The Effects of Implicit Priming on Functional Performance in Persons With Parkinson’s Disease

PURPOSE: Occupational therapy is effective in helping individuals with Parkinson’s disease (PD) maintain levels of functional independence. One evidence-based intervention is use of explicit priming, referred to as RehabSelfPrime-Speech. The technique uses repetitive priming as the individual reads and speaks the priming word to facilitate motor performance needed to complete activities of daily living and instrumental activities of daily living (IADLs). With self-priming, the individual is aware of the prime and the effects the prime. In this study, the researchers examined the effects of implicit priming (IP) on individuals with PD. With IP, the participant is unaware of the prime, which allows for an automatic response to the action or performance. Extensive research has been done on the effects of IP with physically able individuals. This study sought to examine the effectiveness of IP in improving functional movement of individuals with PD.

METHOD: Participants were recruited from a variety of community groups. Participants had to have a diagnosis of PD, to have no other major physical or mental disorder, to be ambulatory and literate in English, and to have no history of frequent falls. The research activities took place over 4 wk with three intervention sessions and homework activities. Following consent, general demographic information was collected, and participants completed the Lawton IADL Scale, the Parkinson’s Disease Questionnaire 39 (PDQ–39), the Geriatric Depression Scale (GDS) Short Form, and the Timed Up and Go (TUG) test.

After all baseline measures were obtained, the participants were instructed to complete a 25-set word scramble activity. This protocol was developed based on previous research looking at the effects of the word scramble in IP in physically able populations. Each sentence set contained five words with only one possible four-word sentence combination (e.g., Drinks: Coke: Diet: Turn: Sally; turn is the extra word). The extra word was either a priming word (walk or turn) or a nonaction neutral word (think, feel, view, plan); 60%–70% of the extra words were the priming words. After the participant completed all sentence scrambles, they were instructed to flip the paper over and write the words they most commonly left out of the sentences.

The participants then completed three simple motor tasks and repeated each one three times. The activities stand, walk, turn, retrieve an item from a tabletop, and place an item on a raised surface were meant to reinforce the prime. The participants went home with 4 days of word scramble activities and instructions to do the motor tasks, and they returned in 1 wk, when the procedures were repeated. They then went home for 2 wk with eight sets of word scrambles and instructions to do the motor tasks. When they returned 2 wk later, they repeated the assessments and were debriefed.

RESULTS: The research was completed with 13 participants (five male, eight female; M age = 70, SD = 10.76; M yr since diagnosis = 6.5, SD = 5). Descriptive statistics were performed on all assessment variables. A paired-sample t test was conducted to compare pre and post scores on the PDQ–39 (total and subscales), Lawton IADL Scale, TUG test, and GDS. Nonparametric testing (Wilcoxon signed-rank test) was also performed to compare pre and post scores. No significant differences were found in all areas.

CONCLUSION: Past literature has validated the use of IP; however, further research needs to be conducted within the area of IP in persons with PD to determine its usefulness. A small sample size, methodological issues (e.g., sensitivity of measures), use of a control group, and control for severity of illness should be addressed in future research. Occupational therapists have a role in treatment of individuals with PD to identify possible interventions that have the potential to improve quality of life.

References

Ashford, K. J., & Jackson, R. C. (2010). Priming as a means of preventing skill failure under pressure. Journal of Sport and Exercise Psychology, 32, 518–536. https://doi.org/10.1123/jsep.32.4.518

Chartrand, T., & Bargh, J. (1996). Automatic activation of impression formation and memorization goals: Nonconscious goal priming reproduces effects of explicit task instructions. Journal of Personality and Social Psychology, 71, 464–478. https://doi.org/10.1037/0022-3514.71.3.464

Foster, E., Bedekar, M., & Tickle-Degnen, L. (2014). Systematic review of the effectiveness of occupational therapy–related interventions for people with Parkinson’s disease. American Journal of Occupational Therapy, 68, 39–49. https://doi.org/10.5014/ajot.2014.008706

Maitra, K., Richard, L. F., & Park, H. Y. (2015). Cognitive priming for movement initiation via self-speech in people living with Parkinson’s disease. In I. Söderback (Ed.), International handbook of occupational therapy interventions (pp. 619–631). Cham, Switzerland: Springer International.