Purpose. Visual search measures have been used to evaluate the effects of pattern-related visual stress (PRVS), and its alleviation by colored filters, but tasks and results have varied between studies. Performance on a high-difficulty search task was measured in individuals having low- and high-PRVS susceptibility. methods. Two PRVS groups (low and high) were formed on the basis of participants’ responses to a visual symptoms questionnaire and perceptions of a high-contrast grating pattern. Each participant searched for multiple instances of a single-digit number (target) within an array of similar numbers (distractors). Performance was measured by response time and error count. A three-factor, mixed-factorial ANOVA design was used to investigate the effects of PRVS group, a high-contrast background PATTERN, an overlay of an individually-selected COLOR. results. Individuals classified with high visual stress were found to experience significantly greater improvement in reading performance (F _(1,26) = 24.579, P < 0.001) and reduction in the number of errors (F _(1,26) = 9.502, P = 0.005) when performing the Wilkins Rate of Reading Test with a colored overlay than those with low visual stress. Error count was significantly higher in the high-PRVS group, when subjects were performing a visual search task, in the absence of either PATTERN or COLOR, but response time was not significantly different. Neither response time nor error count was significantly affected by background PATTERN and/or colored overlay. conclusions. Results of this and previous studies confirm that visual search measures may be helpful in the assessment of PRVS, but several important methodological issues may limit their application in this context.

Brédart, Valentine, Calder and Gassi (1995) described an interactive activation and competition (IAC) model in which the lexical representations of people’s names have inhibitory connections between each other, but do not receive inhibition from the representation of biographical properties. The model predicts that people would be slower to name a celebrity for whom two names are equally available than they would be to name an equally familiar celebrity for whom only one name is available. However, naming should only be slowed by competition from a competing name; a highly available biographical property should not increase face naming latency. These predictions were confirmed in a simulation of the model. The effect is referred to as the nominal competitor effect. Experiment 1 showed that participants who had practiced naming actors using both the actor’s name (e.g. John Cleese) and the character’s name (e.g. Basil Fawlty) were slower to produce the actor’s name at test than were participants who had practiced producing only the actor’s name. However, practice in naming the relevant television series (e.g. Fawlty Towers) did not inhibit subsequent production of the actor’s name. In contrast to the semantic competitor effect in picture naming, the effect reported here was found to be long-lasting (Experiment 2).