EFFECTS OF TOPICAL VOCA
MESSAGES ON CONVERSATIONS WITH SEVERELY APHASIC COMMUNICATORS
Kathryn L. Garrett, Ph.D., CCC-SLP Duquesne University,
Pittsburgh, PA
Kelly M. Sestric, MS, CFY Mt. Lebanon School District, Pittsburgh,
PA
A poster presentation at the ASHA 2000
Convention, Washington D.C.
In
this single subject experiment, two communicators with severe aphasia conversed
with partners about a personal event and a news event in baseline, VOCA topical
messages, and VOCA + instruction conditions. Dependent variables included exchanges per topic,
participant initiations, successful exchanges, modality, and elapsed topic
time. Qualitative ratings were also
obtained.
Because
of their extensive communication deficits, many people with severe aphasia are
nonspeaking or have extremely limited expressive communication skills. They have difficulty sharing adequate
amounts of specific information to sustain in-depth topical conversations; therefore
the communication partner often carries the burden of an interaction (Packard
& Hinkley, 1997). A variety of
alternative communication strategies have been proposed to assist persons with
severe aphasia to communicate more effectively, including a written choice
conversational strategy (Garrett & Beukelman, 1995); pre-stored information
in communication notebooks or voice output devices (Garrett & Beukelman,
1992); and use of naturalistic, nonverbal communication modalities such as
writing, gesturing, and drawing (Doyle & DeRuyter, 1995; Glosser, Weiner,
& Kaplan, 1986; Lyon, 1995).
Although having external, printed information available may assist some
nonspeaking persons with aphasia to communicate, it is not clear whether
individuals with very severe aphasia can initiate consecutive messages
in a conversational exchange.
Garrett, Heldman, and Dunning (1994) described a case study in which a
gentleman with severe aphasia successfully learned to use a voice output
communication aid (VOCA) to communicate consecutive messages in a practiced
conversation about farming. In
this particular case, the VOCA appeared to simplify the message initiation
process. However, no controlled
data are presently available to validate this intervention.
Specifically,
the present study investigated: 1)
the impact of pre-stored topical messages in a voice output communication aid
(VOCA) on the conversational behaviors of persons with severe aphasia; and 2)
the ability of persons with aphasia to learn to purposefully use these
pre-stored messages in conversations given specific instructional
intervention. 3) the impact
of topic types on interactions
(current event vs. personal event).
A modified single subject (ABAC) sequential design was utilized.
Experimental
Conditions/Procedures:
a)
Baseline (condition A): Participants were instructed to discuss a
pre-selected personal event or current event in detail for as long as possible
with their partner in a dyadic exchange.
No context or messages were provided.
b)
VOCA-Only Condition (condition B): Prior to data collection,
the primary investigator stored 2-to-4 messages for each current event or
recent personal event (total of 6-to-8 messages) on the VOCA. Messages included: 1) a starter
question – “Have you heard about (topic)?; 2) opinions represented
with a 3-point graphic scale (good—so-so—bad); 3) “Yes”
and “No” if the participant could not communicate these with head
nods or verbally; and 4) 3-4 messages about the current event or personal
event. Messages were reviewed with
the participant prior to data collection.
c)
Instructional Phase (condition C ):
Following review of
topical VOCA messages, the primary investigator then provided the following
verbal and written instructions:
1. You can use the
machine to tell them something
interesting! [demo]
2. You
can ask them a question to get
things going! (demo: Have you heard about..........?):
3. Tell them your opinion
with the rating scales on the machine.
4. Take turns - first you go, then she goes.
5. Here’s
an example of a conversation (shows them a large print written script)
The
primary investigator and the participant then role-played a conversation about
the current event topic using a printed script as a reference if necessary. Speech-language pathology students
served as a conversational partners in the dyadic condition. They were trained and given written
instructions prior to the initiation of the study to ensure that their interactional
behaviors conformed to the procedural requirements of this investigation. An emphasis was placed on teaching the
experimental partners to interact in an open-ended, naturalistic manner with
the participants. Target behaviors
for the experimental partners included:
pausing, asking open-ended questions, attempting to confirm
participants’ turns, limiting the number of yes/no questions, and
changing topics after 2 consecutive attempts to repair communication
breakdowns. Topics were changed for each experimental session. Messages for recent personal events
were obtained by having the participant’s spouse or significant other
complete an information form.
Current events were selected from a daily newspaper. Topics were introduced in alternate
order across all sessions and conditions to prevent an order effect.
CURRENT EVENT TOPIC
DATA
|
||||||
Participant 1 (T.K.)
|
Time
(secs) |
#
Exch. |
#
Ss turns |
Turns/exch |
%
SS inits |
%success |
|
Ave
A |
181 |
7.6 |
25.6 |
6.37 |
.3 |
.14 |
|
SD |
100 |
4.16 |
16.9 |
1.47 |
.18 |
.15 |
|
Ave
B |
204 |
11 |
24.5 |
4.61 |
.39 |
.3 |
|
SD |
87.57 |
3.91 |
8.58 |
.46 |
.09 |
.18 |
|
Ave
C |
268 |
12 |
32.5 |
5.6 |
.4 |
.08 |
|
SD |
70 |
2.82 |
12.02 |
1.27 |
.02 |
.02 |
Participant (A.A.)
|
Time
(secs) |
#
Exch |
#SS
Turn |
Turns/ex |
%SS
inits |
%success |
Ave A
|
162 |
8.5 |
22.8 |
6.04 |
.14 |
.59 |
|
SD |
.69 |
1.73 |
6.18 |
1.19 |
.14 |
.19 |
Ave B
|
166.2 |
13.8 |
32 |
5 |
.25 |
.84 |
|
SD |
25.5 |
3.56 |
10 |
1.3 |
.08 |
.07 |
Ave C
|
136 |
13.8 |
24.3 |
3.7 |
.28 |
.68 |
|
SD |
33.3 |
2.98 |
5.18 |
.91 |
.21 |
.23 |
PERSONAL EVENT TOPIC
DATA
|
||||||
Participant 1 (T.K.)
|
Time
(secs) |
#
Exch. |
#
Ss turns |
Turns/exch |
%
SS inits |
%success |
|
Ave
A |
173 |
6.4 |
19.4 |
6 |
.24 |
.53 |
|
SD |
48 |
2.5 |
5.9 |
1.8 |
.11 |
.09 |
|
Ave
B |
285 |
12.67 |
31.3 |
4.79 |
.44 |
.78 |
|
SD |
157 |
5.5 |
20 |
1.21 |
.14 |
.07 |
|
Ave
C |
277 |
14 |
34.5 |
4.89 |
.44 |
.82 |
|
SD |
36.7 |
2.82 |
7.77 |
.08 |
.08 |
.09 |
Participant (A.A.)
|
Time
(secs) |
#
Exch |
#SS
Turn |
Turns/ex |
%SS
inits |
%success |
Ave A
|
122 |
8.5 |
20 |
5.4 |
.08 |
.30 |
|
SD |
52 |
3.41 |
8.2 |
1.5 |
.09 |
.28 |
Ave B
|
157.8 |
13.8 |
32 |
5.2 |
.11 |
.1 |
|
SD |
76.4 |
5.26 |
15 |
.99 |
.08 |
.11 |
Ave C
|
162.7 |
18.75 |
34.75 |
3.83 |
.18 |
.22 |
|
SD |
70.6 |
3.3 |
10.21 |
1.04 |
.11 |
.16 |
These
descriptive data revealed potential Condition effects: Length of interaction for Participant
1; total communicative turns increased for both participants for the Personal
Event topic. % Initiations
increased for both topics from baseline to VOCA conditions across both
participants. Participant 1
demonstrated incremental increased in successfulness of exchanges in the VOCA condition. However, increases were very slight for
Participant 2. Participant
Effect: Observations that
Participant 1 was a more tenacious, resourceful communicator were supported
empirically – there was more of a tx effect with regard to # of
exchanges, initiations, and % successfulness for T.K. than AA. Topic Effect: Length of interaction was greater for
personal event; however, initiations increased for the current event (AA.), as
did successfulness of exchanges in the VOCA condition. Additional statistical analyses
will be performed to determine if statistically significant differences existed
between conditions.