Learning

The hard lessonWilliam-Adolphe Bouguereau's painting.

Learning is the process through which skills, knowledge, behaviors and values are acquired and developed. It is the result of attention, study, experience, instruction, reasoning, observation, as well as the influence of external factors with which we interact. This process can be analyzed from different perspectives, which is why there are different learning theories. It is one of the most important mental functions in humans, animals and artificial systems. Various factors intervene in it, ranging from the environment in which the human being develops. In the latter, the principles of learning for every individual are established and the knowledge received is strengthened, which forms the basis for subsequent learning.

Human learning is related to education and personal development. It must be properly oriented and is optimal when the individual is motivated. The study on how to learn is of interest to Educational Sciences, pedagogy, neuropsychology, educational psychology and anthropology, which includes the peculiarities of each stage of human development. It conceives its theoretical, methodological and didactic approaches for each one of them. Within it are framed, for example, pedagogy and andragogy, the education of children and adults respectively.

It is produced through the changes in behavior that the experiences produce. And, although maturational factors, biological rhythms and diseases intervene in these changes, they are not determinants as such. It is the process through which a certain skill is acquired, information is assimilated or a new strategy of knowledge and action is adopted. It is also a process through which the person appropriates knowledge in its different dimensions, concepts, procedures, attitudes and values.^{[citation required]}

As an establishment of new temporal relationships between a being and its environment, it has been the subject of numerous empirical studies, carried out both in animals and in humans. By measuring the progress achieved in a certain time, learning curves are obtained, which show the importance of the repetition of some physiological predispositions, of "trials and errors", of rest periods after which progress accelerates. They also show the last relationship of learning with conditioned reflexes.

Definition

Learning is defined as:

... the process through which an activity originates or is modified responding to a situation provided that the changes cannot be attributed to the growth or temporary state of the organism (such as fatigue or the effect of drugs).

Ernest Hilgard

Also, learning can be defined as a process of relatively permanent change in a person's behavior generated by experience (Feldman, 2005). This process of changes involves a behavioral change, it must be lasting over time and it occurs through practice or other forms of experience (eg, observing other people).

Before Feldman (2005), Rojas, F (2001) also spoke of learning as a change in behavior, defining it as "the result of a potential change in behavior -either at an intellectual or psychomotor level- that manifests when external stimuli incorporate new knowledge, stimulate the development of skills and abilities or produce changes from new experiences”.

Learning is the change of attitude of a person, when learning is acquired, the attitude is definitively modified through new knowledge or experiments. For example, when a person receives training, they change their attitude, without a change in attitude there was no learning.

We must indicate that the term conduct is used in the broad sense of the term, avoiding any reductionist identification of it. Therefore, when referring to learning as a process of behavioral change, we assume the fact that learning implies acquisition and modification of knowledge, strategies, abilities, beliefs and attitudes (Schunk, 1991). In the words of Schmeck (1988a, p. 171):

... learning is a by-product of thought... We learn thinking, and the quality of the learning result is determined by the quality of our thoughts.

Learning is not an exclusively human capacity. The human species shares this faculty with other living beings that have undergone a similar evolutionary development; in contrast to the majority condition in all species, which is based on the imprinting of behavior towards the environment through genetic patterns.

Human learning

The game is necessary for the development and learning of children

Human learning consists of acquiring, processing, understanding and, finally, applying information that has been "taught" to us, that is, when we learn we adapt to the demands that the contexts demand of us. Learning requires a relatively stable change in the individual's behavior. This change is produced after associations between stimulus and response.

Communication is a phenomenon inherent to the relationship that living beings maintain when they are in a group. Through communication, people or animals obtain information regarding their environment and can share it with the rest; Communication is an elementary part of learning.

Play is necessary for children's development and learning. The fundamental process in learning is imitation (the repetition of an observed process, which involves time, space, skills, and other resources). In this way, people learn the basic tasks necessary to survive and develop in a community.

In humans, learning ability has come to constitute a factor that surpasses common ability in the same evolutionary branches, consisting of behavioral change depending on the given environment. So, through the continuous acquisition of knowledge, the human species has achieved to some extent the power to become independent of its ecological context and even to modify it according to its needs.

Human learning occurs linked to a structure determined by reality, that is, to natural facts. This position regarding learning in general has to do with the reality that determines the language, and therefore the subject who uses the language.

Within human learning, disorders and difficulties in spoken language or literacy, coordination, self-control, attention or calculation may appear. These affect the ability to interpret what is seen or heard, or to integrate such information from different parts of the brain, these limitations can manifest in many different ways.

Learning disorders can be maintained throughout life and can affect different areas: work, school, daily routines, family life, friendships and games, among other aspects.

To achieve the reduction of these disorders, there are learning strategies, which are a set of planned activities and techniques that facilitate the acquisition, storage and use of information. These strategies are classified according to the objective they pursue, there are primary and support.

The primary strategies are applied directly to the content to be learned and are:

• Paraphrase: Explanation of a content by own words.
• Categorization: Organize categories with information.
• Conceptual networks: They allow to organize information through diagrams.
• Imagine: The information is mentally presented with images.

Support strategies are used to create and maintain an environment conducive to learning. They are between them:

• Planning: As your name indicates, situations and moments to learn should be planned.
• Supervision: In it you should develop the ability to introspecte and self-guide during the task to know your own learning style (seeing, hearing, writing, doing or talking).

Beginnings of learning

In ancient times when human beings began their learning processes and did so spontaneously and naturally with the purpose of adapting to the environment. The primitive human had to study the surroundings of his home, distinguish the plants and animals from which food and shelter could be given, explore the areas where they could get water and orient themselves to get back to their home. In a more summarized sense, humans were not concerned about the study. Over the centuries, intentional teaching arises. The organization arose and the knowledge began to be drawn in subjects, these each time on the increase. There was then the need to group them and combine them in concentration and correlation systems. In short, humanity turned to the study of geography, chemistry and other elements of nature through the system of subjects that had been modified and restructured over time. Studies and research on nature contributed to the analysis of these matters.

Neurophysiological Basis of Learning

Because the brain has an extremely complex function in the development of the person, nature has foreseen that it is most available for learning at the stage that needs it most. Thus, at the time of delivery, a baby's brain weighs around 350 grams, but its neurons do not stop multiplying during the first three years. It is precisely during this expansion process that maximum receptivity occurs and all the data that reaches it is classified and archived so that it is always available. This is what learning to have knowledge and various resources that serve as a platform to achieve our goals consists of.

Not much is known about the neurophysiological basis of learning. However, there are some important indications that this is related to the modification of synaptic connections: Specifically, it is commonly accepted as a hypothesis that:

• Learning is the result of strengthening or abandoning synaptic connections between neurons.
• The learning is local, that is, the modification of a synaptic connection depends only on the activity (electric power) of pre-synaptic and post-synaptic neurons.
• The modification of sinapsis is a relatively slow process compared to the typical times of changes in the electrical potentials that serve as a signal between the neurons.
• If the pre-synaptic or post-synaptic neuron (or both) are inactive, then the only existing synaptic modification consists of the potential deterioration or decay of sinapsis, which is responsible for oblivion.

Learning process

The learning process is an individual activity that takes place in a social and cultural context. It is the result of individual cognitive processes through which new information (facts, concepts, procedures, values) is assimilated and internalized, new significant and functional mental representations (knowledge) are built, which can then be applied in situations other than the contexts where they learned. Learning not only consists of memorizing information, it is also necessary other cognitive operations that involve knowing, understanding, applying, analyzing, synthesizing and evaluating.

Learning, being a modification of behavior constrained by experiences, entails a change in the physical structure of the brain. These experiences are related to memory, shaping the brain thus creating variability between individuals. It is the result of the complex and continuous interaction between three systems: the affective system, whose neurophysiological correlate corresponds to the prefrontal area of the brain; the cognitive system, made up mainly of the so-called PTO circuit (parieto-temporo-occipital) and the expressive system, related to the areas of executive function, language articulation and motor homunculus, among others. We realize that learning occurs when we observe that there is a true change in behavior.

Thus, faced with any stimulus in the face of which the mental structures of the human being are insufficient to make sense of it and the praxical abilities do not allow it to act adaptively, the brain performs a series of affective operations (assess, project and choose). This has the function of contrasting the information received with previously existing structures, generating interest (curiosity to know about this), expectation (knowing what would happen if they knew about it) and meaning (determining the importance or need for new learning). Ultimately, the attentional disposition of the subject is achieved. In addition, the interaction between genetics and upbringing is of great importance for the development and learning that the individual receives.

If the affective system evaluates the stimulus or situation as significant, the cognitive areas come into play, taking charge of processing the information and contrasting it with prior knowledge. From complex processes of perception, memory, analysis, synthesis, induction, deduction, abduction and analogy, the assimilation of new information takes place. Subsequently, based on the use of mental operations and knowledge tools available for learning, the human brain executes a greater number of synapses between neurons to store this data in short-term memory (Feldman, 2005). The brain also receives electrical and chemical events where a nerve impulse stimulates the input of the first neuron that stimulates the second, and so on, in order to store information and/or data.

Subsequently, and from the exercise of what is understood in hypothetical or experiential scenarios, the expressive system appropriates the practical implications of these new mental structures, giving rise to a manifest performance in communication or in behavior with respect to what has just been assimilated. It is there, where a first learning cycle culminates, when the new understanding of reality and the meaning that human beings give to it enables them to act in a different and adaptive way in the face of it.

All new learning is by definition dynamic, which is why it is susceptible to being revised and readjusted from new cycles that involve the three mentioned systems. For this reason, it is said that it is an unfinished and spiral process. In short, it can be said that learning is the progressive qualification of the structures with which a human being understands his reality and acts in response to it (starts from reality and returns to it).

To learn we need four fundamental factors: intelligence, previous knowledge, experience and motivation.

• Although all factors are important, we must point out that without motivationany action we do will not be completely satisfactory. When talking about learning, motivation is the "want to learn", it is essential that the student have the desire to learn. Although motivation is limited by the personality and willpower of each person.
• La experience is the "know-how", since learning requires certain basic techniques such as: understanding techniques (vocabulary), conceptual (organizing, selecting, etc.), repetitive (reciting, copying, etc.) and exploratory (experimentation). Good organization and planning is needed to achieve the goals.
• Finally, we have the intelligence and prior knowledgethat at the same time relate to the experience. With respect to the first, we say that in order to learn, the individual must be in a position to do so, that is, he has to have the cognitive abilities to build new knowledge.

Other factors are also involved, which are related to the previous ones, such as psychological maturation, material difficulty, active attitude and the distribution of time to learn and the so-called Theories of Learning Motivation (learning theories).

Teaching is one of the ways to gain knowledge in the learning process.

There are several processes that are carried out when any person prepares to learn. Students, when doing their activities, perform multiple cognitive operations that make their minds develop easily. These operations are, among others:

1. One data reception which represents a semantic-synactic recognition and elaboration of the elements of the message (words, icons, sound) where each symbolic system demands the action of different mental activities. The texts activate the linguistic skills, the images the perceptive and spatial competences, etc.
2. La understanding of information received by the student who, from their previous knowledge (with those who establish substantial connections), their interests (which give meaning to them to this process) and their cognitive skills, analyze, organize and transform (have an active role) the information received to develop knowledge.
3. One long-term retention of this information and the associated knowledge developed.
4. La transfer from knowledge to new situations to solve with your contest the questions and problems that arise.

Types of learning

The following is a list of the most common types of learning cited in the pedagogy literature:

• Receptive learning: It is the kind of learning in which the subject only needs to understand the content to be able to reproduce it, but does not discover anything.

• Learning for Discovery: the subject does not receive the contents passively; he discovers the concepts and their relationships and reordenas them to adapt them to his cognitive scheme.

• Cognitive learning: Active learning focused on supporting the student to make the most of his brain capacity. It seeks to integrate the new information with existing ideas, deepening in its memory and its retention capacity.

• Metacognitive learning: It is a learning strategy that is based on the reflection and research of one's own actions, thoughts, beliefs and emotions. i.e. a way to act consciously on cognitive processes to improve them.

• Repetitive learning: occurs when the student memorizes contents without understanding them or relating them to their previous knowledge, it finds no meaning to the contents studied.

• Significant learning: is the learning in which the subject relates his previous knowledge to the new ones thus giving them coherence regarding their cognitive structures.

• Observational learning: type of learning that is given when observing the behavior of another person, called model.

• Latent learning: learning in which new behavior is acquired, but it is not demonstrated until some incentive is offered to manifest it.

• Learning from essay-error: learning by means of behavioral models that seek answers to the problem.

• Dialog learning: Dialogical learning is the result of equal dialogue; in other words, it is the consequence of a dialogue in which different people give arguments based on claims of validity and not of power. Dialogical learning can be given in any situation in the educational field and has an important potential for social transformation.
• Dialog learning:

• Creative learning: It is the sensitive way to perceive the problems, deficiencies, gaps in knowledge, elements overlooked, lacks of harmony, etc.; the attainment of validity in the information; to define the difficulties or to identify the forgotten element; to seek solutions; to hypothesize on the deficiencies; to examine and re-examine these ones, modifying them and rechecking them, perfecting them and finally communicating their results. This definition describes a natural human process in which stages are involved (motivations). In the educational process, those who present a certain sensitivity to some problems, detect gaps in the information, deficiencies or inconsistencies that can create at that time the feeling of something incomplete, that the class or the course is not going well, or that it is not practical (tension). Motivates the state of need of the student. Whatever the qualifier we use, you need to download your tension. If you do not know how to give a correct answer to this concern, or if your usual forms of response are inadequate, you will try to find the possible explanations, both in the archive of your own memory and in other sources: books or experiences of others eluding the teacher. The adult student will seek alternative solutions, investigating, diagnosing, manipulating, reordering, reconstructing and making guesses and approaches. Until these conjectures or hypothesis are untested, modified and re-examined, the one that learns feels uncomfortable. It remains motivated to continue trying to perfect your response until it seems satisfactory, both aesthetically and logically.

Learning style

Although it is true that each human being is unique, it is also true that each person learns differently, so it would be quite useful and interesting to know what those ways in which learning occurs, which would obviously facilitate the teaching process for the educator and learning for the student.

The learning style is the way an apprentice begins to focus on new and difficult information, trafficking and retaining it.

Dunn et Dunn, 1985

The learning style describes an apprentice in terms of the educational conditions that are more susceptible to favoring his learning. (...) certain educational approaches are more effective than others for him.

Hunt, 1979, Chevrier J., Fortin, G. et al., 2000

The learning style is the set of psychological characteristics that are usually expressed together when a person must face a learning situation; in other words, the different ways in which an individual can learn. It is believed that a majority of people use a particular method of interaction, acceptance and processing of stimuli and information. The characteristics on learning style are usually part of any psycho-pedagogical report that is prepared on a student and is intended to give clues about the didactic strategies and reinforcements that are most appropriate for the child. There are no pure styles, just as there are no pure personality styles: all people use different learning styles, although one of them is usually the predominant one.

There are various classifications of learning styles, such as the Representation System (NLP), which identifies students according to their predominant style, be it visual, auditory or kinesthetic; the Type of Intelligence (Gardner), which identifies eight types of intelligence, according to which what is important is not the "quantity" but the specific way of being intelligent; Information Processing (Kolb), which maintains that there are students: Active, Reflective, Pragmatic and Theoretical, and; the Cerebral Hemisphere, which says that learning can be logical or holistic.

Classification of learning styles

Carrying out the task of learning is somewhat complicated, even more so when we do not know what characteristics we have as learners; Knowing the way in which we carry out the information process will allow us to develop the aspects that facilitate or complicate our learning.

Although it is true, the way we learn is a cultural process because we are taught to learn in a very similar way; in fact, until a few years ago it was thought that we all learned the same way; It is also an individual and unique process since each human being builds his own learning according to his own characteristics.

According to Ofelia Contreras and Elena del Bosque, in general, learning has to do with the way in which we acquire, process and use information, everyone uses different strategies, different rhythms, with more or less precision, even though we have the same motivation, age, religion, race, etc. This is because the learning styles are different.

There are several classifications of learning styles according to:

Representation System (NLP)

Visual: It is the teaching-learning system, which uses graphic organizers, for the contribution of knowledge, increasing the visualization of ideas. Below we describe some of the most used Graphic Organizers (OG) in educational processes:

• Visual classifiers
• Conceptual maps
• Maps of ideas
• Spiders
• Diagrams Cause- Effect
• Time lines.

Aural: is aimed at students whose learning style is more oriented towards the assimilation of information through the ear. For a smaller number of people, auditory stimuli are a way of acquiring learning, rather than visual stimuli.

Kinesthetic: When information is processed by associating it with the sensations and movements of the body, the kinesthetic representation system is being used. This system is used naturally when learning a sport, but also for many other activities. Despite being the slowest learning system, it is the most effective, once our body learns to do something, it is never forgotten, like when a baby learns to walk, or learns to ride a bicycle.

Intelligence Type

Logical-mathematical: reasoning and deduction are used, one has the ability to handle numbers accurately by reasoning logically. They use their left hemisphere. Used by mathematicians and physicists

Verbal-linguistic: is the one used to use words effectively, facilitating communication either orally or in writing. Used by writers or speakers

Corporal-kinesthetic: used to express all kinds of feelings and ideas using the body and hands, physical skills are developed. Used by athletes, dancers, craftsmen, etc.

Spatial: It is the ability to perceive and think about images in three dimensions, used to locate ourselves in the space where we move. Used by sculptors, architects or painters.

Musical: It is the sensitivity towards rhythms, tones and timbres, which enable us to perceive, create or transform sounds and music. Used by composers or musicians.

Interpersonal: It is the ability to interrelate, making us more sensitive, to perceive the body language of other people. Used by psychologists, politicians, salesmen, etc.

Intrapersonal: It is the ability to understand and value ourselves, which includes self-control, self-esteem and self-understanding. Used by philosophers, theologians, etc.

Naturist: It is the ability and sensitivity to use and coexist with our environment, including surroundings, and living beings such as plants and animals. Used by ecologists, botanists and people who love nature.

Information processing (Kolb)

Active: People who act first and think later, open to new experiences, like to work with people leading the charge.

Reflective: They are observers and analysts, doing it in detail, before reaching a conclusion, they are cautious in what they do.

Pragmatist: They are more experimental, they like to try new ideas, theories and techniques, and see if they work in practice.

Theoretical: They use logic and rationality, analyzing and synthesizing information, making complex theories, following the step by step.

Learning Theories

Learning and the theories that deal with the processes of knowledge acquisition have had an enormous development during the last century, mainly due to advances in psychology and instructional theories, which have tried to systematize the mechanisms associated with the processes mindsets that make learning possible. There are various theories of learning, each of them analyzes the process from a particular perspective.

Some of the most widespread are:

Behavioral theories:

• Classic conditioning. From the perspective of I. Pávlov, at the beginning of the centuryXX., proposed a type of learning in which a neutral stimulus (type of stimulus that prior to the conditioning, does not naturally generate the answer that interests us) generates an answer after it is associated with a stimulus that naturally causes that response. When the condition is completed, the first neutral stimulus becomes a conditioned stimulus that causes the conditioned response.
• Conducting. From the conductist perspective, formulated by B. F. Skinner (operating conditioning) towards the mid-centuryXX. and that starts from Pavlov's psychological studies on classical conditioning and Thorndike's work (instrumental conditioning) on effort, tries to explain learning from common laws and mechanisms for all individuals. They were the initiators in the study of animal behavior, later related to the human. Conductism states that learning is a change in the form of behavior based on changes in the environment. According to this theory, learning is the result of the association of stimuli and responses.
• Reinforcement. B. F. Skinner proposed for repetitive learning a type of reinforcement, by which a stimulus increased the likelihood of repeating a certain previous behavior. From Skinner's perspective, there are several reinforcers who act in every human being in a variety of ways to induce the repetitiveness of a desired behavior. Among them we can highlight: bonds, toys and good grades serve as very useful reinforcers. On the other hand, not all reinforcers serve equally and significantly in all people, there may be a type of reinforcer that does not propitiate the same rate of repetitiveness of a conduct, even it may cease completely.
• Theory of social learning. Albert Bandura proposes observational or vicar learning. According to his theory, new behaviors are learned through reinforcement or punishment, or through observational learning, in the absence of direct reinforcement through observation of behavior in other subjects and the rewards or punishments that they obtain.

Cognitive theories:

• Learning for discovery. The perspective of learning by discovery, developed by J. Bruner, attaches great importance to the direct activity of students on reality.
• Significant learning (D. Ausubel, J. Novak) postulates that learning must be meaningful, not memoristic, and for that purpose new knowledge must be related to the previous knowledge that the apprentice possesses. In the face of Bruner's discovery learning, he defends reception learning where the teacher structure the contents and activities to perform so that the knowledge is meaningful to the students. David Ausubel was convinced that the most important thing for the efficient production of learning was through the deepening of the knowledge that the student already brought with him, taking into account that all girls and boys are full of experiences gained through the experiences of his day to day, this becomes an even more useful knowledge when it is taken into account by the teacher, if so an incredible benefit of the human potential would be gained. All this is summarized in one of your thoughts:“If I had to reduce all educational psychology to one principle, I would say this: the most important factor that influences learning is what the student already knows. Find out this and show yourself accordingly (Ausubel, 1986). The individual learns by means of “ Meaningful Learning” means meaningful learning to incorporate the new information into the individual’s cognitive structure. This will create an assimilation between the knowledge that the individual possesses in his cognitive structure with the new information, facilitating learning.
• Cognitivism. Cognitivist psychology (Merrill, Gagné...), based on the theories of information processing and also collecting some behavioral ideas (refuerzo, task analysis) and meaningful learning, appears in the 1960s and intends to give a more detailed explanation of the learning processes.
• Constructivism. The constructivist approach, in its pedagogical current aspect, is a determined way of understanding and explaining the ways in which we learn. Psychologists who leave this approach emphasize the figure of the apprentice as the agent who ultimately is the engine of their own learning. Teachers, parents, and the community are, according to this approach, facilitators of the change that is operating in the mind of the educating, but not the main piece. This is because, for constructivists, the human being does not literally interpret what comes from the environment, either through nature itself or through the explanations of teachers or facilitators. The constructivist theory of knowledge speaks to us of a perception of one's own experiences that will always be subject to the student's interpretation. Jean Piaget proposes that for learning it is necessary an optimal gap between the schemes that the student already possesses and the new knowledge proposed. "When the object of knowledge is removed from the schemes available to the subject, it cannot attribute any significance to it and the teaching/learning process will be unable to demolish." However, if knowledge does not present resistance, the student will be able to add it to their schemes with a degree of motivation and the teaching/learning process will be achieved correctly.
• Topology of Robert Gagné: Gagné considered that there are internal and external conditions that regulate the learning process. The former refer to the acquisition and storage of capacities that are preconditions for learning, or which help to achieve it; the latter refer to the various types of contextual events that should be programmed to facilitate learning. The learning tasks that Gagné proposed for the cognitive sphere are organized in a hierarchy of progressive complexity, ranging from perceptive recognition to problem solving:

1. Reaction to a signal that causes a stimulus: Pavlov's classic conditioned response, in which the individual learns to give a diffuse response to a signal.
2. Stimulus-response: Thorndike's connectionism, Skinner's discriminated operator, sometimes called instrumental response, are chained two or more stimulus-response connections.
3. Chaining: Two or more connections of a stimulus-response are chained.
4. verbal association: chains that are verbal.
5. Multiple discrimination: Identify responses to stimuli that resemble each other, so that interference occurs.
6. Concept learning: A common answer for a class of stimuli.
7. Learning principles: A string of two or more concept reflected in a rule as “if A, then B”, where A and B are concepts. # Troubleshooting: Thought intervenes, principles are combined according to a “higher order rule”.

This hierarchy, in turn, gives rise to a necessary sequence of instruction, which establishes the steps to achieve effective learning:

1. Pay attention.
2. To inform the student of the objectives.
3. Stimulate the memory of previous teaching.
4. Present stimulating material.
5. Provide guidance to the student.
6. Allow the practice of what has been learned.
7. Provide feedback.
8. Evaluate performance.
9. Improve retention and transfer.

• Socio-constructivism. Based on many of Vygotski's ideas, he also considers learning as a personal process of building new knowledge from previous knowledge (activities), but inseparable from the situation in which it occurs. Learning is a process that is intimately related to society.

Information processing theory:

• Theory of information processing. The theory of information processing, influenced by the cyber studies of the 1950s and 1960s, presents an explanation of the internal processes that occur during learning.
• Connectivism. It belongs to the digital age, it has been developed by George Siemens that has been based on the analysis of the limitations of behaviorism, cognitiveism and constructivism, to explain the effect that technology has had on the way we currently live, communicate and learn.

Learning difficulties

• Neurophysiological theories
  • Doman, Spitz, Zucman and Delacato (1967): The most controversial and controversial theory about learning difficulties. Known as “theory of neurological organization”, the same indicates that children with learning impairments or brain injuries do not have the ability to evolve with the greatest normality as a result of bad organization in their nervous system. The thrusters of this theory tested a method of recovery concentrated on motor exercises, diets and a CO2 treatment ensuring that it modified the child's brain structure and facilitated the development of a normal neurological organization.
  • Goldberg and Costa (1981): Based on Orton's theory, they developed a model known as "dynamic model". They claim that the left hemisphere is more specialized in unimodal processing and the retention of simple codes, while the right hemisphere is more capable of intermodal integration and processing new and complex information. Hence the fact that brain dysfunction in learning would not only consist of an alteration or deficiency of the necessary circuits or brain connections, but would rather relate to the alteration of appropriate processing and strategies to carry out learning satisfactorily.
• Genetic theories
  • Hallgren (1950): He studied 276 people suffering from dyslexia and their families, and found that the incidence of deficiencies in the reading, writing and spelling found indicated that such alterations may be subject to inherited factors.
  • Hermann (1959; in Mercer, 1991, p. 83): He studied the learning difficulties of 33 twin couples and compared the results obtained with those of 12 twin couples. Finally, he found that all members of twin couples suffered from serious reading problems, while 1/3 of twin couples showed some reading disorder.
• Biochemical and Endocrine Factors
  • Vitamine deficiency: In relation to learning difficulties, hyperactivity and these vitamine deficiencies, a study was carried out by Thiessen and Mills (1975) in order to determine this relationship. At the end of their experiment, they concluded that there were no differences between a control group and the experimental one (which was applied to the vitamine complex) in their relationship with the reading ability and spelling, despite the fact that such treatment resulted in a decline in hyperactivity behaviors, sleep disorders, perceptive dysfunctions and some linguistic skills.
  • Hyper and hypothyroidism: It seems that overproduction of thyroxine is related to hyperactivity, irritability, weight loss, emotional instability and difficulties in concentration of attention, a factor that is associated with learning difficulties and the decline in school performance. It has been indicated that hypothyroidism causes learning difficulties when presented in childhood and is not treated in time. Cott (1971)
• Theories of gaps in development or mature delays
  • Delays in the maturation of selective care: Proposal by Ross (1976) and known as “Theory of selective care”. It consists of the assumption that selective care is a crucial variable that marks the differences between normal children and those with learning difficulties. Ross points out that children with learning difficulties have an evolutionary delay in selective care, and because this poses an indispensable requirement for school learning, the mature delay hinders their ability to memorize and organize knowledge, in the same way generates cumulative failures in their academic performance.