The mirror neuron system: grasping others’ actions from birth?

In the adult human brain, the presence of a system matching the observation and the execution of actions is well established. This mechanism is thought to rely primarily on the contribution of so-called 'mirror neurons', cells that are active when a specific gesture is executed as well as when it is seen or heard. Despite the wealth of evidence detailing the existence of a mirror neuron system (MNS) in the adult brain, little is known about its normal development. Yet, a better understanding of the MNS in infants would be of considerable theoretical and clinical interest, as dysfunctions within the MNS have been demonstrated in neurodevelopmental disorders such as autism spectrum disorder. Arguments in favor of an innate, or very early, mechanism underlying action understanding mainly come from studies of neonatal imitation, the existence of which has been questioned by some. Here, we review evidence suggesting the presence of an MNS in the human child, as well as work that suggests, although indirectly, the existence of a mechanism matching the perception and the execution of actions in the human newborn.     

Sécurité des patients et développement des recherches : de la loi Bertrand à la loi Jardé

The legislator has successively adopted two laws amending deeply the legal framework of research. The first one is the law “Bertrand” no. 2011-2012 of 29 December 2011 on strengthening the safety of the drug and health products, which emphasizes the need for transparency of links of interest and opens wider opportunities for using post-marketing authorization trials. The second one is the law “Jardé” no. 2012-300 of March 5, 2012 on researches involving the human person, reforming all the rules governing researches and which establishes a national commission of researches involving the human person. If the first one is a clear move towards strengthening the protection of patients in research, it is possible to be more reserved about the effects of the latter, which seems more oriented towards an easing of constraints on researchers.     

Some but not all dispreferred turn markers help to interpret scalar terms in polite contexts

In polite contexts, people find it difficult to perceive whether they can derive scalar inferences from what others say (e.g., does “some people hated your idea” mean that not everyone hated it?). Because this uncertainty can lead to costly misunderstandings, it is important to identify the cues people can rely on to solve their interpretative problem. In this article, we consider two such cues: Making a long Pause before the statement, and prefacing the statement with Well. Data from eight experiments show that Pauses are more effective than Wells as cues to scalar inferences in polite contexts—because they appear to give a specific signal to switch expectations in the direction of bad news, whereas Well appears to give a generic signal to make extra processing effort. We consider the applied value of these findings for human–human and human–machine interaction, as well as their implications for the study of reasoning and discourse.     

People believe each other to be selfish hedonic maximizers

Current computational models of theory of mind typically assume that humans believe each other to selfishly maximize utility, for a conception of utility that makes it indistinguishable from personal gains. We argue that this conception is at odds with established facts about human altruism, as well as the altruism that humans expect from each other. We report two experiments showing that people expect other agents to selfishly maximize their pleasure, even when these other agents behave altruistically. Accordingly, defining utility as pleasure permits us to reconcile the assumption that humans expect each other to selfishly maximize utility with the fact that humans expect each other to behave altruistically.     

Field perspective deficit for positive memories characterizes autobiographical memory in euthymic depressed patients

Research on autobiographical memory (AM) and the ability to retrieve specific autobiographical events in euthymic depressed patients yielded divergent results. The main goal of the present study was to further explore episodic specificity of AM among fully remitted depressed patients. Twenty euthymic depressed patients and 20 matched healthy controls were given a semi-structured interview, which assesses episodic specificity of positive and negative autobiographical memories regarding event and details' specificity, autonoetic consciousness (remember/know procedure) and visual perspective (field/observer procedure). Results showed an impairment of episodic specificity of AM in euthymic depressed patients. This impairment was explained by a field perspective deficit for positive memories only. These results suggest that euthymic patients continue to exhibit discrepancy between their current self and their self for positive past behaviors, which maintains an unfavorable view of their current self. Specific cognitive interventions may improve the self-relevance of their positive memories.     

Eye movements disrupt episodic future thinking

Remembering the past and imagining the future both rely on complex mental imagery. We considered the possibility that constructing a future scene might tap a component of mental imagery that is not as critical for remembering past scenes. Whereas visual imagery plays an important role in remembering the past, we predicted that spatial imagery plays a crucial role in imagining the future. For the purpose of teasing apart the different components underpinning scene construction in the two experiences of recalling episodic memories and shaping novel future events, we used a paradigm that might selectively affect one of these components (i.e., the spatial). Participants performed concurrent eye movements while remembering the past and imagining the future. These concurrent eye movements selectively interfere with spatial imagery, while sparing visual imagery. Eye movements prevented participants from imagining complex and detailed future scenes, but had no comparable effect on the recollection of past scenes. Similarities between remembering the past and imagining the future are coupled with some differences. The present findings uncover another fundamental divergence between the two processes.     

Influence of education on the pattern of cognitive deterioration in AD patients: the cognitive reserve hypothesis

The cognitive reserve hypothesis proposes that a high educational level could delay the clinical expression of Alzheimer's disease (AD) although neuropathologic changes develop in the brain. Therefore, some studies have reported that when the clinical signs of the disease emerge, high-educated patients may decline more rapidly than low-educated patients because the neuropathology is more advanced. However, these studies have only investigated the decline of global cognition or an isolated cognitive process. To study the differential deterioration pattern of several cognitive processes according to education, the performance of 20 AD patients with a high educational level and a low educational level were compared with the performance of 20 control subjects on a neuropsychological battery. The results showed that cognitive deterioration of AD patients is different according to education, although the global performance was similar in AD patients. The high-educated patients exhibited greater impairment of abstract thinking whereas the low-educated patients showed greater impairment of memory and attentional function. This confirms that some cognitive processes, such as abstract thinking, decline more rapidly in high-educated patients whereas others seem to evolve more slowly if compared to low-educated patients. In this latter case, high-educated patients may still benefit from cognitive reserve after the diagnosis of the dementia.     

Cognitive slowing and learning of target detection skills in pre-demented subjects

Alzheimer's disease produces a generalized slowing of cognitive processing increasing with the progression of dementia. However little is known about this phenomenon in the pre-demented stages. Our purpose was to investigate cognitive slowing in pre-demented subjects and their ability to develop target detection skills while performing a cancellation task. The results on 16 pre-demented subjects and 32 matched controls show that cognitive slowing is already present 3 years before subjects fulfill dementia criteria, at a stage where errors are still not different between pre-demented and control subjects. Additionally, the two groups significantly improved their time performances all along the test suggesting that both groups including the pre-demented group were able to progressively acquire a target detection skill.     

Neural substrates of impaired categorical perception of phonemes in adult dyslexics: an fMRI study

Phonological developmental dyslexics remain impaired in phonetic categorical perception (CP) even in adulthood. We studied the brain correlates of CP in dyslexics and controls using a block design fMRI protocol and stimuli from an phonetic continuum between natural /Pa/ and /Ta/ syllables. Subjects performed a pseudo-passive listening task which does not imply voluntary categorical judgment. In the control group, categorical deviant stimuli elicited specific activations in the left angular gyrus, the right inferior frontal gyrus and the right superior cingulate cortex. These regions were not activated in the dyslexic group in which activation was observed for acoustic but not phonetic changes in stimuli. Failures to activate key regions for language perception and auditory attention in dyslexic might account for persistent deficits in phonological awareness and reading tasks.     

Centering on figurative features during the comprehension of sentences describing scenes

Summary Subjects were asked to read sentences which described scenes containing objects. In the scene described in each sentence, a specific part of a particular object was necessarily implied as having an important role. The object was named but none of its parts were. The assumption was that the subjects, while processing the sentence and immediately afterward, would cognitively center on the important part, as a function of the context created by the sentence. Immediately after reading the sentence, the subjects were probed with a picture of either the important part, or of an unimportant part of the object. Judgments of the compatibility of this picture probe with the sentence were faster for pictures of important parts than for pictures of other parts. This was taken as supporting the hypothesis of cognitive centration. In a second experiment, in which words were used as probes instead of pictures, a purely verbal process to account for the results was ruled out. In a third experiment, subjects were given instructions to intentionally form visual images of the scenes described by the sentences. In this case, overall response times to the picture probes were shorter than in the absence of such instructions, but this decrease was greater for pictures of unimportant parts. This finding was interpreted as showing that imagery instructions increase the rate of activation of features to varying degrees as a function of the previous level of activation.