It may be debated whether individual neurons are "tuned" to react to only asingle tastant such as salt or sugar--and therefore signal only one tastequality--or whether the activity in a given neuron contributes to the neuralLine representation of more than one taste. Studies show that both peripheral and(5) central gustatory neurons typically respond to more than one kind of stimulus,and although each neuron is attuned most acutely to one tastant, it usually alsogenerates a reaction to others with dissimilar taste qualities. How then can thebrain represent various taste qualities if each neuron is receptive to manydifferent-tasting stimuli(10) Electrophysiological studies of gustatory sensory neurons, first performedby Pfaffmann, demonstrated that peripheral neurons are not specificallyresponsive to stimuli representing a single taste quality (which might besymbolized by the pattern of activity across gustatory neurons because theactivity of any one cell was ambiguous) but instead record a spectrum of tastes.(15) But in the 1970s and 1980s several scientists began to accumulate data indicatingthat individual neurons are tuned maximally for one taste, and they interpretedthis as evidence that activity in a particular type of cell represented a given tastequality--an idea they called the labeled-line hypothesis. According to this idea,activity in neurons that experience the strongest reaction to sugar would signal(20) "sweetness," activity in those that are most sensitive to acids would signal"sourness", and so forth.Smith later proved that the same cells that previous researchers hadinterpreted as labeled lines actually defined the similarities and differences inthe patterns of activity across taste neurons, suggesting that the same neurons(25) were responsible for taste-quality representation, whether they were viewed aslabeled lines or as critical parts of an across-neuron pattern. These investigatorsfurther established that the neural distinction among stimuli of differentqualities depended on the simultaneous activation of different cell types, muchas with the function of color vision, but unlike auditory perception. These and(30) other considerations have led us to favor the idea that the patterns of activityare key to coding taste information.Scientists now know that things that taste similarly evoke similar patternsof activity across groups of taste neurons. Furthermore, we can compare thesepatterns and use multivariate statistical analysis to plot the similarities in the(35) patterns elicited by various tastants. Taste researchers have generated suchcomparisons for gustatory stimuli from the neural responses of hamsters andrats and these correspond very closely to similar plots generated in behavioralexperiments, from which we may infer which stimuli taste alike and which tastedifferent to animals. Such data show that the across-neuron patterns contain(40) sufficient information for taste discrimination and this may be a reasonableexplanation for neural coding in taste, though researchers continue to debatewhether individual neuron types play a more significant role in taste coding thanthey do in color vision. Scientists question whether taste is an analytic sense, inwhich each quality is separate, or a synthetic sense like color vision, where(45) combinations of colors produce a unique quality. Which of the following statements about the individual gustatory neuron is true, based on information provided by the passage()
A. It creates a neurological signal only when it comes into contact with its primary tastant.
B. Its function is not to identify tastes, but to identify similarities and differences between them.
C. Its primary importance is in distinguishing between the various qualities of a mixed stimulus.
D. It provides roughly equivalent signals when in contact with a major stimulus and a minor one.
E. It plays a fairly minor role in the across-pattern theory, compared to the labeled-line theory.
The distinction between making art and thinking and writing about itshould imply neither a mutual exclusiveness nor a hierarchic differentiation ofthese processes. Leonardo demonstrated that producing art and theorizing aboutLine it need not be antithetically opposed activities and that meaningful contributions(5) can be achieved successfully in more than one field. Inexplicably, few theoristshave built as memorable architectural structures as his and even fewer artistshave been entrusted with the directorship of an influential art institution.Unfortunately, as theory and practice became more specialized in the modernera and their operational framework clearly defined both in the cultural milieu(10) and the educational process, their independent paths and boundaries havecurtailed possibilities of interaction. The creations of categories and divisionshave further emphasized highly individualized idiosyncrasies and, by exposingdifferences, diminished the value of a unifying artistic vocabulary. Thetransformative cultural process of the last decades has critically examined the(15) artificial separations between theoretical and studio practices and disclosedviable connections between making, writing, thinking, looking and talkingabout art. The recent dialogue between the various components of the artisticdiscourse has recognized the common denominators shared by theoreticalanalyses and artistic production, one of which is clearly exposed by the(20) argument that the central objective of the theorist and artist is to unmask andunderstand artistic meanings in painting or text.The notion that "true" art is the product of individuals who are incapable ofin-depth understanding, in stark contrast to erudite, restrained and controlledscholars, is an outdated model. The assumption that artists make art but cannot(25) or do not have to talk or write about it and that theorists rarely know anythingabout the creative process, has been consistently refuted by the many textswritten from Leonardo da Vinci to Mary Kelly. Even van Gogh, a martyr of thestereotypical "misunderstood genius," whose artistic career has been distortedby scores of films and books, wrote with lucidity and insight about art and his(30) work. Apparently, the "mystery" of the creative process, jealously protectedby artists but also selectively cultivated by some art historians has been both afascination and frustration for those extrinsic to the process and artists haveexposed the intimacy of creativity while acknowledging the role of cognition increativity.(35) Even the ironic and subversive demise of authorship of the post-modern andelectronic age acknowledges, at least indirectly, the value of the artist’sindividual participation. However, many contemporary artists have abandonedthe hierarchic segregation of the inner realm of the creator and, by combiningtheoretical and studio practices, brought a reconciliatory tone to the processes(40) of making art and analyzing it. Their works, which are often simultaneouslyartistic productions and critique of the artistic discourse, make use of visual andtextual forms to expose the connection between looking and thinking as theessential attribute to both creating and understanding art. It can be inferred from the passage that prior to the modern era artistic practice was regarded as()
A. a hermetic field without potential for collaboration, given that it was almost exclusively populated by "misunderstood geniuses"
B. a field less isolated from the practice of critical analysis than the artistic process of the present era
C. more meaningful and useful as a self-critical force than the aesthetic judgments of non-artists, especially art historians
D. primarily concerned with the masking and concealment of artistic meanings from the general public
E. seldom times as specialized as the various branches of science from which art has traditionally been distinguished