376 research outputs found
Learning to tie the knot: The acquisition of functional object representations by physical and observational experience
Here we examined neural substrates for physically and observationally learning to construct
novel objects, and characterized brain regions associated with each kind of learning using
fMRI. Each participant was assigned a training partner, and for five consecutive days practiced
tying one group of knots (“tied” condition) or watched their partner tie different knots
(“watched” condition) while a third set of knots remained untrained. Functional MRI was
obtained prior to and immediately following the week of training while participants performed
a visual knot-matching task. After training, a portion of left superior parietal lobule demonstrated
a training by scan session interaction. This means this parietal region responded
selectively to knots that participants had physically learned to tie in the post-training scan
session but not the pre-training scan session. A conjunction analysis on the post-training
scan data showed right intraparietal sulcus and right dorsal premotor cortex to respond
when viewing images of knots from the tied and watched conditions compared to knots that
were untrained during the post-training scan session. This suggests that these brain areas
track both physical and observational learning. Together, the data provide preliminary evidence
of engagement of brain regions associated with hand-object interactions when viewing
objects associated with physical experience, and with observational experience without
concurrent physical practice
The Review of Economic Performance and Social Progress 2001: The Longest Decade: Canada in the 1990s
In this chapter, Kathleen Day and R. Quentin Grafton explore the relationship between the economy and the environment. One approach sees economic growth leading to environmental degradation by imposing stresses on limited natural resources and ecosystems and by increasing emissions of pollutants. A second perspective argues the opposite relationship holds. Economic growth, once a certain level is achieved, leads to a cleaner environment as the higher income shifts societal preferences toward a better quality of the environment and at the same time provides the resources to produce such an environment. In addition, it is argued that economic growth is increasingly service-based, decoupling pollution from economic activity. The authors examine the relationship between economic growth and environmental degradation in Canada. The implication of their findings is that economic growth by no means resolves environmental problems.Growth, Environment, Emissions, Emission, Pollution, Pollutants, Pollutant, Natural Resources, Natural Resource, Non-renewable, Nonrenewable, Renewable
The Review of Economic Performance and Social Progress 2002: Towards a Social Understanding of Productivity
In this chapter, Quentin Grafton, Stephen Knowles and Dorian Owen examine the implications for productivity arising from the level of social diversity along a variety of dimensions, including ethnic, linguistic and religious differences and inequalities between rich and poor. Their basic intuition is that human beings tend to associate and communicate most readily with people similar to themselves, and their hypothesis is therefore that "social divergence" generates social barriers to communication among groups, inhibiting the diffusion of knowledge and lowering the level of productivity in the economy. As a consequence, the more diverse the society and the greater the number of distinct social groups, the higher are the communication costs and the greater are the barriers to the exchange of ideas and innovation.Social Divergence, Social Values, Social Capital, Total Factor Productivity, Multifactor Productivity, Multi-factor Productivity, Fractionalization, Homogeneity, Heterogeneity, Productivity, Labour Productivity, Labor Productivity, Growth, Inequality, Educational Inequality, Networks, Trust, Social Networks, Language, Education, Religion, Social Cohesion, Cohesion
Harm to self outweighs benefit to others in moral decision making
This is the final version. Available from the national Academy of Sciences via the DOI in this record. How we make decisions that have direct consequences for ourselves and others forms the moral foundation of our society. Whereas economic theory contends that humans aim at maximizing their own gains, recent seminal psychological work suggests that our behavior is instead hyperaltruistic: We are more willing to sacrifice gains to spare others from harm than to spare ourselves from harm. To investigate how such egoistic and hyperaltruistic tendencies influence moral decision making, we investigated trade-off decisions combining monetary rewards and painful electric shocks, administered to the participants themselves or an anonymous other. Whereas we replicated the notion of hyperaltruism (i.e., the willingness to forego reward to spare others from harm), we observed strongly egoistic tendencies in participants’ unwillingness to harm themselves for others’ benefit. The moral principle guiding intersubject trade-off decision making observed in our study is best described as egoistically biased altruism, with important implications for our understanding of economic and social interactions in our society
Spatio-Temporal Dynamics of Human Intention Understanding in Temporo-Parietal Cortex: A Combined EEG/fMRI Repetition Suppression Paradigm
Inferring the intentions of other people from their actions recruits an inferior fronto-parietal action observation network as well as a putative social network that includes the posterior superior temporal sulcus (STS). However, the functional dynamics within and among these networks remains unclear. Here we used functional magnetic resonance imaging (fMRI) and high-density electroencephalogram (EEG), with a repetition suppression design, to assess the spatio-temporal dynamics of decoding intentions. Suppression of fMRI activity to the repetition of the same intention was observed in inferior frontal lobe, anterior intraparietal sulcus (aIPS), and right STS. EEG global field power was reduced with repeated intentions at an early (starting at 60 ms) and a later (∼330 ms) period after the onset of a hand-on-object encounter. Source localization during these two intervals involved right STS and aIPS regions highly consistent with RS effects observed with fMRI. These results reveal the dynamic involvement of temporal and parietal networks at multiple stages during the intention decoding and without a strict segregation of intention decoding between these networks
Observing human interaction with physical devices
Previous study has shown that if we observe another person operating a tool or physical device, then the action rule of the observed action is automatically activated and can subsequently facilitate own actions. In this study, the mechanisms responsible for this automatic priming of actions are investigated. In two experiments, the question is raised whether priming arises from the observation of the physical device and its movements, or whether it is modulated by aspects of the person’s behaviour. Whereas experiment 1 shows that priming effects are not influenced by the effector used by the observed person, experiment 2 demonstrates that they are modulated by the handle (and associated action rule) that is used to operate the device. These results suggest that motor resonance mechanisms are sensitive to the specific interaction between movements of an actor and associated movements of a physical device
Transient disruption of M1 during response planning impairs subsequent offline consolidation
Transcranial magnetic stimulation (TMS) was used to probe the involvement of the left primary motor cortex (M1) in the consolidation of a sequencing skill. In particular we asked: (1) if M1 is involved in consolidation of planning processes prior to response execution (2) whether movement preparation and movement execution can undergo consolidation independently and (3) whether sequence consolidation can occur in a stimulus specific manner. TMS was applied to left M1 while subjects prepared left hand sequential finger responses for three different movement sequences, presented in an interleaved fashion. Subjects also trained on three control sequences, where no TMS was applied. Disruption of subsequent consolidation was observed, but only for sequences where subjects had been exposed to TMS during training. Further, reduced consolidation was only observed for movement preparation, not movement execution. We conclude that left M1 is causally involved in the consolidation of effective response planning for left hand movements prior to response execution, and mediates consolidation in a sequence specific manner. These results provide important new insights into the role of M1 in sequential memory consolidation and sequence response planning
First report of generalized face processing difficulties in möbius sequence.
Reverse simulation models of facial expression recognition suggest that we recognize the emotions of others by running implicit motor programmes responsible for the production of that expression. Previous work has tested this theory by examining facial expression recognition in participants with Möbius sequence, a condition characterized by congenital bilateral facial paralysis. However, a mixed pattern of findings has emerged, and it has not yet been tested whether these individuals can imagine facial expressions, a process also hypothesized to be underpinned by proprioceptive feedback from the face. We investigated this issue by examining expression recognition and imagery in six participants with Möbius sequence, and also carried out tests assessing facial identity and object recognition, as well as basic visual processing. While five of the six participants presented with expression recognition impairments, only one was impaired at the imagery of facial expressions. Further, five participants presented with other difficulties in the recognition of facial identity or objects, or in lower-level visual processing. We discuss the implications of our findings for the reverse simulation model, and suggest that facial identity recognition impairments may be more severe in the condition than has previously been noted
The Effect of the Visual Context in the Recognition of Symbolic Gestures
Background: To investigate, by means of fMRI, the influence of the visual environment in the process of symbolic gesture recognition. Emblems are semiotic gestures that use movements or hand postures to symbolically encode and communicate meaning, independently of language. They often require contextual information to be correctly understood. Until now, observation of symbolic gestures was studied against a blank background where the meaning and intentionality of the gesture was not fulfilled. Methodology/Principal Findings: Normal subjects were scanned while observing short videos of an individual performing symbolic gesture with or without the corresponding visual context and the context scenes without gestures. The comparison between gestures regardless of the context demonstrated increased activity in the inferior frontal gyrus, the superior parietal cortex and the temporoparietal junction in the right hemisphere and the precuneus and posterior cingulate bilaterally, while the comparison between context and gestures alone did not recruit any of these regions. Conclusions/Significance: These areas seem to be crucial for the inference of intentions in symbolic gestures observed in their natural context and represent an interrelated network formed by components of the putative human neuron mirro
Conceptual knowledge for understanding other’s actions is organized primarily around action goals
Semantic knowledge about objects entails both knowing how to grasp an object (grip-related knowledge) and what to do with an object (goal-related knowledge). Considerable evidence suggests a hierarchical organization in which specific hand-grips in action execution are most often selected to accomplish a remote action goal. The present study aimed to investigate whether a comparable hierarchical organization of semantic knowledge applies to the recognition of other’s object-directed actions as well. Correctness of either the Grip (hand grip applied to the object) or the Goal (end-location at which an object was directed) were manipulated independently in two experiments. In Experiment 1, subjects were required to attend selectively to either the correctness of the grip or the goal of the observed action. Subjects were faster when attending to the goal of the action and a strong interference of goal-violations was observed when subjects attended to the grip of the action. Importantly, observation of irrelevant goal- or grip-related violations interfered with making decisions about the correctness of the relevant dimension only when the relevant dimension was correct. In contrast, in Experiment 2, when subjects attended to an action-irrelevant stimulus dimension (i.e. orientation of the object), no interference of goal- or grip-related violations was found, ruling out the possibility that interference-effects result from perceptual differences between stimuli. These findings suggest that understanding the correctness of an action selectively recruits specialized, but interacting networks, processing the correctness of goal- and grip-specific information during action observation
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