Chapter 5. Integrating Prospective and Retrospective Cues to the Sense of
5.4.1. Prospective vs Retrospective Cues
For Group 1 studies, which focused on outcome identity, interactions with the prospective cue emerged. In addition to agency ratings increasing over time, we found a concurrent increase in selection fluency effects. There was a shallower increase over time in agency ratings for dysfluent actions (incongruent priming/flankers), relative to fluent actions (congruent priming/flankers). For Group 2 studies, which focused on AOI, there were no interactions between retrospective and prospective cues to agency. As there was no change in agency ratings across trials, selection fluency effects remained stable throughout. Dysfluent actions (incongruent priming) led to lower agency ratings than fluent actions (congruent priming) across trials. We will now evaluate the 4 possible mechanisms outlined in the introduction with regards to our results.
22.214.171.124. Learning to be Prospective: Fluency Effects Are Not Context-Specific The interaction between selection fluency and outcome identity observed for Group 1 studies are in line with the prediction of the “learning to be prospective” account. This view proposes that we learn to use selection fluency as a cue to agency in a context-
specific manner: We learn that fluent actions are associated with specific outcomes, and come to rely on selection fluency as a prospective proxy for the action outcome. From this perspective, there should be no fluency effects at the start of a block, because there is no a priori knowledge about how fluency informs SoA (hypothesis a), in Figure 5.1). This was indeed the pattern observed in Group 1 studies (see Figure 5.5).
However, this account cannot explain the general effects of selection fluency found in Group 2 (see Figure 5.5). In those studies, similar fluency effects were present from the start of a block, and independently of outcome identity. Therefore, the relation between selection fluency and SoA had to be learnt in advance. Note that this does not preclude the possibility that the association between selection fluency and action outcomes could still be strengthened in particular contexts, and further enhance the contribution of prospective cues to SoA. For example, in complex tasks, e.g. sports, as expertise increases, greater fluency in action selection will typically be associated with greater accuracy in outcome prediction (Gray et al., 2007). Thus, the experience of fluency might gradually become an even more reliable advance predictor of action outcomes, and agency.
126.96.36.199. Optimally Prospective: No Reduction in Fluency Effects
The present results seem to rule out the “optimally prospective” account. Assuming prior knowledge about the relation between selection fluency and SoA, this account suggests that we rely most on selection fluency as a cue to agency when other cues are unreliable/unavailable. An optimal cue integration account (Moore & Fletcher, 2012; Synofzik et al., 2013) would have predicted that the prior reliability of the selection fluency cue could have served to compensate for the low reliability of outcome identity at the start of a block, and perhaps that its contribution to SoA might reduce with outcome learning, given that agency ratings should have been tracking the outcomes (hypothesis b), in Figure 5.1). In contrast, results showed either a constant or an increasing contribution of selection fluency to SoA across trials. These findings question the use of an optimal integration across all cues to SoA (Sidarus et al., 2013), although it may apply when integrating some cues. Current proposals do
not easily account for changes in reliability over time, such as those found for outcome identity during instrumental learning. Moreover, it remains unclear how these processes can handle the integration of cues that become available at different times within a trial, e.g. prospective vs. retrospective.
188.8.131.52. Generally Prospective: Selection Fluency as a General Heuristic
These findings clearly support the “general heuristic” account described above: Selection fluency can serve as a heuristic cue to agency, which can be employed in novel circumstances, independently of one’s knowledge about action-outcome contingencies (hypothesis c), in Figure 5.1). In Group 2 studies, we did not find a general increase in agency ratings, as predicted by hypothesis c), but, importantly, selection fluency effects were similar across trials.
These findings suggest that the relevance of selection fluency to agency is likely learned through everyday experience, rather than being specifically linked to any given environment. Regardless of a specific link between fluency/difficulty and particular outcomes, fluent action selection is more likely associated with desired or predicted outcomes than dysfluent selection. These findings are also consistent with the view that response conflict is an aversive signal (Botvinick, 2007), with negative affective consequences that can affect subsequent events (Fritz & Dreisbach, 2013). Relatedly, many studies have shown general influences of fluency/difficulty, e.g. in stimulus processing, on a variety of judgements, such as liking or familiarity (Alter & Oppenheimer, 2009).
184.108.40.206. Prospective Effects on Action-Outcome Learning
The increased effects of selection fluency on agency across trials seen in Group 1 would also be consistent with the “prospective effects on learning” account. From this perspective, outcomes that follow dysfluent actions would be less easily associated with their corresponding action, relative to outcomes that follow fluent actions. Assuming agency ratings would be tracking action-outcome knowledge, ratings would increase more slowly for outcomes that followed dysfluent actions, thus the difference in ratings relative to outcomes that followed fluent actions would
increase. This could potentially result from action representations being disrupted by response conflict, and, in turn, be less effectively associated with outcomes. It may be adaptive to learn less about the consequences of dysfluent actions, than of fluent actions. For example, a novice playing darts who hits the bull’s-eye at the first throw should recognise that this successful hit may have been partly due to luck. Her lack of practice with the game means her action selection was likely not very fluent or precise, and she is unlikely to easily replicate such an ideal hit.
In fact, sensorimotor predictions can be influenced by selection fluency (Stenner, Bauer, Heinze, et al., 2014), and thus alter action-outcome linkage. Otherwise, the negative affect induced by conflict could also impair the associative process. Interestingly, this view would suggest that selection fluency effects previously found with block-wise agency ratings (e.g. Wenke et al., 2010) could result from better or worse associative links between particular outcomes and their corresponding actions
Finally, under the instructions to focus on outcome identity, agency ratings may have been very low at the start of a block, since participants did not have any outcome information yet. It is possible that this floor effect could have masked the general, and typically stable, influence of selection fluency on agency, which then gradually emerged as outcome knowledge was gathered, and ratings started to vary. Further research is needed to test these hypotheses, namely by directly testing knowledge about action-outcome associations.