Protocol to examine the neural basis of symbolic and non-symbolic quantity processing in human brain with fMRI.

Number perception is among the basic cognitive abilities necessary to understand our environment. Here, we present a protocol to examine the neural underpinnings of numerosity comparison regarding symbolic and non-symbolic stimuli using functional magnetic resonance imaging (fMRI). This protocol gives instructions for screening participants, followed by steps to perform an event-related fMRI experiment and data analysis with SPM12. This protocol will be informative for investigating numerical cognition in various groups including children with dyscalculia or people at different developmental stages. For complete details on the use and execution of this protocol, please refer to Üstün et al. (2021) and Vatansever et al. (2020).

Development of Sensory Sensitivity Scales (SeSS): Reliability and validity analyses.

BACKGROUND: Although adults are known to have sensory sensitivity differences, existing sensitivity scales have been mostly developed for children. The limited number of adult scales measure social/emotional features and modalities together. AIMS: To develop scales for adults that evaluate visual, auditory and somatosensory sensitivities as separate domains and independent of social/emotional features. METHODS AND PROCEDURES: Two consecutive studies (visual-auditory part and somatosensory part) were conducted using the same methods. Both studies included a pilot (n1 = 405 and n2 = 294) and a main group (n1 = 425 and n2 = 603). An exploratory factor analysis produced a single-factor solution for the visual and auditory domains and a three-factor solution for the somatosensory domain (touch, pain, and itch) of Sensory Sensitivity Scales. OUTCOMES AND RESULTS: A confirmatory factor analysis revealed good construct validity in the the visual (CFI = .973, TLI = .965, and RMSEA = .075) auditory (CFI = .943, TLI = .927, and RMSEA = .074) and somatosensory (CFI = .955, TLI = .946, and RMSEA = .048) scales. The categories were internally consistent (αv = .86, αa = .79, αs = .69). As an indicator of convergent validity, higher autistic traits were related to higher sensitivity (rs-v = .17, rs-a = .25, rs-s = .14). CONCLUSIONS AND IMPLICATIONS: Sensory Sensitivity Scales (SeSS) can be used to screen sensory sensitivity variability or identify and follow up the outcome of sensory interventions in adults.

Developmental alterations of the numerical processing networks in the brain.

Neuroimaging studies revealed that number perception is mainly located in parietal cortex. Although controversial, it was suggested that number is processed in the frontal lobe in childhood and in the parietal cortex in adulthood. The purpose of this study is to investigate developmental differences in the neural correlates of number representation with fMRI. Sixteen healthy young adults (age:21.69 ± 0.79) and 15 healthy children (age:11.87 ± 0.52) performed a numerosity comparison paradigm which consists of two numerical conditions with two difficulty levels. Adults showed broad parietal cortex activation, as well as activation in the inferior parietal lobes, dorsolateral and medial prefrontal cortex, anterior and posterior cingulate cortex, and peristriate cortex (PC) during number processing. Children showed activations in the intraparietal sulcus and PC. Group differences were observed in the posterior insula, fusiform gyrus, and PC whose coordinates correspond to the number form area (NFA). Region of interest analysis was performed for these clusters to get the time series of hemodynamic responses which were estimated with a finite impulse response function. In contrast to the prominent frontoparietal shift theory, no age-related differences were observed in the frontoparietal regions. Overall, the presented study suggests developmental changes in the brain's number processing revolving around the NFA.