The user has requested enhancement of the downloaded file. All in-text references underlined in b... more The user has requested enhancement of the downloaded file. All in-text references underlined in blue are added to the original document and are linked to publications on ResearchGate, letting you access and read them immediately.
We investigated how the emotional valence of an action outcome influences the experience of contr... more We investigated how the emotional valence of an action outcome influences the experience of control, in an intentional binding experiment. Voluntary actions were followed by emotionally positive or negative human vocalisations, or by neutral tones. We used mental chronometry to measure a retrospective component of sense of agency (SoA), triggered by the occurrence of the action outcome, and a prospective component, driven by the expectation that the outcome will occur. Positive outcomes enhanced the retrospective component of SoA, but only when both occurrence and the valence of the outcome were unexpected. When the valence of outcomes was blocked – and therefore predictable – we found a prospective component of SoA when neutral tones were expected but did not actually occur. This prospective binding was absent, and reversed, for positive and negative expected outcomes. Emotional expectation counteracts the prospective component of SoA, suggesting a distancing effect.
The most popular tasks with which to investigate the perception of subjective synchrony are the t... more The most popular tasks with which to investigate the perception of subjective synchrony are the temporal order judgment (TOJ) and the simultaneity judgment (SJ). Here, we discuss a complementary approach—a dual-presentation (2x) SJ task—and focus on appropriate analysis methods for a theoretically desirable " roving " design. Two stimulus pairs are presented on each trial and the observer must select the most synchronous. To demonstrate this approach, in Experiment 1 we tested the 2xSJ task alongside TOJ, SJ, and simple reaction-time (RT) tasks using audiovisual stimuli. We interpret responses from each task using detection-theoretic models, which assume variable arrival times for sensory signals at critical brain structures for timing perception. All tasks provide similar estimates of the point of subjective simultaneity (PSS) on average, and PSS estimates from some tasks were correlated on an individual basis. The 2xSJ task produced lower and more stable estimates of model-based (and thus comparable) sensory/decision noise than the TOJ. In Experiment 2 we obtained similar results using RT, TOJ, ternary, and 2xSJ tasks for all combinations of auditory, visual, and tactile stimuli. In Experiment 3 we investigated attentional prior entry, using both TOJs and 2xSJs. We found that estimates of prior-entry magnitude correlated across these tasks. Overall, our study establishes the practicality of the roving dual-presentation SJ task, but also illustrates the additional complexity of the procedure. We consider ways in which this task might complement more traditional procedures, particularly when it is important to estimate both PSS and sensory/decisional noise.
Background: Sense of agency is the experience of being in control of one's own actions and their ... more Background: Sense of agency is the experience of being in control of one's own actions and their consequences. The role of frontal cortex in this aspect of action control and awareness remains unclear. Objective/hypothesis: Given the role of dorsolateral prefrontal cortex (DLPFC) in action selection, we predicted that DLPFC may contribute to sense of agency when participants select between multiple actions. Methods: We performed a series of experiments by manipulating a range of task parameters related to action selection and action outcomes while participants were exposed to tDCS stimulation of the left DLPFC. We measured the temporal association between a voluntary action and its outcome using the intentional binding effect, as an implicit measure of sense of agency. Results: Fixed-effect meta-analysis of our primary data showed a trend towards a frontal tDCS, together with considerable heterogeneity between our experiments. Classifying the experiments into subsets of studies, according to whether participants endogenously selected between alternative actions or not, explained 71% of this heterogeneity. Anodal stimulation of DLPFC increased the temporal binding of actions towards tones in the subset of studies involving endogenous action selection, but not in the other studies. Conclusions: DLPFC may contribute to sense of agency when participants selected between multiple actions. This enhanced feeling of control over voluntary actions could be related to the observed therapeutic effects of frontal tDCS in depression.
In this chapter, we present intentional binding as a measure of agency. Intentional binding is an... more In this chapter, we present intentional binding as a measure of agency. Intentional binding is an implicit measure of the conscious experience of agency that is generalizable. First, we introduce the idea behind intentional binding and its use as an implicit measure. Second, we present a method for timing subjective events, describe how data may be collected and analysed, and discuss the method generally. Third, we discuss important considerations in relation to measuring agency. Finally, we look at future directions for research on intentional binding and measuring agency.
Objective: To investigate whether standardised cigarette packaging increases the time spent looki... more Objective: To investigate whether standardised cigarette packaging increases the time spent looking at health warnings, regardless of the format of those warnings.
Study Design: A factorial (two pack styles x three warning types) within-subject experiment, with participants randomised to different orders of conditions, completed at a university in London, U.K.
Methods: Mock-ups of cigarette packets were presented to participants with their branded portion in either standardised (plain) or manufacturer-designed (branded) format. Health warnings were present on all packets, representing all three types currently in use in the U.K.: black & white text, colour text, or colour images with accompanying text. Gaze position was recorded using a specialised eye tracker, providing the main outcome measure, which was the mean proportion of a five-second viewing period spent gazing at the warning-label region of the packet.
Results: An opportunity sample of 30 (six male, mean age = 23) young adults met the following inclusion criteria: 1) not currently a smoker; 2) <100 lifetime cigarettes smoked; 3) gaze position successfully tracked for > 50% viewing time. These participants spent a greater proportion of the available time gazing at the warning-label region when the branded section of the pack was standardised (following current Australian guidelines) rather than containing the manufacturer’s preferred design (mean difference in proportions = 0.078, 95% confidence interval 0.049 to 0.106, p < 0.001). There was no evidence that this effect varied based on the type of warning label (black & white text vs. colour text vs. colour image & text; interaction p = 0.295).
Conclusions: During incidental viewing of cigarette packets, young adult never-smokers are likely to spend more time looking at health warnings if manufacturers are compelled to use standardised packaging, regardless of the warning design.
The user has requested enhancement of the downloaded file. All in-text references underlined in b... more The user has requested enhancement of the downloaded file. All in-text references underlined in blue are added to the original document and are linked to publications on ResearchGate, letting you access and read them immediately.
We investigated how the emotional valence of an action outcome influences the experience of contr... more We investigated how the emotional valence of an action outcome influences the experience of control, in an intentional binding experiment. Voluntary actions were followed by emotionally positive or negative human vocalisations, or by neutral tones. We used mental chronometry to measure a retrospective component of sense of agency (SoA), triggered by the occurrence of the action outcome, and a prospective component, driven by the expectation that the outcome will occur. Positive outcomes enhanced the retrospective component of SoA, but only when both occurrence and the valence of the outcome were unexpected. When the valence of outcomes was blocked – and therefore predictable – we found a prospective component of SoA when neutral tones were expected but did not actually occur. This prospective binding was absent, and reversed, for positive and negative expected outcomes. Emotional expectation counteracts the prospective component of SoA, suggesting a distancing effect.
The most popular tasks with which to investigate the perception of subjective synchrony are the t... more The most popular tasks with which to investigate the perception of subjective synchrony are the temporal order judgment (TOJ) and the simultaneity judgment (SJ). Here, we discuss a complementary approach—a dual-presentation (2x) SJ task—and focus on appropriate analysis methods for a theoretically desirable " roving " design. Two stimulus pairs are presented on each trial and the observer must select the most synchronous. To demonstrate this approach, in Experiment 1 we tested the 2xSJ task alongside TOJ, SJ, and simple reaction-time (RT) tasks using audiovisual stimuli. We interpret responses from each task using detection-theoretic models, which assume variable arrival times for sensory signals at critical brain structures for timing perception. All tasks provide similar estimates of the point of subjective simultaneity (PSS) on average, and PSS estimates from some tasks were correlated on an individual basis. The 2xSJ task produced lower and more stable estimates of model-based (and thus comparable) sensory/decision noise than the TOJ. In Experiment 2 we obtained similar results using RT, TOJ, ternary, and 2xSJ tasks for all combinations of auditory, visual, and tactile stimuli. In Experiment 3 we investigated attentional prior entry, using both TOJs and 2xSJs. We found that estimates of prior-entry magnitude correlated across these tasks. Overall, our study establishes the practicality of the roving dual-presentation SJ task, but also illustrates the additional complexity of the procedure. We consider ways in which this task might complement more traditional procedures, particularly when it is important to estimate both PSS and sensory/decisional noise.
Background: Sense of agency is the experience of being in control of one's own actions and their ... more Background: Sense of agency is the experience of being in control of one's own actions and their consequences. The role of frontal cortex in this aspect of action control and awareness remains unclear. Objective/hypothesis: Given the role of dorsolateral prefrontal cortex (DLPFC) in action selection, we predicted that DLPFC may contribute to sense of agency when participants select between multiple actions. Methods: We performed a series of experiments by manipulating a range of task parameters related to action selection and action outcomes while participants were exposed to tDCS stimulation of the left DLPFC. We measured the temporal association between a voluntary action and its outcome using the intentional binding effect, as an implicit measure of sense of agency. Results: Fixed-effect meta-analysis of our primary data showed a trend towards a frontal tDCS, together with considerable heterogeneity between our experiments. Classifying the experiments into subsets of studies, according to whether participants endogenously selected between alternative actions or not, explained 71% of this heterogeneity. Anodal stimulation of DLPFC increased the temporal binding of actions towards tones in the subset of studies involving endogenous action selection, but not in the other studies. Conclusions: DLPFC may contribute to sense of agency when participants selected between multiple actions. This enhanced feeling of control over voluntary actions could be related to the observed therapeutic effects of frontal tDCS in depression.
In this chapter, we present intentional binding as a measure of agency. Intentional binding is an... more In this chapter, we present intentional binding as a measure of agency. Intentional binding is an implicit measure of the conscious experience of agency that is generalizable. First, we introduce the idea behind intentional binding and its use as an implicit measure. Second, we present a method for timing subjective events, describe how data may be collected and analysed, and discuss the method generally. Third, we discuss important considerations in relation to measuring agency. Finally, we look at future directions for research on intentional binding and measuring agency.
Objective: To investigate whether standardised cigarette packaging increases the time spent looki... more Objective: To investigate whether standardised cigarette packaging increases the time spent looking at health warnings, regardless of the format of those warnings.
Study Design: A factorial (two pack styles x three warning types) within-subject experiment, with participants randomised to different orders of conditions, completed at a university in London, U.K.
Methods: Mock-ups of cigarette packets were presented to participants with their branded portion in either standardised (plain) or manufacturer-designed (branded) format. Health warnings were present on all packets, representing all three types currently in use in the U.K.: black & white text, colour text, or colour images with accompanying text. Gaze position was recorded using a specialised eye tracker, providing the main outcome measure, which was the mean proportion of a five-second viewing period spent gazing at the warning-label region of the packet.
Results: An opportunity sample of 30 (six male, mean age = 23) young adults met the following inclusion criteria: 1) not currently a smoker; 2) <100 lifetime cigarettes smoked; 3) gaze position successfully tracked for > 50% viewing time. These participants spent a greater proportion of the available time gazing at the warning-label region when the branded section of the pack was standardised (following current Australian guidelines) rather than containing the manufacturer’s preferred design (mean difference in proportions = 0.078, 95% confidence interval 0.049 to 0.106, p < 0.001). There was no evidence that this effect varied based on the type of warning label (black & white text vs. colour text vs. colour image & text; interaction p = 0.295).
Conclusions: During incidental viewing of cigarette packets, young adult never-smokers are likely to spend more time looking at health warnings if manufacturers are compelled to use standardised packaging, regardless of the warning design.
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Study Design: A factorial (two pack styles x three warning types) within-subject experiment, with participants randomised to different orders of conditions, completed at a university in London, U.K.
Methods: Mock-ups of cigarette packets were presented to participants with their branded portion in either standardised (plain) or manufacturer-designed (branded) format. Health warnings were present on all packets, representing all three types currently in use in the U.K.: black & white text, colour text, or colour images with accompanying text. Gaze position was recorded using a specialised eye tracker, providing the main outcome measure, which was the mean proportion of a five-second viewing period spent gazing at the warning-label region of the packet.
Results: An opportunity sample of 30 (six male, mean age = 23) young adults met the following inclusion criteria: 1) not currently a smoker; 2) <100 lifetime cigarettes smoked; 3) gaze position successfully tracked for > 50% viewing time. These participants spent a greater proportion of the available time gazing at the warning-label region when the branded section of the pack was standardised (following current Australian guidelines) rather than containing the manufacturer’s preferred design (mean difference in proportions = 0.078, 95% confidence interval 0.049 to 0.106, p < 0.001). There was no evidence that this effect varied based on the type of warning label (black & white text vs. colour text vs. colour image & text; interaction p = 0.295).
Conclusions: During incidental viewing of cigarette packets, young adult never-smokers are likely to spend more time looking at health warnings if manufacturers are compelled to use standardised packaging, regardless of the warning design.
Study Design: A factorial (two pack styles x three warning types) within-subject experiment, with participants randomised to different orders of conditions, completed at a university in London, U.K.
Methods: Mock-ups of cigarette packets were presented to participants with their branded portion in either standardised (plain) or manufacturer-designed (branded) format. Health warnings were present on all packets, representing all three types currently in use in the U.K.: black & white text, colour text, or colour images with accompanying text. Gaze position was recorded using a specialised eye tracker, providing the main outcome measure, which was the mean proportion of a five-second viewing period spent gazing at the warning-label region of the packet.
Results: An opportunity sample of 30 (six male, mean age = 23) young adults met the following inclusion criteria: 1) not currently a smoker; 2) <100 lifetime cigarettes smoked; 3) gaze position successfully tracked for > 50% viewing time. These participants spent a greater proportion of the available time gazing at the warning-label region when the branded section of the pack was standardised (following current Australian guidelines) rather than containing the manufacturer’s preferred design (mean difference in proportions = 0.078, 95% confidence interval 0.049 to 0.106, p < 0.001). There was no evidence that this effect varied based on the type of warning label (black & white text vs. colour text vs. colour image & text; interaction p = 0.295).
Conclusions: During incidental viewing of cigarette packets, young adult never-smokers are likely to spend more time looking at health warnings if manufacturers are compelled to use standardised packaging, regardless of the warning design.