Everybody knows that there is a finite span of immediate memory and that for a lot of different kinds of test materials this span is about seven items in length. - George Miller (1956, p. 12 of the reproduced article)
The interactions of language and memory are both obvious and mysterious. Issue editor Lisa Archibald and her group of international and interdisciplinary experts shed new light on some of the mysteries in this issue of Topics in Language Disorders (TLD): "Language Learning and Impairment: Relationships Between Linguistic, Working Memory, and Other Cognitive Processes." Reading these interesting articles sent me back to George Miller's (1956) well-known piece on capacity limits on information processing, from which I drew the quotation that leads this column. As a person whose current research involves test development, Miller's words in the following passage held a particularly strong meaning for me:
If you will now imagine a communication system, you will realize that there is a great deal of variability about what goes into the system and also a great deal of variability about what comes out. The input and the output can therefore be described in terms of their variance (or their information). If it is a good communication system, however, there must be some systematic relation between what goes in and what comes out. That is to say, the output will depend upon the input, or will be correlated with the input. If we measure this correlation, then we can say how much of the output variance is attributable to the input and how much is due to random fluctuations or "noise" introduced by the system during transmission. So we see that the measure of transmitted information is simply a measure of input-output correlation. (p. 82)
When children exhibit difficulty learning spoken or written language, we can consider that their faulty systems must be introducing noise into the system for processing spoken language or print. It is that fluctuation (or variance) that we are attempting to measure when we design input stimuli for assessment purposes, ask children to produce a response, and then measure the output. Does memory allow a child to process the input, or does processing the input allow a child to remember it? In her issue editor Foreword, Archibald (2013a) explains the distinction between the domain-general and domain-specific hypotheses that would underlie these two explanations of the basic relationships between short-term and working memory and language (which could be considered a part of long-term memory).
When people talk about memory problems among children developing language, I always want to know, "Memory for what?" Consider the challenges of trying to remember the unfamiliar sounding name of someone from a cultural-linguistic group different from one's own. A multisyllabic name using unfamiliar phonological structure is much more difficult to retain than a name that is new but constructed of familiar components. I guess this puts me on the side of those theorists in the language and memory discussions who take a domain-specific view of short-term memory and therefore see language weaknesses being at the root of memory weaknesses rather than vice versa. The picture is far more complex, however, than this simplistic example can convey, with implications for language assessment and intervention, as well as for understanding the nature of language disorders.
The authors in this issue of TLD consider the complexities connecting language, memory, and other cognitive factors from many angles. Archibald (2013b) considers evidence for differing factor structures in formal assessments, using verbal and nonverbal stimuli and considering tasks designed to measure short-term and working memory. Kidd (2013) describes evidence for the role of memory in sentence comprehension. Stokes, Moran, and George (2013) report on a study of nonword repetition by young children who had met criteria as late talkers. Leclercq, Maillart, and Majerus (2013) report on the effects of repeating nonwords in French to add to the understanding of the role of intraword complexity on nonword repetition tasks. Finally, Archibald, Joanisse, and Munson (2013), based on their original research, discuss the role of motor speech influences in nonword repetition, with implications for understanding the nature of specific language impairment.
All these articles address multidimensional questions. Later in his article, Miller (1956) wrote,
You may have noticed that I have been careful to say that this magical number seven applies to one-dimensional judgments. ... Objects, faces, words, and the like differ from one another in many ways, whereas the simple stimuli we have considered thus far differ from one another in only one respect. (p. 8 of the reproduced article)
As he developed his arguments further, Miller emphasized the role of learning in the ability to handle more information when it is somehow recoded into larger chunks (often linguistic), noting, "We are dealing here with a process of organizing or grouping the input into familiar units or chunks, and a great deal of learning has gone into the formation of these familiar units" (p. 15 of the reproduced article). Relevant to the current discussion, Miller added, "In particular, the kind of linguistic recoding that people do seems to me to be the very lifeblood of the thought processes" (p. 18 of the reproduced article). By considering how variation in input influences the variations in output by children with and without memory issues, late language emergence, and diagnoses of specific language impairment, the authors of this issue of TLD take readers inside the cognitive-linguistic black box and illuminate issues that can contribute to broader understandings of complex relationships and differences between how children with and without language disorders process the input they are given.
-Nickola Wolf Nelson, PhD
Editor
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