Conference Agenda

Counterfactual actions are action alternatives that could have been chosen and executed, but were not. We investigated memory for counterfactual actions in two behavioural studies. Participants performed the Tower of London task, which involves choosing and executing actions that move coloured balls between pegs to achieve a goal configuration. Immediately after solving each problem, participants were shown several configurations, including the goal, other configurations they had just produced en route to the goal, plausible ‘counterfactual’ configurations drawn from an alternative path to the goal that they could have chosen (but did not), and completely new configurations unrelated to any plausible path. Participants judged if they had seen the shown configuration while solving the immediately-preceding problem. The findings revealed a memory bias: participants erroneously claimed to have seen/executed counterfactual configurations more often than completely new configurations. That is, they made false positive memory areas for counterfactual actions that they might plausibly have planned or executed, but did not in fact execute. One interesting interpretation of this result argues that planning an action is sufficient to encode it in memory, while executing it is not necessary. Our study cannot differentiate between prospective and retrospective influences of counterfactual actions on memory. An ongoing EEG study in the lab aims to target this difference.

Understanding how the brain generates subjective emotional experiences remains a major challenge. Although fear is often thought to be represented similarly regardless of its source, research suggests that our experience of fear might depend on the type of memory involved. For example, machine learning decoders trained to predict Situational Fear (mostly linked to semantic memory) from brain activity can also predict fear driven by Fear Schemas (mostly linked to episodic memory). However, decoders trained on Fear Schemas do not generalize as well to predict Situational Fear. This discrepancy suggests that fear based on Fear Schemas involves broader and more complex brain representations. To explore these differences, we analyzed three fMRI datasets capturing distinct fear experiences associated with different memory types: frightening situations (semantic memory), schema-based fears of animals (episodic memory), and threat conditioning (procedural memory). By comparing decoder performance across 214 regions defined in the Brainnetome atlas, we identified representations to each type of subjective fear. Our results show that Fear Schemas are predicted more accurately than Situational Fear and Threat Conditioning in the occipital, superior temporal, and prefrontal cortices. These findings offer valuable insights into the brain mechanisms underlying mental health issues such as anxiety disorders, which often involve overwhelming Fear Schemas rather than Situational Fear or Threat Conditioning. By taking memory type into account, our work highlights the nuanced interplay between cognitive processes and emotional experience, paving the way for more targeted interventions in mental health.

Self-monitoring is considered crucial for regulatory behavior, yet its influence on performance in basic cognitive tasks remains unclear. We investigated how the requirement to monitor and report one’s response confidence affects performance across three different cognitive domains: visual perception, episodic memory, and semantic memory. Across five experiments with perceptual decision, word recognition, and general knowledge tasks, participants completed a two-response procedure, where they provided initial and final responses. In experimental conditions participants reported their initial response confidence either simultaneously with the initial response or between the two responses. In control conditions, they performed an unrelated visual task, or observed a mask stimulus or a blank screen with no additional task. We hypothesized that explicit confidence reporting would enhance regulatory processes and improve final performance. Contrary to our expectations, across all three domains, we did not find evidence that confidence reports improve performance. When confidence ratings were retrospective, final response improvement was smaller compared to conditions without additional tasks, and changes of mind tended to be less frequent and less corrective. Confidence ratings provided simultaneously with initial responses generally decreased accuracy. In the general knowledge task, while lower confidence was associated with more frequent revisions, the explicit reporting requirement decreased overall revision rates. In general, similar patterns of results emerged in perceptual and memory tasks. These findings indicate that deliberate monitoring might hinder low-level cognitive performance when temporal resources are limited, because it is resource consuming. This interference appears to be domain-general, occurring across perceptual, semantic, and episodic memory tasks.

Behavioral responses to sensory inputs are highly variable, even upon repeated presentations of an identical stimulus. Traditional behavioral analyses (e.g., Signal Detection Theory) assume that this variability stems from uncorrelated noise whose average magnitude is static over time. However, a recent insight, afforded by generalized linear hidden Markov models (GLM-HMMs), is that humans and rodents alternate between discrete and persistent behavioral states during perceptual decision-making. For example, experimental trials can be clustered in states of engaged, disengaged, and biased decision-making strategies. In mice, the probability of being in an engaged behavioral state exhibits an inverted-U relationship to baseline pupil size (a proxy of tonic arousal), consistent with the Yerkes-Dodson Law. By analyzing behavioral, pupil, and neural data from mice (N=9; audio-visual change detection task) and humans (N=69; auditory detection task), the current study investigated 1) whether this relationship generalizes to human participants and 2) what neural mechanisms it is governed by. Mice and humans alternated between several discrete behavioral states and engaged behavioral state probability exhibited an inverted-U relationship with baseline pupil-linked arousal. In mice, preliminary neural analyses further suggest that for visual change detection, this relationship was mediated by pre-change V1 firing rates of putative GABAergic interneurons but not putative pyramidal neurons. These findings imply a general mechanism by which arousal dynamically modulates the cortical state of a primary sensory region to optimize perceptual decision-making. This study furthermore highlights an important insight for consciousness research: conscious perception is governed by discrete and persistent states of altered sensory processing.

The attentional blink (AB) effect – where detecting a first target (T1) in an RSVP stream impairs the perception of a second target (T2) at a critical temporal lag – has been extensively used to investigate the neural correlates of conscious and unconscious processing. However, the validity of these neural correlates has been questioned when participants have a task at hand on the stimulus of interest, leading to the development of no-report paradigms.

In this study, we designed a two-step no-report AB paradigm. In the first phase, participants performed a discrimination task on T1 while being presented with task-irrelevant unique T2 words, which varied in memorability and appeared at either a short or long lag. To establish a behavioral benchmark for T2 conscious perception, we included mind-wandering probes in 25% of trials. In the second phase, participants were tested for their incidental memory of the words. Using simple models, we can separately estimate memory decay and the probability of conscious perception as a function of lag and word memorability.

Preliminary results showed that, during the testing phase, T2 words appeared more often in response to mind-wandering probes when they were outside of the AB period. Furthermore, estimates of detection probability from the incidental recall phase point to a similar result. These results suggest that the AB does not only affect decision-making, but it also affects the spontaneous conscious access of task-irrelevant stimuli. Future work will incorporate EEG recordings to explore the neural dynamics of T2 conscious perception in this no-report AB design.

The attentional blink (AB) describes the phenomenon that reporting the second of two targets (T1 and T2) is impaired when presented in rapid succession. In decades of EEG research, numerous studies have linked awareness of T2 to enhanced early negativities and late positivities in event-related potentials (ERPs). However, they have systematically confounded awareness with task-related post-perceptual processes such as decision-making, motor preparation, and memory updating. Thus, the present study with 116 participants aimed at disentangling neural correlates of awareness, relevance, and decision-making in the AB. Participants were presented with rapid streams of letter strings (T1) and words (T2 and distractors) and randomly assigned to one of three groups: 1) In the unmarked condition, participants could not distinguish T2 from distractors. 2) In the marked condition, T2 was highlighted as the relevant stimulus. 3) In the decision condition, participants additionally performed a T2 discrimination task. Comparing ERPs in response to seen versus unseen T2 stimuli demonstrated that early negativities are reliably enhanced by awareness across task conditions, whereas late positivities depend on decision-making. These findings challenge the conclusions of numerous electrophysiological studies on awareness and attention and suggest that the processes underlying enhanced late positivities are not necessary for awareness.