Responses of the human motor system to observing actions across species: A transcranial magnetic stimulation study

Ample evidence suggests that the role of the mirror neuron system (MNS) in monkeys is to represent the meaning of actions. The MNS becomes active in monkeys during execution, observation, and auditory experience of meaningful, object-oriented actions, suggesting that these cells represent the same action based on a variety of cues. The present study sought to determine whether the human motor system, part of the putative human MNS, similarly represents and reflects the meaning of actions rather than simply the mechanics of the actions. To this end, transcranial magnetic stimulation (TMS) of primary motor cortex was used to generate motor-evoked potentials (MEPs) from muscles involved in grasping while participants viewed object-oriented grasping actions performed by either a human, an elephant, a rat, or a body-less robotic arm. The analysis of MEP amplitudes suggested that activity in primary motor cortex during action observation was greatest during observation of the grasping actions of the rat and elephant, and smallest for the human and robotic arm. Based on these data, we conclude that the human action observation system can represent actions executed by non-human animals and shows sensitivity to species-specific differences in action mechanics.     

Moderating effects of the valence of social interaction on the dysfunctional consequences of perseverative cognition: an ecological study in major depression and social anxiety disorder

Background and Objectives: Major depression disorder (MDD) and social anxiety disorder (SAD) are characterized by the use of perseverative cognition (PC) as a dysfunctional coping strategy. We sought to investigate the dysfunctional physiological and psychological consequences of PC and how the valence of social interactions moderates such consequences in these psychopathological conditions.

Design/Methods: The study combined 24-hour heart rate variability (HRV) and ecological momentary assessments in 48 individuals with MDD, SAD, and sex-matched controls.

Results: In all participants, PC was associated with mood worsening and reduced ability of the parasympathetic nervous system, mainly the vagus, to inhibit sympathetic arousal (i.e., reduced HRV). Individuals with SAD had the highest frequency of daily PC, while those with MDD reported that PC interfered more with their ongoing activities. In SAD, daily PC was associated with significantly lower HRV after negative social interactions. Individuals with MDD reported higher levels of sadness during PC irrespective of the valence of the preceding social interaction but higher levels of anxiety and efforts to inhibit PC following positive interactions.

Conclusions: Results highlight the need to account for important moderators like the valence of social interaction when looking at the physiological consequences of maladaptive emotion regulation strategies.     

‘Please sort these voice recordings into 2 identities’: Effects of task instructions on performance in voice sorting studies

We investigated the effects of two types of task instructions on performance on a voice sorting task by listeners who were either familiar or unfamiliar with the voices. Listeners were asked to sort 15 naturally varying stimuli from two voice identities into perceived identities. Half of the listeners sorted the recordings freely into as many identities as they perceived; the other half were forced to sort stimuli into two identities only. As reported in previous studies, unfamiliar listeners formed more clusters than familiar listeners. Listeners therefore perceived different naturally varying stimuli from the same identity as coming from different identities, while being highly accurate at telling apart the stimuli from different voices. We further show that a change in task instructions – forcing listeners to sort stimuli into two identities only – helped unfamiliar listeners to overcome this selective failure at ‘telling people together’. This improvement, however, came at the cost of an increase in errors in telling people apart. For familiar listeners, similar non-significant trends were apparent. Therefore, even when informed about correct number of identities, listeners may fail to accurately perceive identity further highlighting that voice identity perception in the context of natural within-person variability is a challenging task. We discuss our results in terms of similarities and differences to findings in the face perception literature and their importance in applied settings, such as forensic voice identification.     

Learning From Gesture and Action: An Investigation of Memory for Where Objects Went and How They Got There

Speakers often use gesture to demonstrate how to perform actions—for example, they might show how to open the top of a jar by making a twisting motion above the jar. Yet it is unclear whether listeners learn as much from seeing such gestures as they learn from seeing actions that physically change the position of objects (i.e., actually opening the jar). Here, we examined participants' implicit and explicit understanding about a series of movements that demonstrated how to move a set of objects. The movements were either shown with actions that physically relocated each object or with gestures that represented the relocation without touching the objects. Further, the end location that was indicated for each object covaried with whether the object was grasped with one or two hands. We found that memory for the end location of each object was better after seeing the physical relocation of the objects, that is, after seeing action, than after seeing gesture, regardless of whether speech was absent (Experiment 1) or present (Experiment 2). However, gesture and action built similar implicit understanding of how a particular handgrasp corresponded with a particular end location. Although gestures miss the benefit of showing the end state of objects that have been acted upon, the data show that gestures are as good as action in building knowledge of how to perform an action.     

Is emotion regulation associated with cancer-related psychological symptoms?

Objectives: This study examined the cross-sectional and prospective relationships between subjective (cognitive reappraisal, expressive suppression and experiential avoidance) and objective (high-frequency heart rate variability [HF-HRV]) measures of emotion regulation (ER) and a set of psychological symptoms (anxiety, depression, fear of cancer recurrence [FCR], insomnia, fatigue, pain, and cognitive impairments) among women receiving radiation therapy for non-metastatic breast cancer.

Design: Eighty-one participants completed a battery of self-report scales within 10 days before the start of radiotherapy (T1) and within 10 days after its end (T2; approximately 6 weeks after T1). HF-HRV at rest was measured at T1.

Results: Canonical correlation analyses revealed that higher levels of experiential avoidance and expressive suppression were cross-sectionally associated with higher levels of all symptoms, except pain, at T1 and at T2 (both p’s?<?0.0001). Higher levels of suppression and reappraisal at T1 were marginally associated with reduced FCR and with increased depression and fatigue between T1 and T2 (p?=?0.07). HF-HRV was not associated with symptoms cross-sectionally or prospectively.

Conclusions: Although preliminary, these results are consistent with the hypothesis that maladaptive ER strategies, assessed subjectively, may cross-sectionally act as a transdiagnostic mechanism underlying several cancer-related psychological symptoms.     

Visual variability affects early verb learning

Research demonstrates that within‐category visual variability facilitates noun learning; however, the effect of visual variability on verb learning is unknown. We habituated 24‐month‐old children to a novel verb paired with an animated star‐shaped actor. Across multiple trials, children saw either a single action from an action category (identical actions condition, for example, travelling while repeatedly changing into a circle shape) or multiple actions from that action category (variable actions condition, for example, travelling while changing into a circle shape, then a square shape, then a triangle shape). Four test trials followed habituation. One paired the habituated verb with a new action from the habituated category (e.g., ‘dacking’ + pentagon shape) and one with a completely novel action (e.g., ‘dacking’ + leg movement). The others paired a new verb with a new same‐category action (e.g., ‘keefing’ + pentagon shape), or a completely novel category action (e.g., ‘keefing’ + leg movement). Although all children discriminated novel verb/action pairs, children in the identical actions condition discriminated trials that included the completely novel verb, while children in the variable actions condition discriminated the out‐of‐category action. These data suggest that – as in noun learning – visual variability affects verb learning and children's ability to form action categories.     

A non‐representational approach to imagined action

This study addresses the dynamical nature of a “representation‐hungry” cognitive task involving an imagined action. In our experiment, participants were handed rods that systematically increased or decreased in length on subsequent trials. Participants were asked to judge whether or not they thought they could reach for a distant object with the hand‐held rod. The results are in agreement with a dynamical model, extended from Tuller, Case, Ding, and Kelso (1994). The dynamical effects observed in this study suggest that predictive judgments regarding the possibility or impossibility of a certain action can be understood in terms of dynamically evolving basins of attraction instead of as depending on representational structures.     

A foundation beam for studying morality from a personological point of view: Are individual differences in moral behaviors and thoughts consistent?

Morality is a topic of burgeoning scientific interest, and the relevance of personological factors to moral behavior has interdisciplinary implications for the social sciences, public policy, and philosophy. However, relatively little research has investigated the role of personological factors in moral life, perhaps because of lingering skepticism about the robustness of moral traits. The purpose of this paper is to determine whether morality is consistent across many occasions of everyday life, implying that personological factors play an important role in moral behavior. A novel method of assessing moral behaviors was developed and employed in two experience sampling studies (4075 total observations). Results showed that moral behavior is consistent in many different ways, suggesting that personological factors substantially impact moral life.     

A Bayesian hierarchical diffusion model decomposition of performance in Approach–Avoidance Tasks

Common methods for analysing response time (RT) tasks, frequently used across different disciplines of psychology, suffer from a number of limitations such as the failure to directly measure the underlying latent processes of interest and the inability to take into account the uncertainty associated with each individual's point estimate of performance. Here, we discuss a Bayesian hierarchical diffusion model and apply it to RT data. This model allows researchers to decompose performance into meaningful psychological processes and to account optimally for individual differences and commonalities, even with relatively sparse data. We highlight the advantages of the Bayesian hierarchical diffusion model decomposition by applying it to performance on Approach–Avoidance Tasks, widely used in the emotion and psychopathology literature. Model fits for two experimental data-sets demonstrate that the model performs well. The Bayesian hierarchical diffusion model overcomes important limitations of current analysis procedures and provides deeper insight in latent psychological processes of interest.