Discussion

Race models and analogy theories: A dead heat? Reply to Seidenberg

Models of visual word recognition have been assessed by both factorial and regression approaches. Factorial approaches tend to provide a relatively weak test of models, and regression approaches give little indication of the sources of models’ mispredictions, especially when parameters are not optimal. A new alternative method, involving regression on model error, combines these two approaches with parameter optimization. The method is illustrated with respect to the dual route cascaded model of reading aloud. In contrast to previous investigations, this method provides clear evidence that there are parameter-independent problems with the model, and identifies two specific sources of misprediction made by model.

We use a false memory paradigm to investigate the extent to which phonologically relations of a target word may be implicated in semantically driven access of that target word. We are specifically interested in understanding how access to orthography may limit the scope of this implication. Our interest in these questions is directly motivated by the claim that the probability of deep dyslexics making a semantic error in reading a word is affected by the number of close phonological relations of the word (Buchanan, L., Hildebrandt, N., & MacKinnon, G. E. (1994). Phonological processing of non-words by a deep dyslexic patient: A rowse is implicitly a rose. Journal of Neurolinguistics, 8, 163–181; Buchanan, L., Hildebrandt, N., & MacKinnon, G. E. (1996). Phonological processing of non-words in deep dyslexia: Typical and independent? Journal of Neurolinguistics, 9, 113–133). We use the study list in a false memory paradigm to semantically prime words. We look for false recognition effects among phonological relations of the semantically primed words in both modalities, with and without simultaneous orthographic overlap. The critical lures of interest in the experiments are words that are related by orthographic or phonological overlap to the unseen semantic target. We found increased false recognition rates for phonological associates of the unseen semantically-primed target in the auditory modality, only among words with no orthographic overlap with the unseen semantically-primed target. The locus of overlap and the phonological neighborhood size of the phonological relation also plays a role in the false memory rate. In a related experiment, we showed that the phonological neighborhood and concreteness of critical lures also mediates the probability of a semantic false memory. These results are discussed with respect to a frontal lobe disconnection theory of deep dyslexia, which posits that semantic errors in deep dyslexia are result from impoverished constraints to prefrontal regions that are implicated in semantic and phonological access of written words.

We report the performance of LC, a deep dyslexic. We investigated extensively her errors according to serial cognitive neuropsychological models of oral reading. Initial evaluation of her reading suggested impaired access to the phonological output lexicon (POL). Impaired grapheme-to-phoneme conversion (GPC) and semantic errors in reading suggested that LC read via an impoverished semantic route. However, a serial model of oral reading could not explain error differences in reading, picture naming, spontaneous speech, and repetition. Neologisms occurred in oral reading but not in spontaneous speech and repetition. Semantic errors in naming exceeded those in oral reading. To account for these different error patterns we propose that the semantic route, the direct route from the orthographic input lexicon to the POL, and GPC activate simultaneously during reading, converging at the POL to constrain phonological selection. These routes are modular but not functionally encapsulated. For LC, the POL receives ambiguous information due to degradation of all routes, causing reading errors.

The influence of phonology on visual word perception tasks is often indexed by the presence or absence ofconsistency effects.Consistency concerns whether there exists more than one way to pronounce a spelling body (e.g., _INT as in HINT and PINT versus _EAP as in HEAP and LEAP). The present study considers a similar factor.Feedbackconsistency concerns whether there is more than one way to spell a pronunciation body (e.g., /_ip/ as in HEAP and DEEP versus /_Ob/ as in PROBE and GLOBE). Two experiments demonstrate a robust feedback consistency effect in visual lexical decision. Words with phonologic bodies that can be spelled more than one way (e.g., _EAP as in HEAP) produce slower correct “yes” responses than words with phonologic bodies that can be spelled only one way (e.g., _OBE as in PROBE). This result constitutes strong support for feedback, top-down models of performance in word perception tasks. Furthermore, the data suggest that previous tests of consistency effects may be misleading because they did not take into account feedback consistency.

Four experiments investigated priming by inconsistent word-body neighbors in pronunciation. Experiment 1 replicated the retardation of naming that is observed for a regular inconsistent word (MUSH) when it is preceded by an exception neighbor (BUSH), compared with a regular consistent control prime. The priming effect was comparable when the prime occurred 1 or 10 trials before the target. Experiment 2 showed priming interference at the 10-trial prime-target delay when the target was an exception word and the prime was a regular inconsistent neighbor. Experiment 3 replicated at the 10-trial prime-target delay the bias in pronunciation of a pseudoword (FUSH) by regular versus exception inconsistent word neighbors. In Experiment 4, 24 subjects read aloud a block of regular and exception prime words and 24 subjects pronounced these primes when cued by sentences from which the noninitial letters of the prime had been deleted. Subjects reading the primes showed significantly greater bias in subsequent pseudoword pronunciation than did subjects generating the primes. The results of the four experiments are compatible with an interpretation of inconsistency priming as weight changes on links between sublexical letter clusters and a phonological representation, rather than as ephemeral activation effects of the prime.

Three experiments were conducted to investigate the psychological processes underlying character naming. Experiment 1 was designed to investigate the locus of frequency effects in the character-naming task. The results of Experiment 1 showed that high-frequency characters were named faster than low-frequency characters, which indicated that the locus of frequency effects is in the lexical access phase of character naming. Experiments 2 and 3 investigated regularity and consistency effects and how these effects interacted with frequency. The results showed that regular-inconsistent characters and irregular characters were named much more slowly than regular-consistent characters; however, the effects were found only for low-frequency characters. Two models of visual word recognition and naming were evaluated on the basis of these results.