Decreasing self-stimulatory hand-mouthing behavior: Research Review

Research Review by Michelle Rodgers (CUNY Queens College)

Title: Effects of providing sensory stimulation to decrease self-stimulatory behavior: using additional food to suppress hand-mouthing behavior

Citation: Yang, J.L. & Bruner, J.D. (1996). Effects of providing sensory stimulation to decrease self-stimulatory behavior:using additional food to suppress hand-mouthing behavior. Behavioral Interventions, 11, 119-130.

Purpose of this study: The goals of this study were three-fold:
First, the authors wanted to validate the functional relationship between sensory reinforcement and self-stimulatory behavior. Second, the authors wanted to determine what role sensory stimulation could play when provided as a treatment procedure. Third, the authors wanted to determine if food could serve as a sensory reinforcer to replace hand-mouthing behavior.

Participants: The participant in this study was a 30.5 year old nonverbal male with profound mental retardation.

Settings: The setting was the large dining room within the state care facility in which the participant resided. The participant typically sat with three of his classmates.Target behaviors: Hand mouthing was defined as momentary insertion of any finger covering the first knuckle between the lips.

Procedure: Data were collected twice a day during baseline and treatment conditions. The data were collected during a structured morning activity and during a less structured activity in the afternoon. During the baseline phase, the participant received his usual meals, with no additional food given. Any hand-mouthing that was observed and recorded were never stopped or interrupted. During the intervention phase, the participant was given his usual meals. However, he was also given additional portions of bread, fruit and milk. He was able to eat as much or as little as he wanted. Data was collected for three months after treatment was employed.

Results: The participant’s hand-mouthing behavior decreased from 67% in morning activities to 13% after treatment, His hand-mouthing behavior in the afternoon decreased from 47% to 17%. During the follow-up, the participant averaged 12.5% hand-mouthing behavior in the morning and 10.4% in the afternoon. The participants weight was also observed. The participant gained 19.5 pounds during this study and was within his ideal body weight. In addition to the behavior decrease, the participant’s hands healed and he was able to sleep longer throughout the night. He no longer needed insomnia medication or restraints to prevent tissue damage to his hands.

Implications: In this particular case, the functional analysis of the hand-mouthing behavior allowed the authors to conclude that food would be a viable replacement. This study is somewhat limited in its generality to other individuals engaging in hand-mouthing behavior because there was only one participant. Although increased food intake worked for this individual it may not work for others.

However, with that being said, increased food decreased the hand mouthing and was less labor intensive for the staff at the facility. Permitting extra food at meal times was an easy solution to the hand-mouthing behavior and was not aversive to the participant nor did it pose an ethical dilemma for the staff as the restraints had. On the other hand, with increased food comes weight gain. This particular individual happened to need to gain weight but other participants may end up with a health problem. It is therefore suggested that individuals undergoing this increase in meals to prevent hand-mouthing, get additional exercise and perhaps some foods that provide chewing sensations without significant calories, for example chewing gum.