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Background noise is the irregular variation across repeated measurements of human performance. Background noise remains after task and treatment effects are minimized. Background noise refers to intrinsic sources of variability, the intrinsic dynamics of mind and body, and the internal workings of a living being. Two experiments demonstrate 1/f scaling (pink noise) in simple reaction times and speeded word naming times, which round out a catalog of laboratory task demonstrations that background noise is pink noise. Ubiquitous pink noise suggests processes of mind and body that change each other's dynamics. Such interaction-dominant dynamics are found in systems that self-organize their behavior. Self-organization provides an unconventional perspective on cognition, but this perspective closely parallels a contemporary interdisciplinary view of living systems.

The vast literature concerning printed word identification either contradicts or provides ambiguous support for each of the central hypotheses of dual-process theory, the most widely accepted theory of printed word identification. In contrast, clear, positive support exists for an alternative subsymbolic approach that includes a central role for the process of phonologic coding. This subsymbolic account is developed around a covariant learning hypothesis, derived from a design principle common to current learning algorithms within the subsymbolic paradigm. Where this hypothesis applies, and it may apply broadly, it predicts a common empirical profile of development.

Van Orden (1987) reported that false positive errors in a categorization task are elevated for homophonic foils (e.g., HARE for A PART OF THE HUMAN BODY). Two new experiments replicate this finding and extend it to nonword homophone foils (e.g., SUTE FOR AN ARTICLE OF CLOTHING). False positive errors to nonword homophone foils substantially exceed false positive errors to nonhomophonic nonword spelling controls, showing that the phonological characteristics of the nonword foils are critical. Because nonwords are not represented in the lexicon, this new result implicates computed phonological codes as a source of the categorization errors. Additionally, in each of two experiments, matched word and nonword homophones produced virtually identical error rates. If stimulus nonword homophones are viewed as extremely unfamiliar words, compared with the relatively familiar stimulus word homophones, then our failure to observe an effect of stimulus familiarity strengthens the case that phonological coding plays a role in the identification of all printed words. The fact that the results are obtained in a categorization task that requires reading for meaning (rather than a lexical decision task) makes it difficult to avoid the conclusion that phonological mediation plays a role in normal reading of text for meaning.

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