A pesar de la relativamente corta historia de la Psicologia como ciencia, existen pocos constructos psicologicos que perduren 90 anos despues de su formulacion y que, aun mas, continuen plenamente vigentes en la actualidad. El factor «g» es sin duda alguna uno de esos escasos ejemplos y para contrastar su vigencia actual tan solo hace falta comprobar su lugar de preeminencia en los modelos factoriales de la inteligencia mas aceptados en la actualidad, bien como un factor de tercer orden en los modelos jerarquicos o bien identificado con un factor de segundo orden en el modelo del recientemente desaparecido R.B.Cattell.

The g Factor: The Science of Mental Ability

and general: a + b = b + a. All algebraic formulas and equations are decontextualized statements. Syllogisms can be decontextualized: Which statement (1 or 2) is false? (1) All Xs are Y; all Ys are Z; therefore all Xs are Z. (2) All Ps are Q; all Ns are Q; therefore all Ps are N. Now notice how much easier equivalent syllogisms seem when they are contextualized: (1) All men are persons; all persons are human; therefore all men are human. (2) All chickens are fowl; all ducks are fowl; therefore all chickens are ducks. A person who is unable to decontextualize a syllogism would most likely declare the following syllogism to be false, although in terms of pure logic (but not experience) it is true: All apples are fruit; all fruits are green; therefore all apples are green. Syllo­ gisms are no longer used in IQ tests, because syllogisms are uniformly easy for persons who solve them by using Venn diagrams. Since knowing or not knowing the ' 'trick'' of using a Venn diagram is the main determinant of passing or failing a syllogism, syllo­ gisms are poor items for an IQ test. Different persons with the same IQ differ much too markedly on \"syllogism ability,\" a difference often attributable to their either having learned or not having learned the \"trick\" of using Venn diagrams for verifying syllo­ gisms. However, syllogisms would be suitable items in an achievement test, to determine whether a student had mastered the use of Venn diagrams after receiving instruction. 28. Lynn, 1987a, 1987b, 1989, 1990a, 1990b; Lynn & Pagliari, 1994. 29. Schoenthaler et al., 1991. A good, though far from comprehensive, article on the effects of nutrition on IQ (Ricciuti, 1994) offers a somewhat more conservative assess­ ment than the articles by Lynn and by Schoenthaler. Eysenck (1995) discusses the use of nutrients as a means of sudying intelligence differences experimentally. Eysenck and Schoenthaler (1997) provide the most recent and comprehensive review of experimental studies of the effects of nutrition on IQ. 30. Jensen (1997a) reviews much of the recent literature on the effects of the biological environmental factors (including mother-fetus immunogenic incompatibility factors) on mental development. Most of the environmental variance in IQ is attributable to the cumulative effect of such biological factors. Jensen (1996a) replies to an article by Flynn (in the same book) and summarizes the specific environmental factors hypothesized to play some part in the secular rise in IQ. 31. Modern mass-production poultry farms make use of this phenomenon, by keeping chicks under bright electric lighting twenty-four hours a day, to hasten their rate of growth and the time needed to reach their maximum egg-laying capacity. 32. (a) Lucas et al., 1992; (b) Ryan et al., 1991.

The g factor.

Context Hippocampal volume is lower than expected in patients with schizophrenia; however, whether this represents a fixed deficit is uncertain. Exercise is a stimulus to hippocampal plasticity. Objective To determine whether hippocampal volume would increase with exercise in humans and whether this effect would be related to improved aerobic fitness. Design Randomized controlled study. Setting Patients attending a day hospital program or an outpatient clinic. Patients or Other Participants Male patients with chronic schizophrenia and matched healthy subjects. Interventions Aerobic exercise training (cycling) and playing table football (control group) for a period of 3 months. Main Outcome Measures Magnetic resonance imaging of the hippocampus. Secondary outcome measures were magnetic resonance spectroscopy, neuropsychological (Rey Auditory Verbal Learning Test, Corsi block-tapping test), and clinical (Positive and Negative Syndrome Scale) features. Results Following exercise training, relative hippocampal volume increased significantly in patients (12%) and healthy subjects (16%), with no change in the nonexercise group of patients (−1%). Changes in hippocampal volume in the exercise group were correlated with improvements in aerobic fitness measured by change in maximum oxygen consumption ( r  = 0.71; P  = .003). In the schizophrenia exercise group (but not the controls), change in hippocampal volume was associated with a 35% increase in the N -acetylaspartate to creatine ratio in the hippocampus. Finally, improvement in test scores for short-term memory in the combined exercise and nonexercise schizophrenia group was correlated with change in hippocampal volume ( r  = 0.51; P Conclusion These results indicate that in both healthy subjects and patients with schizophrenia hippocampal volume is plastic in response to aerobic exercise.

https://jamanetwork.com/journals/jamapsychiatry/articlepdf/210578/yoa90066_133_143.pdf

Hippocampal Plasticity in Response to Exercise in Schizophrenia

This target article considers the relation of fluid cognitive functioning to general intelligence. A neurobiological model differentiating working memory/executive function cognitive processes of the prefrontal cortex from aspects of psychometrically defined general intelligence is presented. Work examining the rise in mean intelligence-test performance between normative cohorts, the neuropsychology and neuroscience of cognitive function in typically and atypically developing human populations, and stress, brain development, and corticolimbic connectivity in human and nonhuman animal models is reviewed and found to provide evidence of mechanisms through which early experience affects the development of an aspect of cognition closely related to, but distinct from, general intelligence. Particular emphasis is placed on the role of emotion in fluid cognition and on research indicating fluid cognitive deficits associated with early hippocampal pathology and with dysregulation of the hypothalamic-pituitary-adrenal axis stress-response system. Findings are seen to be consistent with the idea of an independent fluid cognitive construct and to assist with the interpretation of findings from the study of early compensatory education for children facing psychosocial adversity and from behavior genetic research on intelligence. It is concluded that ongoing development of neurobiologically grounded measures of fluid cognitive skills appropriate for young children will play a key role in understanding early mental development and the adaptive success to which it is related, particularly for young children facing social and economic disadvantage. Specifically, in the evaluation of the efficacy of compensatory education efforts such as Head Start and the readiness for school of children from diverse backgrounds, it is important to distinguish fluid cognition from psychometrically defined general intelligence.

http://www.keithstanovich.com/Site/Research_on_Reasoning_files/FluidBBS06.pdf

How similar are fluid cognition and general intelligence? A developmental neuroscience perspective on fluid cognition as an aspect of human cognitive ability

Darwin considered an understanding of the evolution of the human mind and brain to be of major importance to the evolutionary sciences. This groundbreaking book sets out a comprehensive, integrated theory of why and how the human mind has developed to function as it does. Geary proposes that human motivational, affective, behavioral, and cognitive systems have evolved to process social and ecological information (e.g., facial expressions) that covaried with survival or reproductive options during human evolution. Further, he argues that the ultimate focus of all of these systems is to support our attempts to gain access to and control of resources - more specifically, the social (e.g., mates), biological (e.g., food), and physical (e.g., territory) resources that supported successful survival and reproduction over time. In this view, Darwin's conceptualization of natural selection as a "struggle for existence" becomes, for us, a struggle with other human beings for control of the available resources. This struggle provides a means of integrating modular brain and cognitive systems such as language with those brain and cognitive systems that support general intelligence. To support his arguments, Geary draws on an impressive array of recent findings in cognitive science and neuroscience as well as primatology, anthropology, and sociology. The book also explores a number of issues that are of interest in modern society, including how general intelligence relates to academic achievement, occupational status, and income. Readers will find this book a thought-provoking read and an impetus for new theories of mind.

The Origin of Mind: Evolution of Brain, Cognition, and General Intelligence

The discrepancy between current and premorbid ability is a relevant indicator of acquired mental impairment, which itself is closely related to general cerebral dysfunction. The use of tests sensitive to cerebral dysfunction, raises relatively few problems compared with tests being resistant that are used to estimate premorbid mental ability. For premorbid ability, verbal tests assessing knowledge, especially vocabulary, have been shown to be valid. A test, possibly more insensitive to brain dysfunction than the ones usually administered, is the multiple choice vocabulary test (MWT = Mehrfachwahl-Wortschatz-Test). At present only German versions are available. They are presented in some detail because of their advantages. Construction of the MWT is simple, and it can be easily administered in about five minutes. The results correlate fairly well with global IQ in healthy adults (median of r = 0.72 in 22 samples) and are more insensitive to current disturbances than such tests as the WAIS vocabulary test. The limitations of premorbid tests with respect to diagnostic validity are discussed. It is concluded, that studies which do not control premorbid intelligence have to be considered as a "malpractice" and should not be accepted by scientists.

Multiple choice vocabulary test MWT as a valid and short test to estimate premorbid intelligence

The basic parameters of human information processing: Their role in the determination of intelligence

Adherents of the Galton paradigm favour the concept that the simple parameter ‘speed of information processing’ has a physiological basis and determines complex achievements assessed in intelligenc...

Bernd Fischer

Papers

Multiple choice vocabulary test MWT as a valid and short test to estimate premorbid intelligence

The basic parameters of human information processing: Their role in the determination of intelligence

A basic information psychological parameter (BIP) for the reconstruction of concepts of intelligence

Role of Hyperbaric Oxygenation in Treatment of Infections

Hyperbaric Oxygenation in Plastic Surgery and Dermatology