The goal of our first literature search assignment in Behavioral Research is to identify possible research studies that could lead to a research proposal AND to practice reading empirical research articles and identifying key information.
By way of example, I will also complete this assignment along with my students. On Tuesday, we will complete a research article “scavenger hunt” in class that involves highlighting key pieces of information in the article. So, for this “annotation”/summary of research I decided to select an article I had printed off already so I could also complete this scavenger hunt. I shuffled through my filing cabinet of articles from grad school until I came across an article that described a behavioral research study and wasn’t already marked up with my highlighting and notes.
Article 1 (of 3)
Sakaki, Niki, & Mather (2012) ask whether individuals process biologically relevant stimuli more automatically that socially relevant stimuli. A biologically emotional stimulus relates to survival or reproduction (e.g., a snake, appetizing food, sexual images). A socially emotional stimulus relates to social life (e.g., money, smiling people).
The authors hypothesized that participants would process biologically relevant stimuli more automatically than socially relevant stimuli. In their first of three studies, Sakaki, Niki, & Mather’s (2012) sample consisted of 22 undergraduate and graduate students who attended the University of Tokyo.
Sakaki, Niki, & Mather (2012) used a dot-probe task to measure attentional engagement (automaticity) and subsequent memory (higher level processing). The dot-probe task is measures selective attention by asking participants to identify the location of a dot after viewing a neutral or emotional image. The emotional image is presented in the center of the screen. Then a dot appears on the left, center, or right of the screen. The participant’s job is to press a key that corresponds to the position of the dot. If it takes longer for the participants to respond to the dot, this indicates that it is more challenging to disengage from the image. Sakaki, Niki, & Mather predicted that participants would take longer to disengage from biologically emotional images than socially emotional images because the biologically emotional images hold attention more automatically.
The independent variable in this research is the stimulus type. There were four levels to this IV: biologically emotional images, socially emotional images, neutral images, and a control condition (a fixation). Participants viewed 10 biological, 10 social, and 10 neutral images for a total of 30 images (and 10 fixations) and 40 trials. Participants were exposed to each level of the independent variable, meaning this was a within participants research design (aka a repeated measures design)*. The first dependent variable was the participants’ reaction time (ms) with slower reaction times indicating difficulty disengaging from the images. The second dependent variable was memory (hit rate). More specifically, following the dot-probe task the participants were asked to complete a surprise memory task.
The authors found support for their hypothesis. Specifically, participants responded more slowly to the dot probe when engaged with biologically emotional stimuli compared to other types. However, in the surprise memory test, participants recalled both biologically and socially emotional images better than neutral images indicating that early attentional processes do not affect later memory.
The authors conducted another study that showed divided attention impaired memory for socially emotional stimuli but not for biologically emotional stimuli. This further supports their hypothesis that biologically relevant stimuli engage automatic attention processes whereas socially relevant stimuli engage more elaborative (slower) processing. In other words, socially emotional stimuli require more effortful, cognitive processing than biologically relevant stimuli.
One concern I had with these studies was statistical power. They could have both increased their trials and the number of participants included in the studies. In addition, I need to more carefully read through the supplemental materials because the designation of socially and biologically relevant stimuli is not entirely obvious to me (and they recognize that the lines between these two types of stimuli are blurred in some cases).
One question I thought of as a result of reading this study was whether individuals with addictions (e.g., social media) or substance use/abuse problems treat stimuli in the “addictive” category as biologically or socially relevant? I think this could be an interesting spin on this study (actually I’m pretty sure this has already been done, in a quick search I see a couple of examples). In order to conduct a study akin to this at UWP, the student researchers would want to be prepared to develop an attention task like the dot probe task.
Sakaki, M., Niki, K., & Mather, M. (2012). Beyond arousal and valence: The importance of the biological versus social relevance of emotional stimuli. Cognitive, Affective, & Behavioral Neuroscience, 12, 115-139.
*Technically, they also included valence (negative, positive) and arousal (high, low) as factors meaning this was a factorial design, but they did not find these factors to modify the results most directly relevant to their hypothesis.