The functional role of cardiac activity in perception and action

SKORA, L.I., J.J.A. LIVERMORE and K. Roelofs. The functional role of cardiac activity in perception and action. NEUROSCI BIOBEHAV REV X(X) XXX-XXX, 2022. Patterns of cardiac activity continuously vary with environmental demands, accelerating or decelerating depending on circumstances. Simultaneously, cardiac cycle affects a host of higher-order processes, where systolic baroreceptor activation largely impairs processing. However, a unified functional perspective on the role of cardiac signal in perception and action has been lacking. Here, we combine the existing strands of literature and use threat-, anticipation-, and error-related cardiac deceleration to show that deceleration is an adaptive mechanism dynamically attenuating the baroreceptor signal associated with each heartbeat to minimise its impact on exteroceptive processing. This mechanism allows to enhance attention afforded to external signal and prepare an appropriate course of action. Conversely, acceleration is associated with a reduced need to attend externally, enhanced action tendencies and behavioural readjustment. This novel account demonstrates that dynamic adjustments in heart rate serve the purpose of regulating the level of precision afforded to internal versus external evidence in order to optimise perception and action. This highlights that the importance of cardiac signal in adaptive behaviour lies in its dynamic regulation.

Awareness is required for autonomic performance monitoring in instrumental learning: Evidence from cardiac activity

Performance monitoring is a vital aspect of successful learning and decision‐making. Performance errors are reflected in the autonomic nervous system, indicating the need for behavioral adjustment. As part of this response, errors cause a pronounced deceleration in heart rate, compared to correct decisions, and precede explicit awareness of stimulus–response outcome contingencies. However, it is unknown whether those signals are present and able to inform instrumental learning without stimulus awareness, where explicit performance monitoring is disabled. With mixed evidence for unconscious instrumental learning, determining the presence or absence of autonomic signatures of performance monitoring can shed light on its feasibility. Here, we employed an unconscious instrumental conditioning task, where successful learning is evidenced by increased approach responses to visually masked rewarding stimuli, and avoidance of punishing stimuli. An electrocardiogram (ECG) assessed cardiac activity throughout the learning process. Natural fluctuations of awareness under masking permitted us to contrast learning and cardiac deceleration for trials with, versus without, conscious stimulus awareness. Our results demonstrate that on trials where participants did not consciously perceive the stimulus, there was no differentiation in cardiac response between rewarding and punishing feedback, indicating an absence of performance monitoring. In contrast, consciously perceived stimuli elicited the expected error‐related deceleration. This result suggests that, in unconscious instrumental learning, the brain might be unable to acquire knowledge of stimulus values to guide correct instrumental choices. This evidence provides support for the notion that consciousness might be required for flexible adaptive behavior, and that this may be mediated through bodily signals.

Performance monitoring is vital to successful learning. We provide novel evidence that autonomic performance monitoring, indexed by cardiac deceleration, is only engaged in conscious, but not unconscious, instrumental learning. This result provides support for the notion that consciousness is required for flexible adaptive behaviour, and that this relationship may be mediated by bodily signals.

Cardiac Concomitants of Feedback and Prediction Error Processing in Reinforcement Learning

Successful learning hinges on the evaluation of positive and negative feedback. We assessed differential learning from reward and punishment in a monetary reinforcement learning paradigm, together with cardiac concomitants of positive and negative feedback processing. On the behavioral level, learning from reward resulted in more advantageous behavior than learning from punishment, suggesting a differential impact of reward and punishment on successful feedback-based learning. On the autonomic level, learning and feedback processing were closely mirrored by phasic cardiac responses on a trial-by-trial basis: (1) Negative feedback was accompanied by faster and prolonged heart rate deceleration compared to positive feedback. (2) Cardiac responses shifted from feedback presentation at the beginning of learning to stimulus presentation later on. (3) Most importantly, the strength of phasic cardiac responses to the presentation of feedback correlated with the strength of prediction error signals that alert the learner to the necessity for behavioral adaptation. Considering participants' weight status and gender revealed obesity-related deficits in learning to avoid negative consequences and less consistent behavioral adaptation in women compared to men. In sum, our results provide strong new evidence for the notion that during learning phasic cardiac responses reflect an internal value and feedback monitoring system that is sensitive to the violation of performance-based expectations. Moreover, inter-individual differences in weight status and gender may affect both behavioral and autonomic responses in reinforcement-based learning.

Feedback processing in schizophrenia: effects of affective value and remedial action

Error-monitoring deficits in schizophrenia have been found, but results with respect to feedback processing and remedial action were unclear. The present study examined the role of emotion in feedback processing in medication-free patients with recent-onset schizophrenia. Patients and controls performed a time-estimation task, and brain activation was measured with functional magnetic resonance imaging (fMRI). Participants had to estimate a 1-s interval and received feedback about their performance in the form of words or facial expressions. Patients performed the task at the same level as the controls and used the feedback to improve performance. Brain activation following the feedback stimuli in the rostral cingulate zone differed between groups, but this effect depended on the modality of the feedback stimulus. Patients showed a differential response to verbal and facial feedback in the rostral cingulate zone, whereas healthy controls did not differ between modalities. Furthermore, activation in the rostral cingulate zone following facial feedback was negatively related to severity of the disease as expressed by the scores on positive symptom subscale of the Positive and Negative Syndrome Scale. Both findings point in the direction of a specific deficit in patients which is related to the emotional impact of external feedback.

Decomposing developmental differences in probabilistic feedback learning: a combined performance and heart-rate analysis

Learning on the basis of outcome feedback shows pronounced developmental changes, however, much is still unknown about its underlying processes. In the current study, we aimed at decomposing how value updating, feedback monitoring and executing behavioral control contribute to children's probabilistic feedback learning. Children (ages 8-9), young adolescents (ages 11-13) and young adults (ages 18-24), performed two probabilistic feedback tasks: one required building a value representation on the basis of feedback (noninformed task), while in the other value representations were explicitly presented (informed task). Heart-rate was recorded to augment performance measures of feedback processing. We observed substantial developmental differences in heart-rate responses toward feedback in the noninformed task. Adult's heart-rate slowed more to negative compared to positive feedback relative to the children and young adolescents. In contrast, in the informed task all age groups showed larger heart-rate slowing toward negative compared to positive feedback. These results indicate that children are not impaired in monitoring probabilistic feedback per se, but have a specific deficit in building a task-appropriate value representation on the basis of probabilistic feedback.

Dissociation between medial frontal negativity and cardiac responses in the ultimatum game: Effects of offer size and fairness

In the present study, we examined the role of fairness and offer size on brain and cardiac responses in the ultimatum game (UG). Twenty healthy volunteers played the role of responder in a computerized version of the UG in which the fairness and size of the offers were systematically varied. Both fairness and size of the offer influenced the acceptance rates in a predictable way, leading to fewer accepted unfair and low offers. Only unfair high, but not unfair low offers were accompanied by a medial frontal negativity. An unexpected stronger cardiac deceleration to fairer offers was found, which was not affected by the size of the offers. Cardiac and electrocortical measures showed a different relation with performance, and both measures were correlated only modestly. This dissociation between cardiac responses and brain potentials is discussed in terms of a possible differential sensitivity to effects of stimulus probability and violation of the social rules.

The anterior cingulate cortex responds differently to the validity and valence of feedback in a time-estimation task

This study examined the role of the medial frontal cortex in the processing of valence and validity of performance feedback using a time-estimation paradigm. Participants had to produce 1s intervals followed by positive and negative feedback that could be valid or invalid (i.e., related or unrelated to task performance). Performance results showed that participants used the validity information to adjust their time estimations to negative feedback. The rostral cingulate zone (RCZ) was more active after valid feedback than after invalid feedback, but was insensitive to the valence of the feedback. The rostral anterior cingulate cortex (rACC), posterior cingulate and right superior frontal gyrus, however, appeared to be primarily sensitive to the valence of the feedback; being more active after positive feedback. The results are discussed along the lines of the ACC's cognitive and affective subdivisions and their structural and functional connections.