Controlled Lab Experiments

For this initial discussion I would like to contrast controlled laboratory experiments and naturalistic observations research methods. In controlled laboratory experiments, the researchers conduct their studies in a controlled setting. Conversely, studies involving naturalistic observation, examine participants in their natural environment. Below I present a contrast of the most essential features of each of these methods of research.
Controlled laboratory experiments:
• Objective: Seek to compare two or more conditions.
• The independent variables (precedent conditions that the experimenter purposely manipulate to evaluate the outcome of behavior) and dependent variables (show the change in behavior) are central axis. Researchers will try to control as many possible variables.
• Samples: are usually random. Additionally, they should be representative to allow generalization.
• Strengths: It is one of the best ways to answer hypothesis questions. Statistical analysis makes it relatively
easy to apply to representative samples of a population.
• Weaknesses: It is not always possible to generate results beyond a place, time, and task. Behavior of the participants in the laboratory may not be on par with their behavior in natural environments.
Naturalistic Observation:
• Objective: To observe the behavior of participants in a unobtrusive manner (without them realizing it), or direct observation (while they participate in an activity).
• Variables are usually not controlled by the experimenter.
• Samples: There is no random assignment. Not always are in control of the experimenter. Generalizability is usually aimed at a particular type of population.
• Strengths: The natural behavior of participants in a natural environment can be observed. In addition, the experimenter has the flexibility to shift attention to some other interesting behavior occurring.
• Weaknesses: No convincing hypothesis can be established. The data must be encoded and usually depends on the judgment of observant researcher, (Graziano & Raulin, 2010; Sternberg, 2009).

An example of a controlled laboratory experiment is the study: How does the prefrontal cortex 'listen' to classical and techno music?
A functional near-infrared spectroscopy (fNIRS) conducted by Bigliassi, León-Dominguez, and Altimari. This study was conducted in a laboratory. Thirty subjects participated in the study: 15 men and 15 women. The aim of the study was to explore the effects of techno and classical music on emotional reactions and brain activity. ANOVA results showed statistical significance: both musical genres increase prefrontal cortex (PFC) activity. However, after conducting a post hoc test, analysis indicated that classical music caused grater activity in the dorsolateral region. Moreover, classical music was able to increase parasympathetic activity, while techno music decreased parasympathetic activity after 10 minutes of music exposure. Analysis also showed that men were more affected by classical music than women, (Bigliassi, León-Domínguez, & Altimari,
2015).

I consider that the method of controlled laboratory experimentation was the most appropriate for this type of research. The use of sophisticated equipment was necessary: the fNIRS measured PFC activity; while emotions were measured using a heart rate monitor to notice heart rate variability during the exposure of music, and also a questionnaire (The Self-Assessment Manikin) to assessed affective valence and felt arousal. Specific analysis of the data using ANOVA and post hoc test Bonferroni, enabled the experimenters prove their hypotheses and establish strong conclusions. Conclusions as those established by Bigliazzi and colleagues would not have been possible with a naturalistic observational research.