Are the limits of the mind expandable?

Considering the faculty for learning as a primary human characteristic and means to adaptation, any influence that may reduce this faculty becomes a hazard. Sensory and cognitive stimulation of inappropriate strength, both underload and overload, appears to be one such hazard. The central theme of this paper is overload, in contrast to writings in the 1950s and 1960s which dealt mainly with the ill effects of sensory and cognitive deprivation. The presentation consists of four parts: An account of the author's investigation in which the learning performance of students was correlated with varying input loads; critiques of overload by commentators of different backgrounds; the effects of input on man in the perspective of evolution and of brain-mind identity; a recommendation of physiological and biochemical testing of students exposed to varying input loads in correlation with their learning performance. The physical testing is either to ratify or to invalidate two conclusions reached in observations on the behavioral level. These conclusions are (1) that overload, quantitative or qualitative, obstructs the human capacity for learning, and that such interference may to some extent be a reflection of undesirable changes in autonomic conditions; and (2) that preventive measures can be taken by the structure of an input that reduces it in the perception of its receivers.