Lucie Charles’s research while affiliated with Queen Mary University of London and other places

The capacity for voluntary action is a distinctive feature of human minds. However, experimental studies of volition struggled to capture defining features of human voluntariness. Here we developed a competitive game which incentivised participants to innovate their action choices to find the right time to avoid a collision with an opponent who predicted the timing of the participant’s action choice. One group of participants received explicit information about the competitor’s action-selection rules, while a second group had no information about the competitor. Both groups showed increased behavioural stochasticity when adapting to a competitor who punished participant’s choice biases. However, the group who had no explicit information generated their action choices in a way that avoided the action that the competitor was likely to take. In contrast, the group who explicitly knew the competitor’s action-selection rules avoided the same action they took in preceding trials so that the competitor could not easily exploit the participant’s behavioural patterns. These findings suggest that people can develop beliefs about other agents in the social environment within which they work, and can adapt voluntary action choices accordingly. However, explicit explanations about the other agent facilitate model-based planning in the voluntary generation of novel action patterns.

The capacity for voluntary action is a distinctive feature of human minds. However, experimental studies of volition struggled to capture defining features of human voluntariness. Here we developed a competitive game which incentivised participants to innovate their action choices to find the right time to avoid a collision with an opponent who predicted the timing of the participant’s action choice. One group of participants received explicit information about the competitor’s action-selection rules, while a second group had no information about the competitor. Both groups showed increased behavioural stochasticity when adapting to a competitor who punished participant’s choice biases. However, the group who had no explicit information generated their action choices in a way that avoided the action that the competitor was likely to take. In contrast, the group who explicitly knew the competitor’s action-selection rules avoided the same action they took in preceding trials so that the competitor could not easily exploit the participant’s behavioural patterns. These findings suggest that people can develop beliefs about other agents in the social environment within which they work, and can adapt voluntary action choices accordingly. However, explicit explanations about the other agent facilitate model-based planning in the voluntary generation of novel action patterns.

In everyday life, decision-makers need to integrate information from various sources which differ in how reliable the correct information is provided. The present study addressed whether people can optimally use explicit information about the trustworthiness of the information source and whether people know how information sources affect their decisions. In each trial, we presented a sequence of six information sources which indicated a correct colour (red or blue) each with a different level of reliability. Each source was explicitly labelled the reliability percentage, i.e., the likelihood that a source provides correct information. Participants were asked to decide which colour was more likely to be correct. In the first series of three experiments, we found that participants failed to make use of explicit reliability cues optimally. In particular, participants were less able to use reliably wrong information sources (reliability below 50%) than reliably correct information sources (reliability above 50%), even though these two types of information sources were equally informative. In addition, participants failed to ignore the colour displayed by unreliable sources (50% reliability), although these sources gave just random information for a binary decision. In the second series of two experiments, we asked participants, after each choice, to report their subjective feelings of whether they followed or opposed a colour suggested by sources with a specific reliability percentage. We found that the ratings of the participant's influence report tracked the amount of evidence which supported the choice they just made. Further, participants were able to introspect their own choice bias guided by unreliable information sources. These findings suggest that human choice behaviour deviates from Bayesian integration. However, people have a good metacognitive monitoring of how their decisions are driven by external stimuli.

Even when identified, misleading and unreliable information lead to poor decision-making. We investigated whether people actively compensate for this by seeking additional information. Across six experiments, participants predicted the outcomes of lotteries based on information they received from several information sources, each with an explicitly-stated level of reliability. Before making their prediction, participants were given the opportunity to bid to view an additional information source. In different conditions, sources either had only positive reliability (reliably right), or contained some random (unreliable), or below-chance reliability (reliably wrong) information. Though the same information was conveyed in each condition, exposure to unreliable and reliably wrong information reduced choice accuracy. Crucially, we also found it paradoxically reduced information-seeking. In follow-up experiments, participants rated their decision confidence. Confidence was reduced when unreliable or reliably wrong sources were present, suggesting that decreased information-seeking occurred despite lower confidence. In conclusion, even when labelled, misleading and unreliable information negatively impacts belief formation, and also paradoxically reduces curiosity.

Intelligent agents need to understand how they can change the world, and how they cannot change it, in order to make rational decisions for their forthcoming actions, and to adapt to their current environment. Previous research on the sense of agency, based largely on subjective ratings, failed to dissociate the sensitivity of sense of agency (i.e., the extent to which individual sense of agency tracks actual instrumental control over external events) from judgment criteria (i.e., the extent to which individuals self-attribute agency independent of their actual influence over external events). Furthermore, few studies have examined whether individuals have metacognitive access to the internal processes underlying the sense of agency. We developed a novel two-alternative-forced choice (2FAC) control detection task, in which participants identified which of two visual objects was more strongly controlled by their voluntary movement. The actual level of control over the target object was manipulated by adjusting the proportion of its motion that was driven by the participant's movement, compared to the proportion driven by a pre-recorded movement by another agent, using a staircase to hold 2AFC control detection accuracy at 70%. Participants identified which of the two visual objects they controlled, and also made a binary confidence judgment regarding their control detection judgment. We calculated a bias-free measure of first-order sensitivity (d') for detection control at any given level of participant's own movement. The proportion of pre-recorded movements determined by the stairecase could then be used as an index of control detection ability. We identified two distinct processes underlying first-order detection of control: one based on instantaneous sensory predictions for the current movement, and one based on detection of a regular motor-visual relation across a series of movements. Further, we found large individual differences across 40 particpants in metacognitive sensitivity (meta-d') even though first-order sensitivity of control detection was well controlled. Using structural equation modelling (SEM), we showed that metacognition was negatively correlated with the predictive process component of detection of control. This result is inconsistent with previous hypotheses that detection of control relies on metacognitive monitoring of a predictive circuit. Instead, it suggests that predictive mechanisms that compute sense of agency may operate unconsciously.

Do people know when they act freely and autonomously versus when their actions are influenced? While the human aspiration to freedom is widespread, little research has investigated how people perceive whether their choices are biased. Here, we explored how actions congruent or incongruent with suggestions are perceived as influenced or free. Across three experiments, participants saw directional stimuli cueing left or right manual responses. They were instructed to follow the cue's suggestion, oppose it or ignore it entirely to make a 'free' choice. We found that we could bias participants' 'free responses' towards adherence or opposition, by making one instruction more frequent than the other. Strikingly, participants consistently reported feeling less influenced by cues to which they responded incongruently, even when response habits effectively biased them towards such opposition behaviour. This effect was so compelling that cues that were frequently presented with the Oppose instruction became systematically judged as having less influence on behaviour, artificially increasing the sense of freedom of choice. Taken together, these findings demonstrate that acting contrarian distorts the perception of autonomy. Crucially, we demonstrate the existence of a novel illusion of freedom evoked by trained opposition. Our results have important implications for understanding mechanisms of persuasion.

The capacity for autonomous behaviour is key to human intelligence, and fundamental to modern social life. However, experimental investigations of the cognitive bases of human autonomy are challenging, because experimental paradigms typically constrain behaviour using controlled contexts, and elicit behaviour by external triggers. In contrast, the sources of human autonomy and freedom are assumed to be endogenous. Here we propose a new theoretical construct of adaptive autonomy, meaning the capacity to make behavioural choices that are free from constraints of both immediate triggers and habitual responding. Participants played a competitive game in which they had to choose the right time to act, in the face of an opponent who punished (in separate blocks) either choice biases, habitual sequences of action timing across trials, or habitual responses to the effects of reinforcement. Adaptive autonomy with respect to each habit was measured by the ability to maintain performance against the opponent even when the corresponding habit was punished. We found that participants were able, under pressure from their opponent, to become free from habitual choices of when to act, but were not able to free themselves from win-stay, lose-shift patterns of reinforcement, even when these resulted in punishment. These results propose a new testing ground of autonomous behaviour as a flexible adaptation of more or less habitual behaviours that co-exist with different classes of external constraint.

How much can people resist influence in choice? In this study, we explored participants’ abilities to voluntarily detach from irrelevant information to make free choices. Participants saw random-dot-motion stimuli and a colour-cue indicating whether their response should be congruent or incongruent with the direction of dot-motion. Importantly, in a third condition, the colour-cue instructed participants to detach from dot-motion direction and to freely choose how to respond. After each trial, participants rated how much they felt their decision was influenced by the stimulus. Our results showed that participants conflated opposition and independence: responses incongruent with the stimulus were systematically associated with a greater sense of freedom and detachment, whether these responses were instructed or made freely. Further, this effect seemed stronger in participants who tended to oppose the stimulus more frequently. Taken together, these results suggest that feelings of freedom rely on opposing suggestion and breaking from our habits.

How do we avoid unwanted influence when making a choice, and how do we know when our choices are free from such influences? Research shows that human decision processes are often biased by extraneous information and by previous habits. In the present study, we investigated whether free choices are biased in the same ways, and whether the subjective feeling of choosing freely can accurately track these sources of bias. Across three studies, we presented participants with a visual target cueing one of two directions. Participants were instructed to respond by adhering to the suggested direction, to oppose it, or to ignore it and make a ‘free’ choice. We varied the frequency of occurrence of each instruction (experiment 1), of each motor response (experiment 2), and of each visual cue (experiment 3). We found that previously learned stimulus-response mapping affected the ability to make free choices, as participants tended to follow the trained mapping. Moreover, in the detachment condition, participants consistently reported stronger subjective sense of freedom when their actions opposed the cue, rather than followed it. Strikingly, when participants learned through experience to oppose a cue, subsequent free choices evoked by that cue were associated with a boost in subjective freedom, irrespective of whether the response followed or opposed the cue. Thus, the increased subjective sense of freedom associated with opposition appeared to stick to the stimulus that had been repeatedly opposed. Taken together, these findings demonstrate the strong relationship between oppositional responding and subjective experience of freedom, showing for the first time that an illusory sense of autonomy can be acquired through trained opposition.