This is the assignment directions:

 The Literature Review provides the background and context for the research problem and illustrates to the reader that the researcher is knowledgeable about the study. This section shares with the reader the results of others studies that closely related to the study being reported. It also related a study to the larger, ongoing dialogue in the literature about a topic, filling in gaps and extending prior studies.  Summarize previous studies related to a topic them in a succinct manner. In a proposal, the literature review is generally brief and to the point.
Review various articles and dissertations, as they may help one to understand how to write and summarize previous research. When writing the literature review, it is wise to separate the various studies one finds into different categories.  Under these categories, create “Level 2 subheadings” in APA style. These subheadings are formatted just like Level 1 headings, but they are aligned left. See the subheadings below for an example. 
1stSubheading 
 Choose one evident theme or topic that became apparent when researching your study. Briefly share the results of the various studies, including the most pertinent information such as the studies’ hypotheses, population, methodology, and results.Relate the study to an ongoing dialogue of the literature pertaining to the research topic. This means that each study one lists should relate to new, proposed study in some way. Report the studies sequentially if possible, building upon the findings of prior studies. Remember to separate each category of studies with a new subheading. Do this as many times as needed.  another evident theme or topic that became apparent when researching your study.

The topic I have written Is: Yoga and Decreased Levels of Depression in the Elder Population.  

You will need to find 8-10 articles relevant to this topic and write in the literature review about it. Again It has to be 4 pages long. And all articles must be cited in APA format