“It’s very exciting to find support for your hypothesis”: Inferring the Capacity and Mechanism of Verbal Working Memory

(Photo provided by Brooke Scott)

“I think there are many intriguing and exciting parts to research, such as the conceptual puzzles and learning about all the different aspects that must be considered when designing an experiment. But I think the most exciting part is what we learn from the results.” ~Brooke Scott

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*In the following interview, TS refers to The Synapse and BS refers to Brooke Scott;

TS: Could you briefly introduce yourself, your supervisor, the topic of your thesis, and the field it contributes to?

BS: I’m Brooke and I completed an Honours in Psychology with a minor in biology. My supervisor, Dr. Biljana Stevanovski, conducts research related to memory and cognition. Dr. Stevanovski had designed a novel task - called verbal change detection - to infer the capacity of verbal working memory. My thesis focused on a pilot study for the task to assess its accuracy and reliability relative to current tasks that are used.

TS: What was the inspiration for your study, your research question, and the main results?

BS: The inspiration for the study came from a need for a task that would both infer the capacity of verbal working memory and consider additional processes that affect it, such as attentiveness. Current methods for measuring verbal working memory can infer the capacity of verbal working memory, but provide no insight beyond storage capacity (i.e. how many words can be retained). A verbal change detection task, however, should allow additional processes that regulate verbal working memory to be discerned as well. As Dr. Stevanovski had designed a verbal change detection task, our research question was: “Is a verbal change detection task an accurate and reliable method to infer the capacity of verbal working memory?”

Briefly put, the verbal change detection task involves memorizing and recalling a list of words. Accuracy on the verbal change detection task decreased as list length (i.e. ‘set size’) surpassed 3-4 words. This suggests that the capacity of verbal working memory is approximately 3-4 words. Furthermore, ‘K estimates’ - a measure of the quantity of items held in one’s working memory - revealed that a maximum of 4 words were held in working memory even across larger set sizes of 5-6 words. This supports the idea that a verbal change detection task is an accurate and reliable measurement of verbal working memory: consistent with other results in literature, only 3-4 items are being held in working memory at a time.

A strategy survey was also completed by participants, and revealed that the majority of participants read and repeated the words to themselves while completing the task. This suggests that verbal working memory is recruited for the task. However, some participants also reported that they paid attention to the visual characteristics of the words, which suggests that visual working memory contributed as well.

TS: Could you provide a brief summary of the methods and experimental procedure used in this study?

BS: The verbal change detection task is a computerized task. During the task, participants were presented a list of 2 - 6 words to memorize. After a brief pause, participants were presented with a second list of words. The second list of words were either the same as the first or differed by one word in the list; the participants were to determine if the second list was the same or not. This allowed us to infer the capacity of the participants' verbal working memory: the participants would have held the first list of words in their working memory for comparison with the second list.

A survey was also used to ask participants about their memorization strategies. This helped ensure that participants recruited verbal working memory while completing the verbal change detection task.

TS: Are there any future studies that will be conducted based on your method or results?

BS: Yes - the graduate student I worked with in Dr. Stevanovski’s lab will be using this method for a study. As the verbal change detection task has shown to be an effective measure of verbal working memory, it will be used to investigate the relationship between anxious tendencies (called ‘trait anxiety’) and verbal working memory.

TS: What would you consider the most intriguing part of your research?

BS: I think there are many intriguing and exciting parts to research, such as the conceptual puzzles and learning about all the different aspects that must be considered when designing an experiment. But I think the most exciting part is what we learn from the results. I was very lucky that our results were exactly what we had expected - it’s very exciting to find support for your hypothesis. Though I think that results are exciting regardless of whether they support your current hypothesis or not: either way, you have learned something about the phenomenon that you’re studying, and requiring a change in hypothesis will still bring you closer to understanding it.

TS: Is there anything else you wish to share about the research experience?

BS: As exciting as research is, it can require long and tedious work. If I had to say anything else, it would be to make time for yourself. It’s very easy to get caught up in your work, but it’s important to make time to cook healthy meals you enjoy and go outside for a little exercise. Make sure to set aside time to do the things that you enjoy. Ψ

Created for The Synapse by Incé Husain.