Teleological Reasoning in 4-Month-Old Infants: Pupil Dilations and Contextual Constraints

Four-month-old infants were presented with feeding actions performed in a rational or irrational manner. Infants reacted to the irrational feeding actions by dilating their pupils, but only in the presence of rich contextual constraints. The study demonstrates that teleological processes are online at 4 months of age and illustrates the usefulness of pupil dilations as a measure of social cognitive processes early in infancy

Sense of agency predicts severity of moral judgments

Sense of Agency (SoA) refers to the awareness of being the agent of our own actions. A key feature of SoA relies on the perceived temporal compression between our own actions and their sensory consequences, a phenomenon known as “Intentional Binding.” Prior studies have linked SoA to the sense of responsibility for our own actions. However, it is unclear whether SoA predicts the way we judge the actions of others – including judgments of morally wrong actions like harming others. To address this issue, we ran an on-line pilot experiment where participants underwent two different tasks designed to tap into SoA and moral cognition. SoA was measured using the Intentional Binding task which allowed us to obtain both implicit (Intentional Binding) and explicit (Agency Rating) measures of SoA. Moral cognition was assessed by asking the same participants to evaluate videoclips where an agent could deliberately or inadvertently cause suffering to a victim (Intentional vs. Accidental Harm) compared with Neutral scenarios. Results showed a significant relation between both implicit and explicit measures of SoA and moral evaluation of the Accidental Harm scenarios, with stronger SoA predicting stricter moral judgments. These findings suggest that our capacity to feel in control of our actions predicts the way we judge others’ actions, with stronger feelings of responsibility over our own actions predicting the severity of our moral evaluations of other actions. This was particularly true in ambiguous scenarios characterized by an incongruency between an apparently innocent intention and a negative action outcome

Blocking facial mimicry affects recognition of facial and body expressions

Facial mimicry is commonly defined as the tendency to imitate-at a sub-threshold level-facial expressions of other individuals. Numerous studies support a role of facial mimicry in recognizing others' emotions. However, the underlying functional mechanism is unclear. A prominent hypothesis considers facial mimicry as based on an action-perception loop, leading to the prediction that facial mimicry should be observed only when processing others' facial expressions. Nevertheless, previous studies have also detected facial mimicry during observation of emotional bodily expressions. An emergent alternative hypothesis is that facial mimicry overtly reflects the simulation of an "emotion", rather than the reproduction of a specific observed motor pattern. In the present study, we tested whether blocking mimicry ("Bite") on the lower face disrupted recognition of happy expressions conveyed by either facial or body expressions. In Experiment 1, we tested participants' ability to identify happy, fearful and neutral expressions in the Bite condition and in two control conditions. In Experiment 2, to ensure that such a manipulation selectively affects emotion recognition, we tested participants' ability to recognize emotional expressions, as well as the actors' gender, under the Bite condition and a control condition. Finally, we investigated the relationship between dispositional empathy and emotion recognition under the condition of blocked mimicry. Our findings demonstrated that blocking mimicry on the lower face hindered recognition of happy facial and body expressions, while the recognition of neutral and fearful expressions was not affected by the mimicry manipulation. The mimicry manipulation did not affect the gender discrimination task. Furthermore, the impairment of happy expression recognition correlated with empathic traits. These results support the role of facial mimicry in emotion recognition and suggest that facial mimicry reflects a global sensorimotor simulation of others' emotions rather than a muscle-specific reproduction of an observed motor expression

Attentional Demands of Movement Observation as Tested by a Dual Task Approach

Movement observation (MO) has been shown to activate the motor cortex of the observer as indicated by an increase of corticomotor excitability for muscles involved in the observed actions. Moreover, behavioral work has strongly suggested that this process occurs in a near-automatic manner. Here we further tested this proposal by applying transcranial magnetic stimulation (TMS) when subjects observed how an actor lifted objects of different weights as a single or a dual task. The secondary task was either an auditory discrimination task (experiment 1) or a visual discrimination task (experiment 2). In experiment 1, we found that corticomotor excitability reflected the force requirements indicated in the observed movies (i.e. higher responses when the actor had to apply higher forces). Interestingly, this effect was found irrespective of whether MO was performed as a single or a dual task. By contrast, no such systematic modulations of corticomotor excitability were observed in experiment 2 when visual distracters were present. We conclude that interference effects might arise when MO is performed while competing visual stimuli are present. However, when a secondary task is situated in a different modality, neural responses are in line with the notion that the observers motor system responds in a near-automatic manner. This suggests that MO is a task with very low cognitive demands which might be a valuable supplement for rehabilitation training, particularly, in the acute phase after the incident or in patients suffering from attention deficits. However, it is important to keep in mind that visual distracters might interfere with the neural response in M1

Gradual enhancement of corticomotor excitability during cortico-cortical paired associative stimulation

Cortico-cortical paired associative stimulation (ccPAS) is an effective transcranial magnetic stimulation (TMS) method for inducing associative plasticity between interconnected brain areas in humans. Prior ccPAS studies have focused on protocol’s aftereffects. Here, we investigated physiological changes induced “online” during ccPAS administration. We tested 109 participants receiving ccPAS over left ventral premotor cortex (PMv) and primary motor cortex (M1) using a standard procedure (90 paired-pulses with 8-ms interstimulus interval, repeated at 0.1 Hz frequency). On each paired-pulse, we recorded a motor-evoked potential (MEP) to continuously trace the emergence of corticomotor changes. Participant receiving forward-ccPAS (on each pair, a first TMS pulse was administered over PMv, second over M1, i.e., PMv-to-M1) showed a gradual and linear increase in MEP size that did not reach a plateau at the end of the protocol and was greater in participants with low motor threshold. Participants receiving reverse-ccPAS (i.e., M1-to-PMv) showed a trend toward inhibition. Our study highlights the facilitatory and inhibitory modulations that occur during ccPAS administration and suggest that online MEP monitoring could provide insights into the malleability of the motor system and protocol’s effectiveness. Our findings open interesting prospects about ccPAS potential optimization in experimental and clinical settings

Primary somatosensory cortex necessary for the perception of weight from other people's action: a continuous theta-burst TMS experiment

The presence of a network of areas in the parietal and premotor cortices, which are active both during action execution and observation, suggests that we might understand the actions of other people by activating those motor programs for making similar actions. Although neurophysiological and imaging studies show an involvement of the somatosensory cortex (SI) during action observation and execution, it is unclear whether SI is essential for understanding the somatosensory aspects of observed actions. To address this issue, we used off-line transcranial magnetic continuous theta-burst stimulation (cTBS) just before a weight judgment task. Participants observed the right hand of an actor lifting a box and estimated its relative weight. In counterbalanced sessions, we delivered sham and active cTBS over the hand region of the left SI and, to test anatomical specificity, over the left motor cortex (M1) and the left superior parietal lobule (SPL). Active cTBS over SI, but not over M1 or SPL, impaired task performance relative to sham cTBS. Moreover, active cTBS delivered over SI just before participants were asked to evaluate the weight of a bouncing ball did not alter performance compared to sham cTBS. These findings indicate that SI is critical for extracting somatosensory features (heavy/light) from observed action kinematics and suggest a prominent role of SI in action understanding