Luria: Neuropsychological Studies in the USSR, A Review

AR Luria (Part I) Proc Nat Acad Sci USA 70:959-964 1973
(Part II) IBID 70:4 1278-83 1973

Definition of the central problem of neuropsychology: "localization of functions in the brain cortex"

Luria proposes radically revising the concept of "function" and "localization." Every behavioral function is "really a functional system" with feedback for control of the behavior and feedforward to establish plans and programs which is decisive for the elaboration of complex behaviors. Functional systems (as opposed to reflex circles) was formulated by Russians Anokhinand Bernstein and Pribham. A "new" physiology of activity (not reactivity) is based on coordinated functions (or constellations) of cerebral zones which have some overlap. Rather than localizing a cerebral function, n,'s try to discover how a functional system is distributed in different parts of the brain. However, lesions of different functional zones lead to deterioration of different functions. Luria stresses the importance of "double dissociations"the idea of which he credits to
Teuber. Certain zones that contain a specific"factor" of psychological "qualification" disturb the functional zone.

Luria proposes the temporal zone is decisive in acoustic analysis of speech sounds, perception of words and writing, but not computation or maps. Parietal zones associate with spatial analysis. Studying "qualifications of the system"leads to discovery of "factors"

Luria states that the "ideation center" that creates "motor schemes" that are superimposed on the "sensation of movement" ie praxis centers, "does not yet have a physiologic reality." NA Bernstein proposed a rule of the "impossibility of regulation of movements only by efferent impulses" and required that afferent influences give constant information about the changing positions of joints and flexibility of muscles. These "afferent fields" are organized from primitive (spinal cord) to high level (cortical) sensory systems. These afferent fields provide stable "afferent corrections" of motor acts and at first they are "secondary" or passive movements, later they become "primary type of correctionss" with feed forward mechanisms. The feed forward organization of flexible movements provides what Anokhin called the "acceptor of action." Lesions of the postcentral gyrus cause "afferent paresis" of "afferent ataxia" as first described by Foerster (1936).Inferoparietal or parietooccipital zones of the "spatial afferent fields"cause a "spatial apraxia" with confusion of the vertical, horizontal and sagittal planes. Lesions of the premotor areas cause a loss of fluid shifts from one movement to another with breakdown of the "kinetic melodies" of movement. Involvement of the subcortex causes a pathological inertia of movement with motor perseverations. Prefrontal lesions cause a loss of goal linked actions and their replacement with inert stereotypes or incorrect imitations.