- Title
- Mindful appraisal of facial expressions
- Creator
- Pua, Yeow Khoon
- Relation
- University of Newcastle Research Higher Degree Thesis
- Resource Type
- thesis
- Date
- 2024
- Description
- Research Doctorate - Doctor of Philosophy (PhD)
- Description
- The premise behind mindfulness is conceptually simple – when the mind is still, thoughts and feelings will naturally settle, while clear and equanimous awareness will arise. Nonetheless, mindfulness has defied a unified definition. Current instruments mostly operationalise mindfulness as aspects of non-judgmental knowing and reacting to one's inner and external phenomena. They miss measuring elements that are key to the development of that awareness. In this thesis, we attempted to measure mindfulness within its canonical Buddhist definition of mental development. We developed a behavioural test that examines peoples’ cognitive ability to apply and sustain the application of task-relevant rules. The assessment required participants to use specific judgment criteria to categorise happy and angry expressions. The protocol was created and refined over three studies, and its sensitivity to mental development was evaluated in the fourth and final study. In Study 1, using existing behavioural and EEG data from 20 participants, we evaluated four computational cognitive decision-making models (EZ2, RobustEZ, Ratcliff Diffusion and Linear Ballistic Accumulator) and validated their estimates against the event-related potential P3b. We found that the Linear Ballistic Accumulator provided the best-fitting estimates for the cognitive processes underlying a speeded, forced-choice, angry and happy expression categorisation task. Study 2 extended the experimental protocol with task-relevant, expression-specific judgment criteria. The 20 online participants were asked to categorise the faces as either “angry or not angry” in one task and “happy or not happy” in another. Before each trial, the participants were prompted to look for the specific expression. We found that cognitive acuity was lower when the judgment and facial expression matched than when they did not. Study 3 compared the decision-making differences between 20 regular meditators and 20 non-meditators. The non-meditators performance reflected the trends seen in Study 2. Their acuity was lowest when the judgment rule and the facial expression matched. The regular meditators maintained similar acuity levels. Their responses were faster and more accurate than the non-meditators. Due to a combination of higher cognitive acuity and deliberation, their decision-making was more efficient. They required less evidence to give correct responses. This is the expected result when participants consistently apply the judgment criteria and suggests that the regular meditators might have applied the expression-specific judgment criteria more effectively than the non-meditators. In Study 4, we utilised the developed protocol to assess novice meditators before and after eight weeks of daily 15-minute self-paced online meditation training. The protocol’s estimates were verified against event-related potential components and facial electromyography and compared against other self-report instruments and physiological measures of mindfulness. The 56 participants were randomly assigned to mindfulness of breath meditation, loving-kindness meditation, integrated loving-kindness and mindfulness of breath meditation, or white noise active control groups. We tracked the participants’ usage of their assigned online audio. In the pre-training assessment, the participants’ performances were similar to those of the non-meditators in Study 3. For the 26 participants who consistently accessed their audio, the changes in their post-test results were in the direction of Study 3’s regular meditators results. Their cognitive acuity and decision efficiency increased. The improved cognitive acuity correlated positively with changes in self-reported mindfulness scores. On the other hand, the 13 participants who did not consistently access their audio failed to show equivalent changes. Interestingly, the active control group’s improvements were comparable to the treatment groups. However, in contrast to Study 3’s regular meditators, this study’s participants’ decision efficiency was not higher when the presented expressions and judgment criteria matched. The novice meditators might still be ineffective in applying expression-specific judgment. These results suggest that this protocol could assess the cognitive ability to apply task-relevant rules. This ability may be linked to the Buddhist definition of mindfulness as the mental faculty that recalls, directs and sustains applications of the mind. The correlations between cognitive acuity and specific mindfulness subscales’ scores suggest that this protocol may be a supplementary behavioural assessment to current mindfulness instruments. Furthermore, in mindfulness research, the development of mindfulness remains little explored. This protocol’s sensitivity to mindfulness changes may help identify the factors facilitating its growth.
- Subject
- mindfulness; behavioural measures; mental development; cognitive/perceptual acuity; facial expression categorisation; evidence accumulation decision-making models; Linear Ballistic Accumulator; N170; P3b; fEMG
- Identifier
- http://hdl.handle.net/1959.13/1512425
- Identifier
- uon:56615
- Rights
- Copyright 2024 Yeow Khoon Pua
- Language
- eng
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| Thumbnail | File | Description | Size | Format | |||
|---|---|---|---|---|---|---|---|
| View Details Download | ATTACHMENT01 | Thesis | 7 MB | Adobe Acrobat PDF | View Details Download | ||
| View Details Download | ATTACHMENT02 | Abstract | 105 KB | Adobe Acrobat PDF | View Details Download |