Alice F. Healy

Detection errors on the word the: evidence for reading units larger than letters.

In four experiments, subjects read 100-word passages and circled instances of the letter t. Subjects missed a disproportionate number of ts in the word the. Evidence was provided against explanations of this effect involving the location and pronunciation of the t in the and against an explanation in terms of the redundancy of the. Rather the high frequency of the appeared to be critical, and it was suggested that high-frequency words are read in terms of units larger than the letter.

Separating item from order information in short-term memory

Two experiments were conducted in order to separate experimentally the processing of item and order information. These experiments provided support for the notion that order and item errors are caused by two different processes. This support came in part from finding bowed serial-position curves when only order information had to be learned but not when only item information had to be learned. An additional goal of the present investigation was to determine the extent to which subjects are limited to phonemic coding in short-term memory. There was evidence that subjects employed phonemic coding in the present situations even though it was an inefficient strategy.

How changing the focus of attention affects performance, kinematics, and electromyography in dart throwing☆

Research has found an advantage for an external focus of attention in motor control and learning; instructing subjects to focus on the effects of their actions, rather than on body movements, can improve performance during training and retention testing. Previous research has mostly concentrated on movement outcomes, not on the quality of the movement itself. Thus, this study combined surface electromyography (EMG) with motion analysis and outcome measures in a dart throwing task, making this the first study that includes a comprehensive analysis of changes in motor performance as a function of attentional focus. An external focus of attention led to better performance (less absolute error), decreased preparation time between throws, and reduced EMG activity in the triceps brachii. There was also some evidence of increased variability for kinematic measures of the shoulder joint under an external focus relative to an internal focus. These results suggest improved movement economy with an external focus of attention.

Detection errors onthe andand: Evidence for reading units larger than the word

In five experiments, subjects read lO0-word passages and circled instances of a given target letter, letter group, or word. In each case subjects made a disproportionate number of detection errors on the common function wordsthe andand. The predominance of errors on these two words was reduced for passages in which the words were placed in an inappropriate syntactic context and for passages in which word-group identification was disturbed by the use of mixed typecases or a list, rather than a paragraph, format. These effects for the wordand were not found for the control wordant. These results were taken as evidence that familiar word sequences may be read in units larger than the word, probably short syntactic phrases or word frames. A tentative model of the reading process consistent with these results is proposed.

Short-term order and item retention

This paper evaluates two hypotheses: (a) that transposition errors made in the recall of letter strings occur as a by-product of acoustic confusion errors and do not represent the loss of order information, and (b) that order and item information are independently retained in short-term memory. An experiment was conducted in which four-consonant strings containing exactly zero or two acoustically confusable items were recalled in order after retention intervals of 3, 8, or 18 intervening digits, all characters being successively presented at a rate of 400 msec per item and read aloud by the subject. An analysis of errors in relation to intra- and extrastimulus sources of acoustic confusion, retention interval, and serial position produced results that refute hypothesis (a) and support hypothesis (b). The implications of the present results for an adequate theory of the short-term retention of ordered strings are indicated.

On the cognitive structure of basic arithmetic skills: Operation, order, and symbol transfer effects.

In 2 experiments, college Ss practiced extensively on single-digit multiplication and division problems (e.g., = 6 × 9; 42 = × 6) and were tested on both practice problems and several altered versions of those problems, which were constructed by changing the required operation, operand order, or arithmetic symbol. There was strong positive transfer to test problems that had exactly the same elements (the numbers and the required operation) as a practice problem, regardless of whether other factors such as operand order or symbol were changed, but little if any positive transfer to test problems that did not have the same elements as a practice problem. An identical elements framework is used to interpret these results and implications for existing computational models of arithmetic fact retrieval and for the development of arithmetic skill are discussed

Investigating the Boundaries of Reading Units: Letter Detection in Misspelled Words.

In two experiments, subjects searching for the letter t in passages that contained some misspellings made many more errors on the word the than on other correctly spelled words. Accuracy increased dramatically when the word the and the other words containing t were misspelled, even when the misspelled word was the same shape as the original. These findings define a word-inferiority effect, which stands in contrast to the superior perception of letters in words over nonwords commonly found in tachistoscopic studies. In a third experiment, subjects searched for the letter n in passages typed normally or typed with all interword spaces replaced by the symbol +. Detection errors on the word and were greatly reduced when the interword spaces were replaced by +s, but errors on other words, including those ending in the suffix morpheme -ing, were not affected by this manipulation. These results suggest that frequent function words are processed in terms of reading units that are larger than the letter and include the interword spaces.

Letter detection: a window to unitization and other cognitive processes in reading text

Experiments are reviewed that use the letter-detection task, in which subjects read text and circle target letters. Evidence is provided that the letter-detection task reveals the processing units used in reading text and is influenced as well by visual, phonetic, and a combination of semantic and syntactic factors. Specifically, it is shown that circling a target letter in a word depends on the familiarity of the word’s visual configuration, the location of the word in the reader’s visual field, the phonetic representation of the letter in the word, and a combination of the word’s meaning and its grammatical function.

Categories and context in the perception of isolated steady-state vowels.

The noncategorical perception of isolated vowels has been attributed to the availability of auditory memory in discrimination. In our first experiment, using vowels from an /i/-/I/epsilon) continuum in a same-different (AX) task and comparing the results with predictions derived from a separate identification test, we demonstrated that vowels are perceived more nearly categorically if auditory memory is degraded by extending the interstimulus interval and/or filling it with irrelevant vowel sounds. In a second experiment, we used a similar paradigm, but in addition to presenting a separate identification test, we elicited labeling responses to the AX pairs used in the discrimination task. We found that AX labeling responses predicted discrimination performance quite well, regardless of whether auditory memory was available, whereas the predictions from the separate identification test were more poorly matched by the obtained data. The AX labeling reponses showed large contrast effects (both proactive and retroactive) that were greatly reduced when auditory memory was interfered with. We conclude from the presence of these contrast effects that vowels are not perceived categorically (that is, absolutely). However, it seems that by taking the effects of context into account properly, discrimination performance can be quite accurately predicted from labeling data, suggesting that vowel discrimination, like consonant discrimination, may be mediated by phonetic labels.

Long-term repetition effects for motoric and perceptual procedures

Two experiments examined the relationship between implicit and explicit measures of memory for information encoded in a motoric task, called data entry. In both experiments, subjects entered lists of digit sequences with a computer keypad. They were retested on the same task after a delay of up to 1 month. At retention, implicit memory for the digit lists was evidenced by faster entry of old relative to new lists in both experiments. In Experiment 1, subjects were able to discriminate old from new lists. Recognition memory of old lists was better after than before entering the lists. In Experiment 2, perceptual and motoric contributions to the old/new difference in typing speed were isolated by means of a transfer paradigm. The results showed that the entry-speed advantage for the old lists was due to the separate reinstatement at the retention test of both perceptual and motoric procedures encoded earlier. Implicit and explicit measures of memory were found to be dependent rather than independent. The findings from this study are interpreted within a framework of memory based on procedural reinstatement.