Biomedical subjects

Kate Mayall

Publications and source records attributed to Kate Mayall.

5 recordsLinked to original sources

PubMed2003

The time course of negative repetition effects in post-cue naming.

It has previously been shown that when picture pairs are repeated across blocks in a post-cue naming task, former distractors are named faster than former targets: the "negative repetition effect" (Mayall, Humphreys, & Kotsanis, 2002). In the present study the time course of this effect was examined. Experiment 1 demonstrated that the effect became apparent after a lag of only two intervening trials, with former targets being named faster than former distractors after a lag of zero trials. Experiment 2 used a new baseline condition with repeated picture pairs for which no response was required on the first presentation. Comparisons with this baseline indicated that the negative repetition effect is the result of suppression of former targets as opposed to facilitation of former distractors. The results support the proposal of Mayall et al. that the negative repetition effect reflects a form of speech monitoring that is applied when there is competition in the process of mapping from semantics to name representations.

Adult↗

PubMed2003

The PIG in sPrInG: evidence on letter grouping from the reading of buried words.

We introduce a novel procedure for investigating factors that determine selective attention to letters in words. Participants were presented with words (in Experiments 1 and 3) and nonwords (in Experiment 2) that contained a buried word whose letters differed in color relative to the other letters present (e.g., pig, in spring). The strings were presented in single case or mixed case, keeping the letters of the buried words in one case (SpRiNg). The time in which the whole stimulus was named was shorter for same-case than for mixed-case strings (for spring: spring < SpRiNg). In contrast, the time in which buried words were named was shorter in mixed- than in same-case strings (for pig: spring > SpRiNg). Across items, the effects of case mixing were negatively correlated across the two tasks. The positive effect of case mixing for buried words also occurred irrespective of whether the whole string was a word or a nonword, and there were contributions from similarity of both letter size and case. The results suggest that case mixing can facilitate selective attention to letters, which is otherwise disrupted by size- and case-based grouping across letter strings. The study provides evidence for letter grouping using size and case information.

Attention↗

PubMed2002

Presentation and task effects on migration errors in attentional dyslexia.

We report a case study of a patient, FL, who shows symptoms of attentional dyslexia. He performs better at reading aloud single words than pairs of words, where he tends to make letter migration errors. These letter migrations are particularly prevalent from the word presented on the right into FL's response to the word presented on the left. Performance on the word pair reading task is improved if the two words are presented in different cases or the space between them is increased. Further, FL performs better at reading a target word if he is only required to name the initial letter of a distractor word rather than read the whole word. However, single letter distractors then produce more interference than whole words. These findings are consistent with FL having poor letter location coding when attention is diffuse [Cognitive Neuropsychol. 18 (2001) 551; Cognitive Neuropsychol. 13 (1996) 205]. In addition, representations on the left side of his attentional space are particularly weak, and so vulnerable to stimuli on the right when FL adopts a wide spatial window for the task. The data point to a pre-categorical deficit in reading in this case.

Aged↗

PubMed2002

How not to revisit Highway 61: negative repetition effects in a post-cue naming task.

Repetition effects were studied in a post-cue naming task, in which participants were cued to name one of two stimuli following their presentation. When pairs of pictures were repeated in a second block, former distractors (not named in Block 1) were named faster than former targets (named in Block 1). This negative repetition effect was not found when two words rather than two pictures were used or when a semantic categorization task was used with two pictures. From this we conclude that the effect reflects a process of mapping from a semantic representation to a name. Negative repetition was not found with a simultaneous selection cue, suggesting that it arose only when there was competition for name selection. It was also dependent on memory for previous acts of semantic naming. We propose that negative repetition reflects a form of speech monitoring that is applied when there is competition in the process of mapping from semantic to name representations.

Cues↗

PubMed2002

Case-mixing effects on children's word recognition: lexical feedback and development.

Presenting words in MiXeD cAsE has previously been shown to disrupt naming performance of adult readers. This effect is greater on nonwords than it is on real words. There have been two main accounts of this interaction. First, case mixing may disrupt naming via non-lexical spelling-to-sound correspondences to a greater extent than it disrupts lexical naming. Alternatively, stored lexical knowledge of words may feed back to a visual analysis level during processing of a visually presented word, helping known words to overcome the visual disruption caused by case mixing. In the present study, when young children (aged 6 and 8 years) were tested, case mixing did not disrupt nonword naming more than word naming. However, slightly older children (aged 9 years) demonstrated the same pattern of performance as adults. These results support the view that top-down lexical information can aid overcoming visual disruption to words, and that beginning readers have not developed the stored word knowledge necessary to allow this. In addition, a greater case-mixing effect on high-frequency words for the youngest age group (6-year-olds) suggests that their word recognition may be based more on wholistic visual features than is that of older children.

Attention↗