The nature and causes of auditory memory difficulties

The nature and causes of auditory memory difficulties

Short term auditory memory is sometimes called working memory because it is the system which we use when we have to hold information for a brief period of time while we process it. Working memory is a limited-capacity system, and unless rehearsed or transferred to longer-term storage, information in working memory is only retained for a few seconds (Baddeley, 1986). For example, in order to understand what a person is saying to us we have to hold their words in working memory until they get to the end of a sentence (or equivalent break), then we can process those words for their meaning. We cannot process each individual word for meaning as we hear it because by themselves words do not convey sufficient meaning. Furthermore, words heard later in an utterance can substantially alter the meaning of words heard earlier (e.g. ‘The man opened the magazine – then he carefully extracted the remaining bullets it contained’).

In the same way that it is necessary to hold spoken words in memory in conversation, the student must hold letters and syllables in memory when decoding words. This is very important in the development of phonic skills. The majority of dyslexic students have problems in this area of cognitive processing (Thomson, 1982). Awaida and Beech (1995) found that phonological memory at age 5 predicted non-word reading (i.e. phonics skills) at 6 years. When reading continuous text for meaning the student must also hold words in memory until the end of the phrase or sentence. Poor working memory will thus affect reading comprehension. Of course, visual memory skills will be involved in much of this cognitive activity, especially for more competent readers whose capacity for rapid visual recognition of words steadily increases with age. Nevertheless, auditory working memory remains a significant factor in reading development and in writing as well. Students with weaknesses in auditory working memory also tend have difficulty in monitoring their written output, and are inclined to miss letters, syllables and/or words out when they are writing (Baddeley, 1986; Brady, 1986; Jorm; 1983; Wagner and Torgeson, 1987.)

Further research has suggested a very close connection between auditory memory span and articulation (speech) rate (Avons and Hanna, 1995; McDougall and Hulme, 1994). It could well be that articulation rate is an index of the efficiency with which phonological representations of words can be located in memory and activated (i.e. spoken). In turn, this could be closely related to how quickly cognitive representations of words being read can be located in the orthographic and semantic lexicons and activated (i.e. recognised and understood). The three lexicons (phonological, orthographic and semantic) are all believed to be closely related (Rayner and Polatsek, 1989). The fact that Races was a significant predictor of later literacy skills (despite not involving the child in any speech) suggests that sequential processes in auditory working memory are nevertheless important in reading, independently of articulation rate.

Case study- auditory working memory difficulties

Inspection of Robert’s report (see Figures 35a and 35b) suggests that he does not have any major problems in visual information processing. His phonological awareness (Rhymes) and auditory discrimination skills (Wock) are also satisfactory. On the other hand, he has major difficulties in auditory working memory, both associative (Letter names) and sequential (Races). Consequently, Robert would be expected to have problems in acquiring effective phonic skills. The recommendations would be for a well-structured multisensory phonic approach to literacy learning with ample practice to compensate for his memory weakness, but using his strong visual channel to maintain confidence in his skills. He will almost certainly have problems in writing and spelling, especially with regular words and new or uncommon words. Word processing activities (especially with a talking word processor) would be a great help.

 

Figure 35a. Case study – Robert

Figure 35b. Case study – Robert