Deciphering the neural bases of cognitive processing by studying the behavior and brain acitivity
Title: The culturally co-opted mind and brain
Abstract: Reading as a recent cultural invention has not been shaped by evolutionary processes and thus must make use of cognitive systems and brain networks which are either domain-general or have evolved for other purposes. Research on the effect of literacy thus is a powerful tool to investigate how cultural inventions impact on cognition and brain functioning. During my talk, will draw on evidence from both behavioural experiments and neurobiological studies. In the first half of the talk, I will present the results of a series of visual world eye-tracking studies in which we found that illiterates, less proficient young readers, and adults with dyslexia show similar delays in language-mediated anticipatory eye movements. I will discuss potential primary influences of reading that may underlie these effects of literacy on ‘speech prediction’. In the second part of the talk, I will present the results of a longitudinal study with completely illiterate participants, in which we measured brain responses to speech, text, and other categories of visual stimuli with fMRI (as well as resting state activity and structural brain differences) before and after a group of illiterate participants in India completed a literacy training program in which they learned to read and write Devanagari script. A literate and an illiterate no-training control group were matched to the training group in terms of socioeconomic background and were recruited from the same societal community in two villages of a rural area near Lucknow, India. This design permitted investigating effects of literacy cross-sectionally across groups before training (N=86) as well as longitudinally (training group N=25). Our findings crucially complement current neurobiological concepts of normal and impaired literacy acquisition and highlight the need for the inclusion of diverse participant populations in psychological and neurobiological research.
Examination of visual reliance and the exploitation of visual information in old adults’ postural control and navigation abilities
Absctract: Healthy aging is characterized by a decline in many perceptual, cognitive and motor abilities. Although not exacerbated to the point of pathology, such age-related deficits are considered to affect daily living tasks in old adults, ultimately leading to loss of autonomy and health risks, most notably falls. Postural control and safe/successful navigation require the integration of sensory information (visual, vestibular and kinesthetic) that are associated with multiple executive functions (e.g. attention, planning, memory). Sensory signals must be appropriately weighed depending on the environment and motor task difficulty (for example when walking in a crowded setting or on hazardous ground surfaces), in order to maximise their reliability and, consequently, modulate their contribution to postural control for stance and locomotion. Among the factors contributing to daily living risks in old age, some may be associated with a degradation in sensory (re)weighting, leading to a greater reliance on visual cues. Indeed, with old age, there is a greater reliance on visual feedback for postural control, especially with regards to the ground surface (Agathos et al., 2017a). Visual reliance however implies a lack of adaptability (Isableu et al., 2010) and an exploitation of visual cues that may not always be optimal given that old adults are less able to ignore disorienting visual contextual information and to allocate and share visual attention resources (Agathos et al., 2015). Postural control is therefore a greater challenge for old adults whilst in unfamiliar, complex or dynamically changing environments. Faced with such challenges, old adults’ visual reliance leads to postural alterations by adopting more rigid strategies (Agathos et al., 2017b) which can increase fall risk (Barr et al., 2016). In a counter-intuitive fashion, however, old adults are less able to use visual landmarks for reorientation in spatial navigation. Indeed, work in our laboratory has demonstrated that old adults preferentially use geometry to reorient themselves and tend to direct their gaze toward the ground (Bécu et al., 2017). This may be a strategy to minimize the attentional resources required to both explore a visual environment and guide action. Such a strategy can be characterized by old adults’ gaze-postural dynamics during learning and reorienting in a novel ecological environment.
Boris Burle est directeur de recherche CNRS, laboratoire de neurosciences cognitives à l'université d'Aix-Marseille. A Avignon où Sciences et Avenir l'a rencontré, il des mécanismes de contrôle cognitif concernant les erreurs
Après 2013 et 2015, la cinquième édition du Forum du CNRS a eu lieu le 25 et 26 novembre dernier à Paris. Une centaine de chercheurs, venus de toute la France, ont présenté les grandes découvertes de l’année, échangé avec le public sur les applications de demain et débattu sur de grandes problématiques et sujets de société.
Jean-Luc Velay et Jérémy Danna y ont présenté leurs travaux sur la sonification de l’écriture manuscrite dans la présentation « L’écriture bientôt audible »
A cette occasion, Jean-Luc Velay a participé au grand début sur « Les mécanismes de l’apprentissage bientôt dévoilés ».