Recent developments on the optimal viewing position (OVP) effect suggest that it may be caused by the same factors that underlie the right visual field advantage in word recognition. This raises the question of the relationship between foveal and parafoveal word recognition. Three experiments are reported in which participants identified tachistoscopically presented words that were presented randomly in foveal and parafoveal vision. The results show that both the OVP effect and the right visual field advantage for word recognition are part of a larger extended OVP curve that has the shape of a Gaussian distribution with the mode shifted to the left of the center of the stimulus word. The shift of the distribution is a function of word length, but not of presentation duration; it is also slightly moderated by the information value of word beginning and word end.Tachistoscopic visual half field (VHF) studies are frequently used to assess the laterality of cognitive functions. They are based on the fact that stimuli presented in the left half of the visual field (LVF) are initially projected to the right cerebral hemisphere, and stimuli shown in the right half (RVF) are sent to the left cerebral hemisphere. This anatomical feature has been taken as support for the argument that LVF-RVF differences are an index of asymmetric functioning of the two cerebral hemispheres (for reviews see Bradshaw & Nettleton, 1983;Bryden, 1982;Hellige, 1993). Thus, the repeated finding that words are recognized more easily in the RVF than in the LVF is considered a consequence of left-hemisphere dominance for language processing. Further evidence for this position is obtained by finding that individuals with left hand preference show a reduced RVF superiority for word recognition relative to persons with right hand preference (Kim, 1994; but see Brysbaert, 1994c, for a more cautious account).The interpretation of LVF-RVF differences in word processing as an indication of laterality has not remained unchallenged, however. At least three alternative explanations of the RVF superiority have been proposed. The first considers the

No abstract

M. Oaksford, N. Chater, and J. Larkin (2000) proffered a Bayesian model in which conditional inferences are a direct function of conditional probabilities. In the current article, the authors first considered this model regarding the processing of negatives in conditional reasoning. Its predictions were evaluated against a large-scale meta-analysis (W. J. Schroyens, W. Schaeken, & G. d'Ydewalle, 2001b). This evaluation shows that the model is flawed: The relative size of the negative effects does not match predictions. Next, the authors evaluated the model in relation to inferences about affirmative conditionals, again considering the results of a meta-analysis (W. J. Schroyens, W. Schaeken, & G. d'Ydewalle, 2001a). The conditional probability model is countered by the data reported in literature; a mental models based model produces a better fit. The authors conclude that a purely probabilistic model is deficient and incomplete and cannot do without algorithmic processing assumptions if it is to advance toward a descriptively adequate psychological theory.

We tested theories of eye movem ent control in reading by lookin g at parafoveal processing. According to attention-processing theories, attention shifts towards word n+ 1 only when processing of the ®xated word n is ®nished, so that attended parafoveal processing does not start until the programming of the saccade program ming to word n+ 1 is initiated (Henderson & Ferreira, 1990;Morrison, 1984), or even later when the processing of word n takes too long (Henderson & Ferreira, 1990). Parafoveal preview bene®t should be constant whatever the foveal processing load (M orrison, 1984), or should decrease when processing word n outlasts an eye movement program ming deadline (Henderson & Ferreira, 1990). By manipulating the frequency and length of the foveal word n and the visibilit y of the parafoveal word n+ 1, we replicated the ®ndin g that the parafoveal preview bene®t is smaller with a low-frequency word in foveal vision. Detailed analyses, however, showed that the eye movement programming deadline hypothesis could not account for this ®ndin g which was due not to cases where the low-frequency words n had received a long ®xation, but to cases of a short ®xations less than 240 msec. In addition, there was a spill-ove r effect of word n to word n+ 1, and there was an element of parallel processing of both words. The results are more in line with parallel

Dual-process theories come in many forms. They draw on the distinction between associative, heuristic, tacit, intuitive, or implicit processes (System 1) and rule-based, analytic, explicit processes (System 2). We present the results of contextual manipulations that have a bearing on the supposed primacy of System 1 (Stanovich & West, 2000). Experiment 1 showed that people who evaluated logically valid or invalid conditional inferences under a timing constraint (N=56), showed a smaller effect of logical validity than did people who were not placed under a timing constraint (N= 44). Experiment 2 similarly showed that stressing the logical constraint that only inferences that follow necessarily are to be endorsed (N = 36) increased the size of the validity effect, as compared to that of participants (N=33) given the standard instruction to make "logical" inferences. These findings concur with the thesis in dual-processing frameworks that "Rationality-2 processes" (Evans & Over, 1996), "test procedures" (Chater & Oaksford, 1999), or "conclusion validation processes" (Johnson-Laird & Byrne, 1991; Schroyens, Schaeken, & d'Ydewalle, 2001) serve to override the results of System 1 processes.