Brown bag du 15/10/2018 André Knops, LaPsyDÉ, CNRS & Université Paris Descartes



One circuit to rule them all? On the interaction between the approximate number system and spatial attention during numerical cognition

Parietal cortex hosts two cognitive systems that have been found to be of pivotal importance during numerical cognition. Areas around the intraparietal sulcus (IPS) have been thought to be crucially involved in the perception of numerical information. The hosted cognitive system, called approximate number system (ANS), allows humans to extract a numerical approximation from sensory input. Posterior superior parietal cortex (PSPL) hosts an attentional system that is crucially involved in the planning of eye movements and providing a retinotopic map of the visual field.
In this presentation I will first delineate the parietal mechanisms underlying numerosity perception – both within and outside the subitizing range. In particular, I will present evidence that suggests that we flexibly use attentional resources in posterior parietal areas during the estimation of numerical magnitude. I will also provide results that challenge the idea that the IPS hosts a modality (e.g. auditory vs. visual) or mode (i.e. sequential vs. simultaneous) independent instantiation of the ANS. A second question is how domain-general functions such as (verbal or spatial) working memory and spatial attention contribute to basic arithmetic functions. Third, I will present evidence against the idea that numerical magnitude is automatically extracted from non-consciously perceived visual input.
Together, these lines of evidence suggest that attention is a crucial player in numerical cognition at various levels. Yet, the interaction between PSPL and IPS is far from providing an exhaustive framework for how numerical cognition is neurally implemented.