Perception, Cognition and Thought: Part I Nature, Evolution and Development of Conceptual and Symbolic Processes

“A human being is a part of the whole called by us universe, a part limited in time and space. He experiences himself, his thoughts and feeling as something separated from the rest, a kind of optical delusion of his consciousness. This delusion is a kind of prison for us, restricting us to our personal desires and to affection for a few persons nearest to us. Our task must be to free ourselves from this prison by widening our circle of compassion to embrace all living creatures and the whole of nature in its beauty.”

       - Albert Einstein

Over the last few years, Cancer Investigation has published several articles related to scientific and medical thinking, medical decision-making, errors in judgement and appropriate scientific methods related to causality, bias, confounding, and other analytic methods (1–4). Related discussions of medical thinking and decision-making have been published in similar journals during this time period (5–13). While these have all had some practical application to clinical and scientific thought and judgement, the Journal editors have seen a need for a deeper discussion of the underlying basis of perception, cognition, judgement and decision making including the nature of these processes as well as their origin and evolution over time. This represents a daunting undertaking, the implications of which go far beyond that of clinical medicine and medical research. These issues represent an important foundation and framework for more practical applications of human cognition, language, social interactions, etc. As the reader will see, this journey will take us past more practical applications into the realm of metaphysics, epistemology, philosophy and beyond. It is understood from the start that such discussions may be too far afield for some readers of traditional medical and scientific writings. However, for those seeking a deeper understanding of how we think and make decisions beyond traditional discussions, hopefully, this will be both interesting and thought-provoking stimulating further discussion and research within and across these disciplines.

Our evolution, development and actual survival are dependent upon the ability to successfully navigate our world guided by natural or imposed constraints on our perceptions and cognition in virtually all interactions with the world and without which it would be incomprehensible and unsurvivable. We classify our experience with the world as well as our thoughts by placing constraints upon what we perceive or think based on our evolved and developed perception and cognition. These capacities are the result of our genetics, biology, physiology as well as our prior experiences including education, language and other interactions with the world.

While these constraints enable us to survive and, in fact, thrive in our physical, mental and emotional environment, they also place severe limitations on what we experience including what we see, hear, smell, taste, feel as well as what we think and understand. Therefore, our physical, mental and emotional makeup informs what we can and what we cannot perceive, comprehend and understand. The “real world” beyond our physical, mental and emotional capabilities, remains largely a shadowy glimpse and beyond our reach even given our mental agility, science, and technology. Without the ability to conceptualize and create symbols of constrained reality, the world and all experiences would be an infinite maze of stimuli, impulses, random thoughts constrained only by our biology and physiology without which existence would be but a blur, a cauldron of uninterpretable, unrecognizable and total obstruse experiences incompatible with survival from the earliest age. A few thought experiments highlight the dilemma. Imagine the cognitive world of the newborn whose only experience relates to the in utero environment and whose brain remains largely underdeveloped. Imagine an infant growing up without any human interaction or experiences. Imagine our interactions and attempts to communicate with an extraterrestrial alien species where the underlying biology, physiology, and environment are entirely unlike ours.

At the same time, we must recognize that our perceptions, thought, and language do not provide us with a full comprehension of underlying reality but only reveal only those features which our evolution and development have forged into our neurophysiology and anatomy forged further by our prior experience, education and environmental interactions. These issues are particularly cogent to our concept of time and the impact that language, culture, and environment have on our thinking about the past, the present and the future as well as the relentless linear progression of time. In order to better understand these constraints, like all other knowledge, we need to understand their nature, development and evolution which we will try to do in this series. We will touch on disciplines far afield from traditional medicine and cancer research including cognitive science, linguistics, computer science and artificial intelligence, cognitive psychology and psychiatry, neuropsychology, developmental psychology, biophysics, theoretical biology, primate biology, anthropology, and philosophy and logic among others (14–16). We will focus on the origins, development and evolution of perception, cognition and conceptualization and how experience and symbolization and language affects thought, discovery, concept learning, and executive functioning including updating, switching, inhibition and cognitive reserve. Thought and symbolic phenomena, like other complex processes, require an explanation of the coherent interactions among the constitutional parts as well as a wholistic or integrated understanding of how all the pieces fit together, work together and enable one another to participate in the functioning of the whole at an entirely new level. As we ascend the evolutionary ladder, the very high degree of specialization observed is matched only by the high degree of integrated control provided by the Central Nervous System and its processes.

Thought or the process of thinking often is used as a blanket term for a range of perceptual and cognitive activities including conceptualization, symbolic processing, pattern recognition, use of language, problem-solving, creativity and decision-making. Conceptualization and higher symbolic processing unquestionably involve the relationship of constraints imposed by some integrated behavior on incoming and intrinsic processes forming classes or categories and depends on the acceptance of certain properties of objects as being critical and others as irrelevant. Problem solving involves the discovery or formulation of possible courses of action while decision making is necessary in any situation in which a number of alternative responses are possible. Neuroscientists believe that a certain level of neural maturation is necessary before such categorization processes can arise either phylogenetically or ontogenetically.

Categorization has several purposes including identification of objects in the world around us; reducing the complexity of the environment; reducing the necessity for constant learning; providing direction for instrumental activity; and ordering and relating classes of events (causal relations etc.). Problem-solving often involves the consideration of new categories by the repeated regrouping of objects until an appropriate one is found (17). In addition to inherited perceptions of concepts and those learned through experience and education, humans have evolved the capacity to create concepts by logical or patterned manipulation of symbols which are then tested on and selected by the environment. While conceptual processes can be taught to a machine, man, via his logical and linguistic abilities, can generate new and abstract concepts that in turn organize his environment even more.

The Sapir-Whorf, or Whorfian hypothesis, is that our perception of reality is directly related to our thinking which, in turn, is influenced by our language in many ways shaping our reality. Categorization of knowledge depends on both biological and cultural factors and the structural and functional organization of the individual moderates our worldview as well as our survival potential (18). Obviously, man needs symbolic language to express concepts such as amount, relative size, and order. Once developed, however, these symbol systems have permitted man to rapidly gain mastery over his environment. We may be able to attribute most of man’s uniqueness and dominance to his symbolic activity, while, at the same time, we might attribute many of his diseases, particularly those unique to him, to disordered symbolic activity. Perception is determined by the individual’s psychophysical organization; whereas conceptualization depends on the symbolic systems which are determined, at least in part by, the language structure of the culture (18). Each language embodies and perpetuates a particular world outlook. Those that speak the language are constrained or forced to see the world in basically the same way. In addition, the meaning of one word or phrase affects the meaning of neighboring words or phrases. Overall, the components of the meaning of a larger proposition are integrated such that each supports the others. Others believe that there is no clear-cut or constant correlation between language and thought with a prelinguistic phase in the development of thought. The critical point comes when speech begins to serve intellect and when the child’s sudden active curiosity about words results in a rapid increase in vocabulary.

We must distinguish between direct cause and effect relationships and symbol-object relationships. The symbol does not cause or in any way directly affect the object but represents it abstractly. An algorithm is a symbolic system where, once the set of rules is applied, it is free to run by itself. What features of reality we grasp in our theoretical symbolic system are likely arbitrary and determined by biological, cultural, and linguistic determinants. While the symbol may represent an element of the real world, the algorithm is a symbol-logic system that places constraints on the elements resulting in a new hierarchal level of reality. As opposed to cause-and-effect relationships, there is no physically enforced link between the symbol and its object which is arbitrary. The former link is produced by conditioning whereas the symbol-object link has significance within a closed system. In fact, a symbol only has meaning based on a complex set of coordinated constraints. The symbol system provides meaning which goes beyond simple stimulus-response pairing and the search for increased survival. In fact, it appears that there would be no meaning or order to our world without our use of symbols. Symbolic activity is used for the communication of cognitive information permitting the development of languages and the communication of emotional information leading to the development of myth and artistic values.

As early man developed the capacity to form symbols, conceptual symbols could be used internally to reason and form memories and traditions rather than the simple use of trial and error (18). Gradually primitive man dissociated what appeared to be a causally related imitation into separate object and representations and insight was reached where cognitive symbols took on meaning. Bertalanffy argued that higher-level cognitive behavior is primary. Constraints imposed by biological evolution, experience, culture, education and language are superimposed enhancing the human ability to make discoveries while imposing constraints on what we are able to observe and the thoughts that we are likely thus limiting the possible aspects of reality yet to be discovered or created (18). The challenge of education is to provide the foundation of knowledge from the past while not limiting the capacity for novel thoughts, insights and discovery capable of expanding or reframing human knowledge. While facts (observations, prevailing hypotheses etc) change over time, logic and critical reasoning persist and can be applied regardless of the underlying assumptions or facts. What remains unclear is the extent to which the highest levels of cognition and symbolic processing can be nurtured and further developed by the environment. What is needed is a balance between providing information while encouraging novel thought, creativity and vision replacing prior concepts with a new view of the world. Finding this balance between prior knowledge and creativity and discovery is the major challenge to a better understanding of underlying reality and finding meaning in it.

A somewhat perplexing observation has come out of the neurophysiologic studies of Benjamin Libet and colleagues (19). They asked subjects to move their wrist at will and note precisely the time when they decided to take action using a moving dot indicating time. Participants reported the intention to move about 200 milliseconds (msecs) before the actual movement occurred. What is particularly fascinating is that the intention to move based on electrophysiologic activation in the supplementary motor area involved in controlling movements was recorded some 550 msecs before the actual movement or some 350 msecs before the subject was aware of making a decision to move. Some have argued that this demonstrates that the awareness of making a decision to move appears to be the result of subconscious brain processes rather than the cause of the subsequent movement.

For decades, Jean Piaget studied the development of the child’s cognitive ability with the underlying hypothesis that the child is not a passive observer but an active discoverer and constructor of his/her environment (20). He sees biological factors, mainly hereditary transmission of an organism’s nervous system and of various innate reflexes, creating what he calls psychological structures which form the basis of mental activity but can be transformed by experience. He postulates that these structures have two basic functions (1): to organize processes into coherent systems or higher-order structures and (2) to adapt by changing responses to accommodate existing structures in dealing with the environment (assimilation). Kagan has shown that the infant’s attention is attracted to objects with sharp boundaries, have light-dark contrast or which move across the field of vision (21).

The human being is an active discoverer and, in a sense, a creator of his or her world. The use of symbols and words allows for the use of experience to handle new situations, thoughts, and social communication. The basis of perceptual and conceptual processes starts with information processing by sensory receptors which is transformed by on-going spontaneous activity before reaching the central cognitive setting. There is an intimate relationship between cognitive and symbolic processes governed by the universal properties of all hierarchical systems. Language appears to emerge both phylogenetically and ontologically from the development of a general cognitive ability to analyze and synthesize both sensory information and internal symbolic processing while striving for understanding and meaning in the world.

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