Working memory: A developmental study of phonological recoding

A cross-sectional study using children aged 3 to 7 years and a cross-sequential study using children aged between 5 and 8 years showed that the development of phonological recoding in working memory was more complex than the simple dichotomous picture portrayed in the current literature. It appears that initially children use no strategy in recall, which is proposed to represent the level of automatic activation of representations in long-term memory and the storage capacity of the central executive. This is followed by a period in which a visual strategy prevails, followed by a period of dual visual-verbal coding before the adult-like strategy of verbal coding finally emerges. The results are discussed in terms of three working memory models (Baddeley, 1990; Engle, 1996; Logie, 1996) where strategy use is seen as the development of attentional processes and phonological recoding as the development of inhibitory mechanisms in the central executive to suppress the habitual response set of visual coding.     

Working memory: a developmental study of phonological recoding

A cross-sectional study using children aged 3 to 7 years and a cross-sequential study using children aged between 5 and 8 years showed that the development of phonological recoding in working memory was more complex than the simple dichotomous picture portrayed in the current literature. It appears that initially children use no strategy in recall, which is proposed to represent the level of automatic activation of representations in long-term memory and the storage capacity of the central executive. This is followed by a period in which a visual strategy prevails, followed by a period of dual visual-verbal coding before the adult-like strategy of verbal coding finally emerges. The results are discussed in terms of three working memory models (Baddeley, 1990; Engle, 1996; Logie, 1996) where strategy use is seen as the development of attentional processes and phonological recoding as the development of inhibitory mechanisms in the central executive to suppress the habitual response set of visual coding.     

Contextual coding and recoding of infants' memories.

Six-month-old infants recognize a well-learned cue 24 h after training in the original context but not in a different one. In the present studies, we demonstrated that this contextually based retrieval deficit could be overcome if, following some training experience in one context, infants were briefly and passively exposed to a novel context. The impact of this procedure was retroactive, leading the immediately preceding training episode to be contextually recoded. However, it did not override the debilitating effect of a novel context on memory reactivation 3 weeks later and, surprisingly, it blocked the effectiveness of the actual training context as a reminder. We conclude that each individual training episode is encoded in terms of the context in which it occurs. The memory of a given episode, however, is recoded in terms of the most recent context in which it is active. This mechanism permits memories that are highly context-specific to be updated and subsequently retrieved in new and potentially appropriate settings.     

A cross-sequential analysis of developmental differences in speed of visual information processing

Development of processing speed was examined in three backward masking studies. The first verified the central nature of backward masking for children aged 8 and 11 years and for adults. The second suggested that task requirements were equivalent for children similar to those in Study 1, and that age differences in performance were not attributable to nonprocessing variables. The main cross-sequential study estimated speed of processing in 80 children (approximately 6 years to 13 years) and young adults using an inspection time task. Target exposure duration was varied to establish the time required to achieve a high level of discriminative accuracy. Estimates of processing speed increased until about 11-13 years of age; beyond this, the trend was less obvious, and it is possible that inspection time asymptotes at around the onset of adolescence. Performance improvement after 1 year could not be explained as resulting from practice since improvement among controls over a period of 2 weeks was significantly less. Correlations between estimates of inspection time made up to 2 years apart found the measure to be reliable.     

Test of the phonological recoding hypothesis using a letter-delay task

In some English words is a silent letter in the letter strings, e.g., PSALM. This type of word provides room to manipulate phonological similarity against the words with a nonsilent letter in the corresponding position, e.g., PASTA, to test the phonological recoding hypothesis. Letter strings excluding the silent letter or the sounding letter, e.g., _salm and a phonological condition, _asta as an orthographic condition, were presented. A "psalm-type word" was processed faster than pasta-type word," indicating that phonology plays a leading role in word recognition.     

A follow-up developmental study of hypothesis behavior among mentally retarded and nonretarded children

To clarify the roles of IQ and mental age (MA) in hypothesis behavior, MA-matched subjects at three levels of IQ (70, 100, and 130) and three levels of MA ($\text{5}\text{1}\text{2}\text{, 7}\text{1}\text{2}\text{,}\text{and}\text{9}\text{1}\text{2}\text{years}$) received blank-trial discrimination learning problems using procedures designed to discourage position-oriented responding. With position responding discouraged, earlier findings were contradicted in that no hypothesis measure showed a main effect of IQ. This suggest that previously reported IQ group differences in hypothesis behavior may not reflect cognitive deficits inherently linked to low IQ, but instead may reflect the influence of specific methodological factors. The finding and interpretation are consistent with Zigler's (American Journal of Mental Deficiency, 1969, 73, 536–556) “developmental” theory of retardation and inconsistent with the general “difference” position. In additional findings, the predictions that subjects at all three MA levels would use hypotheses, and that retarded children from special-education classes would use hypotheses more often than retarded children “mainstreamed” in classes for the nonretarded were confirmed.     

Integrating velocity,time, and distance information: A developmental study

The development of understanding the relationships between velocity, time, and distance was investigated in three tasks. In each task, values of two dimensions were given, and 5-year-olds, 10-year-olds, and adults had to infer values of the third dimension. These inferences were made in all age groups. The integration rules were found to depend upon age and task. In the distance = time × velocity task, all age groups obeyed the normative multiplication rule. In the time = distance ÷ velocity task, the two older age groups obeyed the normative division rule, but the 5-year-olds shifted to a simpler subtraction rule. In the velocity = distance ÷ time task, which was the most difficult, the two older age groups simplified to use of a subtraction rule, and the 5-year-olds simplified even further to use of a distance-only rule. The knowledge level revealed for young children contrasts sharply with results from previous studies using Piagetian choice tasks, which apparently investigate selective attention to one dimension rather than conceptual understanding of relations.     

A developmental study of the effects of irrelevant information on speeded classification

The study examined how well subjects were able to ignore the presence of irrelevant stimulus information as a function of age. Children aged 6, 9, and 12, as well as adult subjects sorted cards with one binary dimension relevant, and zero, one, or two dimensions irrelevant. Speed of classification was measured. Significant effects of age, sex, number of irrelevant dimensions, and relevant dimension on speed of classification were obtained, as well as a number of interactions of these variables. The most important finding was that the presence of irrelevant information interfered with the performance of the task by child subjects and that the magnitude of the interference declined with age. The results were interpreted as implying that developmental trends in attention may be most clearly demonstrated in tasks which require speeded processing of stimuli. The ease of administration of the speeded classification task, coupled with the clear developmental trends obtained, recommend this paradigm as a useful one with which to study the development of selective attention.     

Effects of white noise and irrelevant information on speeded classification: A developmental study

The study examined how well subjects were able to ignore the presence of irrelevant stimulus information in noise and in silence, as a function of age. Children aged six and nine, and adults, performed speeded card-sorting tasks with one binary dimension relevant and zero or two dimensions irrelevant. The presence of irrelevant information interfered with performance, the magnitude of interference declining with age. The interfering effects of irrelevant information were greater when it was (relatively) more salient than when it was less salient, but there was no interaction between relative salience and the effects of noise. Noise (95 dB(A)) slowed down sorting performance of adult subjects in all conditions, it slightly improved the performance of nine-year-old children, and it improved the performance of six-year-old children significantly when irrelevant information was present. The effects of noise on attentional control are discussed, mainly with reference to inhibitory effects of noise on subvocal activity.     

Cognitive gender differences: A developmental perspective

This article reviews the developmental literature on cognitive gender differences and compares past and present trends in gender differences, by age, from the standardizations of the Wechsler Intelligence Scales (1949–1981) and the California Achievement Tests (CAT; 1956–1985). Consistent with prior research, decreases in gender differences were found for adolescents. For children, gender differences were small or nonexistent in the Wechsler and CAT norms from 1949–1985. For adults, notable gender differences were often found on the subtests of the Wechsler scales, and have remained relatively constant over the past generation.I would like to thank Donald Ross Green for providing me with Clark's (1958) paper.     

Race differences and the Spearman hypothesis

Certain published data have been reviewed and new data presented relevant to the so-called Spearman hypothesis concerning the racial differences on cognitive tests of black and white Americans. In the published data, the correlation between the profiles of low socio-economic and high socio-economic status (SES) whites became ?.90 when sex, area of the country, and grade/age were controlled. This nearly mirror-image relationship suggests that the residual across-the-board difference between the two groups is primarily on the general factor in intelligence. In contrast, the same correlation between blacks and the low SES whites was only ?.19. This indicated not only independence of the profiles but the presence of multiple causes of differences in addition to a possible contribution of the general factor. These published interpretations have now been confirmed by obtaining correlations between general factor loadings and the group differences for most of the same tests. For the SES dochotomy in whites this correlation is .86. For blacks and the low SES whites it is .17. When the two distributions of differences are correlated, a value of .42 is obtained. The Spearman hypothesis appears to apply primarily to differences in socio-economic status rather than race. Furthermore, one cannot assume a large genetic component for each set of differences. Nor can one argue that the possibility of a large environmental component for each set indicates common environmental causes.     

Confusing developmental and individual differences

T. Globerson (1985, Developmental Review, 5, 261–273) compared the relative effects of an individual difference variable field dependency (FD/I) with a developmental variable (age) on a measure of M-capacity, in an analysis of variance (ANOVA) design. Age is a highly significant effect and the sum of squares associated with this factor accounts for 66% of the variance in M-capacity. FD/I is not significant and accounts for less than 1% of the variance in M-capacity. This is interpreted as indicating that M-capacity is a purely developmental phenomenon showing negligible individual differences. This paper argues that this result is an inevitable artifact of the experimental design. Further, the design is a common one in developmental psychology, and its dangers are largely unrecognized. The main problems concern (1) dichotomizing a continuous variable and treating the dichotomy as two levels of a factorial variable, (2) drawing inferences about the size of relationship between the continuous variable and the dependent variable on the basis of the variance accounted for by the factorial variable in the ANOVA, (3) differential reliability of measures of the independent variables, and (4) selective control of the sampling of the independent variables. These issues are explored in a simulation of Globerson's data and in an analogous analysis of data relating age and height, as independent variables, with weight as a dependent variable.     

Gender and developmental differences in children's conversations

Extending work on childhood gender differences by J. Block (“Assimilation, Accommodation and the Dynamics of Personality Development,” Child Development, 1982, 53, 281–295) and J. H. Block (“Differential Premises Arising from Differential Socialization of the Sexes: Some Conjunctures,” Child Development, 1983, 54, 1335–1354), the present research investigated assimilative and accommodative discourse devices in the speech of 24 preschool children (12 boys and 12 girls) and 24 middle-childhood youngsters (12 boys and 12 girls) in each of grades 3 and 6. Boys' discourse, regardless of age, contained more accommodative devices. Girls' discourse, regardless of age, contained more assimilative devices. Age effects were apparent; older children, regardless of gender, used more discourse devices of both kinds than younger children.     

The teleological origins of mentalistic action explanations: A developmental hypothesis

In this paper we shall argue that mentalistic action explanations, which form an essential component of a mature theory of mind, are conceptually and developmentally derived from an earlier and purely teleological interpretational system present in infancy. First we summarize our evidence demonstrating teleological action explanations in one-year-olds. Then we shall briefly contrast the structure of teleological vs. causal mentalistic action explanations and outline four logical possibilities concerning the nature of the developmental relationship between them. We shall argue for the view that causal mentalistic action explanations are constructed as useful theoretical extensions of the earlier, purely teleological, nonmentalistic interpretational stance.     

Phonological recoding and rapid orthographic learning in third-graders' silent reading: a critical test of the self-teaching hypothesis

This study examined rapid orthographic learning following silent reading in third-grade children as a function of number of target nonword repetitions and test delay. In each of two test sessions at least 6 days apart, children read a series of short stories, with each story containing a different nonword repeated either four or eight times. In the second session, after the stories had been read, children were asked to read short lists of target nonwords or homophonic alternatives. Children read target nonwords faster than homophones, indicating that they had formed functional orthographic representations of the target nonwords through phonologically recoding them during silent story reading. They also preferred target nonwords to homophones in an orthographic choice task in which the alternatives included the target, the homophone, and a visually similar foil, although here orthographic learning was stronger for items encountered eight times within stories and stronger for items tested immediately. These findings provide critical evidence in support of Share's self-teaching through phonological recoding hypothesis.     

The role of linguistic and visual information in spelling: a developmental study

This study investigated the processes that elementary school children use for spelling. Good and poor spellers in grades 3 through 6 spelled words and nonwords that differed in the types of information (phonological, orthographic, morphological, or visual) that could be used to produce their correct spelling. A multiple choice spelling recognition task was also administered. Error rates on words and nonwords were related to the type of information that could be used to determine the correct spelling. Words that could be spelled on the basis of linguistic information were easier than words that could be spelled only on the basis of visual information. While children were sensitive to the linguistic properties of the stimuli, their use and knowledge of various sources of linguistic information was not uniformly developed. Children had the most difficulty with spellings based on morphological information and the least difficulty with those based on invariant sound-spelling relationships. On the dictation and the nonword tasks, younger children and poorer spellers differed from older children and better spellers in the overall level of their knowledge, but all children showed a similar pattern of results suggesting that they did not use different processes to spell words. However, the data from the recognition task suggested that poor spellers may rely more on visual information than good spellers.