Altering movement parameters disrupts metacognitive accuracy

Correctly estimating the confidence we should have in our decisions has traditionally been viewed as a perceptual judgement based solely on the strength or quality of sensory information. However, accumulating evidence has demonstrated that the motor system contributes to judgements of perceptual confidence. Here, we manipulated the speed at which participants' moved using a behavioural priming task and showed that increasing movement speed above participants' baseline measures disrupts their ability to form accurate confidence judgements about their performance. Specifically, after being primed to move faster than they would naturally, participants reported higher confidence in their incorrect decisions than when they moved at their natural pace. We refer to this finding as the adamantly wrong effect. The results are consistent with the hypothesis that veridical feedback from the effector used to indicate a decision is employed to form accurate metacognitive judgements of performance

Active sampling in visual search is coupled to the cardiac cycle

Recent research has demonstrated that perception and reasoning vary according to the phase of internal bodily signals such as heartbeat. This has been shown by locking the presentation of sensory events to distinct phases of the cardiac cycle. However, task-relevant information is not usually encountered in such a phase-locked manner nor passively accessed, but rather actively sampled at one's own pace. Moreover, if the phase of the cardiac cycle is an important modulator of perception and cognition, as previously proposed, then the way in which we actively sample the world should be similarly modulated by the phase of the cardiac cycle. Here we tested this by coregistration of eye movements and heartbeat signals while participants freely compared differences between two visual arrays. Across three different analyses, we found a significant coupling of saccades, subsequent fixations, and blinks with the cardiac cycle. More eye movements were generated during the systolic phase of the cardiac cycle, which has been reported as the period of maximal effect of the baroreceptors' activity upon cognition. Conversely, more fixations were found during the diastole phase (quiescent baroreceptors). Lastly, more blinks were generated in the later period of the cardiac cycle. These results suggest that interoceptive and exteroceptive processing do adjust to each other; in our case, by sampling the outer environment during quiescent periods of the inner organism

Parental care masks a density-dependent shift from cooperation to competition among burying beetle larvae.

Studies of siblings have focused mainly on their competitive interactions and to a lesser extent on their cooperation. However, competition and cooperation are at opposite ends on a continuum of possible interactions and the nature of these interactions may be flexible with ecological factors tipping the balance toward competition in some environments and cooperation in others. Here we show that the presence of parental care and the density of larvae on the breeding carcass change the outcome of sibling interactions in burying beetle broods. With full parental care there was a strong negative relationship between larval density and larval mass, consistent with sibling competition for resources. In the absence of care, initial increases in larval density had beneficial effects on larval mass but further increases in larval density reduced larval mass. This likely reflects a density-dependent shift between cooperation and competition. In a second experiment, we manipulated larval density and removed parental care. We found that the ability of larvae to penetrate the breeding carcass increased with larval density and that feeding within the carcass resulted in heavier larvae than feeding outside the carcass. However, larval density did not influence carcass decay.The authors were supported by a Consolidator’s Grant from the European Research Council (310785 Baldwinian Beetles). Research was funded by the Natural Environment Research Council, UK (NE/H019731/1), the European Research Council, and the Department of Zoology at the University of Cambridge.This is the final published version. It first appeared at http://onlinelibrary.wiley.com/doi/10.1111/evo.12615/abstract

Using Experimental Evolution to Study Adaptations for Life within the Family.

Parents of many species provision their young, and the extent of parental provisioning constitutes a major component of the offspring's social environment. Thus, a change in parental provisioning can alter selection on offspring, resulting in the coevolution of parental and offspring traits. Although this reasoning is central to our evolutionary understanding of family life, there is little direct evidence that selection by parents causes evolutionary change in their offspring. Here we use experimental evolution to examine how populations of burying beetles adapt to a change in posthatching parental provisioning. We measured the performance of larvae descended from lab populations that had been maintained with and without posthatching parental care (Full Care and No Care populations). We found that adaptation to the absence of posthatching care led to rapid and consistent changes in larval survival in the absence of care. Specifically, larvae from No Care populations had higher survival in the absence of care than larvae from Full Care populations. Other measures of larval performance, such as the ability of larvae to consume a breeding carcass and larval mass at dispersal, did not differ between the Full Care and No Care populations. Nevertheless, our results show that populations can adapt rapidly to a change in the extent of parental care and that experimental evolution can be used to study such adaptation.The authors were supported by a Consolidator’s Grant from the European Research Council (310785 Baldwinian Beetles). Research was funded by the Natural Environment Research Council UK (NE/H019731/1), the European Research Council, and the Department of Zoology at the University of Cambridge.This is the author accepted manuscript. The final version is available from the University of Chicago Press via http://dx.doi.org/10.1086/68050

Dissociation in How Core Autism Features Relate to Interoceptive Dimensions: Evidence from Cardiac Awareness in Children

Interoception in autism is receiving increasing research attention. Previously, differences were identified in autism on both objective and subjective measures of interoception, and an association with anxiety. Yet, it is currently unknown how interoception relates to core autism features. Here, in 49 autistic children, we consider how interoceptive accuracy (measured with heartbeat detection tasks) and sensibility (subjective judgements of awareness) relate to overall severity on the Autism Diagnostic Observation Schedule, and symptom domains of social-affective and repetitive, restricted behaviors. Socio-affective features were related to interoceptive sensibility, while repetitive restricted behaviors were related to interoceptive accuracy. This dissociation suggests disparate interoceptive mechanisms for the formation and/or maintenance of autistic features

Relationship between cardiac cycle and the timing of actions during action execution and observation

Previous research suggests that there may be a relationship between the timing of motor events and phases of the cardiac cycle. This relationship has thus far only been researched using simple isolated movements such as key-presses in reaction-time tasks and only in a single subject acting alone. Other research has shown both movement and cardiac coordination among interacting individuals. Here, we investigated how the cardiac cycle relates to ongoing self-paced movements in both action execution and observation using a novel dyadic paradigm. We recorded electrocardiography (ECG) in 26 subjects who formed 19 dyads containing an action executioner and observer as they performed a self-paced sequence of movements. We demonstrated that heartbeats are timed to movements during both action execution and observation. Specifically, movements were less likely to culminate synchronously with the heartbeat around the time of the R-peak of the ECG. The same pattern was observed for action observation, with the observer's heartbeats occurring off-phase with movement culmination. These findings demonstrate that there is coordination between an action executioner's cardiac cycle and the timing of their movements, and that the same relationship is mirrored in an observer. This suggests that previous findings of interpersonal coordination may be caused by the mirroring of a phasic relationship between movement and the heart

People can identify the likely owner of heartbeats by looking at individuals' faces

For more than a century it has been proposed that visceral and vasomotor changes inside the body influence and reflect our experience of the world. For instance, cardiac rhythms (heartbeats and consequent heart rate) reflect psychophysiological processes that underlie our cognition and affective experience. Yet, considering that we usually infer what others do and feel through vision, whether people can identify the most likely owner of a given bodily rhythm by looking at someone's face remains unknown. To address this, we developed a novel two-alternative forced-choice task in which 120 participants watched videos showing two people side by side and visual feedback from one of the individuals' heartbeats in the centre. Participants' task was to select the owner of the depicted heartbeats. Across five experiments, one replication, and supplementary analyses, the results show that: i) humans can judge the most likely owner of a given sequence of heartbeats significantly above chance levels, ii) that performance in such a task decreases when the visual properties of the faces are altered (inverted, masked, static), and iii) that the difference between the heart rates of the individuals portrayed in our 2AFC task seems to contribute to participants' responses. While we did not disambiguate the type of information used by the participants (e.g., knowledge about appearance and health, visual cues from heartbeats), the current work represents the first step to investigate the possible ability to infer or perceive others' cardiac rhythms. Overall, our novel observations and easily adaptable paradigm may generate hypotheses worth examining in the study of human and social cognition

What We Know Currently about Mirror Neurons.

Mirror neurons were discovered over twenty years ago in the ventral premotor region F5 of the macaque monkey. Since their discovery much has been written about these neurons, both in the scientific literature and in the popular press. They have been proposed to be the neuronal substrate underlying a vast array of different functions. Indeed so much has been written about mirror neurons that last year they were referred to, rightly or wrongly, as "The most hyped concept in neuroscience". Here we try to cut through some of this hyperbole and review what is currently known (and not known) about mirror neurons

Grasp-specific motor resonance is influenced by the visibility of the observed actor

Motor resonance is the modulation of M1 corticospinal excitability induced by observation of others' actions. Recent brain imaging studies have revealed that viewing videos of grasping actions led to a differential activation of the ventral premotor cortex depending on whether the entire person is viewed versus only their disembodied hand. Here we used transcranial magnetic stimulation (TMS) to examine motor evoked potentials (MEPs) in the first dorsal interosseous (FDI) and abductor digiti minimi (ADM) during observation of videos or static images in which a whole person or merely the hand was seen reaching and grasping a peanut (precision grip) or an apple (whole hand grasp). Participants were presented with six visual conditions in which visual stimuli (video vs static image), view (whole person vs hand) and grasp (precision grip vs whole hand grasp) were varied in a 2 × 2 × 2 factorial design. Observing videos, but not static images, of a hand grasping different objects resulted in a grasp-specific interaction, such that FDI and ADM MEPs were differentially modulated depending on the type of grasp being observed (precision grip vs whole hand grasp). This interaction was present when observing the hand acting, but not when observing the whole person acting. Additional experiments revealed that these results were unlikely to be due to the relative size of the hand being observed. Our results suggest that observation of videos rather than static images is critical for motor resonance. Importantly, observing the whole person performing the action abolished the grasp-specific effect, which could be due to a variety of PMv inputs converging on M1

An evolutionary switch from sibling rivalry to sibling cooperation, caused by a sustained loss of parental care.

Sibling rivalry is commonplace within animal families, yet offspring can also work together to promote each other's fitness. Here we show that the extent of parental care can determine whether siblings evolve to compete or to cooperate. Our experiments focus on the burying beetle Nicrophorus vespilloides, which naturally provides variable levels of care to its larvae. We evolved replicate populations of burying beetles under two different regimes of parental care: Some populations were allowed to supply posthatching care to their young (Full Care), while others were not (No Care). After 22 generations of experimental evolution, we found that No Care larvae had evolved to be more cooperative, whereas Full Care larvae were more competitive. Greater levels of cooperation among larvae compensated for the fitness costs caused by parental absence, whereas parental care fully compensated for the fitness costs of sibling rivalry. We dissected the evolutionary mechanisms underlying these responses by measuring indirect genetic effects (IGEs) that occur when different sibling social environments induce the expression of more cooperative (or more competitive) behavior in focal larvae. We found that indirect genetic effects create a tipping point in the evolution of larval social behavior. Once the majority of offspring in a brood start to express cooperative (or competitive) behavior, they induce greater levels of cooperation (or competition) in their siblings. The resulting positive feedback loops rapidly lock larvae into evolving greater levels of cooperation in the absence of parental care and greater levels of rivalry when parents provide care