Speech and Orienting response

Frontal Lobes and the Regulation of Arousal Processes" ( 1970) was co-authored with E. D. Khomskaya, and appeared in Attention: Contemporary Theory and Analysis. The article reports on the results of studies conducted with normal subjects and brain lesion patients in an effort to ascertain the role of the frontal lobes in the regulation of arousal processes or the orienting reflex. The orienting reflex is
a complex functional system which includes a series of somatic, sensory, vegetative, electrocephalographic, and other components. While having a certain autonomy, all components of the orienting reflex obey common laws: they appear with the presentation of stimuli which are new for the organism; they have a nonspecific character, i.e., they do not depend on the modality of the stimulus; they disappear in proportion to repetition; and reappear with any changes in the experimental situation. Another no less important factor that elicits orienting reactions, is the significance or signal meaning of the stimuli. ( Luria & Khomskaya, 1970, pp. 303-304)
The authors demonstrate that, anatomically and neurologically, a number of connections exist between the frontal lobes and those structures of the limbic system and brain stem that are responsible for states of wakefulness, arousal, and the orienting reflex. The latter structures provide the efferent link in the system while the afferent link seems to be located at the cortical level.
The most significant finding of the experiments for our purposes is the fact that in humans one can regulate the orienting reflex by means of speech, which does physiologically modify the same:
If, by means of speech, stimuli are given signal meaning, a series of changes in the system of the orienting reflex occurs, namely: extinguished orienting reactions reappear and become more intensive (their latent period is shortened, their strength and duration is increased), they do not extinguish any more, and they arise for a wider range of intensities (as a result of the lowering of the threshold of sensation and the elevation of the threshold of the defense reaction). In this situation, the orienting reactions become more discriminating. They are not responsive to any outside nonsignal stimuli. Similar changes in the system of the orienting reflex occurring with the introduction of verbal instructions are observed in all normal subjects who are in an awake state (grownups and children, beginning from 8-10 years of age). ( Luria & Khomskaya, 1970, p. 304)
The authors indicate that this regulation of the orienting reflex by means of speech is such an essential characteristic of human mental functioning that it "may serve as an important indicator of the normally functioning brain" ( Luria & Khomskaya, 1970, p. 305). The balance of the article recounts their endeavors to test this hypothesis, and their conclusion


Reviewing his research findings on the role of the frontal lobes in the activation processes, verbally programmed behavior, and problem solving activity, Luria notes that "Each human activity starts from definite intention, directed at a definite goal, and is regulated by a definite program which demands that a constant state of cortical tone be maintained" ( Luria, 1973a, p. 5). It is his conclusion that the frontal lobes have vital roles in the state of activation that arises when the brain has some task to perform.
In addition, the frontal lobes are vital in the process whereby the orienting reflex is intensified and stabilized as a result of verbal instruction, so Luria concludes that they have a vital role in specifically human forms of attention.