it applies to the riddle of the matches. This information, which is not a consequence of the goal but a component in its formation, provides the means to achieve the goal. This synthesis is the result of complex interactions between the puzzle itself and past experiences, and it is a product of a self-organizing unconscious process.
11. In most everyday problems, a goal constructed by such a method, would be successfully achieved, but, due to the ingenuity of the author(s) a quick solution of the riddle seldom occurs. As a result, feedback from the process of solution adds practically nothing to the thinking processes in the brain. New syntheses, therefore, result in the same goal and means and the individual sees no novel direction for the solution. Such a situation is rather rare, since feedback from the solution process usually allows a new goal and means to be synthesized, which the individual acknowledges as a new insight into the situation. The difficulty of solving the six matches riddle challenges the validity of the separation postulate.
12. Another example is Luchins's experiment on how to measure a given quality of liquid using three containers (Luchins & Luchins 1950; Johnson-Laird & Wason 1977, p.18). At first, subjects were presented with a number of identical problems and worked out a complex algorithm for solving them. Afterwards, they applied this algorithm to similar problems for which there was an obvious simpler solution. A conventional explanation for this is that the experiment produced a misleading set, but it is unclear why, despite having appropriate knowledge, the subjects could not alter this set.
13. Yet, suppose that the brain forms the goal "to solve the problem by means of the algorithm" and simultaneously activates the algorithm itself as being the method to achieve the goal. The brain prefers this way, because a familiar procedure under familiar conditions corresponds with principle of minimal synthesis of goal and means. The fact that it is impossible to find an obvious algorithm implies that usage of the algorithm adds no novel information for a new, effective synthesis. Once again, this explanation of the experiment conducted by Luchins and Luchins does not comply with the postulate of separation.
14. The implications of the two examples discussed here are much wider than the very restricted area of experimental problem solving from which they originated. Past experience underlies practically any everyday activity, and context often determines human behaviour. Hence, it is likely that the joint synthesis of goals and means is a condition of any purposeful process and the postulate, which proposes that goals and means should be generated separately, is incorrect. The idea of synthesis is the topic of our further discussion, in which we consider some arguments in favor of this hypothesis.
15. To understand the organization of purposeful processes, our attention should be focused on social or cultural forms of human activity, i.e. those forms that originate from interactions between the individual and other people, or from interactions between the individual and products of social activity, such as laws, rituals, books, tools, and mechanisms. Apart from such social sources, some forms of human activity have a biological basis, but these are either adapted to the social conditions (e.g., polygamy and monogamy as forms of sexual behavior in different social systems), or subject to social control (e.g., urination). Hence, a biological explanation of human behavior is only possible within social forms of activity.
16. In our view, social forms of human activity are goal-directed processes: the goal of such a process is a situation or a state of the organism, which the process should achieve or leave unchanged (Austin & Vancouver 1996). Functional operations or classes of such operations which are constructed or used by the brain for pursuing goals are considered as means. A means, which has cognitive, emotional and motor components, can be rapid and unconscious or may correspond to several conscious actions. The goal (or goals) and means comprise a program, by virtue of which the individual is able to meet the requirements of the situation. Our main idea is that all processes, from educational aspirations and career objectives to the various sorts of eye movements and breathing, originate from the joint synthesis of their goals and means. The synthesis is always unconscious, but results in a conscious representation of the situation. Some arguments in favor of this idea can be formulated as follows.
17. First, numerous facts show that there is a clear separation between biological goals and means in the brains of animals and human beings. Indeed, the centers of biological goals (hunger, thirst, sex) are concentrated in the limbic system and hypothalamus, whereas the cognitive and motor mechanisms necessary to reach the goals are distributed over the cerebral cortex (Pribram 1971, Delgado 1969, Sem-Jacobsen 1968 ). On the other hand, most neuropsychological studies associate the distinctively human features of purposeful behavior and cognition with the prefrontal cortex, since disturbances in this area result in impairments of the motivational and executive functions (Luria 1966, 1973; Pribram 1973). Unlike the anatomical separation between innate goals and means, it seems that, notwithstanding the differences in functions of its various areas, the prefrontal cortex has no means of processing goals and means separately (Luria 1966, 1974, 1982; Courtney et al 1996; Fiez et al 1996). If goals and means share the same brain system and overlap in time, brain processes involved in the formation and execution of goals affect the formation of means and vice versa.
18. Second, the correspondence between goals and means is not "invented" by human brain. Instead it is based on evolutionary principles. Indeed, one of the conditions for survival of any animal is a correspondence between the "architecture" of the animal and its biological targets: a wolf as a predator uses its sharp teeth to kill and eat other animals, lack of teeth means the death of the wolf, because the predator cannot change its biological targets. Similarly, each innate drive is accompanied by corresponding innate means (Hinde 1970). At the human level, nature has simply made this evolutionary principle more flexible.
19. Unlike other animals, humans have a very limited repertoire of innate, effective programs. Instead, a single mechanism of synthesis allows goals to be synthesized, for which there are appropriate means, thus providing a high level of adaptation to various situations [FOOTNOTE 1]. As we have pointed out above, the criterion for such a synthesis is to minimize the brain activity necessary to construct a goal and means. Of course, this criterion constrains human activities, implying, for example, that thought often fails to follow the principles of logical reasoning; it also avoids "combinatorial explosion".
20. The problem of "combinatorial explosion" is a reflection of the fact that "intelligent" computer programs are based on universal, logically correct ideas which allow, in principle, a solution to be found for any problem. The solution of a particular problem is available only through intensive search in the problem space (Newell & Simon 1963). On the basis of the criterion of minimal resources the brain synthesizes a particular representation in order to solve a particular problem, according to the condition and context of the problem, past experience, emotions, motivations or other factors. The representation, which may not always be logically admissible, can produce the solution at once. But if the parsimonious synthesis goes astray, the individual cannot solve the problem, even though theier knowledge, skills, and memory capacity may be sufficient to find the solution. This allows us to understand why it is so difficult to solve such deceptively simple problems as the six matches riddle.
21. It is not suggested that the brain has a special "evaluator" to select a goal and means across possible alternatives in accordance with the criterion of minimal resources. Instead, in order to satisfy the requirements of the situation a process of self-organization is activated over available brain systems, which results in a goal and means. Of course, at present we know very little about how this self-organization occurs. It may be assumed, for example, that in the creation of a program, the brain allocates resources for a few competitive processes which have various goals. Then the process which needs the least resources for construction is selected. During its formation that process captures resources from its competitors, and thus eliminates them (Marcel 1980).
22. If the brain allocates redundant resources produced by high levels of brain activity, a winning process may be formed without the elimination of its competitors. With sufficient resources, one of the latent processes may develop further, reaching the goal on its own. This mechanism offers a possible explanation for the "aha" phenomenon in which sudden insight occurs. Indeed, such insight is usually preceded by high levels of brain activity. A sudden insight can occur either when, after constructing competitive processes, the brain is involved in different tasks (e.g., during sleep, wakening, and rest), or when the brain persists in allocating resources (e.g., in a stressful situation, affect) (Hadamard 1945).
23. Some authors found that the prefrontal lobes of apes are able to maintain working memory functions only while activated by innate drives such as hunger (Batuev, 1981, Inoue, Oomura & Aou, 1985, Thorpe, Rolls & Maddison, 1983). It is proposed that the ontogeny of purposeful processes is based on the ability of the prefrontal lobes of a baby to maintain its activation without influencing innate drives or emotions. As a result of the maintenance and conjugation of various (innate and learned) transient reactions to the environment, the prefrontal lobes of a baby are able to construct new, persisting processes whose goals can be different from the innate, biological goals. Since parents or other people are the main components of the baby's environment, this results in the socialization of a baby. An innate reward/punishment mechanism allows such processes to be reinforced but this mechanism is not a necessary attribute for their development. These new processes can also interact with each other, thus leading to more persisting processes. Accordingly, the ontogeny is a development from short-term, unstable goal-directed processes to long-term, stable ones. At some point, the system of such processes achieves a self-sustaining state. This means that the stage of initial formation of the system has been completed and the system can now maintain goal-directed processes for as long as necessary.
24. Contemporary understanding of how goal-directed processes can be implemented in the brain is still incomplete. It is clear, however, that each process includes three stages: initiation, execution and termination. The goal-directed processes of an adult are components in a hierarchy (Austin & Vancouver 1996), but it is very difficult to describe the structure of processes in a complicated hierarchy. We will therefore concentrate on some basic features of the three stages of a single "ideal" goal-directed process.
25. In order to construct such a process, the prefrontal lobes, which are linked to many other brain structures (Nauta 1972), integrate all available information (incoming sensory input, long-term memory, emotions, etc.), thus activating self-organization. Of course, ther are other brain structures involved in constructing a goal-directed process (Mordvinov 1982, Rosvold 1972). It is not clear what would be the minimal elements of such a process, but a temporal pattern of activity seems a plausible candidate (Hebb 1949, Edelman 1987, de Vries 1991, Prut et all 1998). All available data are converted into numerous patterns which are distributed over the prefrontal lobes, and these patterns start interacting with each other (Prudkov 1994).
26. These numerous patterns will then interact with global patterns, one of which will become dominant, incorporating the others into its structure. This self-organization results in a global and coherent pattern, in which the activity of most neurons involved have common temporal characteristics, thus encoding the given goal-directed process. The main difficulty for the prefrontal cortex in the construction of a goal-directed process is that the prefrontal cortex should always synthesize a novel process from neurons with stochastic activity since each situation has some distinctive features. There may, therefore, be a correlation between the stability of a pattern and the number of its common characteristics, because if the level of coherency in a pattern is insufficient, the pattern can be dissipated through stochastic activity, of the neurons involved. There is a probable correspondence between the amount of neurons involved in a pattern and the conscious awareness of a process encoded by the pattern.
27. It is reasonable to assume that each pattern includes two interconnected components: the goal is encoded by one component, and the second component is responsible for the means. The temporal activity across the neurons of the first component is likely to have more similar features than that of the other component, thus providing some stability for the goal. Such a distribution of neuronal activity is a consequence of self-organization which joins neurons (and groups of neurons) with similar patterns of activity to form functional systems. This implies that the neurons involved in the goal component have mainly local connections within the prefrontal cortex, whereas the neurons of the component encoding means are linked to other brain structures.
28. The main determinant in the construction of a goal-directed process is the relationship between the situation and the past experience accumulated in long-term memory. Situations are a source of necessary but unstable activation. Long-term memory, on the other hand, stores stable but sometimes inadequate patterns of past experience, which are likely to guide the process of self-organization. For a novice, whose knowledge of a situation is small, it is the situation which is a key determinant in the construction of a purposeful process. Since the requirements of the situation are its most salient feature, the conscious awareness of the goal of the process should be clear and maximally similar to the requirements. In contrast, the means may be vague and ineffective. An expert's representation of the situation may be strongly informed by past experience. As a result, goals and means which are formed by self-organization, can be considerably different from those formed by a novice's view on the requirement of the situation. This difference in constructing goal-directed processes allows us to account for the differences in strategy and performance between novices and experts in problem solving (Larkin, McDermott, Simon & Simon 1980). In our view, the difference in strategy originates from the construction of different representations by novices and experts in the same experimental situation of problem solving.
29. Many current findings associate schizophrenia (there is no animal model that accurately approximates this disease) with a dysfunction of prefrontal lobes (Goldman-Rakic 1991, Goldman-Rakic&Selemon 1997, Heckers 1997). For example, Goldman-Rakic and Selemon (Goldman-Rakic & Selemon 1997) consider the symptoms of schizophrenia as a failure in the working memory functions of the prefrontal cortex. They describe working memory as follows: "working memory serves as a computational arena or workspace for holding items of information in mind as they are recalled, manipulated, and associated to other ideas and incoming information". (Goldman-Rakic & Selemon 1997 p.439). It seems that the concept of working memory (Baddeley 1986) allows such schizophrenic symptoms as impoverished thought processes to be explained, but this is an insufficient hypothesis for understanding perceptive (hallucinations) or motivational (paranoia) symptoms.
30. It is possible that schizophrenia results from the impaired organization of goal-directed processes in the prefrontal cortex. Of course, all of the mentioned stages suffer from this dysfunction, however, it isthe stage of construction, according to experiments on apes (Stamm & Rosen 1973, Mordvinov 1982) and to intuitions, which is likely to be the most susceptible. The prefronal cortex of a schizophrenic patient can synthesize the patterns of goal-directed processes, but these patterns are distorted through disturbances at a cellular level such as those in the excitability of the cortical neurons (Goldman- Rakic & Selemon 1997). As a result, various changes in perception, attention, thought, and motivation occur. As the disease develops, the other stages can also be damaged. Finally, a patient is not able to carry out active behavior at all, such a state could be associated with catatonia.
31. Once a goal-directed process is constructed, some activation from the component representing a means, propagates to other brain structures which are necessary to carry out the process, and its performance is initiated. Simultaneously, the components interact with each other, which stabilises the means component while it receives feedback from other brain structures involved in the process. Possibly, some complicated form of reverberation underlies such persistent activity of the prefrontal cortex (Fuster 1973, Kubota& Niki 1971, Vartanian & Pirogov 1988).
32. To complete a goal-directed process , the brain should compare incoming neuronal activity (i.e. the outcome of the process) with the pattern relating to the goal. Some findings allow us to assume that the basal ganglia, which are linked to the prefrontal lobes, limbic system, and sensorimotor areas, and show inhibitory influence on behavior (Bechtereva 1974; Graybiel 1995, 1997; Rosvold 1972), play an important role in the self-organizing process of comparison between those activities. As the brain finds that both the activities are similar, it inhibits the activation relating to the given process and usually forms an emotional reaction to its result. Free neurons are then available to construct a new process, whereas emotional responses may possibly play a role in converting the transient results of a goal- directed process into long-term memory (Izard 1977). With regard to hierarchical processes which include more stages, one hypothesis is that their initial patterns have special characteristics for each subprocess, and that the termination of one subprocess leads to the activation of a following one.
33. The temporal organization of human purposeful processes is a hierarchy, in which three levels can be defined (Austin & Vancouver 1996). The uppermost level consists of life-range processes underlying career preferences, social attitudes, and, perhaps, self-consciousness. It is plausible that emotional influences rather than regular repetitions are involved in the construction of processes at this level. Strong emotional activation, during the first two stages of a process, allows the conversion of ongoing patterns of neuronal activity into long-term memory. As the role of long-term memory in constructing a goal-directed process is increased, the amount of resources (e.g. conscious awareness) required to perform it is decreased. As a result, life-range processes persist unconsciously, since the brain permanently has the amount of activation necessary for their maintenance. The patterns of this level obviously are a background for the patterns of processes at the lower levels.
34. The patterns of the middle level organize ongoing activities, such as reading a book, driving a car, or solving a problem. Since such processes require a high level of activation, their goals can be recognized as intentions and their results are under conscious control. The processes at this level are similar to the ideal process discussed above. This level in turn controls rapid processes at the lowest level, such as reading a word, or unconscious reasoning. These automatic processes are likely to originate from regular repetitions of processes at the middle level. Repeating a process at the middle level, the brain creates in long-term memory a stable version of its initial pattern, the activation of which requires minimal resources, and can be performed without conscious control (Bechtereva et al 1983). Patterns at all the three levels are likely to participate in the construction of any new pattern, the construction of a new pattern, therefore, is neither an 'up-down' nor a 'bottom-up' process.
35. There are several reasons why the postulate of separation is usually taken for granted. First, although biological goals can only be achieved through social means, their activation is autonomous. Second, there is an apparent separation, reflecting a stability in the hierarchy of an adult. Examples from problem solving show that it is often very difficult to understand the true goals of many actions (Polya 1957). On the other hand, such detailed conscious awareness of a failure of the purposeful process is unnecessary in most everyday situations. In a stable case, a new purposeful process, similar to the prior one but often more appropriate, can be constructed ;using relatively few resources. These circumstances imply that the individual only partially recognizes a new representation of the situation, thus suggesting that the goal is invariable.
36. In addition, using language and complex social skills, an individual can "emulate" the separation between goals and means. Indeed, by discussing some ideas with other people or by writing the ideas down and afterwards thinking about them, an individual can concentrate either on the goals or on the means of a goal-directed process. However, such behaviors are only available in a developed hierarchy, and are based on the hypothesis of joint synthesis. It seems clear that ther can be only one mechanism underlying the behavior of literate as well as illiterate individuals.
37. The hypothesis of the synthesis of goals and means has a theoretical basis, and allows us to explain experimental data from various disciplines. In contradistinction, the idea seems inconsistent with the common sense that underlies most models of goal-directed processes. Since the domain of goal-directed processes is very wide and vague (Austin & Vancouver 1996, Leontiev 1975), the test of such a hypothesis requires a complex program of experiments which is beyond the scope of this article. One method of judging the validity of the hypothesis would be to compare it with alternative approaches, in order to select an approach that is maximally consistent with a wide range of facts. The confirmation of an alternative approach will mean the refutation of other approaches.
38. To achieve any goal, an appropriate means is necessary, hence the classification of various approaches to the organization of goal-directed processes can be based on how each approach defines a means appropriate for achieving a goal. From this viewpoint, three approaches seem possible: a separate generation of means and goals; a joint synthesis of goals and means, and an innate origin of basic goals and means (i.e., evolution rather than a single brain forms both goals and means). The second of these three approaches corresponds to our hypothesis. The alternative approaches are considered below.
39. One alternative approach is based on the postulate of separation implicitly shared by most psychologists (Austin & Vancouver 1996, Brody 1983, Pervin 1989) and especially by cognitive scientists (Newell & Simon 1972, Schank & Abelson 1977, Anderson 1993). This approach assumes that an individual is able to construct practically any goal and should then select or search an appropriate means. But as has been mentioned above, the human brain has no areas in which to process social goals and means separately. Disturbances in the prefrontal lobes, the structure associated with such functions by most neuroscientists, lead to impairments in both action and motivation. Another difficulty is how to identify appropriate means when a goal is set up. Since this model implicitly assumes no correspondence between goals and means, searching can be unrealistically long and expensive. This is the problem of "combinatorial explosion" in Artificial Intelligence. Proponents of this approach could suggest that domain-specific knowledge and hierarchical systems of goals are a satisfactory way to define the correspondence (e.g., the goal activates a field of means), thus reducing costs of search but some riddles show that even with domain-specific information, the human thinking system is very reluctant to apply searching procedures to find appropriate means [FOOTNOTE 2]. Searching procedures may be abandoned in favor of the assumption that there are only associative connections from the goals to means. However, such a concept lacks the property of purposefulness (Heckhausen 1980). In our view, reliable arguments in favor of this approach would be the neurophysiological data which showed that the brain processes social goals and means separately.
40. In the other alternative approach, the ability to construct goals and (probably) means is constrained innately. Evolutionary psychology is very explicit in supposing that humans have an innate repertoire of goals and domain-specific procedures (Barkow, Cosmides & Tooby 1992). Some models of motivation (Maslow 1943, Murray 1938, Heckhausen 1980 ) implicitly assume the innate origin of some basic motives without, however, giving clear comments on how these motives can be converted into executable programs. Instead of innate motives, behaviorism assumes that innate mechanisms determine whether any incoming stimulus is good or bad without innate means (Heckhausen 1980). In our view, innate programs are important determinants of cognition and behavior. However, they are not sufficient to understand the diversity and rapid alterations of those processes at the level of a single individual, nor at that of a whole society. Arguments in favor of this approach would probably cite the fact that human behaviour, and especially the mechanisms of learning, have strong genetic limitations, but what if the inability to understand that humans are genetically limited organisms is also innate?
41. Across the three possible approaches, the hypothesis of joint synthesis seems to be the one most consistent with current data and intuitions. No alternative approach offers reliable confirmative evidence. It is of interest, then, to consider some of the consequences of this hypothesis.
42. Since the "General Problem Solver", a computer program created by Newell and Simon (Newell & Simon 1963), the idea that goals and means should be processed separately has been fundamental to numerous models created by AI researchers. From our viewpoint, those models have tried to simulate human thought through methods principally different from the methods really used by human thinking itself. This appears to be one of the reasons why AI researchers have not achieved the goals announced in the sixties, such as computer solutions for complex mathematical problems or effective computer translations between languages. Possibly, the given hypothesis could be a necessary heuristic for new directions in Artificial Intelligence.
43. In order to explain complicated mental phenomena contemporary psychology divides mental life into a number of domains and studies them separately. This approach seems inevitable but leads to serious problems, since mental processes are really holistic. For example, cognitive psychologists usually study cognitive processes without explaining how motivation facilitates and controls these processes. This, in principle, constrains the validity of most cognitive models (Marcel 1988). On the other hand, there is no clear model explaining how the results of interactions between an individual and the world can be converted through cognitive processes into motives and personal traits (Heckhausen 1980). The hypothesis of joint synthesis which supposes a holistic view on mental processes, may be a solution for these problems.
44. Obviously, many social systems, such as religion, morality, and justice are implicitly based on one of the two alternative approaches, especially the first one. But if the hypothesis of joint synthesis is valid, then a new view on these systems may be useful or even necessary.
[1] Of course, each individual is able to construct and even pursue absolutely unachievable goals. Such behaviors are either useful components in adaptive hierarchical processes, or the result of a dysfunction of the adaptive system of goal-directed behavior.
[2] Let us, for example, consider the following simplest chess riddle: White: Ke1, Rf2, Rh1; Black: Ka1. White to play and mate in one. About 10 years ago when one of the authors (P.P.) got acquainted with this riddle he found that poor chess players (and P.P. himself), of course, familiar with the chess rules, could not solve the riddle or solved it after many attempts. P.P. ,then, tested a poor chess program (he regularly defeated the program) on this riddle and the program immediately found the solution: castling O-O. Indeed, since White should mate in one, in order to solve this puzzle it is necessary to generate each move which is formally possible for White in the given position and to test whether this move is the solution of the riddle. Such a searching procedure is available for a computer program but often not available for thinking.
We would like to thank P.H. de Vries for useful comments and help in Correcting and editing the manuscript.
Anderson, J.R. (1993). 'Problem solving and learning.' American Psychologist, 48: 35-44.
Austin, J.T. and Vancouver, J. B. (1996). 'Goal constructs in psychology: Structure, process, and content.' Psychological Bulletin, 120-3: 338-375.
Baddeley, A.D.(1986). Working memory. Oxford University Press.
Barkow, J.H., Cosmides, L. & Tooby, J. (Eds.)(1992). The adapted mind: Evolutionary psychology and the generation of culture. Oxford University Press.
Batuev, A.S.(1981). Vysshyie integrativnye sistemy mozga. Nauka.
Bechtereva, N.P. (1974). Neurophysiologicheskie aspecty psychicheskoy deyatelnosti cheloveka. Meditzina.
Bechtereva, N.P., Gogolitsin, Yu. L., Ilukhina, V.A., Pakhomov, S.V. (1983). 'Dynamic neurophysiological correlates of mental processes.' The international journal of psychophysiology, 1: 49-63.
Brody, N. (1988). Human motivation: commentary on goal-directed action. Academic.
Courtney, S. M., Underleider, L.G., Keil, K., and Haxby J.V. (1996). 'Object and spatial working memory activate separate neural systems in human cortex.' Cerebral Cortex, 6:39-49.
Delgado, J. M.R. (1969). Physical control of the mind. Toward a psychocivilized society. Harper & Row Publishers.
De Vries, P.H. (1991). 'Text-understanding as a process in the brain.' Cognitive systems, 3-2:179-196.
Edelman, G.M. (1987). Neural darwinism. Basic Books.
Fiez, J.A., Raife F.A., Balota, P.A., Schwarz, J.P., Roichle, M.E., and Petersen, S.E.(1996). 'A positron emission tomography study of the short-term maintenance of verbal information.' Journal of Neuroscience, 16: 808-822.
Fuster, J.M. (1973). 'Unit activity in prefrontal cortex during delayed response performance: neuronal correlates of transient memory.' The journal of Neurophysiology, 36-1:61-78.
Goldman-Rakic, P.S. (1991). 'Prefrontal cortical dysfunction in schizophrenia. The relevance of working memory.' In Psychopathology and the Brain, eds., Carrol B.J. & Barret J.E., Raven Press.
Goldman-Rakic, P.S. & Selemon, L.D. (1997). 'Functional and anatomical aspects of prefrontal pathology in schizophrenia.' Schizophrenia Bulletin, 23-3:437-458.
Graybiel, A. M. (1995). 'Building action: repertoires memory and learning function of the basal ganglia.' Current opinion in neurobiology, 5:733-741.
Graybiel, A. M. (1997). 'The basal ganglia and cognitive pattern generators.' Schizophrenia Bulletin, 23-3:459-469.
Hadamard, J.(1945). The psychology of invention in the mathematical field. Dower.
Hebb, D.O. (1949). The organization of behavior. Wiley.
Heckers, S. (1997). 'Neuropathology of schizophrenia: cortex, thalamus, basal ganglia, and neurotransmitter-specific projection systems.' Schizophrenia Bulletin, 23-3:403-421.
Heckhausen, H. (1980). Motivation und Handeln. Springer-Verlag (Russian translation 1986).
Hinde, R.A. (1970). Animal behaviour. A synthesis of ethology and comparative psychology. Mcgraw-Hill book company.
Inoue, M., Oomura, Y., Aou, S. (1985). 'Reward related neuronal activity in monkey dorsolateral prefrontal cortex during feeding behavior.' Brain Research, 326-2: 307-312.
Izard, C.E.(1977). The psychology of emotions. Plenum Press.
Johnson-Laird, P.N. and Wason, P.C. (1977). Thinking. Readings in Cognitive Science. Cambridge University Press.
Kubota, K.& Niki, H. (1971). 'Prefrontal cortical unit activity and delayed alternation performance in monkeys.' The Journal of Neurophysiology 34-3:337- 347.
Larkin, J.,McDermott, J,Simon, D.P.&Simon, H. A. (1980). 'Expert and novice performance in solving physics problems.' Science, 208(4450): 1335-1342.
Leontiev, A.N.(1975). Dejatelnost, soznanie, lichnost. Politizdat.
Luchins, A.S. and Luchins, E.H. (1950). 'New experimental attempts at preventing mechanization in problem solving.' Journal of Experimental Psychology ,42: 279-297.
Luria, A.R. (1966). Higher cortical functions in man. Tavistock Publications, Andover, Hants.
Luria, A.R. (1973). Osnovy neuropsyhologii. MGU.
Luria, A.R. (1974). Neuropsychologia pamyati. Pedagogika
Luria, A.R. (1982). Varianty "lobnogo syndroma". In Functii lobnyh dolei mozga. ed., Homskaya E.D. & Luria A.R. Nauka.
Marcel, A.J. (1980). 'Conscious and preconscious recognition of polysemous words: locating the selective effects of prior verbal context.' In Colheart M. (Ed), Attention and Performance VIII. Lawrence Erlbaum Ltd.
Marcel, A.J. (1988). Phenomenal experience and functionalism. In Consciousness in contemporary science, eds., Marcel A.J. & Bisiach E.,Clarendon Press.
Maslow, A. H. (1943). 'A theory of human motivation.' Psychological Review, 50, 370-96.
Miller, G.A., Galanter, E. & Pribram, K. (1960). Plans and the structure of behavior. Holt , Rinehart and Winston.
Mordvinov, E. F.(1982). Electophysiologicheskii analyz otcrochennoro povedenia. Nauka.
Murray, H. A. (1938). Explorations in personality. New York: Oxford Press.
Mussen, P.H., Conger, J.J., Kagan, J., Huston, A.C. (1984). Child development and personality. Harper & Row, Publishers.
Nauta, J.H. (1972). 'Neural associations of the frontal cortex.' Acta neurobiol. experimental, 32: 125-140.
Newell, A. and Simon, H.A. (1963). 'GPS, a program that simulates human thought.' In Computers and thought, eds. Feigenbaum E. & Feldman J, McGraw-Hill.
Newell, A. and Simon, H.A. (1972). Human problem solving. Prentice-Halls.
Pervin, L.A. (1988). Goal concepts in personality and social psychology. Erlbaum.
Polya, G. (1957). How to solve it. Doubleday.
Powers, W.T. (1973). Behaviour: the control of perception. Adlins.
Pribram, K.H. (1971). Languages of the brain: experimental paradoxes and principles in neuropsychology., Prentice-Hall.
Pribram, K.H. (1973). The primate frontal cortex-executive of the brain, In Psychophysiology of the frontal lobes, ed. Pribram K.H. & Luria A. R.,Academic Press.
Prudkov, P. (1994). 'A model of self-organization of cognitive processes.' Cognitive Systems, 4-1: 1-19.
Prut, Y., Vaadia, E., Bergman H., Haalman, I,Slovin, H., and Abeles M. (1998). 'Spatiotemporal structure of cortical activity: properties and behavioral relevance.' The Journal of Neurophysiology,79-6: 2857-2874.
Reason, J. (1990). Human Error. Cambridge University Press.
Rosvold, H.E. (1972). 'The frontal system: cortical-subcortical interrelationships.' Acta Neurobiological Experiments, 32-2: 439-460.
Sem-Jacobsen, C.W. (1968). Depth electrographic studies of the human brain and behavior. Springfield.
Shank, R.C.& Abelson, R.P. (1977). Scripts, plans, goals, and understanding. Erlbaum.
Stamm, J.S. and Rosen S.C. (1973). The locus and crucial time of implication of prefrontal cortex in the delayed response task. In Psychophysiology of the frontal lobes. New York.
Thorpe, S.J., Rolls, E.T., Maddison, S.(1983). 'The orbitofrontal cortex: neuronal activity in the behaving monkey.' Experimental Brain Research, 49-1:93-115.
Vartanian, G.A., Pirogov, A.A. (1988). Mechanismy pamyati centralnoy nervnoy systemy. Nauka.