We return to Rapid Automatic Naming (RAN) as an example. Here we ask—why should the naming of objects be significantly predictable for naming words, unless the two share some fundamental cognitive processes, as discussed earlier while reviewing successive processing?
A recent study by Bowers, Vigliocco, Stadthagen-Gonzalez, and Vinson (1999) caught our attention. This study offered both theoretical reasoning and experimental evidence, demonstrating that the perception of objects and written words share some common features. These common features include grammatical encoding, phonological (syntactic) encoding, and articulation demand. They differ in that object recognition involves a semantic or conceptual system, whereas for naming written words, a syntactic system is sufficient.
The syntactic system interacts with the semantic one; without such an interrelation, the reader would not automatically search for a meaning, when presented with a pseudo-word, let alone a real word. However, the search may not always be successful. Further, the presence of syntactic and semantic interaction explains why a word in the text of a sentence and paragraph may be read faster than when presented in isolation (Pollasteck and Rayner, 1993).
Here we have attempted to present the relationship between selected components of object naming and reading. Part of the figure also shows the relationship with the two PASS processes, simultaneous and successive processing. External information to be processed is shown in the three dark gray boxes—Naming Objects, Oral Reading, and Articulation Object (also color patches) naming starts with a perceptual system; so does a written word.
Articulation is an external event that has a speech output; it works as external information for processing speech when the individual is required to read aloud. The palest shading represents internal events—these are semantic, object’s name, visual, phonological, assembled, as well as two consequences of articulation. The only one of the internal events that clearly acts as a piece of information to be processed is the object name. Since finding the name and processing it further are both internal events, their shading is very pale. All of these remarks are speculative but we hope they will be generally accepted.
The other labels relate predominantly, but by no means solely, to simultaneous and successive processing operations that characterize the mental events. The two other PASS components, Planning and Attention, are involved in various degrees, along with the two preeminent processes. Objects can be named by linking the perception of the object to a conceptual system (Bowers et al., 1999); inasmuch as it involves categorization and labeling, the semantic/ conceptual system is utilizing a knowledge base.
But finding the name of the observed object is a matching process, which is a simultaneous operation. Object naming from this point onward shares the same processing and output components, except that the reader is denied direct visual access to the object’s name. Therefore, it is suggested that unlike whole-word reading, naming the object (or a color patch or ideograph) is a phonologically recoded procedure that produces a sublexically accessed name. However, one may argue otherwise and propose that the word for the object appear as an image, and then it may be read as a whole.
Phonological recoding involves mainly successive processing as we have argued earlier, both on the basis of the theory and its correlation with tests of successive processing. Assembling pronunciation requires a sequencing activity as well as matching with an item in the lexicon for pronunciation (knowledge base). Processing one’s own speech, we suggest, involves both simultaneous and successive processes.
Finally, articulation is a sequential speech act, but we think it may require motor planning, unless articulation is automated. Articulation of pseudo-words and long or unfamiliar words requires both successive processing and deliberate (not automatic) planning. With regard to comprehension, we have suggested that this is the same as a conceptual system, predominantly requiring simultaneous processing and a knowledge base.
Reading and STM
Three other issues alluded to earlier, will be discussed briefly. The first one is the double deficit (Wolf and Bowers, 1999). This implies dissociation between STM-related aspects of word-decoding deficit and RAN. The second is the characterization of the phonological loop. The third relates to heterogeneous groups of dyslexics. All three are connected in various ways and have implications for the PASS model as well. This part of the book recognizes the contemporary issues, but awaits further research.
The double or dual deficits are found among a majority of dyslexics, as Wolf and Bowers (1999) have suggested. Only a minority of dyslexics exclusively show either a RAN or STM deficit. How do we understand it in the context of a successive processing deficit that, according to our research, is preeminently prevalent among the true dyslexics, that is, those with a specific rather than pervasive cognitive deficit? The PASS theory and tests have included both types of measures.
STM and Working Memory are required in processing serial recall (Word Series, Sentence Repetition, and Sentence Question in the CAS), whereas Speech Rate, Naming Time and Color Naming (see Das, Naglieri, and Kirby, 1994 for a review of PASS tests) share the essential operations of RAN. According to the double deficit hypothesis, should these two sets of tasks load on separate orthogonal factors? We cannot find any evidence either in favor of or against it. On the other hand, the factors may be substantially correlated as both share the same successive processing.