1. Evaluating the Procedural Deficit Hypothesis in Preschool Children
with Speech, Language and Motor Deficits
Renee Fabus1 and Peter Gordon2
1 Brooklyn College 2 Teachers College, Columbia University
The Procedural Deficit Hypothesis (PDH)
1. Comorbidity of Language, Memory and Motor Skills
Children with Language Impairments often exhibit co-occurring fine motor deficits (Hill 1998, 2001; Owens 1997, Sommers,1988)
Ullman (2001) proposed that deficits in rule-based aspects of language, working memory, and motor ability are based on common neural pathways underlying the procedural memory systems
Underlying pathways include tracts connecting DLPFC, Basal Ganglia, and Cerebellum
2. Differential Disruption of Language Abilities
Rule-based aspects of language are said to constitute a form of procedural knowledge (“knowing how”) as opposed to lexical aspects stored in declarative memory (“knowing what”)
PDH predicts children with procedural deficits will show both motor impairment and specific deficits on regular past tense forms (-ed) but not on irregular past tense forms (run - ran), which are stored in the declarative memory system
Full Test Battery
2. Are relations between language and motor abilities mediated through -motor-speech systems or directly through cognitive-level linguistic processes?
Speech
Goldman Fristoe-2 Test of Articulation
Khan Lewis Test of Phonological Processes
Memory
Children’s Test of Non-Word Repetition
Language
Test of Language Development 2 (Primary-TOLD)
Regular and Irregular past tense elicitation task
Non-Verbal
Block Design Subtest of the WPPSI
Fine Motor
Peabody Developmental Motor Scales
Peg-Moving
Bead-Threading
Tasks from HELP Checklist: cut circle, draw stick figure, fold paper 3x, and build tower with blocks
r. = .48,p< r=-.24, p= r.=-.14, p=.2
Language correlated with motor ability while speech did not, and Speech and Language did not correlate with each other. Therefore these data do not indicate that comorbitiy of language and motor ability are mediated via motor-speech systems
Correlations do not improve with removal of ceiling effect data
3. Do relationships between motor and language abilities involve working memory?
r. = .52, p< r=-.35, p= r.=-.50, p=.003
Verbal STM correlated with Language, Speech and Motor suggesting prominent role for working memory in all of these abilities and in accounting for comorbidity of impairments
1. How are speech, language, working memory, and motor ability affected in preschoolers who have been referred for Speech-Language therapy or occupational therapy for fine motor impairments?
Unaffected control groups performed better on all tasks except Speech (Goldman-Fristoe) where the SLP group performed as well as the control group
The SLP group performed worse than all groups on language tasks (TOLD) suggesting a profile resembling Specific Language Impairment (SLI)
Comorbidity of Language and Motor Ability
Children in Speech Language Therapy (SLP & Both) performed poorly in fine motor tasks compared to controls
Children in therapy for fine motor impairment (OT) showed poor performance on speech and language tasks
Results confirm comorbidity of Speech, Language and Motor Skills in this population
Working Memory and Spatial Ability
All impaired groups showed impairments in STM non-word repetition tasks (p< .001) and Spatial Block Design (p<.001)
STM is hypothesized to be part of procedural system
Connections of procedural system to parietal cortex, and procedural aspects of Block Design
Questions
How are speech, language, working memory, and motor ability affected in preschoolers who have been referred for Speech-Language therapy or occupational therapy for fine motor impairments?
Are relations between language and motor abilities mediated through -motor-speech systems or directly through cognitive-level linguistic processes?
Do relationships between motor and language abilities involve working memory?
Are regular past tense forms more affected by deficits than irregular past tense forms as predicted by the PDH?
4. Are regular past tense forms more affected by deficits than irregular past tense forms as predicted by the PDH?
Past Tense Elicitation Task
110 verbs: 43 regular verbs 67 irregular verbs w/ pictures
She eats everyday. Everyday she eats. Yesterday she … (ate)
Impaired vs. Contols
Regular Past Tense forms:
t=2.69, p = .006
Irregular Past Tense forms:
t=2.46, p=.02
Results
Impaired groups showed deficits in both regular and irregular past tense forms
Impaired groups showed characteristic perseveration of 3rd person verb forms (“…yesterday, she eats”)
Performance was very low for all groups in the irregular verb condition
No support for differential deficits on rule-based forms
Age group might be too young to elicit differences in past tense forms. However, if early forms are stored rather than computed, then these results do not support procedural deficit
Participants
28 preschool children between 4 and 5 years of age:
7 no therapy services (Control)
7 occupational therapy (OT)
7 speech-language therapy (SLP)
7 both OT and SLP therapy (Both)
Groups matched for mean age, range and SES
Native English Speakers
Normal Hearing
No psychological or clear neurological disorder
POSTER DOWNLOADS AT: