Nous sommes un laboratoire de recherche publique situé à Paris spécialisé dans la psychophysique expérimentale et la psychologie développementale de la perception, de l´action, et du langage. Pour plus d’informations sur le LPP cliquez sur les liens à gauche.
Le LPP est une unité mixte Université Paris Descartes – CNRS – ENS. Pour le CNRS, nous sommes rattachés au département des sciences du vivant (section 27)
Notre rapport est disponible ici.
lun29Jan201811hSalle de réunion du LPP, H432, 4ème étage, Centre Biomédical des Saints Pères 45 rue des Sts Pères, 75006 ParisShow details
Brain activations associated with attention to speech and text
In our recent functional magnetic resonance imaging (fMRI) study (Moisala et al., Front. Hum. Neurosci., 2015), young adult participants (N = 18) were presented with concurrent spoken and written sentences and they were to attend to either sentence or to both of them. Dividing attention between the spoken and written sentences was associated with bilateral activity enhancements in dorsolateral and -medial prefrontal areas. These areas showed also smaller activity enhancements during selective attention to speech or text at the presence of task-irrelevant text and speech, respectively, suggesting that dealing with distracting information involves the same brain areas as dividing attention. In our subsequent study applying the same experimental paradigm (Moisala et al., NeuroImage, 2016), we found in healthy adolescents and young adults (N=149) more right prefrontal activity and less accurate performance during attention to speech or text at the presence of irrelevant text or speech, respectively, the more the participants multitasked in their daily life. These results suggest that habitual multitasking may lead to enhanced distractibility. Yet, in another experimental condition (Moisala et al., Brain Res., 2016), the adolescent and young adult participants (N = 167) showed better performance and higher dorsolateral prefrontal activity during a demanding bimodal verbal working-memory task the more they played computer and video games in the daily life, suggesting that computer gaming may enhance attention and memory skills. Moreover, comparison of results from these attention and working-memory studies (Moisala et al., submitted) suggests development of prefrontal executive functions during adolescence. In our very recent study (Leminen et al., in preparation), we investigate selective attention to speech in more naturalistic conditions where the participants see the facial movements of speakers attended selectively at the presence of irrelevant speech on the background. According to our preliminary results, higher activity is observed in superior temporal and inferior parietal areas for higher quality of attended speech (natural vs. noise-vocoded speech) and for more perceivable speech-related facial movements (non-masked vs. masked). Moreover, right superior parietal and dorsolateral prefrontal areas show higher activity for lower speech quality suggesting enhanced demand for attention.
lun05Fév201811hSalle de réunion du LPP, H432, 4ème étage, Centre Biomédical des Saints Pères 45 rue des Sts Pères, 75006 ParisShow details
Prefrontal neuronal circuits controlling emotional behavior
When facing danger, mammals display a broad range of fear behavior ranging from active (avoidance) to passive (freezing) fear responses. The canonical model of fear circuits posits that the basolateral amygdala directly controls fear responses through projections to the brainstem. Using state of the art behavioral, electrophysiological and optogenetic manipulations we provide evidence challenging this view. Our results indicate that (i) specific cell populations within the medial prefrontal cortex support different coding strategy for fear behavior and (ii) that specific manipulation of prefrontal neurons projecting to the brainstem directly regulate conditioned fear responses.
Invited by Vision Team
lun12Fév201811hSalle de réunion du LPP, H432, 4ème étage, Centre Biomédical des Saints Pères 45 rue des Sts Pères, 75006 ParisShow details
Automaticity and attentional control in neural language processing
A long-standing debate in the science of language is whether our capacity to process language draws on attentional resources, or whether some stages or types of this processing may be automatic. I will present a series of experiments in which this issue was addressed by removing attention to linguistic stimuli or by modulating the level of attention on the language input while recording brain activity. The overall results of these studies show that the language function does possess a certain degree of automaticity, which seems to apply to different types of information including lexical access, semantic processing, syntactic parsing and even acquisition of new lexemes. Furthermore, such an automaticity appears to exist in both auditory speech perception and visual processing of written words. It can be explained, at least in part, by robustness of strongly connected linguistic memory circuits in the brain that can activate fully even when attentional resources are low. At the same time, this automaticity is limited to the very first stages of linguistic processing (<200 msec from the point in time when the relevant information is available in the input, e.g. word recognition point). Later processing steps are, in turn, more affected by attention modulation and possibly reflect a more in-depth, secondary processing or re-analysis of input, dependant on the amount of resources allocated. The results will be discussed in the framework of distributed neural circuits which function as memory traces for language elements in the human brain.
Invited by Speech Team