Phonological Impairment’s Relation to Phonological Awareness, Working Memory, and Literacy

Monica Gordon Pershey, Ed.D., CCC-SLPDepartment of Speech and Hearing

Cleveland State UniversityCleveland, OH

mgpershey@att.net

Patricia A. Clickner, M.A., CCC-SLPLorain County Board of Mental Retardation and Developmental Disabilities

Elyria, OHpclickner@loraincountymrdd.org

BackgroundDevelopmental phonological impairment may arise from inadequate mental representations of speech sounds and/or difficulty accessing representations of speech sounds.

Possibly 35% of children with phonological impairment evidence subsequent reading and spelling difficulties.

Some children with phonological impairment may have difficulty acquiring phonological awareness, i.e., the metalinguistic ability to reflect upon and manipulate speech sounds. Phonological awareness bootstraps onto the child’s speech system, with instabilities in the

speech system potentially constraining phonological awareness. Strong and accurate internal phonological representations – meaning accurate speech sound productions – provoke the association of phoneme to grapheme, allowing reading and spelling to develop.

The question remains whether it is weakness in phonological awareness alone that places children with phonological impairment at risk for reading and spelling difficulties. There is ample research evidence that a “double deficit” in two core processing deficits underlie reading disability: (1) undeveloped phonological awareness and (2) inadequate rapid naming of visual symbols. For children with phonological impairment, a proposed double deficit would involve (1) a weakness in internally representing and/or accessing speech sounds that impacts upon phonological awareness and that coexists with (2) difficulty rapidly retrieving names for visual symbols.

BackgroundA Proposed Double Deficit for Children with Phonological Impairment:Some children with phonological impairment may have comorbid deficits in verbal

working memory that manifest as difficulties with short term storage and manipulation of information that is encountered as auditory and/or verbal input.

Verbal working memory span allows phonological and/or orthographic information to be “On Screen” for a long enough period of time for manipulations to be performed. Rapid naming of colors, letters, or numbers demonstrates verbal working memory.

Rapid naming of letters reveals additional, separate cognitive-linguistic processes critical for learning to read. Each time a letter is encountered, it must be matched to letter templates or prototypes stored in visual memory and then matched to its name. Trouble rapidly naming letters shows deficiencies related to (a) orthographic representations (i.e., difficulties with visual symbols that enter memory as icons which are then arbitrarily named and stored as semantic memory), and/or (b) adequate storage of visual information but inadequate semantic labels for the names of letters, and/or (c) interference from inadequate phonological representations, with instabilities in the speech system constraining knowledge of letter names and/or sounds. For children with phonological impairment, we must also rule out diminished naming speed that can be attributed to reduced articulatory proficiency.

Purpose

The purpose of this study was to explore whether children with phonological impairment would show associated deficits in speech motor control, phonological awareness, verbal working memory, reading, and spelling. This research explored whether deficits in phonological awareness and rapid naming converged in a sample of children with phonological impairment and determined the combined impact of this “double deficit” on reading and spelling.

Research QuestionsResearch Questions

Group Comparisons:Do children with phonological impairment evidence lower scores on tests of

physiologically-based functions, namely suprasegmental quality of speech and oral motor control, than typically developing peers?

Do children with phonological impairment evidence lower scores on cognitive-linguistic tasks that tax verbal working memory than typically developing peers?

Do children with phonological impairment perform more poorly on rapid naming testing than typically developing peers?

Do children with phonological impairment evidence lower scores on phonological awareness testing than typically developing peers?

Do children with phonological impairment perform more poorly on reading testing than typically developing peers?

Do children with phonological impairment perform more poorly on spelling testing than typically developing peers?

Research QuestionsResearch Questions

Measures of Association Among Variables:Are deficits in physiologically-based functions, namely suprasegmental

quality of speech and oral motor control, related to the presence of phonological impairment?

Are deficits in cognitive-linguistic tasks that tax verbal working memory related to the presence of phonological impairment?

Are deficits in rapid naming associated with phonological impairment?Are deficits in phonological awareness associated with phonological

impairment?Are deficits in reading associated with phonological impairment?Are deficits in spelling associated with phonological impairment?

MethodologyParticipants

Group 1 - 23 English-speaking children (12 in 1st grade, 8 in 2nd grade, 3 in 3rd grade) diagnosed with phonological impairment

Group 2 - 23 phonologically unimpaired peers (12 in 1st grade, 8 in 2nd grade, 3 in 3rd grade) matched for race, gender, age (range 6.4 - 9.1), grade level, free lunch status, and IQ (normal range)

From 10 elementary schools in one Midwest county, median household income $60,000

All Group 1 and 2 students had passing scores for hearing acuity: Pure-tone air-conduction hearing screening at 20 db HL for 500, 1000, 2000, and 4000 Hz

Groups 1 and 2 are significantly different due to level of phonological impairment as assessed by the Goldman-Fristoe Test of Articulation-2 (GFTA-2) (with findings used to compute Percentage of Consonants Correct); [ANOVA] F(1, 44) = 55.16, p <.0001

MethodologyMethodology

Three areas of capabilities were assessed for all participants.Administration of tests was conducted by the second author in

randomized order over three individual testing sessions per child.Mean scores on all measures for groups 1 and 2 were computed.

Area 1 - Physiological factors:To assess suprasegmental qualities of speech: A brief conversational

sample analyzed for each participant for presence/absence of adequate quality; scored as “0" for normal, “1" for deviated 10% or less of the time, or “2" for deviated greater than 10% of the time

To assess oral motor skills: Zelvis Oral Peripheral Screening - scored as “1" for normal diadochokinetic rate or “2" for abnormally slowed diadochokinetic rate for each participant

Methodology

Area 2 - Cognitive-linguistic factors:To assess verbal working memory: The Clinical Evaluation

of Language Fundamentals-3 (CELF-3) subtests for word forms (sentence recall allows child to generate needed syntax/grammar/morphology), following directions, sentence repetition; Standard scores obtained for each participant

To assess rapid naming: The Comprehensive Test of Phonological Processes (CTOPP) Rapid Naming Subtests - colors, digits, letters, and non-words; Standard scores obtained for each participant

To assess phonological awareness: CTOPP (Composite of Elision, Blending, Sound Matching subtests); Standard scores obtained for each participant

Methodology

Area 3 - Reading and Spelling:

Reading and Spelling subtests from The Kaufman Test of Educational Achievement (K-TEA) brief form; Standard scores obtained for each participant

ResultsGroup Comparisons:

Area 1Do children with phonological impairment evidence lower scores on

tests of physiologically-based functions, namely suprasegmental quality of speech and oral motor control, than typically developing peers?

Suprasegmental QualityThe difference between groups is significant [ANOVA] F(1, 44)

=7.48, p =.009

Oral Motor Control22% of Group 1 children had abnormal diadochokinetic performanceThe difference between groups is significant [ANOVA] F(1, 44)

=6.11, p =.017

ResultsGroup Comparisons:

Area 2Do children with phonological impairment evidence lower scores on cognitive-linguistic tasks that tax verbal working memory than typically

developing peers?CELF-3 Word FormsThe difference between groups is not significant [ANOVA] F(1, 44) =3.67, p =.062

CELF-3 Direction FollowingThe difference between groups is not significant [ANOVA] F(1, 44) =3.04, p =.088

CELF-3 Sentence RepetitionThe difference between groups is significant [ANOVA] F(1, 44) =5.55, p =.023

CTOPP Non-word RepetitionThe difference between groups is significant [ANOVA] F(1, 44) =10.39, p =.002

Do children with phonological impairment perform more poorly on rapid naming testing than typically developing peers?CTOPP Rapid Naming mean composite standard score Group 1 45th percentile average performance range Group 2 61st percentile average performance rangeThe difference between groups is significant [ANOVA] F(1, 44) =4.72, p =.035

Do children with phonological impairment evidence lower scores on phonological awareness testing than typically developing peers?CTOPP mean composite of standard scores for subtests Group 1 25th percentile > 1 SD below normGroup 2 60th percentile average performance rangeThe difference between groups is significant [ANOVA] F(1, 44) = 28.04, p <.0001

ResultsArea 3Do children with phonological impairment perform more poorly on reading testing than typically developing peers?K-TEA Reading standard score Group 1 34th percentile < 1 SD below normative meanGroup 2 74th percentile < 1 SD below normative meanThe difference between groups is significant [ANOVA] F(1, 44) =31.72, p <.0001

Do children with phonological impairment perform more poorly on spelling testing than typically developing peers?K-TEA Spelling standard score Group 1 37th percentile < 1 SD below normative meanGroup 2 68th percentile < 1 SD below normative mean The difference between groups is significant [ANOVA] F(1, 44) =9.84, p =.003

“Just to be sure” - How different are these two groups? A Multivariate Analysis of Variance (MANOVA) compared groups based on all variables combined - speech

physiology, phonological awareness, verbal working memory, rapid naming, reading, spellingThe difference between groups is significant[MANOVA] F(1, 44) =14.25, p <.0001

MANOVA compared groups based on two variables combined - reading and spellingThe difference between groups is significant[MANOVA] F(1, 44) =15.58, p <.0001

ResultsMeasures of Association Among Variables for Children with Phonological ImpairmentPhonological impairment was associated with deficits in oral motor control and working memory,

including rapid naming, but not phonological awareness, reading, or spellingPearson Product Moment Correlations of Mean Scores - Percentage of Consonants Correct

correlated with Other VariablesAre deficits in physiologically-based functions, namely suprasegmental quality of speech and oral

motor control, related to the presence of phonological impairment?Suprasegmental Quality - No CorrelationOral Motor Control - Significant Correlation r =-.597, p =.003Lower Percentage of Consonants Correct scores were associated with higher (poorer)

diadochokinetic scores, creating an inverse relationship

Are deficits in cognitive-linguistic tasks that tax verbal working memory related to the presence of phonological impairment?

CELF-3 Word Forms - Significant Correlation r =.517, p =.012

CELF-3 Direction Following – Significant Correlation r =.612, p =.002

CELF-3 Sentence Repetition – Significant Correlation r =.464, p =.026

CTOPP Non-word Repetition - No Correlation

ResultsAre deficits in rapid naming associated with phonological impairment?CTOPP Rapid Naming Composite - Significant Correlationr =.405, p =.05

Are deficits in phonological awareness associated with phonological impairment?

CTOPP Phonological Awareness Composite - No correlation

Are deficits in reading associated with phonological impairment?K-TEA Reading - No correlation

Are deficits in spelling associated with phonological impairment?K-TEA Spelling - No correlation

ResultsStepwise Regression DataCorrelational data did not fully describe whether phonological impairment was associated with deficits in rapid naming (at p =.05), phonological awareness, reading, and/or spellingWhich test scores for children with phonological impairment accounted for variance in reading and spelling test scores?41% of the variance in K-TEA Reading scores could be accounted for by performance on CTOPP Phonological

Awareness Composite (p <.001)

69% of the variance in K-TEA Reading scores could be accounted for by performance on CTOPP Phonological Awareness Composite and CTOPP Rapid Naming Composite scores as a combined independent variable (p <.0001) [Coefficient analysis: PA at p <.0001; RN at p =.004 - indicates adequate stringency for each predictor variable]

64% of the variance in K-TEA Spelling scores could be accounted for by performance on CTOPP Phonological Awareness Composite (p =.008)

49% of the variance in K-TEA Spelling scores could be accounted for by performance on CTOPP Rapid Naming Composite (p =.012)

Need to finally reduce to explained/unexplained variance:66% of the variance in K-TEA Reading and Spelling scores as a combined dependent variable could be accounted for

by performance on CTOPP Phonological Awareness Composite and CTOPP Rapid Naming Composite scores as a combined independent variable (p <.0001) [Coefficient analysis: PA at p <.0001; RN at p =.009 - indicates adequate stringency for each predictor variable]

ConclusionsThe difference between children with phonological impairment and matched

unimpaired children was significant for all measures except two verbal working memory tasks (not rapid naming).

The presence of speech motor deficits was not ruled out. Phonological impairment correlated with poorer performance on speech motor tasks.

Children with phonological impairment performed below the normative mean on tests of rapid naming, phonological awareness, reading, and spelling. Phonological impairment correlated with poorer performance on cognitive-linguistic tasks that tax verbal working memory and on rapid naming.

Depressed rapid naming and phonological awareness coexisted as a “double deficit” in this sample of children with phonological impairment.

Findings support prior research that children with reading deficits may have difficulties with verbal working memory.

Findings support prior reports that children with phonological impairments may manifest deficits in verbal working memory, specifically rapid naming.

ConclusionsPractical ApplicationsSpeech disturbances which render a child difficult to understand should not be dismissed as

developmental motor skill.For children with phonological impairment who have weak phonological awareness and rapid naming,

the double deficit hypothesis is applicable –– internal representations of speech sounds must be continually monitored and reinforced.

All children with phonological impairment should be assessed by a speech-language pathologist and a reading specialist for deficits in rapid naming, phonological awareness, reading, and spelling.

Intensive speech, language, and literacy interventions should be applied for children with coexisting phonological impairment and verbal memory deficits.

Future ResearchCan research distinguish when deficient rapid naming ability reflects difficulties with verbal memory

AND/OR difficulties with speech motor control? Studies need to separate these performance components to isolate the memory vs motor aspects of rapid naming.

Can research establish subtypes of phonological impairment, as in with verbal memory impairment, with speech motor impairment, or with both?

Research is needed to explore any and all connections between phonological impairment and literacy acquisition.

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