reducing the cognitive/linguistic load of persons with aphasia and traumatic brain injury who rely...
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Reducing the Cognitive/Linguistic Load of Persons with Aphasia and Traumatic
Brain Injury Who Rely on AAC
David Beukelman
University of Nebraska, Lincoln
With support from:
AAC-RERC/NIDRR/USDE
Technology Transfer Partner
Dynavox
AAC: Augmentative and Alternative Communication
• A range of strategies to support communication for those with unmet communication needs
Aphasia
• Language limitation due to damage language center in the left (usually) hemisphere – Range of symptoms– Range of severity– Range of recovery– 30% do not achieve full recovery– ??% with minimal functional verbal expression
Traumatic Brain Injury
• Range of communication limitations– Motor speech– Cognitive/Linguistic– Combination
– Pattern of communication limitations changing as medical interventions improve.
– More combined communication limitations
Intervention Strategies
• Restoration--restore verbal expression
• Compensation--provide alternatives to natural speech
• Combined--Integrate AAC and natural speech
Cognitive/Linguistic Limitations Related to AAC
• Representation of Meaning
• Navigation through the AAC Interface
• Formulating Messages
• Organizing Content
Aphasia: AAC Acceptance & Use
• Long history of low tech AAC use to support residual verbal expression– Communication books and boards– Drawing– Handwriting– Photography– Remnant books
Aphasia: AAC Acceptance & Use
• High tech AAC use for specific tasks– Answering phone– Calling for help– Ordering in restaurants and stores– Giving speeches– Saying prayers– Engaging in scripted conversations
Rationale for Using Visual Scene Displays (Aphasia)
• Make use of preserved skills of people with chronic aphasia– Visual-spatial processing– Retention of information about life
experiences (episodic information)– Retention of general world knowledge
Strategy: To incorporate Contextually Relevant Visual Scenes
• Provide a way to represent meaning
• Support navigation within an AAC system
• Serve as a shared platform for co-constructing messages with listener(s)
• Establish a shared communication space
• Allow for integration with other types of communication supports
Evaluating Images for Contextual Richness of a Visual Scene
Four criteria:– Environmental context (setting, people,
objects, and activities)– Interaction with people or the environment– Personal relevancy– Clarity regarding elements key to the implied
relationships
Environment: HighInteraction: HighPersonal relevance: High Clarity: HighComment: Satisfies all the elements for being a good contextually-rich picture to support a story
Environment: AbsentInteraction: Absent Personal relevance: High Clarity: HighComment: Typical portrait that does not convey any contextual or interaction information
Environment: Absent
Interaction: Absent
Personal relevance: Absent
Clarity: High
Comment: Only serves to identify an
object; typical of pictures available in stimulus sets
VSD Navigational Strategies (High Tech)
Themes• Organizational strategy for • navigation
Color & CONTRAST• Learning • Memory• Pattern recognition• Organization
“Link Deeper”• Continue on same topic
Three Levels Content Management Strategies
• 1. People who rely on AAC
• 2. AAC Facilitator/General Clinician
• 3. AAC Specialists
VSD Features
• Drag and drop images from• Enter messages from onscreen keyboard• Hide and reveal buttons• Select from a range of templates• Navigate themes• Navigate deeper into themes• Enter content with requiring detailed
programming knowledge
Research Strategy
Case Reports and Small N Studies of Clinical Interventions with Current Technology
Experimental Studies PreferenceMessage representationNavigation of Interface
Usability Evaluations of Technology Revisions
Aphasia: Participant 1
0
10
20
30
40
50
60
70
80
90
Per
cent
Tim
e U
sed VSD
Low Tech
Vocalizations
Gestures
Writing
Basic Needs New Information Social Closeness
Aphasia: Participant 2
0
10
20
30
40
50
60
70
80
90
Perc
en
t Tim
e U
sed VSD
Low Tech
Vocalizations
Gestures
Writing
Basic Needs New Information Social Closeness
Message Representation: Preference
– N = 8– Miechelle McKelvey Dissertation
Results Summary: Preference– Personally Relevant Pictures: 85%– Non-personally Relevant Pictures: 13%– Iconic Symbols: 3%
Message Representation: Accuracy
– N = 8– Miechelle McKelvey Dissertation
Summary Results: AccuracyPersonally Relevant Pictures: 98%
– Non-personally Relevant Pictures: 55%– Iconic Symbols: 34%
Learning New Themes
• Strategy:– Series of Small N Studies – Completed during field tests
• Conclusion: – Instruction/practice on FIRST THEME varied– Minimal instruction/practice on Subsequent
Themes after the FIRST THEME was mastered.
Traumatic Brain Injury with Complex Communication Needs (N = 30)
• Summary from Fager et al. Survey (2006)• 32% used low-tech AAC
– Regained speech– Lack of Facilitator support– Lack of funding for high-tech AAC
• 68% used high-tech AAC– Of these, 87% used letter by letter spelling without message
retrieval– Minimal use of message retrieval strategies– Remainder used iconic symbols--
• TBI before learning to spell• Severe cognitive/language issues
VSD with Onscreen Keyboard Option
VSD
to support episodic message retrieval
to support multiple themes
to support narrative organization
to supplement residual speech
Onscreen keyboard with speech synthesis output to support spelled messages
VSD for Severe Cognitive Conditions
• Subset of People with TBI are unable to communicate through speech and experience such severe cognitive limitations that spelling is not an option for some them.
• VSD appears to be an option provided that visual issues are managed with large pictures and print.
• Field Trials Ongoing
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