Implication–Realization

Background

Humans are future-oriented animals, so expectation constitutes a central topic in psychology, ranging from perception to emotion. Leonard B. Meyer's 1973 book Explaining Music offered in part 2 (“Explorations”) a cognitive theory of musical expectation based on identifying a small number of melodic archetypes. Framed largely within gestalt laws (continuations, similarities, proximities, common fates, streaming, symmetries, etc.), Meyer's work spurred a new interest in expectation in both music theory and cognitive psychology. Eugene Narmour coined the term implication-realization model in the 1970s, and over the next few decades the theory was refined so as to make portions of it empirically testable.

Narmour's formalization of the model greatly expanded Meyer's original concept of expectation by hypothesizing two distinct sources of implication and realization, one from the bottom up (BU), the other from the top down (TD). BU is hypothesized as perceptually mechanistic, automatic, and largely implicit, whereas TD is said to be stylistically flexible, cognitively learned, and stylistically explicit.

The Two Systems of Implication

The IR model hypothesizes that postsensory signals are encoded in a primary BU system, which extracts events according to separate parameters (pitch sets, contours, consonances and dissonances, timbres, durations, meters, etc.). Secondary BU processing then operates on these primitives according to gestalt principles, creating coherent implications and realizations for higher-level syntactic analysis.

From this parsing, primary TD processing subsequently identifies modes, scale-step functions, chord types, metric hierarchies, and other such preprimed information. The TD system likewise activates a secondary level that relies on mapping previously learned, hierarchically complex, time-ordered schematic expectations (voice leading, harmonic processes, tonal strategies, formal constancies, etc.). In short, the BU system is essentially a servo-mechanism that enables the TD system to access stylistic norms of implications and realizations, whether conditioned, habituated, or associated. Fed back to the BU system, TD levels of complexity channel one's attention to implicative input that deviates from explicit mapping. When the auditory world is as one expects it, the BU system runs unconsciously in the background.

Bifocal operations such as this minimize implicative error. Feed-forward causes the higher-level system to hunt continuously for conformance in order to invoke the most statistically relevant schemata, while feedback frees up lower-level systems to abstract novel or nuanced auditory information. Neither system overrides the other, as novelty must always be learned, updated, and transformed into higher-level memory. Likewise, TD schemata must remain attuned to redundant input, which statistically codifies or rejuvenates old memory in order to anticipate complexities apt to recur in upcoming contexts. Significant mismatches between what was implied vis-à-vis what was realized produce felt arousal and tension (moods, affects, emotions).

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