Brain tumor . Depending on where it is, it can cause different types of hallucinations. If it's in an area that has to do with vision, you may see things that aren't real. You might also see spots or shapes of light. Tumors in some parts of the brain can cause hallucinations of smell and taste.
One of the key factors in this process is the identification and operational definition of variables -- traits, characteristics, or other measurable factors that can have different values -- that impact the phenomenon of interest. One is primarily interested in two types of variables: independent variables and dependent variables. The independent variable is the variable that is being manipulated by the researcher. For example, Dr. Harvey has a theory that the way that people dress affects how they are treated by others in the workplace.
The dependent variable is the variable that is being measured in an experiment. For example, in a study looking at how tutoring impacts test scores, the dependent variable would be the participants' test scores. In a psychology experiment, researchers are looking at how changes in the independent variable cause changes in the dependent variable. One way to help identify the dependent variable is to remember that it depends on the independent variable.