Letters and shapes: Developmental changes in search strategies

Abstract

In search tasks that are otherwise identical, adults process strings of letters differently from strings of other shapes (Hammond & Green, 1982). This result has implications for word recognition and reading, and it is important to establish its developmental sequence. Two groups of primary school children and an adult control group completed a similar visual search task: determining whether a predesignated target character occurred in a subsequently displayed character string. The mean search latency decreased with age, and the results showed a qualitative difference in the processing of letters and shapes for even the youngest group. However, the left to right processing of letter strings does become more established with age.

On the role of consonants and vowels in visual-word processing: Evidence with a letter search paradigm

“…For instance, the search function obtained with the letter search task seems to reflect the directional scanning process required for reading: Prior evidence suggests that there is a relation between the search function and the orthographic properties of a given language. For example, using the letter search task with random letter strings, Green et al (1983) found that the letter search function obtained in alphabetic orthographies was M shaped, whereas the one obtained for logographic strings was U shaped. They concluded that the search function reflects procedures adapted to the demands of the orthographic script (see Green & Meara, 1987;Ktori & Pitchford, 2008;Ziegler & Jacobs, 1995).…”

“…In a visual letter search task (see Green, Hammond, & Supramamian, 1983;Green, Liow, Tng, & Zielinski, 1996;Green & Meara, 1987;Ktori & Pitchford, 2008;Pitchford, Ledgeway, & Masterson, 2008Ziegler & Jacobs, 1995), participants have to identify whether or not a previously cued letter is embedded within a random letter string (e.g., 'does the letter 'Ā' appear in the sequence RBFAD?'). This task allows the position in which the target appears in the test string to be manipulated.…”

Scanning in Different Scripts: Does Jawi interfere with Bahasa Malaysia and English?

“…Whilst the 'end-effects' seen with native English speakers is beginning to appear as a phenomenon which is peculiar to English, the heightened attention to stimuli in the centre of an array is a feature of nearly all array-scanning experiments. As discussed above, it is found with native English speakers scanning shape arrays; it is found with native English speakers scanning letter and digit arrays (Green and Supramanian, 1983); it is found with Arab subjects scanning Roman alphabet arrays and Arabic arrays, with Arab subjects and digit arrays (Randall, forthcoming) and with Chinese speakers scanning Chinese characters (Green and Meara, 1987). In fact, the persistence of this feature led many psychologists to look for the explanation of array perception in terms of the mechanisms of foveal perception rather than cognitive processes (Lefton, 1974).…”

“…If, however, they are presented with letters, they still see the centre of the array quickly, but they also see the two ends of the array relatively quickly and scan through the array from left to right, producing an upwardly-sloping M-Shaped pattern (see Figure la). This pattern has been observed by a number of experimenters (Hammond and Green, 1982;Mason, 1982) and the difference between shape and letter search patterns appears very early on in reading (Green, Hammond and Supramanian, 1983).…”

Recognizing numbers in different scripts

“…The results of these experiments with native English speakers has thrown up some very interesting results. The most significant finding with regard to the way that linguistic material is perceived, is that English native speakers appear to scan arrays of letters in quite a different manner from arrays of shapes (Green, Hammond and Supramanian, 1983;Hammond and Green, 1982;Mason, 1982;Mason and Katz 1976). All these studies indicate a highly stable search strategy in which English native speakers produce a U-shaped search pattern for non-linguistic material (i.e., they see the centre shape in the array more quickly than the shapes to the edge of the array) whereas they produce an upwardlysloping M-shaped search pattern when scanning arrays of letters (see Figure 1).…”