Automatic imitation? Imitative compatibility affects responses at high perceptual load.

Imitation involves matching the visual representation of another’s action onto the observer’s own motor program for that action. However, there has been some debate regarding the extent to which imitation is “automatic” – i.e., occurs without attention. Participants performed a perceptual load task in which images of finger movements were presented as distractors. Responses to target letter stimuli were performed via finger movements which could be imitatively compatible (requiring the same finger movement), or incompatible, with the distractor movements: in this common stimulus-response compatibility manipulation, the stimulus set comprises images of the response movements, producing an imitative compatibility effect. Attention to the distractor movements was manipulated by altering perceptual load through increasing the number of non-target letter stimuli. If imitation requires attention, then at high perceptual load, imitative compatibility should not affect response times. In contrast, imitative compatibility influenced response times at high perceptual load, demonstrating that distractor movements were processed. However, the compatibility effect was reversed, suggesting that longer response times at high perceptual load tap into an inhibitory stage of distractor movement processing. A follow-up experiment manipulating temporal delay between targets and distractor movements supported this explanation. Further experiments confirmed that non-movement distractor stimuli in the same configuration produced standard perceptual load effects, and that results were not solely due to effector compatibility. These data suggest that imitation can occur without attention

The specificity of the link between alexithymia, interoception and imitation

Alexithymia is a subclinical condition traditionally characterized by difficulties identifying and describing one’s own emotions. Recent formulations of alexithymia, however, suggest that the condition may result from a generalized impairment in the perception of all bodily signals (“interoception”). Interoceptive accuracy has been associated with a variety of deficits in social cognition, but recently with an improved ability to inhibit the automatic tendency to imitate the actions of others. The current study tested the consequences for social cognition of the hypothesized association between alexithymia and impaired interoception by examining the relationship between alexithymia and the ability to inhibit imitation. If alexithymia is best characterized as a general interoceptive impairment, then one would predict that alexithymia would have the same relationship with the ability to control imitation as does interoceptive accuracy. Forty-three healthy adults completed measures of alexithymia, imitation-inhibition, and as a control, inhibition of nonimitative spatial compatibility. Results revealed the predicted relationship, such that increasing alexithymia was associated with an improved ability to inhibit imitation, and that this relationship was specific to imitation-inhibition. These results support the characterization of alexithymia as a general interoceptive impairment and shed light on the social ability of alexithymic individuals—with implications for the multitude of psychiatric, neurological, and neurodevelopmental disorders associated with high rates of alexithymia

The imitation game:effects of social cues on ‘imitation’ are domain-general in nature

AbstractImitation has been hailed as ‘social glue’, facilitating rapport with others. Previous studies suggest that social cues modulate imitation but the mechanism of such modulation remains underspecified. Here we examine the locus, specificity, and neural basis of the social control of imitation. Social cues (group membership and eye gaze) were manipulated during an imitation task in which imitative and spatial compatibility could be measured independently. Participants were faster to perform compatible compared to incompatible movements in both spatial and imitative domains. However, only spatial compatibility was modulated by social cues: an interaction between group membership and eye gaze revealed more spatial compatibility for ingroup members with direct gaze and outgroup members with averted gaze. The fMRI data were consistent with this finding. Regions associated with the control of imitative responding (temporoparietal junction, inferior frontal gyrus) were more active during imitatively incompatible compared to imitatively compatible trials. However, this activity was not modulated by social cues. On the contrary, an interaction between group, gaze and spatial compatibility was found in the dorsolateral prefrontal cortex in a pattern consistent with reaction times. This region may be exerting control over the motor system to modulate response inhibition

Mirror neuron brain regions contribute to identifying actions, but not intentions

Previous studies have struggled to determine the relationship between mirror neuron brain regions and two distinct “action understanding” processes: identifying actions and identifying the intentions underlying those actions. This may be because the identification of intentions from others' actions requires an initial action identification process. Disruptive transcranial magnetic stimulation was administered to left inferior frontal gyrus (lIFG) during a novel cognitive task to determine which of these “action understanding” processes is subserved by mirror neuron brain regions. Participants identified either the actions performed by observed hand actions or the intentions underlying those actions. The extent to which intention identification was disrupted by lIFG (vs. control site) stimulation was dependent on the level of disruption to action identification. We subsequently performed functional magnetic resonance imaging during the same task. During action identification, responses were widespread within mirror neuron areas including lIFG and inferior parietal lobule. However, no independent responses were found in mirror neuron brain regions during intention identification. Instead, responses occurred in brain regions associated with two distinct mentalizing localizer tasks. This supports an account in which mirror neuron brain regions are involved in an initial action identification process, but the subsequent identification of intentions requires additional processing in mentalizing brain regions

Theory of mind is not theory of emotion:A cautionary note on the Reading the Mind in the Eyes Test

The ability to represent mental states (theory of mind [ToM]) is crucial in understanding individual differences in social ability and social impairments evident in conditions such as autism spectrum disorder (ASD). The Reading the Mind in the Eyes Test (RMET) is a popular measure of ToM ability, validated in part by the poor performance of those with ASD. However, the RMET requires recognition of facial emotion, which is impaired in those with alexithymia, which frequently co-occurs with ASD. Thus, it is unclear whether the RMET indexes emotion recognition, associated with alexithymia, or ToM, associated with ASD. We therefore investigated the independent contributions of ASD and alexithymia to performance on the RMET. ASD and alexithymia-matched control participants did not differ on RMET performance, whereas ASD participants demonstrated impaired performance on an alternative test of ToM, the Movie for Assessment of Social Cognition (MASC). Furthermore, alexithymia, but not ASD diagnosis, significantly influenced RMET performance but did not affect MASC performance. These results suggest that the RMET measures emotion recognition rather than ToM ability and support the alexithymia hypothesis of emotion-related deficits in ASD

No evidence for a common self-bias across cognitive domains

It is generally acknowledged that humans have an egocentric bias; processing self-related stimuli in a specialised, preferential manner. The self-bias has been studied within cognitive domains such as memory, attention and perception; but never across cognitive domains in order to assess whether self-biases are a product of a common bias, or independent. This has relevance for conditions such as Autism Spectrum Disorder: certain self-biases are reduced in those with autism, but the pattern of results is not consistent across different cognitive domains. Self-bias was measured across the attentional and perceptual domains on two well-established tasks: the attentional blink (attention) and shape-label matching (perception) tasks. Processing of each participant's own name was compared to processing of the name of another individual very familiar to the participant (to control for familiarity), and the name of an unfamiliar other. In the attentional domain, the attentional blink for the participant's own name was reduced compared to that for the name of a familiar or unfamiliar other. In the perceptual domain, participants showed stronger associations between their own name and a geometric shape than between the other classes of names and associated shapes. Thus, strong evidence of a self-bias, independent of familiarity, was found on both tasks. However, across two experiments, the magnitude of the self-bias on the attentional blink and shape-label matching tasks was not correlated, supporting the idea that self-biases across cognitive domains are distinct. Furthermore, in contrast with extant models, neither type of self-bias was predicted by autistic traits

Investigating the sense of agency and its relation to subclinical traits using a novel task

Tasks measuring the sense of agency often manipulate the predictability of action outcomes by introducing spatial deviation. However, the extent to which spatial predictability of an outcome influences the sense of agency when spatial deviation is controlled for remains untested. We used a novel task to investigate the effect of several factors (action–outcome contingency, spatial deviation, and spatial predictability when controlling for spatial deviation of action outcomes) on the sense of agency. We also investigated trait predictors of metacognition of agency—the degree to which participants’ confidence in their agency judgements corresponds to the accuracy of those judgements. Initial and replication samples completed contingency, deviation, and predictability versions of the task. Across samples, participants’ sense of agency was impacted by action–outcome contingency and spatial deviation of action outcomes. Manipulation of the spatial predictability of action outcomes did not reliably impact the sense of agency. Metacognition of agency was related to alexithymic traits—higher alexithymia scores were associated with reduced metacognition of agency

The 20 item prosopagnosia index (PI20):relationship with the Glasgow face-matching test

The 20 item prosopagnosia index (PI20) was recently developed to identify individuals with developmental prosopagnosia. While the PI20’s principal purpose is to aid researchers and clinicians, it was suggested that it may serve as a useful screening tool to identify people with face recognition difficulties in applied settings where face matching is a critical part of their occupation. Although the PI20 has been validated using behavioural measures of face recognition, it has yet to be validated against a measure of face-matching ability that is more representative of applied settings. In this study, the PI20 was therefore administered with the Glasgow face-matching test (GFMT). A strong correlation was observed between PI20 and GFMT scores, providing further validation for the PI20, indicating that it is likely to be of value in applied settings

Crossmodal classification of mu rhythm activity during action observation and execution suggests specificity to somatosensory features of actions.

The alpha mu rhythm (8-13 Hz) has been considered to reflect mirror neuron activity due to the fact that it is attenuated by both action observation and action execution. The putative link between mirror neuron system activity and the mu rhythm has been used to study the involvement of the mirror system in a wide range of socio-cognitive processes and clinical disorders. However, previous research has failed to convincingly demonstrate the specificity of the mu rhythm, meaning that it is unclear whether the mu rhythm reflects mirror neuron activity. It also remains unclear if mu rhythm suppression during action observation reflects the processing of motor or tactile information. In an attempt to assess the validity of the mu rhythm as a measure of mirror neuron activity, we used crossmodal pattern classification to assess the specificity of EEG mu rhythm response to action varying in terms of action type (whole-hand or precision grip), concurrent tactile stimulation (stimulation or no stimulation), or object use (transitive or intransitive actions) in twenty human participants. The main results reveal that above-chance crossmodal classification of mu rhythm activity was obtained in the central channels for tactile stimulation and action transitivity but not for action type. Furthermore, traditional univariate analyses applied to the same data were insensitive to differences between conditions. By calling into question the relationship between mirror system activity and the mu rhythm, these results have important implications for the use and interpretation of mu rhythm activity