Summary. Forty‐nine children (aged 8:4 to 10:4) were grouped according to reading ability and were tested on lexical decision, naming and spelling of words and non‐words which differed in orthographic neighbourhood size. Friendly words with many neighbours caused significantly fewer errors on all these tasks. Item analysis demonstrated that these effects were robust when corrected for frequency, regularity, word length and age of acquisition. Good readers showed less reliance on neighbourhood size and more evidence of accurate use of grapheme‐phoneme correspondence rules. The results indicate that children find common orthographic sequences easier to read and spell before they have learned to use grapheme‐phoneme correspondences consistently.

Research on children's reading has shown that words high in imageability are easier to read than words low in imageability. It has been suggested that this occurs because low imageability words are acquired later in life than are high imageability words. The effects of age of acquisition and imageability were studied in two reading tasks. In Expt 1, nine-year-old children had to read aloud words differing in age of acquisition (but qatched for imageability, length and frequency). A highly significant effect of age of acquisition on reading accuracy was obtained. The children also had to read aloud words differing in imageability (but matched for age of acquisition, length and frequency). Although imageability affected accuracy, the difference in high and low imageability words was significant only for the poorer readers in the sample. Thus, it appears that age of acquisition of words is a major determinant of reading accuracy and that the imageability effect is attributable to this variable, except for poor readers, who do show a genuine effect of imageability upon reading accuracy. In Expt 2 adult naming latencies were obtained for the same tasks. These latencies were significantly lower for acquired words early than for words acquired later. Word imageability did not affect adult naming latencies.In an early study, Stoke (1929) found that children aged 10-11 years and college students recalled concrete words of higher imageability better than they did low imageability abstract words. Many later experiments reviewed by Paivio (1971) confirmed this finding when word frequency and other variables are controlled. Word lists high in imageability are more memorable in a range of episodic memory tasks and, furthermore, highly imageable sentences are more easily comprehended and remembered than sentences low in imageability (e.g. Holmes & Langford, 1976). Although most of the research on memory has studied adult performance, Vellutino & Scanlon (1985) found that children who were poor readers had special difficulty in recalling low imageability words under conditions of auditory presentation.In addition to the pervasive effects on memory tasks, word imageability has also been found to affect reading performance: it appears to affect reading accuracy in certain types of acquired dyslexics. Marshall & Newcombe (1973) and others (e.g. M. Coltheart et af., 1980) have reported that deep dyslexics, who are notable for the fact that they make semantic errors when reading aloud words presented in isolation, also find highly imageable words easier to read than low imageability words. The deep dyslexic's semantic errors and deficit on low imageability words have been attributed to a disordered semantically mediated reading routine. Interestingly, a 1 P S Y 79

We thank Max Coltheart, Karalyn Patterson, and Derek Besner for comments on a draft of this article. We are also grateful to Philip Smith and Estelle Doctor with whom we had useful discussions.

The procedures used by novice readers to assemble pronunciations for nonwords were investigated. Children in Grades 1-3 read aloud consonant-vowel-consonant and longer monosyllabic nonwords. By the end of Grade 1, children displayed a good grasp of grapheme-phoneme (G-P) correspondences (e.g., ai, ow). Grade 2 and 3 readers increasingly used larger orthographic correspondences termed rimes (e.g., -ook, -ild). However, G-P correspondences determined most responses. Adults likewise used G-P rules when reading aloud nonwords and were more accurate at applying the rules. The strong reliance of Grade 1 and 2 readers on G-P rules was also demonstrated by their superior oral reading of regular words along with a tendency to regularize exception words (e.g., reading bull to rhyme with dull).

The extent to which phonological similarity of list words impairs short-term-memory recall was investigated in two experiments. Experiment 1 showed that the phonological-similarity effect occurred both when list words were repeatedly sampled from a small set and when they were new on every trial, both when word-order information was required and when it was not. Furthermore, the adverse effect of phonological similarity on recall was apparent on the initial lists recalled, did not change over trials, and cannot be attributed to increasing levels of proactive inhibition across lists. In Experiment 2, subjects were required to count repeatedly to six during list presentation. Concurrent irrelevant articulation lowered recall and abolished the phonologicalsimilarity effect for both repeated and novel word lists.The view that short-term memory (STM) for briefly presented letters, words, or objects is chiefly dependent on a phonological (speech-based) code has been supported by a considerable body of evidence since the early studies of Baddeley (1966), Conrad (1964), and Wickelgren (1965). The evidence for phonological coding was that memory errors resembled the visually presented stimuli phonologically (Conrad, 1964) and that span for lists of acoustically similar letters or words was smaller than it was for unrelated or visually similar letters or words (Baddeley, 1966;Conrad & Hull, 1964). From the age of 6 onward, children display phonological similarity effects on STM recall. They are worse at remembering lists of pictures of objects with similar names than they are at recalling those with dissimilar names (Hitch & Halliday, 1983). Younger children's recall is adversely affected by visual similarity of to-be-recalled objects but is unaffected by phonological similarity (Hitch, Halliday, Schaafstal, & Schraagen, 1988). This suggests that younger children use visual coding but not phonological coding in STM recall and that children only use phonological coding from the age of approximately 6 onward.Deaf children are worse at recalling visually similar letters than they are at recallingphonemically similar letters, whereas children of similar age with normal hearing show the opposite pattern (Conrad, 1972). Congenitally speech- less children who can hear and comprehend speech are impaired at recalling pictures of objects with similar names, as are normal children (Bishop & Robson, 1989). Thus, the ability to perceive speech input, but not to produce speech, is required for the development of the use of phonological coding in STM. Presumably the speechless children can represent phonemes even though they are unable to generate them in the form of overt speech.With visual presentation of list items, phonemic similarity impairs recall in adults and older children, as stated above. When subjects are required to articulate irrelevant speech, for example, the, the, the . . . , during list presentation, memory span is reduced and the phonemicsimilarity effect is abolished (Murray, 1968). However, if list presentation is ...

When skilled readers make speeded categorization judgements about printed words, errors occur to homophones of real category exemplars. In Experiments 1 and 2, for example, subjects incorrectly accepted both the word STEAL (as a member of the category A METAL) and the nonword JEAP (as A VEHICLE) significantly more often than incorrect non-homophonic items matched in orthographic similarity to real exemplars. Experiment 3 demonstrated equivalent error rates for homophone targets differing from real exemplars by various types of single-letter change, but reduced error rates, especially for non-word homophones, when subjects were instructed to accept only correctly spelled instances. Experiments 4 and 5 established that the magnitude of the homophone effect is predicted by the degree of orthographic similarity between homophonic mates but not by spelling-sound regularity of the presented homophone. The results suggest that automatic phonological activation plays a major role in the comprehension of written words.

Accuracy of report of words in a rapidly presented sequence is reduced if 1 word is a repetition of a previous word. This is repetition blindness. If, however, the items are pronounceable nonwords, or pseudohomophones, repetition improves recall. A repetition advantage for nonwords also occurs when subjects merely count the items or when the item between the critical nonwords is a familiar word. Familiarizing subjects with the nonwords improved the level of recall but did not affect the repetition advantage. These results are considered in relation to token individuation and other accounts of repetition blindness. The findings suggest that for identical linguistic stimuli the types bound to episodic memory tokens that are vulnerable to repetition blindness are lexical units.

A controversial question in reading research is whether dyslexia is associated with impairments in the magnocellular system and, if so, how these low-level visual impairments might affect reading acquisition. This study used a novel chromatic flicker perception task to specifically explore temporal aspects of magnocellular functioning in 40 children with dyslexia and 42 age-matched controls (aged 7-11). The relationship between magnocellular temporal resolution and higher-level aspects of visual temporal processing including inspection time, single and dual-target (attentional blink) RSVP performance, go/no-go reaction time, and rapid naming was also assessed. The Dyslexia group exhibited significant deficits in magnocellular temporal resolution compared with controls, but the two groups did not differ in parvocellular temporal resolution. Despite the significant group differences, associations between magnocellular temporal resolution and reading ability were relatively weak, and links between low-level temporal resolution and reading ability did not appear specific to the magnocellular system. Factor analyses revealed that a collective Perceptual Speed factor, involving both low-level and higher-level visual temporal processing measures, accounted for unique variance in reading ability independently of phonological processing, rapid naming, and general ability.