The Anterior Cingulate Gyrus Signals the Net Value of Others' Rewards

Evaluating the costs and benefits of our own choices is central to most forms of decision-making and its mechanisms in the brain are becoming increasingly well understood. To interact successfully in social environments, it is also essential to monitor the rewards that others receive. Previous studies in nonhuman primates have found neurons in the anterior cingulate cortex (ACC) that signal the net value (benefit minus cost) of rewards that will be received oneself and also neurons that signal when a reward will be received by someone else. However, little is understood about the way in which the human brain engages in cost-benefit analyses during social interactions. Does the ACC signal the net value (the benefits minus the costs) of rewards that others will receive? Here, using fMRI, we examined activity time locked to cues that signaled the anticipated reward magnitude (benefit) to be gained and the level of effort (cost) to be incurred either by a subject themselves or by a social confederate. We investigated whether activity in the ACC covaries with the net value of rewards that someone else will receive when that person is required to exert effort for the reward. We show that, although activation in the sulcus of the ACC signaled the costs on all trials, gyral ACC (ACC(g)) activity varied parametrically only with the net value of rewards gained by others. These results suggest that the ACC(g) plays an important role in signaling cost-benefit information by signaling the value of others' rewards during social interactions

Vicarious Reinforcement Learning Signals When Instructing Others

Reinforcement learning (RL) theory posits that learning is driven by discrepancies between the predicted and actual outcomes of actions (prediction errors [PEs]). In social environments, learning is often guided by similar RL mechanisms. For example, teachers monitor the actions of students and provide feedback to them. This feedback evokes PEs in students that guide their learning. We report the first study that investigates the neural mechanisms that underpin RL signals in the brain of a teacher. Neurons in the anterior cingulate cortex (ACC) signal PEs when learning from the outcomes of one's own actions but also signal information when outcomes are received by others. Does a teacher's ACC signal PEs when monitoring a student's learning? Using fMRI, we studied brain activity in human subjects (teachers) as they taught a confederate (student) action–outcome associations by providing positive or negative feedback. We examined activity time-locked to the students' responses, when teachers infer student predictions and know actual outcomes. We fitted a RL-based computational model to the behavior of the student to characterize their learning, and examined whether a teacher's ACC signals when a student's predictions are wrong. In line with our hypothesis, activity in the teacher's ACC covaried with the PE values in the model. Additionally, activity in the teacher's insula and ventromedial prefrontal cortex covaried with the predicted value according to the student. Our findings highlight that the ACC signals PEs vicariously for others' erroneous predictions, when monitoring and instructing their learning. These results suggest that RL mechanisms, processed vicariously, may underpin and facilitate teaching behaviors

Uncovering the neurophysiology of mood, motivation and behavioral symptoms in Parkinson’s disease through intracranial recordings

Neuropsychiatric mood and motivation symptoms (depression, anxiety, apathy, impulse control disorders) in Parkinson’s disease (PD) are highly disabling, difficult to treat and exacerbated by current medications and deep brain stimulation therapies. High-resolution intracranial recording techniques have the potential to undercover the network dysfunction and cognitive processes that drive these symptoms, towards a principled re-tuning of circuits. We highlight intracranial recording as a valuable tool for mapping and desegregating neural networks and their contribution to mood, motivation and behavioral symptoms, via the ability to dissect multiplexed overlapping spatial and temporal neural components. This technique can be powerfully combined with behavioral paradigms and emerging computational techniques to model underlying latent behavioral states. We review the literature of intracranial recording studies investigating mood, motivation and behavioral symptomatology with reference to 1) emotional processing, 2) executive control 3) subjective valuation (reward & cost evaluation) 4) motor control and 5) learning and updating. This reveals associations between different frequency specific network activities and underlying cognitive processes of reward decision making and action control. If validated, these signals represent potential computational biomarkers of motivational and behavioural states and could lead to principled therapy development for mood, motivation and behavioral symptoms in PD

Anterior Cingulate Cortex: Contributions to Social Cognition

It has been suggested that the Anterior Cingulate Cortex (ACC) plays an important role in decision-making. Activity in this area reflects processing related to two principles of Reinforcement Learning Theory (RLT): (i) signalling the predicted value of actions at the time they are instructed and (ii) signalling prediction errors at the time of the outcomes of actions. It has been suggested that neurons in the gyrus of the ACC (ACCg) process information about others’ decisions and not one’s own. An important aim of this thesis is to investigate whether the ACCg processes others’ decisions in a manner that conforms to the principles of RLT. Four fMRI experiments investigate activity in the ACCg at the time of cues that signal either the predicted value of others’ actions or that signal another’s predictions are erroneous. • Experiment 1: Activity in the ACCg occurred when the outcome of another’s decision was unexpectedly positive. • Experiment 2: Activity in the ACCg varied parametrically with the discrepancy between another’s prediction of an outcome and the actual outcome known by the subject, in a manner that conformed to the computational principles of RLT. • Experiment 3: Activity in the ACCg varied with the predicted value of a reward, discounted by the amount of effort required to obtain it. • Experiment 4: Activity in the ACCg varied with the value of delayed rewards that were discounted in a manner that conformed to a social norm. These results support the hypothesis that the ACCg processes the predicted value of others’ actions and also signals when others’ predictions about the value of their actions are erroneous, in a manner that conforms to the principles of RLT

Electrophysiological Mapping of Novel Prefrontal – Cerebellar Pathways

Whilst the cerebellum is predominantly considered a sensorimotor control structure, accumulating evidence suggests that it may also subserve non-motor functions during cognition. However, this possibility is not universally accepted, not least because the nature and pattern of links between higher cortical structures and the cerebellum are poorly characterized. We have therefore used in vivo electrophysiological methods in anaesthetized rats to directly investigate connectivity between the medial prefrontal cortex (prelimbic subdivision, PrL) and the cerebellum. Stimulation of deep layers of PrL evoked distinct field potentials in the cerebellar cortex with a mean latency to peak of approximately 35 ms. These responses showed a well-defined topography, and were maximal in lobule VII of the contralateral vermis (a known oculomotor centre); they were not attenuated by local anaesthesia of the overlying M2 motor cortex, though M2 stimulation did evoke field potentials in lobule VII with a shorter latency (approximately 30 ms). Single unit recordings showed that prelimbic cortical stimulation elicits complex spikes in lobule VII Purkinje cells, indicating transmission via a previously undescribed cerebro-olivocerebellar pathway. Our results therefore establish a physiological basis for communication between PrL and the cerebellum. The role(s) of this pathway remain to be resolved, but presumably relate to control of eye movements and/or distributed networks associated with integrated prefrontal cortical functions

Plasticity in Unimodal and Multimodal Brain Areas Reflects Multisensory Changes in Self-Face Identification

Nothing provides as strong a sense of self as seeing one's face. Nevertheless, it remains unknown how the brain processes the sense of self during the multisensory experience of looking at one's face in a mirror. Synchronized visuo-tactile stimulation on one's own and another's face, an experience that is akin to looking in the mirror but seeing another's face, causes the illusory experience of ownership over the other person's face and changes in self-recognition. Here, we investigate the neural correlates of this enfacement illusion using fMRI. We examine activity in the human brain as participants experience tactile stimulation delivered to their face, while observing either temporally synchronous or asynchronous tactile stimulation delivered to another's face on either a specularly congruent or incongruent location. Activity in the multisensory right temporo-parietal junction, intraparietal sulcus, and the unimodal inferior occipital gyrus showed an interaction between the synchronicity and the congruency of the stimulation and varied with the self-reported strength of the illusory experience, which was recorded after each stimulation block. Our results highlight the important interplay between unimodal and multimodal information processing for self-face recognition, and elucidate the neurobiological basis for the plasticity required for identifying with our continuously changing visual appearanc

M2K: I. A Jovian mass planet around the M3V star HIP79431

Doppler observations from Keck Observatory reveal the presence of a planet with Msini of 2.1 Mjup orbiting the M3V star HIP79431. This is the sixth giant planet to be detected in Doppler surveys of M dwarfs and it is one of the most massive planets discovered around an M dwarf star. The planet has an orbital period of 111.7 days and an orbital eccentricity of 0.29. The host star is metal rich, with an estimated [Fe/H] = +0.4. This is the first planet to emerge from our new survey of 1600 M-to-K dwarf stars.Comment: 5 figure

Neural and Cognitive Signatures of Guilt Predict Hypocritical Blame

A common form of moral hypocrisy occurs when people blame others for moral violations that they themselves commit. It is assumed that hypocritical blamers act in this manner to falsely signal that they hold moral standards that they do not really accept. We tested this assumption by investigating the neurocognitive processes of hypocritical blamers during moral decision-making. Participants (62 adult UK residents; 27 males) underwent functional MRI scanning while deciding whether to profit by inflicting pain on others and then judged the blameworthiness of others’ identical decisions. Observers (188 adult U.S. residents; 125 males) judged participants who blamed others for making the same harmful choice to be hypocritical, immoral, and untrustworthy. However, analyzing hypocritical blamers’ behaviors and neural responses shows that hypocritical blame was positively correlated with conflicted feelings, neural responses to moral standards, and guilt-related neural responses. These findings demonstrate that hypocritical blamers may hold the moral standards that they apply to others.<br/

Neural mechanisms for learning self and other ownership

The sense of ownership – of which objects belong to us and which to others - is an important part of our lives, but how the brain keeps track of ownership is poorly understood. Here, the authors show that specific brain areas are involved in ownership acquisition for the self, friends, and strangers