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  • Is It What You Do, or When You Do It? The Roles of Contingency and Similarity in Pro-Social Effects of Imitation

    28 November 2017

    Being imitated has a wide range of pro-social effects, but it is not clear how these effects are mediated. Naturalistic studies of the effects of being imitated have not established whether pro-social outcomes are due to the similarity and/or the contingency between the movements performed by the actor and those of the imitator. Similarity is often assumed to be the active ingredient, but we hypothesized that contingency might also be important, as it produces positive affect in infants and can be detected by phylogenetically ancient mechanisms of associative learning. We manipulated similarity and contingency between performed and observed actions in a computerized task. Similarity had no positive effects; however, contingency resulted in greater enjoyment of the task, reported closeness to others, and helping behavior. These results suggest that the pro-social effects of being imitated may rely on associative mechanisms. © 2013 Cognitive Science Society, Inc.

  • Imitation: Thoughts about theories

    5 December 2017

    © Cambridge University Press 2007 and Cambridge University Press, 2009. Many behavioural features and psychological states can be transmitted between natural systems. A person or animal can acquire through observation of another a tendency to go to the same place, effect the same transformation of an object, perform the same body movements, make the same sounds, feel similar emotions or think similar thoughts. In our discussion of imitation we will focus on cases in which body movements are transmitted or ‘copied’ between model and observer, because these cases present a distinctive explanatory challenge. The problem of producing a movement that matches one observed is made difficult due to the nature of the codes representing the observed and executed movements. The observer must formulate motor commands to match visual input. This is a special case of what has become known as the ‘correspondence problem’ (Alissandrakis et al., 2002; Nehaniv and Dautenhahn, 2001), and it is made particularly difficult when simple perceptual matching cannot be used to produce imitative movements, as in the following example. A tennis coach demonstrates a serve to a novice, which the novice then attempts to imitate. If the novice successfully imitates the coach's action the two actions will not ‘match’ from the novice's perspective. The novice will perceive the coach's actions as a whole body movement, in which the back arches and one arm moves in an overhead arc.

  • Automaticity in Stimulus-Parity Synaesthesia.

    12 December 2017

    Automaticity is a defining characteristic of synaesthesia. Here, we assess for automaticity in stimulus-parity synaesthesia; a subtype that has been documented only 3 times in the literature. Synaesthete R experiences many (nonnumerical) stimuli as being odd or even. She described a toy shape-sorter, which paired odd shapes with even colour slots (and vice versa) and relayed difficulties with the incongruency created by this simple toy. Inspired by this anecdote, we devised a computerised task in which Synaesthete R (and 10 control participants) indicated the location of a target shape, which was presented on a coloured bar. Synaesthete R (but not control participants) was faster to report the location of target shapes presented on colours of congruent synaesthetic parity, relative to target shapes presented on colours of incongruent synaesthetic parity. These results constitute the first objective demonstration as to the automatic nature of associations in stimulus-parity synaesthesia.

  • Differential optimal dopamine levels for set-shifting and working memory in Parkinson's disease.

    6 December 2017

    Parkinson's disease (PD) is an important model for the role of dopamine in supporting human cognition. However, despite the uniformity of midbrain dopamine depletion only some patients experience cognitive impairment. The neurocognitive mechanisms of this heterogeneity remain unclear. A genetic polymorphism in the catechol O-methyltransferase (COMT) enzyme, predominantly thought to exert its cognitive effect through acting on prefrontal cortex (PFC) dopamine transmission, provides us with an experimental window onto dopamine's role in cognitive performance in PD. In a large cohort of PD patients (n=372), we examined the association between COMT genotype and two tasks known to implicate prefrontal dopamine (spatial working memory and attentional set-shifting) and on a task less sensitive to prefrontal dopamine (paired associates learning). Consistent with the known neuroanatomical locus of its effects, differences between the COMT genotype groups were observed on dopamine-dependant tasks, but not the paired associates learning task. However, COMT genotype had differential effects on the two prefrontal dopamine tasks. Putative prefrontal dopamine levels influenced spatial working memory in an 'Inverted-U'-shaped fashion, whereas a linear, dose-dependant pattern was observed for attentional set-shifting. Cumulatively, these results revise our understanding of when COMT genotype modulates cognitive functioning in PD patients by showing that the behavioural consequences of genetic variation vary according to task demands, presumably because set-shifting and working memory have different optimal dopamine levels.

  • ‘Naltrexone Blocks Endorphins Released when Dancing in Synchrony’

    6 December 2017

    © 2017, The Author(s). Group synchronised dance is hypothesised to activate the Endogenous Opioid System (EOS), thereby increasing pain threshold, and encouraging social closeness. Previous studies have been limited to the use of pain threshold as a proxy indicator of EOS activation. We conducted a double-blind administration of placebo and naltrexone (an endorphin antagonist) before groups of strangers danced in synchrony and measured both pain threshold and sense of belonging to the group after dancing. A 100 mg dose of naltrexone resulted in significant hyperalgesic effects compared to the control participants, confirming that increases in pain threshold in the control group are due to activation of the EOS and release of endorphins during synchronised dancing. However, there was no significant effect of treatment on perceptions of social closeness. Social bonding during dance may plausibly be underpinned by elements of the EOS not blocked by naltrexone and/or interactions with other neurohormones and socio-cognitive mechanisms.

  • Memory in 3-month-old infants benefits from a short nap.

    7 December 2017

    A broad range of studies demonstrate that sleep has a facilitating role in memory consolidation (see Rasch & Born, ). Whether sleep-dependent memory consolidation is also apparent in infants in their first few months of life has not been investigated. We demonstrate that 3-month-old infants only remember a cartoon face approximately 1.5-2 hours after its first presentation when a period of sleep followed learning. Furthermore, habituation time, that is, the time to become bored with a stimulus shown repetitively, correlated negatively with the density of infant sleep spindles, implying that processing speed is linked to specific electroencephalographic components of sleep. Our findings show that without a short period of sleep infants have problems remembering a newly seen face, that sleep enhances memory consolidation from a very early age, highlighting the importance of napping in infancy, and that infant sleep spindles may be associated with some aspects of cognitive ability.

  • Development of physical problem-solving competences in human infants and corvids

    27 October 2017

    © 2016 IEEE. Humans, other animals, and artificial systems solve problems posed by their physical environment. Biological agents start with a flexible cognitive architecture but limited abilities, and acquire competences by different combinations of maturation, growth and experience (both social and individual), and some designers of artificial systems try to emulate such processes. By examining the processes leading to the construction of competence in biological agents we hope to inspire and support ideas relevant to the design of intelligent agents in the future. Here we report a study of the emergence of physical problem-solving in human infants aged 15 to 24 months and in both tool-using and non-tool-using corvids. One goal is to examine whether tool-using competence was indicative of general physical intelligence, in which case tool using agents should show greater competence both in tool-related and non-tool related tasks. Another is to test whether in these disparate organisms, experience with combining objects in contexts other than functional tool use (e.g. play) can causally facilitate the emergence of tool use competence. We used a battery of tasks including tool vs. non-tool dependent extractions of target objects. All subjects were initially exposed to a mixture of objects and allowed to interact freely with them. Preliminary results show that while there are strong inter-species differences in tool-related competence, we found no major differences in tasks where tools were not involved. There were strong individual differences within each species, but age effects were only found in human infants, reflecting differences in life-history: Although crows can live for several decades, they reach adulthood (including asymptotic competence in many indices) much faster than humans. From a robotics perspective, the differences reveal available choices regarding the tradeoff of learning vs. performing, or exploration vs. exploitation of skills. The relation between object combinations and individual performance at the tool tasks is still under analysis.

  • The potential of real-time fMRI neurofeedback for stroke rehabilitation: A systematic review.

    1 December 2017

    Real-time functional magnetic resonance imaging (rt-fMRI) neurofeedback aids the modulation of neural functions by training self-regulation of brain activity through operant conditioning. This technique has been applied to treat several neurodevelopmental and neuropsychiatric disorders, but its effectiveness for stroke rehabilitation has not been examined yet. Here, we systematically review the effectiveness of rt-fMRI neurofeedback training in modulating motor and cognitive processes that are often impaired after stroke. Based on predefined search criteria, we selected and examined 33 rt-fMRI neurofeedback studies, including 651 healthy individuals and 15 stroke patients in total. The results of our systematic review suggest that rt-fMRI neurofeedback training can lead to a learned modulation of brain signals, with associated changes at both the neural and the behavioural level. However, more research is needed to establish how its use can be optimized in the context of stroke rehabilitation.