Thesis -Domain Specific Limited Capacity Processing in Visual Word Recognition

The Stroop effect (impaired performance when an irrelevant word is incongruent with a to be identified colour [e.g., BLUE displayed in red] as compared to when the word is congruent [e.g., BLUE displayed in blue]) is one of the most heavily investigated phenomena in cognitive psychology. This Stroop effect is widely interpreted as evidence for the automatic nature of word processing (Stroop, 1935; see MacLeod, 1991, for a review).

Many variants of Stroop’s paradigm have been extensively studied, however the focus of the present research is on a new variant of Stroop’s paradigm wherein a neutral colour carrier (e.g., letter stings, symbols, patches) appears at fixation and is flanked by a colour word distractor, displayed in white. Fifteen experiments investigate the consequences of varying the nature (linguistic vs. non-linguistic) of the colour carrier. The hypothesis advanced here is that the nature of the material at fixation impacts on the allocation of domain specific limited capacity processing resources. Linguistic material at fixation receives most or all of the limited capacity word processing resources such that there were no resources left for processing the colour word distractor. Thus, no Stroop effect will be observed. Non-linguistic material at fixation does not absorb limited capacity word processing resources; thus there are resources available for processing the colour word distractor. Thus, a Stroop effect will be observed.

The data are consistent with the hypothesis advanced and are taken as evidence that it is not the case in the Stroop paradigm that the colour word distractor always affects immediate performance. Instead, the data are consistent with the claim that (i) linguistic processing is capacity limited and domain specific. More generally, if automaticity is defined as being relatively unlimited in terms of processing capacity then the present results are not consistent with the view that visual word processing is automatic.

Future Interests

For the future I am interested in bridging the gap between the developmental reading literature and skilled reading literature. I also hope to further pursue my interests in computational modelling and neuroimaging.

CLLRNet Research Projects

• Acoustic properties of children's voices and their impact on communication

Last Modified: February 04 2002 11:26:34.