Wednesday, November 27, 2019

Order Recall in Verbal Short-Term Memory: The Role of Semantic Networks

Poirier, M., Saint-Aubin, J., Mair, A., Tehan, G., & Tolan, A. (2015). Order recall in verbal short-term memory: The role of semantic networks. Memory and Cognition, 43(3), 489–499. https://doi.org/10.3758/s13421-014-0470-6

Let’s say you were asked to recall the word list, “cheese, steak, wine,”. Because you know all these words, your brain would likely process both the phonological (speech sound) form and the meaning of the word. But how would this unfold? Would you first activate the phonological representation of each and then you draw on semantic knowledge (meaning-based information)? Or would both types of information be activated at the same time?

Verbal short-term memory has often been viewed as operating in separate stores. That is, the phonological form is held in mind and rehearsed using what is called, ‘the phonological loop’. At the point of recall, if the phonological trace has been degraded, then semantic information stored in long-term memory is activated to help with reconstruction of the word, a process referred to as redintegration. According to this view, semantic knowledge held in long-term memory is activated and transferred to short-term memory at the point of recall, and only after phonological information is processed. Recently, this 2-step process has been called into question.

According to the language-based model, verbal short-term memory reflects the direct (and automatic) activation of your phonological, lexical, and semantic representations for each word. There is considerable overlap between verbal short-term memory and language processing from the moment of encounter, and not just at the point of recall. If an integrated network activates all linguistic knowledge related to a word on encounter, then semantic effects should be observed to influence one of the most well-described short-term memory findings: serial recall, the immediate recall of items lists in correct order.

Poirier et al. (2015) completed a series of studies manipulating the semantic relationship of words in the list to a particular target word. In Experiment 1, participants were presented with a 6-item word list wherein the first three items were or were not semantically related to the target word (item 5). Recall of the stimuli in Experiment 1 could have been influenced by a potential grouping strategy, that is, the participants could have grouped semantically related words in the condition where the words were related. Therefore, in Experiment 2, all items were from the same semantic category and were either studied in silence (2a) or under articulatory suppression (2b). Participants were asked to recall the word list in the order presented across all experiments.

Across the three studies, the target word migrated towards earlier positions at the point of recall when semantically related words were present, and this was not the result of a grouping strategy. The authors suggest that the migration occurred as a result of coding serial position (i.e., order information) as part of the semantic network that supports language representations. This provides a new perspective on the processes involved in verbal short-term memory: language processing in short-term memory is closely tied to semantic networks in long-term memory, and thereby, short-term and long-term memory may be more integrated than they are distinct. This may have important implications for word and language learning such as thinking about how phonological rehearsal and semantic processing should be integrated during the learning phase, rather than learned discretely, in order to optimize on retention.

Blogger: Theresa Pham is a student in the combined SLP MClSc/PhD program, supervised by Dr. Lisa Archibald.

Tuesday, November 19, 2019

Morphological Awareness and Word-Level Reading in Early and Middle Elementary School Years

Robertson, E.K. & Deacon, S.H. (2019). Morphological awareness and word-level reading in early and middle elementary school years. Applied Psycholinguistics, 40, 1051-1071.

Much of previous research on reading development has examined the contributions of phonological awareness, but the role of morphological awareness is not as well documented. Morphological awareness is defined as one’s ability to identify and manipulate units of meaning in language, called morphemes. The small body of previous literature examining morphological awareness and reading in elementary school years has yielded mixed findings, with some evidence that its role in reading increases over time, some evidence that its role is relatively stable, and some evidence that its role declines. The present study took a cross-sectional approach to examine how the relationship between morphological awareness, word reading, and pseudoword reading may change in early and middle elementary school years.

Participants in the present study were 375 children in Grades 1 to 4, grouped into two groups for analysis purposes: one group of students in Grades 1 and 2, and a second group of students in Grades 3 and 4. Participants all completed a real word reading task, a pseudoword reading task, and a morphological awareness task which assessed production of the past-tense inflectional morpheme -ed. In this task, participants listened to a sentence and then were asked to finish a second sentence, for example: “We play games. Yesterday, we did the same thing; we ____ (played) games.” To ensure the morphological awareness task was sufficiently difficult for the older participants, it also included pseudoword items, such as “Jill can blick. Yesterday, she did the same thing; she ____ (blicked).” Participants also completed measures of phonological awareness, phonological short-term memory, sentence-level oral language skills, and nonverbal cognition, to be used as control measures in the analyses.

The authors used hierarchical regression analyses to examine the unique contributions of morphological awareness to real word reading and to pseudoword reading. With respect to real word reading, morphological awareness accounted for 1.1% of additional unique variance beyond the control measures in the Grades 1 and 2 group, however, it did not significantly account for additional variance in the Grades 3 and 4 group. With respect to pseudoword reading, morphological awareness explained an additional 1% beyond what was accounted for by the control variables, and no interaction was found with grade group.

These findings suggest that the role of morphological awareness in real word reading declines from early elementary school years to middle elementary school years, whereas its role in pseudoword reading remains stable over these grades. The authors suggest that the reduced contributions of morphological awareness in middle elementary school years maybe be related to the increased role of sentence-level language skills when reading, as children shift from learning to read to reading to learn and are exposed to texts that are more rich in morphosyntactic complexity and vocabulary. These findings suggest that morphology may be an important component of early reading instruction in the classroom and reading intervention, although further research on instruction and intervention approaches is needed to better understand how this might benefit reading outcomes.

Blogger: Alex Cross is an M.Cl.Sc. and Ph.D. Candidate in Speech-Language Pathology, supervised by Dr. Lisa Archibald and Dr. Marc Joanisse.

Friday, November 8, 2019

Executive Functioning and Narrative Language in Children with Dyslexia

Fisher, E. L., Barton-Hulsey, A., Walter, C., Sevcik, R. A., & Morris, R. (2019). Executive Functioning and Narrative Language in Children with Dyslexia. American Journal of Speech-Language Pathology, 28, 1127-1138.


We can think about language skills in terms of its structure, the vocabulary and grammar used to make sentences and send messages. We can also think about language in terms of its function, that is, the meaning of words (semantics) or stories (narratives) in our messages. There are many cognitive processes that support language structure and function. Phonological processing refers to the ability to use speech sounds to support oral and written language, and it supports structural aspects of language. Children with a specific reading disability known as dyslexia have been found to have poor phonological processing, and in particular, poor phonological awareness, or the awareness of understanding the sound structure of one’s language, and phonological recoding, or the ability to map sounds onto the letters of a language. Executive function is a term used to describe the set of skills that allow individuals to establish goal-oriented behaviours such as initiating, planning, and organizing.  Executive functioning consists of three skills: shifting, inhibition and working memory updating, and they support functional aspects of language ability. Some children with dyslexia have been found to have impairments in executive function as well.

The present study examined the influence of executive function on language abilities at the structural and functional level in a sample of children with dyslexia. Children with dyslexia completed measures of language structure and function, and measures of executive function. Results revealed a correlation between measures of inhibition and structural language abilities, and between measures of working memory and both structural and functional language. When examining groups based on both language and executive function, children with both low language and low executive function were found to have more difficulty with narrative language than the other groups. Additional analyses suggested that the working memory measure accounted for variance in the narrative language measures beyond what was accounted for by structural language.

These results suggest executive function skills support a child’s language ability. Specifically, working memory contributes to a child’s narrative retell abilities. This research adds to the evidence that there are a number of factors that support language ability and conducting assessments that look at multiple components of language and executive function will help a child’s language profile.

Blogger: Meghan Vollebregt is a student in the combined SLP MClSc/PhD program working under the supervision of Dr. Lisa Archibald.