Cardiac cycle modulates reward feedback processing: An ERP study

Effects of the cardiac cycle on auditory processing: A preregistered study on mismatch negativity

The systolic and diastolic phases of the cardiac cycle are known to affect perception and cognition differently. Higher order processing tends to be facilitated at systole, whereas sensory processing of external stimuli tends to be impaired at systole compared to diastole. The current study aims to examine whether the cardiac cycle affects auditory deviance detection, as reflected in the mismatch negativity (MMN) of the event-related brain potential (ERP). We recorded the intensity deviance response to deviant tones (70 dB) presented among standard tones (60 or 80 dB, depending on blocks) and calculated the MMN by subtracting standard ERP waveforms from deviant ERP waveforms. We also assessed intensity-dependent N1 and P2 amplitude changes by subtracting ERPs elicited by soft standard tones (60 dB) from ERPs elicited by loud standard tones (80 dB). These subtraction methods were used to eliminate phase-locked cardiac-related electric artifacts that overlap auditory ERPs. The endogenous MMN was expected to be larger at systole, reflecting the facilitation of memory-based auditory deviance detection, whereas the exogenous N1 and P2 would be smaller at systole, reflecting impaired exteroceptive sensory processing. However, after the elimination of cardiac-related artifacts, there were no significant differences between systole and diastole in any ERP components. The intensity-dependent N1 and P2 amplitude changes were not obvious in either cardiac phase, probably because of the short interstimulus intervals. The lack of a cardiac phase effect on MMN amplitude suggests that preattentive auditory processing may not be affected by bodily signals from the heart.

Is providing choices always a good thing? the backfire effect of providing choices on competence restoration

Grounded in self-determination theory (SDT), the purpose of this research is to investigate the influence of providing choices following competence frustration on one's intrinsic motivation in a follow-up task. Study 1 conducted a between-group EEG experiment with 50 participants and used a component of event-related potentials (ERPs) to represent intrinsic motivation. Study 2 was a behavioural experiment with 149 participants, adopting the self-report method to measure intrinsic motivation. The stimuli and procedure in Study 1 are identical to Study 2. All participants were asked to complete a high-difficult time-estimation (TE) task during sessions 1-2, and a moderate-difficult stopwatch (SW) task during session 3 (no choices in the control group vs. providing choices in the experimental group). In Study 1, we observed a smaller reward positivity (RewP) difference wave in the experimental (vs. control) group during session 3. In Study 2, participants' intrinsic motivation in the experimental (vs. control) group is significantly lower. The results suggest that providing choices impairs the competence-frustrated participants' intrinsic motivation in the follow-up task and hinders competence restoration. Thus, the current research contributes original neuroscientific and subjective evidences for the adverse influence of providing choices on the competence-frustrated individual's intrinsic motivation, and suggests important practical implications.

Effects of respiratory phases on the processing of emotional and non-emotional visual stimuli

The number of studies investigating the relationship between respiratory phases and cognitive/neural processing of external events has been increasing, but the findings remain controversial. This registered report examined the effect of the respiratory phase on the discrimination accuracy of visual stimuli in the emotional and non-emotional domains. Forty-two healthy young participants were asked to choose fearful over neutral facial expressions and to choose high-contrast over low-contrast Gabor patches during spontaneous nasal respiration. Event-related potentials (ERPs) were also recorded for each type of stimulus presented during each respiratory phase. It was hypothesized that discrimination accuracy would be higher when the stimuli were presented during inhalation than during exhalation. It was also hypothesized that the amplitudes of ERPs elicited by the stimuli would be greater during inhalation than during exhalation. For comparison, the effect of the cardiac phase was examined, with the expectation that discrimination accuracy would be higher when the stimuli were presented during systole than during diastole. It was also hypothesized that the amplitudes of ERPs elicited by the stimuli would be greater during systole than during diastole. As expected, the results indicated that fear discrimination accuracy was higher during inhalation than exhalation and during systole than diastole. However, this was not the case for contrast discrimination. No differences in ERPs were observed between respiratory phases in either task. These results suggest that natural breathing in through the nose facilitates the discrimination of emotional stimuli, possibly via subcortical processes.

Cardiac cycle affects risky decision-making

This study investigates whether decision-making under uncertainty is influenced by the cardiac cycle. To test this hypothesis, we examined the influence of the cardiac cycle on an individual's decision-making process in a gambling experiment. Participants were asked to choose one option with a sure payout or uncertain option with varying degrees of winning probability, ambiguity, and monetary amounts. The onset of presentation of the options is timed to coincide with either cardiac ventricular systole or diastole. The results show that, for most participants, the risk aversion score was lower in the systole trial than in the diastole trial. Model-based exploratory analysis revealed that the higher propensity to take risks in the systole trial compared with that in the diastole trial could be captured better by the change in the gambling bias against the utility of the risky options, rather than by a change in risk attitude. The results provide evidence that the natural fluctuation of cardiac afferent signals can affect risky decision-making.

Cardiac Cycle Affects the Asymmetric Value Updating in Instrumental Reward Learning

This study aimed to investigate whether instrumental reward learning is affected by the cardiac cycle. To this end, we examined the effects of the cardiac cycle (systole or diastole) on the computational processes underlying the participants’ choices in the instrumental learning task. In the instrumental learning task, participants were required to select one of two discriminative stimuli (neutral visual stimuli) and immediately receive reward/punishment feedback depending on the probability assigned to the chosen stimuli. To manipulate the cardiac cycle, the presentation of discriminative stimuli was timed to coincide with either cardiac systole or diastole. We fitted the participants’ choices in the task with reinforcement learning (RL) models and estimated parameters involving instrumental learning (i.e., learning rate and inverse temperature) separately in the systole and diastole trials. Model-based analysis revealed that the learning rate for positive prediction errors was higher than that for negative prediction errors in the systole trials; however, learning rates did not differ between positive and negative prediction errors in the diastole trials. These results demonstrate that the natural fluctuation of cardiac afferent signals can affect asymmetric value updating in instrumental reward learning.