Juan Pascual-Leone
Juan Pascual-Leone is a developmental neuropsychologist and the founder of the neo-Piagetian approach to cognitive development. He introduced this term to the literature and put forward key neo-Piagetian predictions about mental attention and working memory in the context of developmental growth.
Pascual-Leone pioneered descriptions of developmental cognitive growth from an organismic perspective, i.e. "from within" the subjects' task processing. He calls this perspective "metasubjective", and contrasts it with the external observer's perspective. Metasubjective modeling requires organismic-causal task-analysis. Using this method he clarified distinctions between learning, maturational-developmental processes, and working memory, studying their interrelationships from a constructivist-developmental organismic viewpoint.
His theoretical-and-empirical methods of research and constructivist views on scientific epistemology led to his propounding the Theory of Constructive Operators, his general neuropsychological causal model framed in terms of organismic operators, schemes, and principles.
Education
Pascual-Leone studied medicine at the University of Valencia, specializing in psychiatry and neurology in Santander, on the north coast of Spain, and in Paris. His background as a medical doctor and neuropsychiatrist, and his experience studying psychology with Jean Piaget, contributed to a sophisticated understanding of Piaget's theory; and led to his development of the theory of constructive operators – an organismic-causal expansion and reformulation that integrates the ides of, among others, his mentors Piaget and Herman Witkin ideas.Under the Supervision of Piaget
In 1963–69, Pascual-Leone studied psychology at the University of Geneva, Switzerland, where, in 1964, he obtained his M.A. in Experimental Child Development, and, in 1969, his Ph.D. in psychology. Here, he was under the direct supervision of Jean Piaget, at the peak of his fame as child psychologist and constructivist-development researcher, whom he refers to as "my intellectual father in Psychology". As one of the later graduate students of Piaget, he obtained first-hand knowledge of Piaget's theory, collaborating in Piaget's book on mental image. He was one of the first Piaget's students to explicitly highlight shortcomings of the master's theory.Under the Supervision of Witkin
Pascual-Leone also studied under the American psychologist Herman Witkin. Witkin—a student of Max Wertheimer, a founder of Gestalt Psychology—conducted organismic-experimental research on individual differences in cognitive and perceptional psychology as well as personality development; his focus was on psycho-social processes and cognitive differentiation. Witkin was an innovator who pioneered, from an organismic perspective, theories of cognitive styles, psychological differentiation, and learning styles.Pascual-Leone defended his doctoral thesis in psychology in Geneva, with Piaget and Witkin as supervisors. In 1964–65, Pascual-Leone's did research at Witkin's laboratory at the State University of New York, Downstate Medical Center. This final doctoral research was done under Witkin's sponsordship and supervision with the help of a postdoctoral fellowship from the Foundations Fund for Research in Psychiatry. Working with Witkin influenced Pascual-Leone's later TCO theory, which was more process-analytical and developmental but in line with Witkin's theory.
Early research into cognitive development
Pascual-Leone's now-classic cognitive developmental research in the 1960s led to his seminal paper in 1970, one of the 500 most cited papers in the field of psychology. In this work he proposed a mathematical model of endogenous mental-attention, and explained how it develops as a function of chronological age in normal children. His findings demonstrated for the first time that, when measured behaviorally and via task analysis, children's mental-attentional capacity increases after the age of three, by one symbol-processing unit every other year until it reaches seven units at 15–16 years. Seven units, according to Miller and Pascual-Leone, is the maximum-capacity of mental/executive attention in adults. His mental-attention model was the first to quantify the effective complexity of processing stages in human development. Many of Pascual-Leone's ideas challenged the scientific establishment at the time, and many experts claim his theories continue to do so. Commenting on this work, Barrouillet and Gaillard wrote: "Neo-Piagetian theories have the potential to account for most of the learning difficulties and developmental disorders by cumulating the strength of the functionalist and the structuralist approaches."Quantifying levels of cognitive development
Pascual-Leone analyzed developmental data in terms of a task's constructive complexity. He assessed complexity by number of essential operators, relations, or schemes that children must simultaneously relate to produce a performance. In 1963, he inferred with his analyses that there is a maximum mental demand that each child's age group can cope with – the characteristic mental power of each developmental stage-level. Only when the growth of mental power in a child is equal to or larger than the task's mental demand, can the child reliably solve a task. Today this information is well recognized; but in the nineteen seventies and eighties the idea was not taken seriously. Pascual-Leone was the first to claim, via his task analyses, that the true organismic stages were in fact the sub-stages of Piaget. Recently Arsalidou, Pascual-Leone, Johnson, Morris, and Taylor have produced data suggesting that these levels of functioning may be expressed in adults by incrementation of brain activity in the executive network.Later work
In later years, Pascual-Leone's scientific work received increased recognition. His theory has been validated in his laboratory and by independent researchers, who, often without explicit reference to Pascual-Leone, have supported his original predictions and subsequent results, either using his tasks or methods that converge with his.The impact of Pascual-Leone's work can be seen in three scholarly controversies: the debate over Trabasso's critique of Pascual-Leone's 1970 paper; The multi-author discussion of Kemps, De Rammelaere, and Desmet comparing Pascual-Leone's model of mental attention with Baddeley's model of working memory; and The discussion of Demetriou, Spanoudis, and Shayer's study on speed of processing, working memory, and general intelligence. A further indicator of the interest in Pascual-Leone's work is evidenced by various published interviews.
Cognitive styles
Juan Pascual-Leone was among the earlier developmental researchers to emphasize the role of cognitive styles and individual difference in cognitive development; and he was the first to quantify mental-attention capacity throughout development, which is important because mental attention is a causal maturational component of working memory. His research on children's and adults' mental-attentional capacity and on cognitive styles, as well as his metasubjective analysis, has opened up new perspectives for understanding cognitive processes, and has helped to clarify causal-developmental relations between affect/motivation, cognition, individual differences, and complex/conceptual processes.Pascual-Leone's work can be classified under four diverse categories: Dialectical constructivist epistemology, the theory of constructive operators, a model for quantifying mental/executive attention, and process task analysis; Educational domains: math, visuospatial, logic, language, science education, giftedness; Individual differences, cognitive styles, developmental neuropsychology, and brain semantics; and Mental health: psychotherapy, meditation, and human change.
Regarding his innovative work on individual differences as sources of difficulty/conflict in Piagetian tasks, Case and Edelstein have written:
The nature of this conflict, Pascual-Leone asserted, is the same as the conflict elicited by Witkin's classic embedded figures test As a consequence, the pathways by which a subject must arrive at the solution to the two sorts of different tasks is different. For this reason Pascual-Leone predicted that field-dependent subjects would show a different developmental profile from field-independent subjects in any battery in which both types of developmental task are administered Pascual-Leone was able to predict the pattern of individual differences across a remarkably broad variety of Piagetian and psychometric tasks In the general theoretical system that he evolved, what was seen as universal about development was its inexorable move towards greater complexity, as a result of biennial increases in mental power. What was seen as individual about development were the particular situations to which different children were sensitive, and the particular styles or strategies that they evolved for dealing with these situations. Field independence was just one of the styles Pascual-Leone studied.
Pascual-Leone published two early books in collaboration, but is now completing, with Janice M. Johnson, an ambitious book of synthesis. He has published numerous articles and chapters. In 2006, he received an honorary doctorate from the University of Cyprus.
The theory of constructive operators (TCO)
Pascual-Leone proposed the Theory of Constructive Operators – an organismic cognitive-developmental theory that is neuropsychologically interpretable in terms of physiological brain processes. He was the first to quantify cognitive-processing limitations in novel problem-solving situations and at different stages of development, and was the first to use a formal, explicit method of process-task analysis to estimate with some quantitative accuracy the mental-attention demands of tasks.This theory explains human psychological functioning as the product of the dynamic combination of schemes and "hidden hardware" operators of the brain. Operators acting on schemes generate thoughts, actions, and learning. Hidden operators are brain-resource mechanisms that regulate functioning of schemes. Piaget left these resources unexplained and often referred to them as principles like "regulations", "accommodation", and "equilibration". Operators intervene in all neuropsychological processes that are emergent and not automatized or overlearned: M-operator ; I-operator ; L-operator ; C-learning ; F-operator ; etc. Table 1 shows different operators of the TCO and some of their key brain regions.
Pascual-Leone's model of mental attention includes activation and inhibition processes. The activation component boosts action/representation schemes that should control task performance. M-operator capacity is measured in terms of the maximum number of mental schemes that can be boosted into working memory at any one time. The method of M-measurement evaluates cognitive demands of a task in order to predict age at which a participant can successfully complete it. By refining the method and accumulating research evidence, Pascual-Leone reached interval scales of measurement of this mental-attentional load. Pascual-Leone also highlighted brain regions that sub-serve cognitive processes linked to his theoretical constructs, offering a tentative chronological map of their evolution.
M capacity is the key maturational causal factor of working memory. Working memory refers to all the schemes in a person's repertoire that are sufficiently activated to co-determine the ongoing process of representation or performance. There are other causes of scheme activation ; for this reason the size of working memory is often larger than the size of M-centration.