Alfredo Ardila

Although Lev Vygotsky’s interpretation of human cognition was proposed almost one century ago, new scientific and technological advances have significantly supported many of his ideas and hypotheses. His cultural-historical theory of psychological processes, and his contributions to educational psychology, have continued growing without interruption. In this paper, three of Vygotsky’s hypotheses are examined in light of 21st century scientific developments:

1. The influence of cultural factors on human cognition. A diversity of research studies in different countries has corroborated the crucial impact of culture on cognitive test performance; 
2. The role of language in higher psychological processes. According to Vygotsky’s cultural-historical approach, cognitive processes (“complex psychological processes”) are social in origin, but complex and hierarchical in their structure. Intrinsic to the systemic organization of higher cognitive processes is the engagement of external artifacts (objects, symbols, signs), which have an independent history of development within a culture; and 
3. The hypothesis that thought and general complex cognition is associated with certain “inner speech.” Some contemporary neuroimaging studies (particularly PET and fMRI) analyzing “inner speech” have been carried out. These studies have attempted to find the areas of the brain involved in “inner speech.” These scientific advances significantly support Vygotsky’s interpretation of human cognition. It has been found that inner speech depends on activity in Broca’s area and related brain network activity in the left hemisphere. Hence, inner speech is closely related to grammar, language production, and executive functions.

Vygotsky’s important contribution to the understanding of psychological processes has stimulated, and continues to stimulate, a substantial amount of research in this area.