Stimulus Control

Jacky MaddiCaldwell College

Presentation Overview What is a phobia? How people react to phobias? Types of phobias Prevalence of phobias Treatment options Review of Article

Stimulus Fading and Differential Reinforcement for the Treatment of Needle Phobia in a Youth with Autism

Daniel B. Shabani and Wayne W. Fisher Journal of Applied Behavior Analysis, 2006

What is a phobia?

Phobias are an exaggerated usually inexplicable and illogical fear of a particular object, class of objects, or situation.

Defined as a medical condition in the DSM – IV (300.29)

How do people react to phobias?

Common phobia symptoms and sensations include:

•Shortness of breath or smothering sensation •Palpitations, pounding heart, or accelerated heart rate •Chest pain or discomfort •Trembling or shaking •Feeling of choking •Sweating •Nausea or stomach distress

•Feeling unsteady, dizzy, lightheaded, or faint •Feelings of unreality or of being detached from yourself •Fear of losing control or going crazy •Fear of dying •Numbness or tingling sensations •Hot or cold flashes •Fear of fainting

http://www.nimh.nih.gov/health/publications/anxiety-disorders/complete-publication.shtml#pub6

The National Institute of Mental Health (NIMH) estimates that 5-12% of Americans have phobias. This is almost 6 million Americans. Approximately 7-9% of children have been estimated to have SP.

The mean age of onset depends on the type of phobia.

Fears and phobias are common in young children. Referral rates tend to increase in mid-to-late childhood and early adolescence.

The National Institute of Mental Health (NIMH)

History

Behaviorally, phobias manifest as the need to escape or avoid the feared object or situation.

Phobias are twice as common in women as men.

Similarly, children whose parents display a higher rate of specific phobia have higher rates themselves.

Causes Numerous theories about the etiology of

specific phobias have been offered among them are:

Learning theories Classic conditioning: A previous neutral

stimulus has been paired with an aversive stimulus that elicits a strong fear or emotional response.

Operant conditioning: Parents may

inadvertently reinforce the phobic behavior by providing the child with positive or negative attention surrounding the avoidant behavior.

Cognitive Models

Cognitive models: Because learning theories may not adequately explain the development and persistence of phobias, attention has been focused on the role of cognition.

Children with anxiety disorders are more likely to display distorted and maladaptive thoughts.

Types of Phobias

1) Animal phobias. 2) Natural environment phobias. 3) Situational phobias. 4) Blood-Injection-Injury phobia. 5) Other phobias. This includes all phobias

that don’t fall into one of the first four categories. Examples include fear of choking, fear of illness, fear of injury, fear of death, and fear of clowns

Animal Type

The fear of spiders (arachnophobia)

and the fear of snakes (ophidiophobia)

Natural Environment Type

Like the fear of heights (acrophia)

and the fear of lightning and thunderstorms (astraphobia)

Situational type

Like the fear of small confined spaces (claustrophbia)

Or being "afraid of the dark," (nyctophobia).

OTHER

The fear of the number 13 (triskaidekaphobia),

The fear of clowns (coulrophobia).

Focus of the Article The fear of medical

procedures including needles and injectionsBelonephobia: fear of needlesAichmophobia: fear of pointed objects Algophobia:fear of pain Trypanophobia:fear of injections

Diabetes

There are 20.8 million children and adults in the United States, or 7% of the population, who have diabetes.

http://www.diabetes.org/diabetes-statistics.jsp - American Diabetes Association

Stimulus Fading and Differential Reinforcement for the

Treatment of Needle Phobia in a Youth with Autism

Introduction The purpose of the study was to treat

needle phobia with behavior techniques,

stimulus fading plus a DRO, to reduce the child’s fear and to

facilitate the treatment of a medical condition.

Method Participant – Oliver and 18 year old boy

diagnosed with autism, mental retardation, and Type 2 diabetes.

He attended an out patient clinic 4 days per week for treatment of non-compliance related to his diabetes.

He had not allowed medical professionals to draw blood for 2 yrs.

He had no vocal speech and communicated only through a few manual signs.

Method

Setting – Sessions were conducted in a treatment room (3m X 3m) containing a table, chairs, and assorted reinforcers such as cookies.

Generalization sessions were conducted in the nurses office.

Dependent Variable

The percentage of successful trials which was defined as:

Oliver not moving his hand more than 3cm during a 10s trial.

IOA

IOA was collected trial by trial during 27% of sessions and was always 100%

Preference Assessment

DeLeon & Iwata, 1996

Prior to each session, potential edible reinforcers were identified using a multiple-stimulus-without replacement preference assessment.

Design

An ABAB reversal design was used. The horizontal distance of the lancet to the tip of Oliver’s finger varied upon condition.

The vertical distance stayed the same (8-10 cm).

The starting distance was 61 cm away.

Baseline

Oliver was given a verbal and gentle physical prompt to place his hand on the posterboard. The therapist moved the lancet toward his finger.

Immediately upon the therapist’s movement, Oliver pulled his hand away. The trial was terminated. Baseline trials lasted 10s or less.

Stimulus Fading plus DRO Fading Step 1 – Oliver had his hand on the

within the outline on posterboard

The lancet was horizontally positioned 61 cm from Oliver’s index finger

If he stayed within the outline for 10s he was given a food item that he had chosen earlier.

If he moved more than 3cm – the trial was immediately terminated, all the materials were removed and the experimenter turned away for 10s.

Stimulus Fading plus DRO Fading from each step was done after 2-

3 consecutive sessions at 100% Step F2-F7 the distances were 46, 31,

15, 8, 5, 1cm. Step F8 10 trials with the lancet 1cm

above his index finger and an attempt to draw blood on the 11th trial

Step F9 attempts to draw blood were intermittent

Results

During baseline Oliver pulled his hand away EVERY time they tried to draw blood.

All attempts to draw blood in Step F9 were successful. Drawing blood in the nurses station was also successful.

Graph

Generalization and Maintenance

A two month follow-up was conducted in which blood draw was successful.

Oliver’s mother reported that she was able to draw blood and measure glucose levels on a daily basis with no problems.

Limitations

1.) An analysis of each component was not conducted to determine the independent contributions of the stimulus fading and the DRO components.

Another limitationThe level of distress was not measured during

each trial

Crying, whimpering and negative vocalizations appeared during baseline and at the beginning of treatment but were not there at the end or during follow-up.

A chart like this I used with typical patients to rate their levels of anxiety.

Low Anxiety1–19 Medium Low Anxiety20–39 Medium Anxiety40–59 Medium High Anxiety60–79 High Anxiety80–100

Programming for Generalization based on the 9 categories of

generalizationStokes & Baer (1977)

1.) Train & Hope There was no information on the number of

therapists used, the setting was somewhat limited, and the glucose testing machine was always the same.

2.) Sequential ModificationBehavior change did take place in the therapy sessions and it was generalized to the nurses station and to the home environment. It might be useful to have trained in other locations such as a restaurant or in the car.

Programming for Generalization based on the 9 categories of

generalizationStokes & Baer (1977)

3.) Introduce to naturally maintaining contingencies.

I can’t think of any natural contingencies that would maintain glucose monitoring. However, I would have liked Oliver to be able to test his blood independently.

4.) Train sufficient exemplars Not done. There was no mention of how many therapists were involved,

if the blood taken in the nurses office was done by a nurse, was she wearing a uniform, gloves, mask? The equipment never changed. What if the model of the glucose machine became obsolete?

5.) Train loosely Nope. Could have changes the poster-board, or whether Oliver

was sitting or standing.

Programming for Generalization based on the 9 categories of

generalizationStokes & Baer (1977)

6.) Use indiscriminable contingenciesAlthough I was pleased to see a preference assessment was

conducted there was no mention as to the amount of edible reinforcer was given, a delay in giving the reinforcer was never mentioned, nor was it mentioned if Oliver ever became satiated during the phases that contained 20 trials.

7.) Program common stimuliMom or the nurse could have come into the therapy setting

before Oliver completed the study. Therapists could have continued to work with Oliver at home before mom took over.

Programming for Generalization based on the 9 categories of

generalizationStokes & Baer (1977)

8.) Mediate GeneralizationDue to the fact that Oliver was non-verbal teaching him to self-

instruct may not be possible. Creating a activity schedule of the glucose monitoring procedure could be beneficial in helping Oliver to understand the process in other settings.

9.)Teaching generalization as a behaviorReinforcement in the form of edibles or activity could be given to

Oliver if he allowed mom to test his blood sugar in another room in the house, or an outside location.

References Shabani, D.B., Fisher, W.W. (2006).

Stimulus fading and differential reinforcement for the treatment of needle phobia in a youth with autism. Journal of applied behavior analysis, 39, 449-452.