🧠AP Psychology
Using the source provided, respond to all parts of the question.
1. Your response to the question should be provided in six parts: A, B, C, D, E, and F. Write the response to each part of the question in complete sentences. Use appropriate psychological terminology in your response.
Identify the research method used in the study.
State the operational definition of motor function recovery in the study.
Describe what the mean indicates for the motor function recovery score between the High Sleep Quality Group and the Low Sleep Quality Group.
Identify at least one ethical guideline applied by the researchers.
Explain the extent to which the research findings may or may not be generalizable using specific and relevant evidence from the study.
Explain how the research findings support or refute the concept of neuroplasticity.
This study investigated whether self-reported sleep quality is associated with motor function recovery in patients diagnosed with mild Traumatic Brain Injury (TBI). Understanding this relationship may provide insights into how restorative sleep processes facilitate neuroplasticity—the brain's ability to reorganize and form new neural connections following injury.
Total N: 180
Recruitment: Participants were recruited from three rehabilitation centers specializing in brain injury recovery located in the northeastern United States. Patients were eligible if they had received a mild TBI diagnosis within the previous 30 days and were enrolled in outpatient rehabilitation programs.
Gender: 52.2% male (n = 94), 46.7% female (n = 84), 1.1% non-binary or other gender identity (n = 2)¹
Race/Ethnicity: 58.3% White (n = 105), 18.9% Black or African American (n = 34), 14.4% Hispanic or Latino (n = 26), 5.6% Asian (n = 10), 2.8% multiracial or other (n = 5)¹
Age Range: 25-50 years
Age Mean: 36.4
Age SD: 7.2
Compensation: Participants received a $50 gift card at each of four assessment points ($200 total) as compensation for their time and travel expenses.
Pittsburgh Sleep Quality Index (PSQI): A validated 19-item self-report questionnaire measuring sleep quality and disturbances over the past month, yielding a global score from 0-21 where higher scores indicate poorer sleep quality
Motor Assessment Scale (MAS): A standardized clinical assessment tool evaluating motor function across eight categories including upper limb movements, hand movements, and walking, converted to a 0-100 composite score
Glasgow Coma Scale records: Used to confirm mild TBI diagnosis at intake
Demographic questionnaire: Collected information on age, gender, race/ethnicity, injury circumstances, and medical history
Researchers obtained informed consent from all participants (or their legal guardians when applicable) prior to enrollment, ensuring participants understood the voluntary nature of the study and their right to withdraw at any time without affecting their rehabilitation care.
At intake, research assistants verified mild TBI diagnosis through medical records and administered the demographic questionnaire during participants' regularly scheduled rehabilitation appointments.
Participants completed the Pittsburgh Sleep Quality Index (PSQI) monthly for 12 consecutive months, either in person during rehabilitation visits or through a secure online portal.
Motor function assessments using the Motor Assessment Scale were conducted by trained physical therapists at four time points: baseline (within 30 days of injury), 4 months, 8 months, and 12 months post-enrollment.
Physical therapists conducting motor assessments were blind to participants' sleep quality ratings to prevent potential bias in scoring.
Sleep quality scores were averaged across the 12-month period to create a composite sleep quality rating for each participant.
At the conclusion of data collection, participants were debriefed about the study's hypotheses and provided with a summary of preliminary findings.
All data were de-identified and stored on encrypted, password-protected servers in compliance with HIPAA regulations.
Motor function recovery was operationally defined as the composite score (0-100 scale) on the Motor Assessment Scale administered at the 12-month follow-up assessment, where higher scores indicate better motor function. The scale evaluates performance across eight motor domains: supine to side lying, supine to sitting, balanced sitting, sitting to standing, walking, upper arm function, hand movements, and advanced hand activities. Each domain is scored 0-6 by a trained physical therapist based on standardized criteria, with scores summed and converted to a 0-100 scale for analysis.
Informed consent was obtained from all participants or their legal guardians prior to any data collection. The consent process included detailed explanation of study procedures, potential risks and benefits, confidentiality protections, and the voluntary nature of participation. Participants were reminded at each assessment that they could withdraw from the study at any time without penalty or impact on their rehabilitation services.
Results revealed a significant negative correlation between average PSQI scores and motor recovery scores at 12 months, r = -.47, p < .01. Because higher PSQI scores indicate poorer sleep quality, this negative correlation demonstrates that better sleep quality was associated with higher motor function recovery scores. Additionally, baseline motor scores were positively correlated with 12-month recovery scores (r = .31, p < .01), suggesting that initial motor function was associated with long-term recovery outcomes. Age was not significantly correlated with motor recovery (r = .04, p > .05).
Variable | 1 | 2 | 3 | 4 | 5 |
|---|---|---|---|---|---|
| — | -.47** | .38** | -.22* | .08 |
| -.47** | — | -.29** | .31** | .04 |
| .38** | -.29** | — | -.15* | .11 |
| -.22* | .31** | -.15* | — | .06 |
| .08 | .04 | .11 | .06 | — |
The findings indicate a moderate positive relationship between sleep quality and motor function recovery in mild TBI patients, such that individuals reporting consistently better sleep demonstrated higher motor recovery scores after 12 months. These results align with research on neuroplasticity, suggesting that quality sleep may support the brain's capacity to reorganize neural pathways and strengthen synaptic connections necessary for motor skill reacquisition following injury. However, because this was a correlational study, we cannot conclude that sleep quality directly causes improved motor recovery; it remains possible that a third variable, such as overall health status or injury severity, influences both sleep and recovery, or that patients experiencing better motor recovery subsequently sleep better due to reduced pain or frustration.
Hernandez, R. M., Chen, W. L., & Patterson, A. K. (2023). Sleep quality and motor function outcomes in mild traumatic brain injury: A 12-month correlational investigation. Journal of Rehabilitation Psychology, 68(2), 142-158. https://doi.org/10.1037/rep0000847
- Demographic categories reflect participant self-identification using response options provided on the intake questionnaire. Terminology aligns with current NIH reporting standards, though we acknowledge that such categories may not fully capture the complexity of individuals' identities.
- PSQI (Pittsburgh Sleep Quality Index) scores are reverse-scored for interpretation purposes in the text; on the original scale, higher scores indicate poorer sleep quality. The correlation coefficient presented reflects this original scoring, meaning the negative correlation indicates that poorer sleep quality (higher PSQI scores) is associated with lower motor recovery scores.
