Single switch tasks with children: Analysis considerations

submit of the

Doctorate of

A thesis

of

M. A.

i Of 1990

al fulfilment for the

'I, I

i i

CHAPTER PAGE

" . " " " " " " , , , , , 0 0 " " " " " " " " ' " ' ' ' ' 0" " , , , , , , , , , , @ " " " ' " @ @ ,0 I INTRODUC'I'ION" " """"" 0 " • " " " " @ 0 " " • " • 0 • " • " • • " " " , • " " " • , ,,1 II. REVIEW OF THE THERAPEUTIC LITERATURE

ew" " " • " • " " " • " " " " " " • " " " , " " " • " " " " " • , " , " " ••• " " • 4 at i on .. , . " " .. " " . " " . " . " .. , . , . . . " , . , . " 5 Without Augmentative .. " " . . . . " . . . . • 5 General F 0 • • • • " • • • • • • • • • • • • • • • • • • • • • • • • • • 5

.An Example . . . 8 Conclusions . . . 9

With tch Detailed

Ai d s . . . 9 • . . . • • • . • • • • . . . • . • . • . • • 9

of one programme . . . l1 Interface Ergonomics and Dis Ii . . . 12 and Lewis Research Programme . . . 16 . . . 16

ects . . . 0.17 Method . . . " . 0 " • " • • • G • • • • • • • • • • • • • G O . 17 Ra tionale . . . " . . . " . .. . . . . . 20 Data

Conclusions. " . . . " ... G • • • • • • • • • • • • • • • • • • 24

Behrmann and Lahm Research

Resul ts 0 0 0 0 0 0 " • 0 • • • 0 • • 0 e o • • • • • • • • • • •

's Resource Book. 's PEARL Software . . . .

• 033

33

37

.39 III. REVIEW OF RELEVANT OPERANT RESEARCH

V.

of Human • • 0 0 • • • • • 42

Interval 45

Schedule

Infant FI Performance. . • . • . . • . • • . . . . • . . . • • • . • . 48

Idren' Idren and

ferences FI Performance .. and FI Schedules . . .

.49 .. 51 Schedules . . . 54 . . . 56

8

tates. Data

Skewness

I.

•.. 79

. . . 81

.83 . . . 83

. . . . 8

3

4

. . . " . . . 85

Confl

. . . . 1

c~ • • • • • • • • • • • • • • • • • • • • • • • • • • • • 1 . . . 139

. . . 142

143 . . . . 143

. . . 146

Batches . . . . . . . . 147

. . . . 147

table . . . 0 • • • • • • • • . . . 147

table . . . 0 • • • • • • 1 8 .14 . . . 152

STUDY

®" 0 G ® 0 ' , 0 • • ® 0 0 0 • • • 17 017 1

• 0 • • • • • • • • " <' • • • • ffi • • 0 • • • 189

. . . 189

Database . . . . .189

. . . 1 1

. . . ,' .192

. . . . 192

Performance

J

ect E . . . .

ect M . . . .

XI. CONCLUSION

. . . 216

batches in case tudy one.

Tabl 2 . . . 75 Global summary measures from case study one.

Table 3 . . • . . . • . • • . . • . . . 80 Contrast of reward ratio and slope ratio distribut

Table 4 • . • • . • • . • • • . • • • . . . • . . . . • . • • • . . . . • . • . . . • . . . • • . 96 The number of reward

of responses and the

ods with odd and even numbers lity of this ratio

chance alone.

Table 5 • . . . • . . . 97 Shapiro-Wilk W for each component of the reward period. Table 6 . . • . . . • . . . • . • . . . • . . . 97 Shapiro-Wilk W for each component of the reward period

(with data from ch outs values have been removed) .

Table 7 . . . 101 Sta tical sons th the Gaussian tribut for Delay

i i

Tab 1 e 9 . . . . " 0 0 0 • " • 0 • • 0 • • @ • " • • @ • • • • • • • • • @ 0 0 • • • • • • • • • • • • " • • 10:2

t ti t

for

1 comparisons th the Gaussian tr ion

Tabl e 10 .. " 0 • • . " . 0 0 0 " • • • " " • " • • • • 0 • 0 • • " " • • • 0 " • • • • • @ • " • • 0 .10:2 statis cal comparisons th the Gaussian di tr

for States

Tab 1 e 11. 0 • • 0 0 • • • • • • • • • • • 0 • • • • • • • • • • • • • • • @ • • • • @ @ • • • • • • • • • 103

s

Statistical comparisons with the Gaussian distribution for t components (with outlying values removed). Table 13 . . . c o • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 104

Statistical comparisons th the Gaussian tr

for Change components (with outlying values removed). '1' ab 1 e 14., . . . 0 • • • • • • • • 1 (1) 4

Statistical compari ons th the Gaus ian stribution for States s (with out values removed). Table 15 . . . 112

Central locat est for Delay s.

'I'able 16 . . . 112

Central tes for Wait s .

Table 17 .. c • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • " " " • • • • • • • • • • ".113

Central loc t tate

Tabl . . . 138

cal based on the B al Theorem.

Tab Ie 20 . . . 0 " • • 0 • • • " • • 0 0 • • • • • • • • • " • • • 0 • • • 0 • 0 • • • " • • • 0' " • • e • 138

ca ies based on the Runs-Test.

Tab

1

21...

Decision table for establishing the importance of a feature on the basis of

rat

and randomness

Tab 1 e 22.. 0 • • 0 0 • • • • • • • • • • • • • • • • • • • • • • • • • • " • " • • • " • • • • • • " • •

145

des 1.

Tab Ie 2 3 • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 158 The relationship between subject factors and data

batches in case study two.

Table

24 ... 160

Tab I e

25... 162

x

Tab 1 e :2 6 . . . . 0 • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 0 • • • • • • • 162

The number of the

cond cture reward task and the 15 econd music

Table 27 .•• 0 • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 162 The rat of responses to rewards the 5 second

cture reward task and the 15 second music reward task.

Table 28 . • • . . . " . . . 184 stem and Leaf ays for Delay

Table 29 . . . 185 Stem and Leaf displays for components.

'r

Tab 1 e 31, . . . , . . . . , . . . 187 Stem and Leaf di ays for States components.

Table .32 . . . 188 Stem and Leaf ays for Wait

Table 3.3 . . . , . . . 198

S adopted subject J.

Table 34 . . . , ... , . . . " . . . 204

Parallel ot for Delay components.

2 b . . . 91 Parallel boxplots for Wait components.

2 c . . . .. . . . . 92 Parall I ots for components.

2 d. . . . .. . • . . . • . . . 93

Parallel for states

3a . . . 110 B weight function.

Figure 3b . . . 110 Bimean influence func on.

4 . • . . . 114

Number 1 component.

of central loc e for Delay

5 . . . 114 Number 1 of central loc est for Wait

F

i

7 . . . 115 Number 1

tat

of central location tor for the

8 . . . • . . . • . . . 0 • • • • • • • • 0 • • • • • • • .123

Central location 95% conf s for the Delay

Central location 95% confidence intervals for the Wait

component.

10 . . . 124

Central locat 95% conf e s for the

component.

11.0 . . . 124

Central loc on 95% conf 1 for the

states component.

12 . . . " . . . 127

A cumulat record.

13 . . . 127 A bar

f 12.

repres of same data as in

14 . . . " . . . 131

Bar of reward per to illustrate feature

def tions.

F 15 . . . 135

Patterns of respons used to deduce tenc of

an alternat equence of succes and

17 " •.. 0 • • • Parallel

1

Parallel

19 Parallel

21

3. 22 ••.••.

of States

of

of

of

S

bar

bar

labeled

. . . . • • • . . . • • • • . • 172,

• • . • . . . 17 labeled

.. 17 labeled

.199 for ect J from

24.

26.

18.

state 3.

state 13

29 • . • . • • . . • . . • • . . . state

state

bar

€let L.

bar

bar

bar

5 for €let E from

9

. . . . . • 210 for €let L from

. .210 for €let 111 from

. . . 21 for €let M.

11, ful

eel

Cent Idren'

1::1:1

t the Soci

I :1,

, S

and the ld

We land branch of the

and other did much to

arous my curi i about the tream of consciousne

younger ects and parents me many practical

lessons. I am thankful to the long hour

at di abled formanc I comput tas

mus al mention thos indispensabl tool, th

language and the able , the 13 t

Atari.

t thanks go to my wife th, thout whos

love and support I would have never been able to undertake

s ifwrk or

put it, slH~

each , t

tl'1e1'. Of

"

earn

.

.

i t to et

.the wonderful money, so

.

1i:foma.rl who goes ou to work

A

tied

i

on devel child's

k

t of the cont

development of a s

two s es of norm"ll 'US

Idren. i te

th a ies of the was invest

ffE~rent vers

task. The value of cons ing the dynamics and compe was established with e of

ell

for

task and with of the of pe

programme th four severe ically sabled but mental

and s

t children. Robust computerized

timation of performane system for dat

cl sifica were major c innovat

t the i thos who are world. The part

st are 15

to

ical unable to ful of and mul

ldren who, due to the physi ic te

development. like to deve

many of experiences th high level a ens of learned

th('~

crucial experienc

act the

abled who are of ically dis ch of Ii s essness sabled , can not

t are

further decrease the tion th the

11 and th deve

these Idren make use of , and there

sts a strong for shar ormat about

adaptions of technology for therapy. Thi is supported very little

A liter ture ew establ

that used and outl

r ew highl the need for

Idren th the 15

and ff t t The

lIs needed to fit from more i

al 0

to cll the more bCc?en abl master.

cal research. of

research to date. The research how ated cause ences and

1'he s't s

ied i of human

performance

ch has not

th abl Idren.

1

It 1 11

to o

i

ous to shown that the methodology, and f of operant research on how the tr es used to orm simple cause and ffect tasks. It that simpler tasks than those used in operant research are needed to t those th low level of

impoverished experience at control 1 a task i sed

ical Ii and ronment. lar to tasks used

the de led therapy but

performance data

also

al of research. s i a tas]~ to competent which Ii is not a limitat

ormance.

The focus of this work is on establ an methodology' for

cause and ff ct task.

competent performance on the simple s is a necessary foundation

future research tabli the effect of

particular ons or deve agnosti

ts. The research ch is reported consi of very

detailed f ut Ii of f f i

me tll three

of that

i th a group of

Problems th me

The data

recent

researc.:h are to bear on the . In a

an automated

of used to

It an al to -the usual

of data. These shown have some

another group of

of the task. The of the

then case

an extended programme tb four

A theme

to

may not

the rather

the

for the task.

are then second

from disabled

of

Thi

t

int

target at

4

the ati programmes which aim to ons of evere and mult

I

Ie

e the handic

cal ronmental children. tion is f

population.

t to the characteristics of this Therapy before the emergence of a is shown to have been generally unsuccessful. The ems that were encountered are

1 ed with one programme scussed as an This is then contrasted with the br prospects

off the devel of es which do inc

the us of ative . The al framework behind the movement based on switch adapted toys is outl and the ial of this simple technology is illustrated by a review of another programme. is followed a

of VUVJlLLC pr es for providing

more general di cuss

communication face for the disabled. Discussion then focuses on the issue of how and the skills necessary to

such have to be to severely ically

disabled ant and toddlers. 'rhe two or

1 c 1 earch programme ch have t ted

ed to teach t skill to

children eviewed de 1,

an I i programme.

fi Id,

i progres report from of how

techno are then covered ews of ourc

book and a speech

awn i

f o r t could

The stinct cl

software current di t ted. at at

. Conclus are

tice and where further

of t s

the i i thos severe mult handic children who

have ext ens sensory and neuromuscular deficits. This

population has been labelled as . . . tat

~Nona.mbul

& Sackett, 1978)

~~Severe and Mult

el, 1966)

Mental Retarded (Landesman-Dwyer

c (Behrmann

&

cial Needs (Burkhart, 1987)

cap

of to

ical disabili and of mental

similar syndromes in children. In

all cases the salient feature linking the subject groups is

the lack of

result in s

helplessnes ,

sman.

thei ive

tic

1 t

and work tabas of al motivat Without to Sackett to of el (NPMR) 1 the i

tion', This is s to

sorders, such as learned t

s at ~,qas

(1978) . A or methodol cal

1 e a cl

tiol and 1

t 'nonambul :f

of the

then

uncommon.

In

sbows

f

open )

"For

and Sackett and

note that

many ects,

gave very

results

of

there

related to and

motor control and

relevant

had been

Sackett, 1978, p.79) between 1949 and 1976

All these NPMR

t

or for all

used the

(The

not

ct what would act as re orcer for particular Even after an operant response was successful tablished, the 1 often transient. After

ful end to

there ~~ould be ch no procedural

sudden decl or

1 tter t t of this effect

could recover '. ce and MCDaniel

(19 6) it was tablished that the effect is not due to

t tion or schedule manipulation. This phenomena was termed taneous Extinction' and no explanation was off for

One tri feature of the ewed operant studies is

the arines of the ical response the

pauci of the re s used. In all reported studies the detection of the response and the del of the

on a human exper

switches to detect and ampli the

No use was made of special ect's t behavior and no cal apparatus was used to deliver the reward. There were no t to develop in the ects any skill

(Le. communication method) that could use outs the

1 sett The anat of

extinction could be that ects become frustrated with

f es and difficult task and ultimate fus to cont

indif

the tabli

were

not ronment

diff tie operant e

ted 1

t

the

had ended.

are often

programs, even those to cope a severe

level of mental u due to the f

them. A comes from a

on

of Pre:mack' and

non~verbal

"

responses" 1976, constructed

p.529} of sequences

ensure success, and on

The programme th

th method

a

low level tasks, extends task

a

to have been number of

have

ory ems. " ldren th motor ems that interf with the respons have 1 arned sl and

orne have not been abl to go of

deve

The

" (Carri that

, 1976, and

.54 ces di abili could be deve

as an area for 'further

fficulties experienced

)

.

table for use with . He ment the

in early research programme with the severe

been due to a lack of

ically sabled seem to have ic focus. As the next two sections will show, s need not be the case. Even before

the 1 Ii of computer there were

ilab1e terface methods us very simple technology. These a enable the disabled to t

tasks which are also suitable for research purposes. With Augmentative

One of the simplest aids for enhanc the environmental interactions of a mult sabled child is a tch. Commercial lable tches have if to such an t there has arisen ications which discuss the s of tches and group them ac to

f the method (

.

1976; Silverman, Me Kate 1982,

4) • Often tche are from other purpos

:for th the abled and there ci Ii t

10

tom switches (Burkhart, 1980, 1985; (1987). on construct

ted to the

ces are also to be found journal t, " cation Outlook", :i hed the International Soci for t and tive c tion (ISAAC) , which is subtitled

o oc"Focus on Communication and n . Another

"Communicating

shar

Ii

bat

cial ther" , whose

exper

t publication is

torial aim is providing ... a means of es, systems, and techniques of non-speaking cial attention is to the non-reader's

t communication system and the role of lic _"

At the s t level tches are used with adapted and educat ces. Toys are modi led

on-off

wir tch leI or in series with the tch so i t becomes part of the circuit between bat and motor. The use of standardized plugs on all

switches and mat sockets on s the

ications of choos ate tches for an

1 and so that they can be

with an external tch. Advocates of the on of so can oper ted a simple tch stress the importance

env 1)

their

t t

abl Id oppor to

Lack of such oppor towards " ... les construct

more

elf 1

and 1 0

ay th some ties i een stimul ion to the at tude toward the

..

attached to

full

The

Porber.

use of a morse code (a

. There

connected to

motor

shown

the buzzer)

of v'ery low

and had no of

based on a

The

of sound tone "no" and three tones

a . These

relevant to the

were

A

"

code that tone meant "I need two short tones meant staff to

were from

to ask

t

of

and tten to the

all that could be

t

us that t:he

to . The

documented

between the often

1;

1

the

progra:mIlle of the

, 197 ; 1982b;

use of

iden Harris~Vanderhe 1976, .611), All the

different of a have been ized ac to

b.ow the three ic of c

t elect

t elect elements of message i the most forward and easy to understand indi on method. it are most fied keyboard designs, often of

cial size or th The simplest

modificat are those which guard against accidental and mult e presses due to poor motor control. This is often

achieved with a ctive overlay or by

i monitor of movements to detect and disallow unintentional act t . An example of the latter would be with no automatic when are held down, an ustable delay before a is stered (to screen out acc momentary presses) and programmable to substitute for the multiple simultaneous keying sequences that modern software often . Provision can Iso made for parts other than f to the

such as light beams ted or

e for foot typing. Chord are another ion to llow t election with minimal movement (Kirschenbaum, Friedman

&.

Ie ion systems r and fl e but a

1 mo control.

i the term ied to ituations where mes age 1 presented in equence the us its until

to

most

from

The

for t

that

access the

more

can be

number of

then of

used

t

element can be enhanced

are traversed elements.

rearrange the order of the after each (Heckathorne

th more than one of

the scan.

table for the the very of

the

chart.

, 1 8 ). response opens the the pace and

slow. to

of these

. The

where

look up

than the number of

us code indicat the row and column of ired choice. A more abstract method is to use ial codes

f 1983) or

or, 1981). such Mor (Shannon t a l , 1981; S

(Bolton

t

sc user

i

t suck and f code

quarter of an array of elements until a final reached has also been descr as a of method (Terrell, 1985). The random access nature of schemes allows for greater communication speed than The disadvantages of encoding techniques are that need the mental lity to learn the code and sufficient motor control to operate many switches. As no red wi a set time period, encoding methods doe t those with slower physical movements.

It is tant to note that s and

di ct te be t\1here answer 1 limit

election schemes can all be implemented at various cal levels. Taking scanning as an example, i t can emented as a simple unaided communication technique any two s Is for 'yes' and 'no' are used to a sequence of quest

.

th system cr on i t can be used to the vocabulary being scanned. S e elec c or mechani a1 ces cal move a light through a

of vocabulary 'Ii tener' i still

Connect remove

croproce speech

ce th s level of aid a red to remember the message i t i

t to or sual

rement. Further, allm\fs for t

i the

ay

16

towa.rds ce sUbstitute. f I e of

e is the ce small and robust

to be portabl .

c pr ommunication

i al c

has progresed unders of the basic for erfac a sabled person with a ceo The focus is now on mat a person's Ii and a system, th the goal of maximizing the information transfer rate. Systematic assessment procedures have been devised

l'1ethod for ing

Needs-(e.g. the Handicapped User's tem Development, Behrmann, 1984) and efforts have also been made to devise computerized

rt systems and real t computerized testing batteries to prescribe a ce for an individual (Rosen

&

er, 1982a). How the skills needed to use the aids are to be taught has not been addressed. This is a icularly important issue for children who have been evere disabled since rth and who will never be able to

cate without an augment

The Contingency Intervention ect is a curriculum of

t des to teach multiply handicapped ants control of consequences (Br s 1982a, 1982b, 1982c). It i based around an ant t th

ronment ch arranges events so that

controll an ant's or. Thi

ammc", was the f t to de I of such

" not seem

"

. The ects who were choosen to

the programme were those who to grasp on an

hands, not tent

reach for ects and not resulted two

the programme. There of

of four had Downs and

one had

.

of labelled as

,

and

range of

.

18

it , enabl mult e basel measurement de to be us At the arne time, an observer could us 16

box to enter real-t record of specific observed such I , cr , voe liz t , head rai e , I level of arousal and distract directly into erG to e computer controlled output I could used to turn on and off ces external to the

er ch functioned as 'rewarding consequent events'. Rewards luded images on a computer display, music from an audio tape player, a t pad and electro-mechanical such as a musical toy, a bat powered train and a

A pre-intervention e was used to identify the movements an ant was c e of making, to arrange switches

record a curriculum expec

to automatically basel level of then started with

tor these movements, and to activity. The intervention a task to teach a basic of cause and effect. A t response was associated with a computer delivered reward and the computer an ongo record of act rates from several limbs. The reinforced movement was changed between sessions. If the infant could di ferentiate

then there was a decreas

ch movement produced the reward overall movement and an e

most f

(8r

t t respons " The most r I occurred when sponse was the movement that the infant had made dur the bas I measurement ession

second level wi thin~~

software

of the the cont control 1

curriculum of re the task formanc , c it aga t preselected

tored teria c I a minimum response rate) and the reward target devic which was to be act or the

. The aim was to challenge the infant's expectancies. Br

he ff movement

and Lewis stress the importance of determining cts of a

to make)

to the thout any

contingency rule (which

reinforcement. Renewed st cons

in the type of upon alteration of the number of responses required for delivery of a reward was

taken as of causal awareness. Subjects

showed one of two dist t terns the reaction to such thin- ession changes (Brinker & Lewis, 1982a, p.12. 1982b, p.39). Some ects immediately detected the change and ased the frequency of the new t responses. The behavior of other ects was more complex. Changes in respons

qradual

criteria caused generalized arousal followed ease the proportion of t responses

a

ion. On subs sess this process of response dtf

t '1'he

iation would be the absence of

This is term retention

ted these

1 1 of the curriculum added

20

z tion of esponse as means to an end. Of t

was the par cular s if any, an

of r sponses needed to

ant used to reward.

determine the s

i 1

Br

ont

1 i about s ext ens

and s devote a self confessed 'cons e

to the

awareness

tance of the background concept of

Early research using contingency

awareness with very young infants reported difficulty in

tioned responses. The reason offered was the

pauci of actions e of being linked to an operant

eward r for the reI between action and

reward to be easily perceived and remembered. It took some

time be ore researchers devel tasks which used responses

infants could readi make, such as head turning,

non-"nutri t

from demons

t'l'hether I

stimUlate I

sucking, and eye-movements. Research then moved ons of infant competency to investigation of

in artificial cont situations would

other more natural settings. From this

13r and Lewis deve their a of using a sequence of

tasks, des

cont i

and devel

ontrol

i ieul

the

to e experience and awareness of

as a therapy programme for ically disabled

del ldren ~4'ho f like ants, can

1 events. argue that

i abl to

ieal Ii

lack f motor

cont

i

Ii was

based abled

to

v.ri th per ion and memory ems to e a reduced experienc of having

s

1 1

i

loth)' level of t f thei sabled

tions for the arned as ically

in turn leads to expect ldren

ld. He

ch further reduce essness was s

sabled infants "o •• lose

to est world do not expect to control" (Br & Lewis, 198 c, p.164).

The curriculum is claimed to derive its remedial proper es from the use of crucial developmental ences in an appropriate sequence. An infant's level of psycho-motor devel is agnosed from the of tasks that the infant can successfully perform. Developmental progress to levels is then promoted by experience of the computer task

the

The theoretic justification for the order of in culum was derived from Piaget's description of normal s

Br desc deduced

and

of the from the Reaction stage an

development in the first year of life. reformulated

ant's cognit

Piaget's as

awareness that can be In the Primary Circular

ant es

tivi esponse to a reward. Use of a

levels of motor t behavior in

to others demonstrate S Circular

actions. Elaborat

and 'I'd

e Coordinat on of S c

us of

of Sec C cular Reactions occurs rewarded t

React

act is new ituations.

levels. cated

22

to ither the t or the

for

event s stage. The ('IIould pre

Means-End i s reflected the last level of i um where t of respons are

and s scussed demonstrations of

competenc t the PI' and ear S s s.

It:1. very t to note that the same e in al s stication that inspired Brinker and Lewis's to highlight the competency of handicapped infants, has Iso been used to demonstrate competencies in normal infants that call into question the validity of Piagetian It is now general that an ordered stage formulation of infant development is t and that children's t lity are a result of

increas knowl not tive ability

(Anderson, 1985, pp.400~426). Case studies of individuals who have normal adult cognitive ability in spite of having been infants with minimal motor experience, due to their severe

ical dis lity. a demonstration that

s an 1972;

Pi r formulat further s

det

" lIes' heel" Piagetian theory (Jordan,

&. Shaperman, 1973). Br and Lewis appear to

t i s _{without question. Unfortunately their}

of agetian has been thout

i several ews of work th

abled children. The fi Id wher

tands out as

rec on i ma

pragmat:tc ions.

is 11 the more

the behavioral tance of most workers s field. eri ed cont

A further of

intervent on programme was said to arise from nonsocial

0 1 ie

.

tioned whether an ant can learn that are fully in control of a situation if it involves tion with e. The suggestion is that an infant has more direct experiences of being control when they are left to t with a computer controlled task and that this ence enhances the 1 of contingency awareness. No

was presented to back up this intriguing argument.

On~l

claimed to 'focuses' measured

computer a ' on cumulat movement. The

is of ormance data was oral microscope'. The microscope response rates over time for each computer is used to compare performance with stored data from previous sessions and to cal presentation of results. These di ays are ted by sual tion to generate about how effect an infant is reacting to

cont This is then used to decisions

task ental expectat

fication. There was a reported rise and awarene s of 1

were involved the ta on of the data and

1. of the proces

.

number of made about the pragmati

( ) f us i ed the

It used when there

events

programme for open to

to the means-end

an that

need for a more

or

work of

the further

data collected of

8 8 )

.

to

the

research . How an

level of the

. There also a 'the way of

run rather than jus

records and of

to

The effect

a

"menus'

on abstract

the allows

.) scheme

of an advanced of

programme task.

sound

.

response been mastered the

.

causes the reward to

foods or between

{ are then

select

model

i

choose an i terl!. of

a

should be easy

a cause and rewarded a

selected and of choos

011

selected The

i t

correct accuracy

1\.

that

and the

to chose~

to choose

.

of a reward. method was that

too many at one

allows fOl" a of

these data are collected

the response on each • the the average response

th

and

of from

programrne to common format and

• 'the number of

to and

the ,to move

ects could ze from one to another.

for low Lahm.

/

once

task

level

fol." each measures have

been

results from an

of the programme that

the next more f

(Behrmann Lahrn. 1983a) the programme have been

progress the

used two groups of and

. Half of t:he

at all the

severe motor unable to

program, level

to reach a

cause and effect task. (The

was seconds or less, 8

over three to four

.

of the the that "

tood task. but .•. los

the became more "

and i t that

"

the task, but Lahm 98

effort

i lower when a had

made and due both to the

mental and the amount of

for the to scan between the two

Slower were as

and the of the task was i f

... to

and use of

of the

w, (Behrmann , 1983a, p.198)

In the s very 1

sys programme was

was slow on the

with some ects a decl

to the

task and better

for were

overcome these

the

of

of the

mastered cause and effect

over

. A more assessment

focus became programme to

research

The programme Beh:rmann and

clear for

~ The programme has had

of a of software and malmal enables the tasks to be run on the lIe

hardware (Lahm,

1985). An of research suggested the

'the

A

results would be to concentrate on those the

would

and accuracy

more at

cause and effect level of the taske

cause and effect the

programme' for the

Allen &: 8

for

to

at

for one

30

thi intervention th each client. The account of programme

encountered

izes deve

the lessons learned and ems both the hardware and

The eleven clients in the programme were all in their ar teens to early twent s, were functionally prof retarded (with mental ages below two years), and had sensory-motor handicaps. They were described as being limited their environmental interactions, with low levels of ical movement and showing little learning in any type o situat Such a sample was deliberately chosen to an exacting test of the limitations and capabilities of microcomputers tructional use'.

The major therapeutic goal of the programme was to break a negat

to few ext

feedback cycle where low overt behavior rates lead environmental tions, gradually almost all This problem was to be treated by increas the rate of occurrence of specific motor s. For each subject an individualized educ tional plan def des and rate of response.

Achi the e goal would ed respons Sf

ical deter on and motor skills. were chosen which could act as sites for

1 lIs. It further

i f control of the

t the eff ct of learned he

that the

It was reported that ems were experienced th tch des and acement, and a number of fferent

mi

and a

andum'

tch,

were tried tic cuff rota

it any rection, pneumatic blow/suck

the programme progressed. These

ttached tr to a

inder, a joystick act by a wobble tch, an cushion,

tch. The technique of modeling how to ac te the reward consequence before a session began was developed to 'prime' clients. Rewards were chosen to c talize on visual and hearing skills. These included music on a cassette recorder, cool blown from a hair bat operated and light displays. A trial method was used to determine which items produced highest or rates th no signs of distress. Four seconds of t tories and fan blown were reported to be the two most erred items. Planned refinements of the treatment method luded systematic examination of reward duration, onset and offset parameters, and formalizing a procedure for as sing the effect s of a reward.

Sessions were

f blocks per

to ensure cont 1 ather than the '

structured as three consecutive . The division of a therapeutic was action between staff and clients

and t

a er) and to allow for

• of clients in front ustment to seat

blocks of and

rOlJ, t

of

tch posi

structured a line block where

ed

tch act tion no

unrewarded baseline every ession.

are

success

32

tion was used as the first block of

ted us

f

of the minute blocks.

number of (Blocks are to either 'cont stimulation' or labelled as be

'no consequation' situations.) The effectiveness of the treatment was apparently very varied. One subject produced no response in any condition. Another subject had a varying but response rate, unaffected by reintroduction of the non'--re

increases decl

basel Several subjects showed transient rate, sustained for a few sessions and then into long runs of no responding at all Comments about these ects indicate that their es in

re ided with changes in Finally, one

ect showed very clear and responsive behavior in a classic ABA design situation.

In assessing the effect s of the programme, the 'failures' were due to comment was made that

" ies, not of the computer system, but in our tate of knowl about effect truction with NPMR tudent " (Bourland, Jablonski, Allen & White, 1983, p.147). However the overall tone of the paper reflects optimism about

future devel and ication of method. It

was erted that much had been ac ished in a si on where extensive t was to just assembl the basic t to ement the programme. was

to ication. )

the many that

be

ec on have been

table for of

11 sho~1i1 , s programme is cal

established ied settings. The general and ications are very simple and yet are shown to be worth the development effort. The candid cuss of problems highlights the technical achievements behind the package developed by Behrmann and Lahm. The weakest part of the programme is the limited way in which ormance of the computer task was analysed. The use of e c e exper 1 des and global performance measures was ficient for an adequate evaluation or ion of the level of competent ormance. This contrasts with the potent for using a computer as a

oral microscope as in the Brinker and Lewis programme.

In many situations where computers are used to develop communication s lIs with non~vocal children, the therapists are enthusiasts who develop the own hardware and software. Their practical work is often mentioned fly in speci 1 intere t publicat

eported ormal or devel

and newsletters but is seldom a research programme. One on that is c 1 of movement is a

ourc book (Burkhart, 1987) that a is of many fferent and str from a large number of

acknowl contr la

of backed up

. There of

a the

of have the

for the

on how to for use

t many of the recorder and a looping

message However

1 of

are implernented

of that a be

how of a message It

for some • A

erred over a

because of the can

handle the

as the

screen to

the screen. It

of response

the use of mode from

to cut from

th the use of boxes on the and

alone may not

to

to be the becomes

of

ticated

accommodated, as can a

systems, can all

able vocabulary. It i

i be

that are best

to

ted programme

ite 11 and de

1 before a cated portable device, us one set communication method, is prescr for a child.

The as and actual software listings presented are very e, but the comment is made that the majority of commercially available software is not geared for the low functional level of a child just learning to communicate. Also it is noted that with commercial software the physical responses are often more fficult for a disabled child than the educational concept being taught.

The is of the book is not on computers, switches, tape recorders and , but on using these as a means and motivation

Communicat funct

for functional communicative interaction. is presented as the most important skill for soc ty. The work promotes a therapeutic tra of using contrived play experiences to provide feedback for experimental I

scussion on

This strategy is best cause and effect. illustrated in the

This is introduced a cons tion of the factors that can cause disabled ldren to t limited ways th

the These include learned helplessness,

ration, emot 1 ical and t

limitat and outr lack of oppor

.

because are so effect is outl

arly

crit

devel

o t

ed 0 It i

36

low to . Le cause and

as be a basic 11 that i learned programmes that large awarenes of caus and ffect are tated that it should be able to teach aus and effect ckly if the situation is appropriate. This is followed a ist of points to attend to in

cause and effect: positioning of the child, selection of a switch activation movement, switch selection and posi oning, use of an appropriate reinforcer (with special comments about avoiding over-stimulation), placement f the re cer thin visual , and environmental cons ons to elicit a quiet-alert state. The stricture is to avoid prompting and other 'teaching'

ons, instead letting the child experiment with the se , " .. ,stepping back and letting the child teach himself"

(Burkhart, 1987, p.12).

The on cause and effect training is followed by " ... suggested functional and purposeful activities for the concept of cause and effect into the area of communicative interaction" (Burkhart, 1987, p.13). The f t extension cussed involves establishing a play situation where adult and

ound. The

turn-Id take turns game is then

an activity or

deal with 'games' that use the cause and effect s ommunication situat

t and request ti ,and indic

such choices,

call

i

i

Another cal that many ammes for Ear commercially derived from Elizabeth

e of the

it of lable software

on of a have at

(PEARL). This (Meyers, 1985) , research and therapeutic work conducted from a speech therapy perspective (Meyers, 1984). The only formal presentation of PEARL, apart from the oftware operation manuals, is one written to describe the way the therapy s

a very short descr

was developed. This paper includes ion of some research findings.

The

language use

of the therapeutic programme is to initiate language del toddlers. It is mentioned that ects have included Cerebral Palsy children with ems in oral control and Down's Syndrome children but no comment is made about the level of physical disability of these children. It can be assumed that all Meyer's subjects had a relat ly large amount of physical control because in descr the i t is mentioned that the children had to manipulate objects into and out of a purse, use American ay dress up games and touch labels on different areas of a

The is der from the PI' that

" language i learned context

cat alog th another person" ( , _1984,

p. (l)) • 'l'he ic se s i entered around ay

to

followed

It:;.

The membrane words.

'say' the a

allows for

( ,

context

levels of

and sensory cause and effect, ects and

the can be es to feel

84, p.49).

a

's name

used sheets on the

as

context an " •.. where the

"

the programme a and

to causes a

and to

. The soft:ware and

custom of u text and

control also used to match the

of

under on the

motivat and results more language 1

over " ... other modalities, such as a cs

than control ay on the tor. " , 1984, .43) The overall

ends th f of the

devi as conf e communica and basic formal language kills are built up.

The effect s of PEARL has been verified in an ieal study, which compared the computerized intervention t more traditional speech therapy (O'Connor

&

in stimul communication growth, as assessed standard measures.

PEARL has had an important influence because commercial availabili has led to i t being widely distributed. The oftware is easily adapted for used in basic cause and effect 1

the

therapy with severely disabled children as well as applications for which i t was designed. The general therapy emphasis on structured play sequences which te the use of augmentative is very similar to that advocated by Burkhart. This is

cal of children.

The

ied

es

th severely physically abled

Conclusions

and (1982a, 1982b, 1982c), Behrmann and Lahm (1983, 1984), and Bourland et al (1983) are

thE, only ished research works deal th deve

40

disabled ldren. (Although more informal ical work is Iso being

resource book

, as is reflected the scuss of the Burkhart and the PEARL software.) I three earch studies have the arne basic ic

1 of ronmental tions and combatting

1 arned helplessness . The starting point in all tudies is a very similar basic task, using a single switch face, at developing simple cause and effect awareness.

An issue of contention is how much stress can be placed on this initial s of interaction with a computer. Burkhart, writing from prac cal ence, argues that the basic awareness of cause and effect is taught 'fairly

r when a table

and biomedical

environment factors are

and equipment are attended to. Other sts working in the field have however stressed the difficulties that can occur with this first step in training. For " . . . . Training the student to understand the cause and effect relationship of the tch to the toy, can take a long time, from months to a couple of years, so try to be pa ent, and make sure you are clear on your objec

(Martin, 1988).

"

It is clear that orne sabled individuals have fficul

lot c

a

th the simplest cause and ffect tasks. Half the of Behrmann and Lahm were unable to

tas where t of a tch

reward, and COUldn't progre s to tasks

ects

al (1983 ) of

conducted

fect

up the task,

of task f t for

lower mental and @ Because the

these

work t

all more

disabled i t deserves more research

at areas

The programme

most successful use of a to have

to the reward

of ect's

was the response task.

of

awareness and control. The 'focus' of measurement was on

and between have not

a The

of response totals between tasks responses a task. An

ect uses to

to look more the task.

forward

to date. Other

1 at the

about

CHAPTER. III

Thi ews i of s

that very similar to the based cause~and~effect es used th severe ical sabled Idren. In both situations ects use a single tch as the response device circumstances where reward contingencies are being icit manipulated. Severely physically disabled humans

infra~human subjects ('animals') as

are analogous to

both are without expressive linguistic unknown intelligence, and can only

lity, are of by using the simple s-vJi tch

ronmental

ces. Teaching of cause and effect or interaction is an operant conditioning

It consequences to control

behaviour with the therapeutic aim of developing schedule control of behaviour. Cons ion of the operant literature will be limited to the few papers that have used young children as ects and have touched on developmental issues. The pr reason for s research is to e t.ablish what can be expected of developmental normal children and to look for methodol cal

de s e tch tasks for ical i Of Human

The ear Hammack,

(1958) looked at human

i of ic operant ttent re

ights sabled

our and formance on orcement

how to Idren.

with a s of almost 200 In discuss the

Idren between four and t al comment t years.

specifical on the results rom Interval (FI) chedule which

nega cal

s include knees, mult celerations and, cumulat record

ems' and ities.

runs, second order effects, above all, the absence of the tern al of animal research. The other major feature of this study is the changes to standard operant practices which were made to accommodate the young human subjects. These subjects had complained about a lack of 'novelty' and of the long intervals between re orcements. A procedure involving a continuous sl show in conjunction with other reward

s was developed to infuse the task with interest. Del of the re ement was highl by sounding a buzzer and fl a signal light for two seconds as well as

or trinkets. This reinforcement was acement of a slide with a new one that del

followed

of

remained visible until the next reinforcement was signaled (Long et al. 1958, pp. 331-333). Even th these s attempts to use a younger group of children as ects were unsuccessful because ... the children refused to remain alone the 1 cles for more than a few minutes"

et ale 1958, p. 315).

ffect of

The

children Iso established Zeiler and Kelley (1969) Thei procedure was to

ctures as another

ch used

at the

of black and shorter ten

their

of the and

cartoon to

and

the of

were escape from an absence of

the four to ~ In

that the

the also note

of and that there were

a

The humans had schedule

1987,

of

... anecdotes.

of the

was an

that based

to

1987, p.12).

branch the

call

cumulative records of et al (1958)

in that

of human subjects , 1983. p. 528; Etzel. concern arose among

ects was a that humans was

lead to the of the

area from based on

of Human

, 1987) the (EAHB) ~ The

and

ldren~ It

f o f l i t t l t on I i 1

logy, even from the 1 I I i

i ient tion (Deitz, 1987).

Human F 1 B our

f humcH1 f 1 schedule studi

Lowe (1979) that many st had reported the same

two st t terns of re Performance was

ither at a high s response rate throughout each

1 t 1 o v'] rate th one or two response at

the of the inter reinforcement Neither of the e

patterns r embl the 1 results of a post

forcement pause and then a accelerat rate f

re the

ted stUdies ch show humans to be to marty

of the factors that ed variation 1 performance,

uch as variation in the at of the f

s s 11ave to isolate the variable that ad tl'lese t human performanc patterns.

Response cost has been 1 to the low rate ttern becaus

this pattern occurs when e i reduc or if

i al effort is requ to Previous 1

hi and 1 have al be to

be a caus 1 f ctor th f rati experienc

oci th the t ttern ti 1 i

f f i 1 inf ement f 1 r te

1 1 t f int 1 t t

46

artifacts due to a lack of cal

(Matthews,

with human

f, Cat

&

s

ects do not follow the procedures cal

minimal

1 response

us

d:iffers water a

th exper

ext ens

such

pre~exper

and us er that a time filling

ive The saliency of the re er also

quali as humans are not purposefully food or

ived before an experiment. Another approach has

to isolate controll factors by developing

experimental procedures which produce animal~like results in

humans. (Lowe, 1979, pp. 171-185). Tasks which 'establish

effec s

FI control of human operant behaviour' rely on

temporal cues and use concurrent dual tasks to

fere with verbal counting s es. Even th such

care to remove verbal strategies, subjects s t i l l use

strategies such as visualizing clock movements or counting on

their - fingers to • evade schedule control' (Lowe, 1979,

p. 185). A final 1 of anation has concentrated on

isolating what unique human lities are causal factors. The

most powerful determinant of response was found

to be instruct

prior truct

truct

prior to ormance on a schedule, or

on ects

other schedules, or even self

the absence of any from the

ions of self truction

have and

correlations between

ects' verbal formulation of the i

of the of

that n • • • the effects of when

the verbal of own

consequences" (Lowe, 1984, p. 563). It to

the of

or behaviour and the usefulness of

controlled (e.g.

1984; Horne, 1988) even

research programme (Lowe, 1979). In research has been

effects animal research

The researcb

of wbat can

A

humans and been

has been

of such

several . Further th have also controls

to

48

from the claim that ldren develop the ways of performing f

develop language. If cl

I chedule tasks can be

lop a s

then the ould be extended to

the level of language devel on

performanc basi of performance. could be appropriate for use with Idren becaus i t would use of a e switch

Ii

ch could be to allow for physical

Infant FI Performance

A t ction from the findings of the importance of language controlling human behaviour is that ormances on FI schedules es. An experiment by infants will produce animal-like

because they can't use verbal s

Lowe, Beasty and I (1983) with two ants,

and ten months, produced results that were seen to confirm this hypothesis. Both ects achieved steady state performances characterized by scalloped pattern response rates and both showed cumula record sensitivity to vari

"indist

chedule parameters that were descr e" from those of animals.

as

In this experimental demonstration the way the was had many imilarities to tasks used th disabled children, apart from the icit use of a FI

schedule. A large ic I lec c was

used the res pons c

.

tor both the tch and the schedul ounded i

tone. It was stressed, prel work t

that there was ons abl 1

th the t~vents that

or er

..

.

1 th of an expel' 1 s was t on chedu.l

terval value vJith 12 to 20 reinforcer delivered

chedule of PI 1(1) , PI 20~·s, PI 30~~s _{and FI 50·-s. 'rhe two}

s ects c to work at the expel" al task for 26

43 sessions respect Presentation of results

included of ative records, gr of rat

(the response rate after any post re orcement pause),

comparisons of mean duration of po t re orcement paus , and

plots of mean duration of respons times aga t

ord 1 position in the re orcement

Developmental Differences FI Performance

The result from t e two subjects were extended

follow~up tudy Bentall, Lowe and Beasty (1985) that

looked at the f rval performanc of four groups

6 months to 1.5 years, 2.5 to , 5 to G.

years, and 7.5 to 9 year. All ee ach group

a eved ste state performanc on succes chedule f

FI 0- • FI 70- , FI 25- and a f 1 repetition of FI 40

Members of the two oldest groups ar reported to

It low rate respons pat . In the

t1t~een f half, thes f

patterns took orne to iIi

50

j thE~ Idest groups s Idom

al ses ions, al three r

counted out loud to t the in tlS::rval

11 ted us

In ontr t t the r ult thos f. tlH?

ant group show scalI rate

patterns, had the f Be

ent 11 exper . The group of two and a half to four year

Id Gcts had a fferent f 1 performance pattern to

that of either the older or younger groups. A great varie

of fferent respons terns occurred and "

verbal our" v;Jas reported (Bentall, [,ovJe &: Be 1985,

p. 173). The subj ts auld not deser the exper

eont ies. They were deser as be t

..

transi onal and humcln t···1

our" (Bentall, Lmqe &: Beas , 1985, p. 177) and th

" . . . some that may have eracted th thai

re and s the scalI pattern . . . " (Bentall,

1985, 78). Thi';; ts'

a to be eal of Idren before the age f four to five

who have limited capaci to 1 to 1 the

our. The f 1 ion the paper the

ed for 1 B i t

s

take eOl.mt what 1 11

ontrol' , t our', 'formul

'rule behaviour', 'language' f and"

(Doubl quot used 1

cartoon

a screen

a high level of s s cation. Sl of

sequence were back proj ted onto

of

from a re

ect, and . Del

pop music orcement

1j~as

was s

an

led a ver cal column of ten 1 lighting

puppet,

second sequence. Also a 'Sooty'

by the experimenter from behind the screen, was made

to appear at the top of the screen and drop snack items down

a plastic tube to the subject. Because experimental sessions

for the youngest subjects were conducted at their own homes,

a simpler portable version of this apparatus was used. An

illuminating s light sequence, four to f seconds of

music from a portable recorder, presentation of a cuddly

doll and items were at t used as the reinforcers.

Also with the infant group re was shaped by

successive approximation and in the first two sessions every

occurrence of a response was reinforced.

The majority of data analysis consisted of visual

comparisons of individual cumula records of res

different t of mean post re orcement pause

duration and running rate were also presented. A power

function of the s of mean pause duration t FI

was used to demonstrate how s lar the ant data

was to data exper th or ts

ects.

Idren's Self at and FI Schedules

A s Bentall and Lowe (1987) extends s

a verbal

low~' or

between (low rate

The

on an PI

was to rest

rewards and must not be awoken too soon

or was

was and had to be woken by