Chemistry and the Rhinencephehn NBC News recently reported (1)a government study that 20% of the adult population of the United States is functionally illiterate. At the same time, this study found that 98% of the public enjoys the use of indoor plumbing. A special report on puhlic education in Time magazine ( 2 )revealed that some high school teachers worry mostly about finding another movie to show their students. Multi-media instructional programs, based on the use and adaptation of every conceivable mechanical, optical, and electronic device imaginable are now in vogue in public schools, colleges, and universities. Pioneers in the development, use, and evaluation of instructional aids of all sorts certainly includes the military establishment (3)from which stem many of our common audio-visual devices such as the overhead projector. With all this are we losing our grip on how to educate our students? Achievement scores have declined and reading levels have waned. Is this the result of greater numbers of illprepared students in the system, or have we been distracted from the essential ohjectives of education by jumping onto successive bandwagons that come into vogue? What has happened to the self-guidance of the '50s and relevance and innovation of the '60s? Where has the new math gone? Where is CHEMStudy and CBA? How long will the replacements, IPS, APC, etc, endure? Are these efforts significant mileposts, or are they more or less part of the game of one-upmanship that pervades our society a t large? What have we found out about the actual learning process of the individual student? We lean on all sorts of tricks to get the student to learn. Performance ohjectives, contract grades, no-grades, self-pacing,and such aim to reduce the emotional trauma of evaluation in order to free the student from undue psychological distractions. Anything that permits the student to "cop out" without loss of face seems to be in order. Grades of I (incomplete) have increased 400% in the past five years, and honorable withdrawal from courses 90% completed relieves the student's concern about failure. Sensory Learning It is recognized generally that the bulk of what we learn must a t one time or another come to us through one or more of our several senses. Our nervous system, particularly the brain, has evolved to a remarkably efficient machine that receives sensory information, processes and correlates this information and, to a certain extent, stores this information in the neocortex of the hrain. Thus, we turn to all sorts of devices that supply visual, auditory, olefactory, and other sensual experiences with the hope that such exposures result in learning. At this point, we may he makinga serious error. The sensory portions of the human hrain feed into the central nervous system and secondarily into the neocortex (4). The central nervous system governs our basic drives: the search for survival (food, reproduction, comfort, emotions and such). All animals from the lowest up to the human level have evolved these capacities which we enjoy. In certain respects some animals are more successful than man. The bloodhound has a far better nose (rhinencephelon) and the eagle can outsee any human. Beyond the sensory levels, and well beyond the instinctive drives of the central nervous system, the human has evolved the neocortex to a far greater capacity than any animal. This essentially sets apart the human from lower mammals.
The Neocortex The most highly evolved part of the human brain, the neocortex, is a stranger. T o it are assigned our. abilities to store information, to think, to evaluate, to judge, and to solve problems (5). We know little about how it functions. Supposedly, its capacity is extensive; geniuses may use only a small fraction of it. The Russian chess player Koltanovski played 56 simultaneous games while blindfolded in 1960. He won 50 games and made 6 draws. Obviously, he used a portion of his neocortex to do this. Many of us, however, use the neocortex only sparingly. This is where mental images are created, and possibly where we dream. The neocortex can readily derive and memorize abstract relationships, hut it cannot remember much of what our senses tell us. For example, if ten different shades of red are displayed, our visual sense can distinguish them. We might try to memorize these ten shades so that upon recall we could identify one of them. Such a feat of memory is most unlikely. Even an expert color matcher must rely on a reference color in order to find the proper shade. Sensual fatigue (lack of memory?) indicates that the neocortex, while interacting with our visual sense, does not accommodate colors per se. Little wonder that our chemistry students have difficulty with acid-base indicator endpoints if a color reference is not used. Again, our auditory sense can he highly trained to distinguish a wide range of pitch and intensity. The so-called talent of perfect pitch among musicians is questionable as a memory recall. Finding a pitch may well be made hy searching for a particular resonance frequency through physiological action, much like a bathtub singer can find a resonating pitch which is determined by the size of the bathtub. It is doubtful if the neocortex can bring forth a perfect pitch, though it is ideally suited to store and to evaluate the strains of a complex sequence of interrelated sounds of a classical overture. The neocortex came late in the evolutionary process ( 6 ) , long after the development of sensory capacities which McLean calls the visceral brain. The visceral or primitive brain, along with hormonal guidance, is in total command in lower mamkals. The superposition of the neocortex on the visceral brain sets the human brain apart from that of the lower mammals, but as so often occurred in evolutionary processes, the visceral hrain persists and often overrides or distracts from the activity of the neocortex. In other words, the coupling of the neocortex with the visceral brain is not nerfected. It reauires ereat mental effort for the neocortex to handk 8 tlwught proress if. ar the same time, srrmg srnsurs simaii are o~erarincin thc visceral hmin. Jao,h (lrscrihi~srhii aithough a-jet engine were attached to an old horse cart. We've all heard of the poor student's complaint that "I can't study because my roommate runs his stereo a t 95 db." Instructional Aids and the Neocorlex The popularity of audiovisual devices in instructional programs is no accident. The viewing of films, slides, and transnarencies and listenine" to audio tapes. . . as well as the love affair hetween society and television in all its aspects appeals to the visceral hrain by way of sensory stimulation. The use of audio-visual devices has been strongly supported by the conventional wisdom that what we see and hear leads to an Volume 56. Number 3, March 1979 1 189
education. Hence, the more we see and hear the more we should know. Consequently, with plentiful funds and the blessings of social and institutional guidance, instructional programs K to PhD have become instrumentalized. Educational administrators, in extolling the virtues of their institutions, enumerate the number of projectors and films, the numher of cumputer-programmed instructional materials, and the t,ele&ion resiurces in their inventorv. , Anv , measure of these drvwes on thc ne
