IntroductionThe end of preschool and the beginning of school learning is an important period for cognitive development. According to psychological, neuropsychological, and neurophysiological research, preschool age is a time of significant changes and transformations (Elkonin, 1989; Lisina, 2009; Machinskaya & Farber, 2014; Vygotsky, 1996). Different developmental disorders can be detected at preschool age, and attention deficit disorder with hyperactivity (ADDH) is among of the most frequent of them. In Latin American countries, including Mexico, this diagnosis is so common that even children younger than 3 years old receive it from medical doctors or psychologists. In Mexico, children of all ages with this diagnosis are normally medicated by child neurologists or psychiatrists with methylphenidate (Ritalin). No specific neuropsychological assessment is applied to these children, and no serious psychological help is provided.Various researchers are trying to study ADDH syndrome in preschool children with the objective of detecting mechanisms and levels of disturbance, including possible effects on different levels of the central nervous system. Compromise of the frontal lobes and diverse alterations of aspects of the processes of attention are commonly claimed (Barkley, 1998,2001; Castellanos & Acosto, 2004; Cohen, 1993; Santana, Paiva, & Lustenberger, 2003).Nevertheless, in other studies, other processes and not only attention itself are mentioned as being severely impaired in this syndrome. For example, severe problems with space orientation and other aspects of spatial functions in the activities of preschool children have been observed in previous research (Osipova & Pankratova, 1997; Solovieva, Machinskaya, Quintanar, & Bonilla, 2007; Solovieva, Machinskaya, Quintanar, Bonilla, & Pelayo, 2013; Solovieva, Quintanar, & Bonilla, 2006). It is possible to suppose that not only attention itself and not only frontal lobes are the main problems in ADDH. A direct and unilateral relationship between the process of attention and frontal lobes is not the only point of view in modern neuropsychology and neurophysiology. The participation of complex neuronal systems of cortical and subcortical regulation at different levels is also mentioned by authors who consider the process of attention (Machinskaya & Farber, 2014; Machinskaya & Semenova, 2007).From the point of view of the qualitative clinical approach in neuropsychology, considering complex systems as a basis for the brains functional representation of psychological process is one of the essential methodological principles (Leontiev, 2009; Luria, 1973/1989, 1977,). According to such principles, psychological processes are considered as psychological actions, each of which is directed to a specific (external or internal) cultural goal. Attention itself is never an independent psychological action. According to Galperin, attention can be understood as an internal action of control (Galperin & Kabilnitskaya, 1974) that has its own history starting from early childhood. During preschool age, we can speak about attention as an external action of control directed to external goals in joint activity between an adult and a child. It is clear that in such an interpretation attention could never be related to only one type of brain mechanism or to one determinate brain structure. The action of control at the external level will always include different systems of brain mechanisms that are united for the fulfillment of a necessary goal. The absence of goals within the social situation of development produces the absence of actions and, as a consequence, the impossibility of formation of the corresponding cortical and subcortical functional systems.Historical-cultural neuropsychology, following A.R. Luria's approach, offers functional analysis of brain mechanisms that might help to determine the clinical features of ADDH syndrome in each particular case. …