Component Letters Research Articles

Letter information and orthographic context in word perception.

Theories of word perception in reading can be categorized in terms of the assumption made about whether or not a word context modifies the feature analysis of its component letters. Independence theories assume that the visual information passed on by feature analysis is independent of word context. Nonindependence theories assume that a word context directly influences visual analysis. Some nonindependence theories have assumed that word context enhances feature analysis of letters, others have assumed that word context overrides feature analysis of letters, and some have assumed that word context directs which letters are analyzed. The present experiment provided a critical test between the two classes of theories by independently varying orthographic context and visual letter information in a letter recognition task. The results contradict the qualitative predictions of the class of nonindependence theories and are accurately described by a quantification of independence theory.

Orthographic regularity, positional frequency, and visual processing of letter strings.

Previous research has demonstrated that familiarity with the orthographic structure within a letter string can facilitate the processing of the component letters. The current research was directed at discovering the psychologically relevant properties of this structure. Two fundamental descriptions were independently varied in the construction of six-letter nonword strings. A probabilistic description based on the frequency of occurrence of letters in each position was factorially combined with a rule-governed description defined in terms of graphemic and phonological constraints. College sophomores and sixth-grade readers were asked to indicate whether or not a predesignated target letter was present in these strings. For both groups of readers, orthographic regularity and summed positional frequency were found to have only a small facilitative effect on reaction time (RT). In contrast, RTs to say "no" increased dramatically with increases in the number of letters in the catch string that were physically similar to the target letter. In another experiment, the letter string was presented for a short duration, followed immediately by masking stimulus and then the target letter. College students indicated whether or not the target was present in the test string. Accuracy of performance was critically dependent on the orthographic regularity and summed positional frequencies of the letters in the test string. No effect of letter similarity was observed. The large differences that were observed between these two tasks were accounted for in terms of the stages of processing that are critical for performance in the tasks.

Orthographic regularity, positional frequency, and visual processing of letter strings.

Previous research has demonstrated that familiarity with the orthographic structure within a letter string can facilitate the processing of the component letters. The current research was directed at discovering the psychologically relevant properties of this structure. Two fundamental descriptions were independently varied in the construction of six-letter nonword strings. A probabilistic description based on the frequency of occurrence of letters in each position was factorially combined with a rule-governed description defined in terms of graphemic and phonological constraints. College sophomores and sixth-grade readers were asked to indicate whether or not a predesignated target letter was present in these strings. For both groups of readers, orthographic regularity and summed positional frequency were found to have only a small facilitative effect on reaction time (RT). In contrast, RTs to say "no" increased dramatically with increases in the number of letters in the catch string that were physically similar to the target letter. In another experiment, the letter string was presented for a short duration, followed immediately by masking stimulus and then the target letter. College students indicated whether or not the target was present in the test string. Accuracy of performance was critically dependent on the orthographic regularity and summed positional frequencies of the letters in the test string. No effect of letter similarity was observed. The large differences that were observed between these two tasks were accounted for in terms of the stages of processing that are critical for performance in the tasks.

Gross vision of a word enhances the perceptibility of its component letters: A model

A quantitative model is proposed to explain the order of accuracy for recognizing letters in meaningful words and non-related words. The model is based on the principle that minimum features required for recognition of the whole pattern is equal to or less than the total features required for its component patterns, and the principle that the features extracted in vision are related to the feature density and the field of attention. The condition required for the result of Johnston and McClelland is given.

Are visually presented one-syllable words integral stimuli?

Subjects discriminated between sequences of four letters on the basis of the initial letter (a ‘P’ or an ‘R’). Sequences formed one-syllable words or unpronounceable nonwords. All subjects performed four different discriminations (word simple, word filtering, nonword simple, and nonword filtering). Simple discriminations were based on the first letter of a sequence, with all other letters held constant. Filtering tasks required the same discrimination, but also varied the third letter (variation in only the first letter was relevant to response selection). Results showed no differences between any condition in either reaction time or error rate, suggesting that both monosyllabic words and unpronounceable letter sequences were processed by their component letters. Results are consistent with suggestions that unitization differences between visually presented pronounceable and unpronounceable letter sequences may be due to phonemic recoding.

The effects of letter degradation and letter spacing on word recognition

The role of information in individual letters and in the letter strings in word recognition was investigated by degrading the quality of individual letters and by irregular spacing of letters. Two methods of displaying words were employed to correspond to two models of word recognition so that the effects of letter and spacing information could be tested for both models. The indicator of units processed by the subjects was the relationship between latency of word categorization and word length. Four predictions were derived concerning slope of this relationship. Three of these predictions were confirmed and the fourth prediction left untested. The display of words in mirror-image transformation produced an increase in recognition latency with word length, and letter degradation interacted with this relationship suggesting that subjects were processing component letters. Words displayed in normal orthography produced no change in latency with word length even when letters were degraded. Irregular spacing had no significant effect under either normal or transformed orthography.

Do words conceal their component letters? A critique of on the visual perception of words

Johnson (1975) presents two arguments in support of the idea that word perception does not result from a prior stage of letter perception and that letter analysis must await identification of a word as a unit. It is shown that Johnson's experiments lack necessary controls, and that there already exist empirical reasons to believe that the uncontrolled factors contribute to his effects. In addition, the implications to which Johnson commits prior-letter-processing models are shown not to hold under a variety of plausible assumptions.

Electronic spelling aid for use in speech therapy.

A device was produced to assist in the treatment of aphasia. The effects of this disorder, generally caused by damage to brain tissue, are well documented, and are usually considered to be an inability to construct words, or sentences from their component letters, both in spoken or written languages. It was considered that an electronic spelling device offering a minimal ‘reward’ at each stage would perhaps assist in the treatment of such patients in general and children in particular. Accordingly it was decided to use a system in which the word was illuminated letter by letter as the patient operated a keyboard, on which switches were arranged in alphabetical order. On the successful completion of the spelling, it was arranged that a picture illustrating the word would be illuminated.

Sequential letter and word recognition in deaf and hearing subjects

To examine the processing of sequentially presented letters of familiar and nonsense words, especially among Ss of vastly differing experience on sequential tasks, three groups of Ss were tested on letters of words spelled sequentially on an alphanumeric display and on letters of words fingerspelled. These were a deaf group (N=33) with little or no hearing and who varied in their fingerspelling ability; a staff group (N=12) who taught fingerspelling and were highly proficient; and a hearing group (N=19). Of principal interest was the finding that the hearing Ss did better on nonsense letter recognition, while the deaf group did better on word recognition. Word length was important except to the staff Ss on fingerspelled words, which also suggests that concentration on fingerspelling proficiency forces attention to the whole word and not its component letters. Hearing Ss, who are the group faced with an unfamiliar task, seemed to attend to each letter and hence had more difficulty with recognition of the longer unit.

Conditional and unconditional co-occurrence restrictions in the recall of bigrams

Previous investigations of the free recall of structured bigrams have concluded that Ss are unable to learn simple co-occurrence restrictions; however, only co-occurrence restrictions conditional upon the position in which each component letter occurs have been studied. Results of the present experiment suggest that Ss can and do make use of unconditional co-occurrence restrictions such as those found in a set of bigrams constructed from two classes of letters with the restriction that both letters appearing in a bigram must be drawn from the same class.

Recall and Recognition of Nonsense Syllables

Nonsense syllables chosen for learning material in experimental studies are generally selected on the basis of their associative value, on the assumption that frequency of association makes for ease of learning. That such an assumption is inadequate has been shown by Peixotto, who demonstrated that relative frequency of the component letters is at least as satisfactory a measure of recognitive value as is association.1 She also showed the important role played by positional factors in lists compiled for studies of recognition.2 In the first of her papers cited, she presents a list of 300 nonsense syllables, arranged according to recognitive value, noting at the same time that the values there assigned do not necessarily conform to their value in recall. It is the purpose of this paper to determine the relationship between recall and recognition for some of these syllables, in order to see whether Peixotto's values hold for both methods of testing memory. This problem is of some importance, for, despite the mass of experimental material which has been published in the field of learning, there is relatively little on a comparison of the methods of recognition and recall in the learning process. Procedure. It is obvious that, if learning is to be held constant, the same syllables cannot be used by the same Ss for studying both recall and recognition. Consequently, the method of equated groups was used; each group of Ss studied half the syllables by recognition and the other half by recall, and the syllables used by one group for recognition were used by the other group for recall.