The task-switching paradigm is widely used to examine the processes involved in changing between tasks. Trials in which a switch is required routinely show longer reaction times, possibly due to an extended preparation process or an additional process specific to switching. Previous research suggests that an additional process is required but has not shown this decisively. The current study addresses this issue using a novel task-switching design which includes a switch condition that does not allow task preparation. Additionally, a novel multivariate pattern misclassification analysis EEG data is employed. The results show that two processes are involved in switching, an early frontal process particular to switching and a later general readiness process with a parietal topography.

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Both humans and animals can estimate quantities without counting, but humans additionally use symbolic mathematics to count and perform mathematical operations. It has been proposed that these different abilities rely on two systems: the approximate number system (ANS) and a symbolic mathematical one. In this study authors assessed the accuracy of each participant on the magnitude estimation of numbers and cumulative areas. Both number and cumulative area estimation correlated with the performances obtained in a battery of standardized math tests (controlled for general intelligence). Accuracy in number estimation specifically correlated with arithmetic competence, whereas cumulative area precision covaried with geometry skills. These results indicate partial overlap and interaction between the symbolic mathematical and the nonsymbolic systems.

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Premotor circuits help generate imitative behaviors and can be activated during observation of another animal's behavior. It is possible that these circuits participate in sensory learning that is important to imitation. Here authors tested this hypothesis by focally manipulating the brain activity of juvenile zebra finches, which learn to sing by memorizing and vocally copying the song of an adult tutor. Tutor song-contingent optogenetic or electrical disruption of neural activity in the pupil?s song premotor nucleus HVC prevented song copying, indicating that a premotor structure important to the temporal control of birdsong also helps encode the tutor song. These findings provide evidence that premotor circuits help encode sensory information about the behavioral model before shaping and executing imitative behaviors.

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Languages around the world share striking similarities. According to the functional approach, grammatical structures that facilitate communication are more likely to prevail cross-linguistically. The question of how the functional pressures shape grammar over time remains unknown. In two artificial language learning experiments, the authors explored the possibility that functional pressures operate during language acquisition, biasing learners to deviate from the input they receive. Their results support the hypothesis that some of the structural similarities found in natural languages are shaped by biases toward improvement in communicative efficiency.

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When you see a picture of a hand, how do you know whether it's a right or left hand? The "hand laterality task" was used for the first time more than 30 years ago and it's still adopted in order to study sensory-motor simulation processes. It has been hypothesized that we imagine each of our own hands moving towards the displayed hand in order to judge its laterality. In the present study authors controlled for the position of participants' hands and suggested, based on reaction times, that visual processing interacts with proprioceptive awareness to solve the "hand laterality task". The novel multisensory account for this cognitive skill will be discussed in the Journal Club.

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Interactions between the hippocampus and neocortex during sleep have been proposed to be crucial for memory consolidation but its causal role has not yet been demonstrated. In this paper the authors hypothesized that if hippocampal replay drives memory consolidation, presenting a sensory cue during non-REM sleep should bias this replay towards the previous experience associated with the cue. Rats were trained on an auditory-spatial association task while recording from neuronal ensembles in the hippocampus. During sleep, a task-related auditory cue biased reactivation events towards replaying the spatial memory associated with that cue. These results indicate that sleep replay can be manipulated by external stimulation and provide further evidence for the role of hippocampal replay in memory consolidation.

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The study asks whether the evolution of facial recognition in wasps is associated with specialized face-learning abilities. The paper wasp (Polistes fuscatus) lives in multiple queen social groups and is able to differentiate among individuals based on varying facial markings. This ability could be due to a specialized evolution of face learning to match their highly social environment or to a well-developed form of pattern recognition. To discriminate among these hypotheses, this study compared the facial learning ability in P. fuscatus to that in a related species, P. metricus, which nests singly. P. fuscatus wasps learned faces much more accurately than they did with non-face (or manipulated face) images. Instead, P. metricus wasps were unable to learn faces, despite the fact that both species were able to differentiate equally among images of prey or patterns. The results support the hypothesis of co-evolution of social behavior and face recognition in P. fuscatus.

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The paper presents the analysis of the pupil dilation during a standard attentional blink task in which the participants had to identify zero, one or two temporally close objects. Even though in the raw data the pupillary response to the first event can obscure the response to a second event (or the expectation of a subsequent event, in case they closely follow each other), a deconvolution analysis enables discrimination of temporally close responses. This kind of analysis can be combined with neuroimaging techniques to relate behavioral and physiological data, especially in the field of attention.

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This study investigates the neural substrates of the 'sense of agency', i.e., the experience of controlling one's own actions, and, through them, events in the outside world. Many studies so far have investigated sense of agency as a 'retrospective' phenomenon: after performing an action, one can say 'I did that' if the predictions of the consequences of that action and the actual outcomes match.
Instead, the authors of this study sought for a 'prospective' component of sense of agency that is independent of the outcome of the action and accordingly relies more on an online monitoring of the action selection processing. The results show for the first time that sense of agency is prospectively informed by action selection processes. This evidence highlights the importance of online monitoring processes in generating sensations of volition and conscious free will.

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The amygdala is implicated in fear- and emotion-related processing. In the current study, however, the authors employed electrophysiological recording in patients with epilepsy to show a response selectivity for pictures of animals in the right amygdala, regardless of emotional valence. This right-lateralized effect is consistent with the hypothesis that the right hemisphere is specialized in responding to unexpected and behaviorally relevant stimuli. This evidence also corroborates the view that the brain processes animals differently from other stimulus categories, possibly due to their biological relevance.

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This study aimed at investigating the neural circuit dynamics of working memory decision tasks. Authors studied the activity in the posterior parietal cortex by means of optical imaging, while mice performed a task that combined a perceptual decision and memory-guided navigation in a virtual environment. Results show that individual neurons had transient activation staggered relative to one another in time, suggesting that neurons develop time specificity during performance of the task. Distinct sequences of neurons were triggered on trials with opposite behavioral choices. This evidence is important for understanding the link between perceptual decision making and working memory-based response selection.

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The interest of the paper if twofold. Firstly, it proposes an alternative model for a very well known empirical effect, namely the Mismatch Negativity (MMN), that until now was accounted for as a passive habituation process (May and Titiinen, 2010). Authors propose that this effect instead results from an active prediction mechanism. The model is based upon neurophysiological mechanisms and captures several key features of the MMN. Secondly, relevant predictions build on two very recent theoretical ideas concerning the Bayesian optimal predictive coding, i.e. that information is compressed so that only prediction errors are coded, and that the predictions are formally equivalent to a Bayesian coding. This is probably the first realistic model fleshing out recent theoretical ideas (Friston, 2005).

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Reading deficits affect about 10% of children and it would be very desirable to identify predictors of dyslexia in prereader children, since special training programs can antagonize the disorder. In this longitudinal study authors addressed the performance of a large group of children in cognitive tasks related to reading. Results show that children who developed reading deficits during the first two years of primary school already showed visuo-spatial attention deficits during preschool tests. The evidence has both theoretical and applied significance concerning the development of reading skills.

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The emotional signal conveyed by human tears is well-known, yet it is unclear whether their functional significance goes beyond the mimicry associated to sad emotional states. Inspired by the recent finding that mice tears contain chemosignals modulating social behavior, this study investigates this issue in humans. The authors show in a series of psychophysiological, behavioral and functional magnetic resonance experiments a remarkably consistent pattern of results which suggests that human tears contain chemosignals able to modulate behavior. In particular, exposure to tears taken from female donors was associated with reduced sexual arousal, testosterone levels, and hemodynamic activation of the hypothalamus (among other areas) in male participants. This evidence suggests a previously undocumented chemical function of tears.

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In the past 30 years, the "two visual streams hypothesis" ("what" pathway vs. "where/how" pathway) has been very influential for research and theories about visual processing. Goodale and Milner (1992) reported the case of DF, who showed a striking dissociation on visual processing related to perception and action. Although recent findings challenged the theory, the case of patient DF remained a strong support for the two visual streams hypothesis. In this article, the author could demonstrate that patient DF did not show dissociation between perception and action when she could not rely on somatosensory feedback during the task evaluation. The finding highlights the relevance of the multimodal nature of the sensory control of action. This evidence calls for an alternative account of visual processing, which emphasizes early interstream interactions.

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It is debated to what extent the hippocampus contributes to memory retrieval over time. In this study authors used novel techniques to reversibly inactivate glutamatergic neurons in region CA1 of the hippocampus in mice. Authors found that the hippocampus is the default activator of memory traces for recent as well as remote memories, but also found that the brain can compensate its inactivation under certain conditions. Thanks to the novel insight offered by cutting/edge technologies, this paper advances the field with a set of clear results and mechanistic explanations of previous findings in light of the evidence found.

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The article describes a thorough investigation on the functions of a frontal cortical region in the rat brain involved in orienting and response planning. Results suggest that this area participates in functions subserved by the frontal eye fields in primates. The paper was selected because the clear evidence obtained is relevant for understanding the mechanisms supported by the frontal cortex in rodents.

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