5.1 Firstly, analysis of the cognitive data (measure of EFT) obtained within the present study found no significant differences between groups (High vs Low Anxiety) and no significant interaction between Anxiety Group and Valence condition. However, this information was somewhat secondary within the project as there already exists a range of
information available regarding cognitive differences during EFT and EM for anxiety disorders at the clinical level (Miloyan, Pachana & Suddendorf, 2014). The general findings from studies such as Miloyan, Pachana & Suddendorf (2014) is that anxious participants produce more negative (but not less positive) prospections and memories than healthy controls. For the purpose of this analysis, the only conclusion that can be drawn is that High Anxiety participants did not produce significantly more episodic prospections than Low Anxiety participants, in any valence condition, based on the results of the novel measure used. However, this also raises methodological issues with the self-report questions that measured episodic vs semantic details. This was a novel, brief (two questions; 5-point Likert scales) measure that has not been replicated or utilised in other research before. Therefore, there are no current indications of its psychometric appropriateness or validity within this project. It was used as a proxy measure to obtain self-report data on two factors of episodicity – vividness and
perspective. The reason such a measure was utilised in place of traditional and reliable measures, such as the adapted-AI (Addis & Schacter, 2008) is due to time contraints that are unique to EEG data collection. Specifically, the dense-array EEG hydrocel nets
utilised within the present study rely on an electrolite solution that increases skin conductance, improving accuracy of readings obtained from the scalp. However, these sensors begin to dry out after approximately 30 minutes (EGI, 2017), resulting in a significant deterioration in the quality of data obtained. Tried and tested measures of EFT and EM such as the adapted-AI require timely administration, which would not be compatible with the current study. The present study kept the EEG data collection to below 30 minutes per participant, to maintain a high level of accuracy for EEG data. However, it is noted that these measures (or similarly time-consuming measures) have been utilised within fMRI research, which is not limited by such a practical time-
constraint. Retrospective methodological critique of the present study may call for novel uses of EFT measures such as the adapted-AI. For example, one such design may involve completing the adapted-AI immediately after the EEG tasks. This could involve the same
57 cue words for easy comparison. However, this may cause distortions between memory and prospection as the participant would essentially be remembering their previous prospection from the EEG task. Therefore, it would be significantly unclear whether participants’ EEG recordings were reflective of the level of episodic detail (obtained later by adapted-AI) they generated during the EEG tasks.
5.2 Alternative stimuli could also yield more ecological validity for the phenomenon of EFT. For example, while the present study utilised ANEW (Bradley & Lang, 1994) for
standardised affective stimuli, future research could utilise alternative affective stimuli. The vagueness of presenting a single cue word may not be as useful in generating episodic memories or prospections compared with a small prose text (such as ANET; Bradley & Lang, 2007), or pictorial affective stimuli (IAPS; Lang et al., 2008) or aurally (IADS; Bradley & Lang, 2007). For example, Altgassen, Kretschmer & Schnitzspahn (2017) demonstrated the significantly positive effect increased context and purposeful cue instructions had on generating more episodic details across adolescents and young adults. This suggests that by improving the specificity and personal purpose (goal- directed) of the EFT task, the individual is more able to generate episodic prospections. Future research should similarly investigate whether the mode of affective stimuli significantly effects the level of episodic details produced during EFT or EM.
5.3 D’Argembeau & Mathy (2011) utilised more personally relevant cues for participants and found a significant difference in the level of episodic details produced depending on the type of cue. For example, cues relating to personal life goals (e.g. “to have a job I like” or “to have children”) resulted in the most episodic details, compared with people- or location-based cues. Therefore, personal cue words could be generated in future research and categorised accordingly. Participants could be instructed to complete the adapted-AI and generate prospections that are positive, negative and neutral to them, prior to the EEG task (separate data collection session), and then suggest a cue word or phrase that corresponds to their most episodic prospections for use within the EEG task. However, this presents similar issues to the above suggestions – these prospections would be subject to distortion during the EEG task and not clearly prospections at all. This would risk the data collected reflecting neurophysiological activity related to EM – not EFT – which would be difficult to distinguish because of the significant neural overlap during EM and EFT. These projected difficulties highlight the meta-cognitive nature of EFT as a discrete human faculty, and demonstrate compatability issues with EEG research compared to fMRI research. Future research into EFT differences based on trait anxiety may be better suited to fMRI neuroimaging methods. It allows for better spatial resolution compared to sLORETA EEG techniques; it has been utilised within a range of other EFT research and therefore may allow for better comparison between findings; and it allows for more accurate but time-consuming measures of EFT (such as adapted-AI) compared to EEG.
5.4 Regardless of the measure of EFT utilised, it is the qualitative content of negative future thoughts that is significant and typical of anxiety disorders – the negative threat-bias (Ellis & Hudson, 2010; Hirsch & Matthews, 2012; Goodwin, Yiend & Hirsch, 2017). No measures of EFT to date – to the best of the researcher’s knowledge – incorporate ratings of subjective meta-cognitive threat, fear or anxiety related to the prospection
58 itself. Indeed, even the standardised ratings from the Self-Assessment Manikin – SAM (Lang, 1980) – would only yield ratings of valence (positive – negative), arousal (low – high) and dominance (in control – controlled/dominated). Of these three affective dimensions, dominance would be the most relevant as a proxy measure of how
subjectively “threatening” a prospection may appear to the participant. Possible future research could include the use of SAM for a measure of dominance to investigate possible differences between High and Low Anxiety groups, or GAD and Control groups. This woud allow for analyses of meta-cognitive ratings between groups –
GAD/Subclinical Anxiety participants may rate their negative future prospections (EFT- Negative) as more dominant than Asymptomatic Controls.
Hypothesis 2: There will be significant neurophysiological differences (as measured by EEG)