26.05.2021 - 18:00
On 26 May at 18:00 Gerly Tamm will defend her doctoral thesis “Multiple sources of variation in perception and working memory for facial emotional expressions” for obtaining the degree of Doctor of Philosophy (in Psychology).
Professor Jaanus Harro, University of Tartu
Professor Kairi Kreegipuu, University of Tartu
Professor Nelson Cowan, University of Missouri (USA)
Associate Professor Jukka M. Leppänen, University of Turku (Finland)
How do emotional facial expressions affect what is remembered for a short time and what is not? For example, can a smiling or angry look from a teacher in a mathematics class help or hinder task performance? Why cannot some people discriminate between facial expressions (e.g. sad, angry and happy)? What are the sources of variation in perception and working memory for facial emotional expressions? In my dissertation, I tested hypotheses inspired by these questions. Working memory (WM), or short-term memory, is a process of cognition that binds perceived information to previous knowledge and use it in a purposeful manner to perform a task. Working memory is the foundation of any goal-oriented activity.
I studied the effects that come from: 1) facial stimulus qualities (meaning vs. physical properties), 2) neurobiology, including associations between dopamine, serotonin and noradrenaline system biomarkers, and sex, 3) emotional dispositions (anxiety, depression). Based on the results from six studies, I developed a theoretical model that describes the sources of variation in perception and working memory for facial emotional expressions. Studies I, III, IV, V and VI were conducted as part of the Estonian Children Personality, Behaviour and Health Study, a total of 507 subjects (25 years old) participated. Study II consisted of three experiments with more than 200 volunteers from Tartu and Tallinn (aged 18-50).
The results showed that a positive and motivating context (smiling or happy faces) enhanced memory performance, but not in people with high depression. Additionally, low serotonin (as reflected by low platelet monoamine oxidase activity) was associated with better WM performance regardless of facial expression, but only at an average or high, but not too high dopamine level. Men and women did not differ in WM performance. Sex difference was present only in interaction with genotype in perception of facial expressions. Surprisingly, past diagnosis of social anxiety disorder in contrast to controls, and acute social anxiety predicted inaccurate recognition of angry faces. In conclusion, there is no simple “recipe” that would explain perception and WM performance for facial expressions. However, the results help to understand why people are so different in perceiving and remembering facial expressions.
The defence will be held in Zoom.
Näituse 2–102 (Tartu) and Zoom