Core knowledge of geometry can develop independently of visual experience

• Published in: Cognition 2021-07, Vol.212, p.104716-104716, Article 104716
• Main Authors: Heimler, Benedetta, Behor, Tomer, Dehaene, Stanislas, Izard, Véronique, Amedi, Amir
• Format: Article
• Language: English
• Subjects: Adults; Blindness; Cognition; Cognition & reasoning; Cognitive science; Core-knowledge; Geometric selection; Geometry; Haptics; Preschool children; Psychology; Spatial exploration; Spatial reasoning; Symmetry; Tactile stimuli
• ISSN: 0010-0277; 1873-7838
• DOI: 10.1016/j.cognition.2021.104716

Geometrical intuitions spontaneously drive visuo-spatial reasoning in human adults, children and animals. Is their emergence intrinsically linked to visual experience, or does it reflect a core property of cognition shared across sensory modalities? To address this question, we tested the sensitivity of blind-from-birth adults to geometrical-invariants using a haptic deviant-figure detection task. Blind participants spontaneously used many geometric concepts such as parallelism, right angles and geometrical shapes to detect intruders in haptic displays, but experienced difficulties with symmetry and complex spatial transformations. Across items, their performance was highly correlated with that of sighted adults performing the same task in touch (blindfolded) and in vision, as well as with the performances of uneducated preschoolers and Amazonian adults. Our results support the existence of an amodal core-system of geometry that arises independently of visual experience. However, performance at selecting geometric intruders was generally higher in the visual compared to the haptic modality, suggesting that sensory-specific spatial experience may play a role in refining the properties of this core-system of geometry. •Is being a geometry-thinker limited to vision or does it extend to touch?•We showed haptic-driven geometry reasoning in blind without any visual experience.•Comparable results were also found in sighted blindfolded participants.•Haptic and visual geometric selections were highly correlated.•These results hint to the existence of a core-system of geometry shared by senses.