The interest in understanding how language is “localized” in the brain has existed for centuries. Departing from seven meta-analytic studies of functional magnetic resonance imaging activity during the performance of different language activities, it is proposed here that there are two different language networks in the brain: first, a language reception/understanding system, including a “core Wernicke’s area” involved in word recognition (BA21, BA22, BA41, and BA42), and a fringe or peripheral area (“extended Wernicke’s area:” BA20, BA37, BA38, BA39, and BA40) involved in language associations (associating words with other information); second, a language production system (“Broca’s complex:” BA44, BA45, and also BA46, BA47, partially BA6-mainly its mesial supplementary motor area-and extending toward the basal ganglia and the thalamus). This paper additionally proposes that the insula (BA13) plays a certain coordinating role in interconnecting these two brain language systems.

Illiterates represent a significant proportion of the world's population. Written language not only plays a role in mediating cognition, but also extends our knowledge of the world. Two major reasons for illiteracy can be distinguished, social (e.g., absence of schools), and personal (e.g., learning difficulties). Without written language, our knowledge of the external world is partially limited by immediate sensory information and concrete environmental conditions. Literacy is significantly associated with virtually all neuropsychological measures, even though the correlation between education and neuropsychological test scores depends on the specific test. The impact of literacy is reflected in different spheres of cognitive functioning. Learning to read reinforces and modifies certain fundamental abilities, such as verbal and visual memory, phonological awareness, and visuospatial and visuomotor skills. Functional imaging studies are now demonstrating that literacy and education influence the pathways used by the brain for problem-solving. The existence of partially specific neuronal networks as a probable consequence of the literacy level supports the hypothesis that education impacts not only the individual's day-to-day strategies, but also the brain networks. A review of the issues related to dementia in illiterates is presented, emphasizing that the association between the education level and age-related cognitive changes and education remains controversial. The analysis of the impact of illiteracy on neuropsychological test performance represents a crucial approach to understanding human cognition and its brain organization under normal and abnormal conditions.

We are proposing that, in the future, tests included in psychological and neuropsychological batteries should fulfil the following criteria. (1) Have a large enough normative database (“normative criterion”). Performance of subjects of different ages and different educational levels, including illiterates, should be well established. Normative data from different countries and cultural contexts should be available. (2) Know the effects of brain damage on different characteristics on the test (“clinical criterion”). (3) Know how the brain is activated when the test is performed (“experimental criterion”). (4) Know how this test correlates with other cognitive tests (“psychometric criterion”). Few contemporary tests fulfil all these criteria. A notable exception is Semantic Verbal Fluency test using the category ANIMALS. This test requires the generation of words corresponding to a specific semantic category, such as animals, fruits, vegetables, etc. Typically, the number of correct words produced in 1 minute is counted. Semantic verbal fluency taps lexical knowledge and semantic memory organization. Using regional cerebral blood flow measures, it has been reported that both frontal and temporal activation are observed while performing this test. Optimal fluency performance involves generating words within a subcategory and, when a subcategory is exhausted, switching to a new subcategory. Although different semantic categories have been used in this test, ANIMALS is the most frequent due to some significant advantages: (1) it is a clear enough semantic category across languages and cultures; (2) it is a relatively easy semantic category with only minor differences among people living in different countries, different educational systems, or belonging to different generations; and (3) it is an easy‐to‐administer, short, and common test included in different neuropsychological test batteries. It is concluded that obtaining similar information for other cognitive tests represents a huge research endeavour for psychology and neuropsychology during the 21^st century.

The potential effect of gender on intellectual abilities remains controversial. The purpose of this research was to analyze gender differences in cognitive test performance among children from continuous age groups. For this purpose, the normative data from 7 domains of the newly developed neuropsychological test battery, the Evaluación Neuropsicológica Infantil [Child Neuropsychological Assessment] (Matute, Rosselli, Ardila, & Ostrosky-Solis, 2007), were analyzed. The sample included 788 monolingual children (350 boys, 438 girls) ages 5 to 16 years from Mexico and Colombia. Gender differences were observed in oral language (language expression and language comprehension), spatial abilities (recognition of pictures seen from different angles), and visual (Object Integration Test) and tactile perceptual tasks, with boys outperforming girls in most cases, except for the tactile tasks. Gender accounted for only a very small percentage of the variance (1%-3%). Gender x Age interactions were observed for the tactile tasks only. It was concluded that gender differences during cognitive development are minimal, appear in only a small number of tests, and account for only a low percentage of the score variance.