Using the Correlational Method to Study Sleep Through the Lifespan

The purpose of this paper is to evaluate the correlational method as a means for examining the relationship between REM sleep and memory.  I will describe previous research and then investigate how REM and memory are associated in young people and in older people.  In some ways, the sleep patterns of these two groups are very similar, but in some ways they are not. The complete sleep cycle of an individual is composed of two stages: NREM and REM stage. NREM includes the stage 1 to stage 2 of sleep and the REM stage started from stage 3 to 4. The NREM comprises approximately 75% to 80% of the entire sleeping time of the person; the second stage, REEM has the longer span which lasts for 90 to 120 minutes. Marquet (2007) cited that REM in adults increases as the night progresses and is observed to be in its longest span in the third stage  of the sleep episode. REM occurs to the presence of desynchronized brain wave activity which characterized by low-voltage or mixed frequency, muscle atonia and occurences of rapid eye movement. In the study conducted, it was found out that dreams are associated with REM. It even affected the genetal arousal of the person. Marquet (2001) cited that roughly 80% of the recollection of dreams resulted from the genetal arousal which occurred on this stage. In studies conducted in yound adults about the genetal arousal showed that genital arousal decreases with increasing age because adults experiences frequent awakenings during sleep as compared to the young individuals. REM is indeed characterized by faster rhythm of electroencephalograph (EEG) with low amplitude and frequency, and is associated with rapid eye movement with declined toning of the muscles. As the persons gets older,  the REM waves changes and this eventually affects the sleeping patterns of the adult individual as compared to the younger ones. The circadian rhythm had a crucial impact on the person’s memory and thinking abilities. The circadian rhythm controls the body’s secretion of GABA, a neurochemical that affects the learning process and memory encoding of the person (Maquet, 2001). The circadian rhythm is affected by several factors such as aging, stress and environamnet pressure.

Several previous research studies have pointed to the importance of REM sleep in forming new memories.  However, a complete understanding of the roles of REM and non-REM sleep in learning and memory has been elusive.  Maquet (2001) cited that the REM stage of sleep has great impact on the consolidation of memory because it permites the neurons to be reactivated and allows the development of distinctive contexts. Kamel & Gammack (2006) on the other hand revealed that having a poor quality of sleep is assocaited with declined memory and reduces concentration and it can also cause impairment of the individual’s psychomotor perfomance. However, these facts does not necessary mean that they are unnecesary in learning because NREM are the preliminary stages before chieving REM. Animals produce ponto-geniculo-occipital (PGO) waves that are essential in attaining REM stage of sleep. Hence, it is observed that when animals are prevented from sleeping then they have difficulty in learning because they lack the PCO waves which can promote the brain development and facilitates the agility of the brain which are necessary in the learning process. Scientists found out that during REM stage the brain produces neurotransmitters that can enhance the learninga and thinking ability of the brain. Among these neuro transmitters are PGO pr ponto-geniculo-occipital waves which ply important role in the oscillation of the brain cells (Maquet, 2001). Acetylcholine is another neurotransmittesr that enhances brain activity and encourages learning and enhances memory.

The architecture of sleep is different between the young and the old.  Differences between groups in the amount and quality of REM may predict differences in learning.  It is conceivable that the relationship between learning and REM is stronger in the young than in the old. The figure showed the difference on the length of time for REM to occur. It can be observed that young adult have longer time of achieving REM as compared to the adult individuals. Kamel & Gammack (2006) that old peple tend to suffer more of insomnia as compared to younger ones because of several factors that include occurrence of acute medical illness, alterations in the sleeping environment, disturbance in the circadian rhythm, occurrence of sleep disorders such as apnea, advanced-phased sleep syndrome and behavioral factors which may include taking nap at daytime or being lack of exercise and physical activities. Aging is a mulit-faceted process along with some environmental factors are associated with the decrease in the physiolgican and neurobehavioral process (Maquet, 2001). This also means that the occurrence of REM in adults and elderly has  lesser importanace in the development of brain activities such as memory encoding and in the learning process. Correlational method can be used in evaluating the relationship between learning and REM is stronger among yonger adults as compared with the elderly. This can be done by tracing the similarities/differences in the time of REM occurences between the two groups of individual and evaluating also the learning activities that the two groups have achieved.

Data were collected from a group of young people and a group of older people who first learned a list of non-words to test the hypothesis using the correlational method. Each participant was measured on: (1) total time spent asleep, (2) duration of REM sleep, and (3) percentage accuracy in learning the list of non-words. In the study conducted it was found out that adult individuals have more variable sleep patterns as compared to the young individuals. This can be infered based on the table of comaprison between the sleep patterns of young and eledrly repsondents. Having a varied sleep patterns in adults can be contributed to the changes in the hormones and chemicals secreted by the body such as the leptin and ghrelin. The elvetaion of blood pressure and the changes of the circadian rhythm are some of the factors that affect the sleep pattern alterations among adults. Based on the results obtained, it can be inferred that the sleeping patterns of adult individuals greatly affect  their memory skills and learning process. It can be inferred further that there is a series of evidence that support the impact and role played by the REM and sleeppatterns on the memory process of the person and in the reactivation of hormones and neurons that can enhance REM and can improve the post training sleep given among respondents of both group.

The results of the correlational method were valuable in addressing the hypothesis under study.  However, future investigations may need to adopt techniques that improve upon those used here. This study assume that: a) there is a significant correlation between sleeping patterns and the learning and memory process, and b) there is a significant difference in the sleeping REM patterns between younger and elderly and this has an impact on the memorya nd learning process of individuals. It was found out that there is indeed an impact on the performance and memory scale among younger indidual as compared to the elderly and this implies the correlation on the length of time aseep. One of the weaknesses that must be improved in the study is the number of respondents in each group. Having 10 respondents is so limited that it cannot have a fair represenation of the entire population. Hence, it is suggested that additional number of respondents from each group must be used in the future studies with related subject.

References

Kamel, N.S., & Gammack, J.K. (2006).  Insomnia in the elderly.  American Journal of Medicine, 119, 463-469.

Maquet, P. (2001). The role of sleep in learning and memory. Science, 294.  1048-1052.