Magnitude processing of symbolic and non-symbolic proportions: an fMRI study

Abstract

BackgroundRecent research indicates that processing proportion magnitude is associated with activation in the intraparietal sulcus. Thus, brain areas associated with the processing of numbers (i.e., absolute magnitude) were activated during processing symbolic fractions as well as non-symbolic proportions. Here, we investigated systematically the cognitive processing of symbolic (e.g., fractions and decimals) and non-symbolic proportions (e.g., dot patterns and pie charts) in a two-stage procedure. First, we investigated relative magnitude-related activations of proportion processing. Second, we evaluated whether symbolic and non-symbolic proportions share common neural substrates.MethodsWe conducted an fMRI study using magnitude comparison tasks with symbolic and non-symbolic proportions, respectively. As an indicator for magnitude-related processing of proportions, the distance effect was evaluated.ResultsA conjunction analysis indicated joint activation of specific occipito-parietal areas including right intraparietal sulcus (IPS) during proportion magnitude processing. More specifically, results indicate that the IPS, which is commonly associated with absolute magnitude processing, is involved in processing relative magnitude information as well, irrespective of symbolic or non-symbolic presentation format. However, we also found distinct activation patterns for the magnitude processing of the different presentation formats.ConclusionOur findings suggest that processing for the separate presentation formats is not only associated with magnitude manipulations in the IPS, but also increasing demands on executive functions and strategy use associated with frontal brain regions as well as visual attention and encoding in occipital regions. Thus, the magnitude processing of proportions may not exclusively reflect processing of number magnitude information but also rather domain-general processes.

The Relational SNARC: Spatial Representation of Nonsymbolic Ratios

“…First, the current study provides further evidence for the human ratio processing abilities and extends the present understanding of its operation. Participants performed quickly and accurately on a perceptually based task comparing nonsymbolic ratio magnitudes, adding to recent work demonstrating human perceptual sensitivity to nonsymbolic ratio magnitudes in various formats (e.g., Bonn & Cantlon, ; Duffy, Huttenlocher, & Levine, ; Jacob et al, ; Lewis, Matthews, & Hubbard, ; Matthews et al, ; Mock et al, ; see also Spence, ; Stevens & Galanter, ; Hollands & Dyre, ). This stands alongside recent work showing that this ratio perception is in some respects automatic (Fabbri, Caviola, Tang, Zorzi, & Butterworth, ; Matthews & Lewis, ; Yang, Hu, Wu, & Yang, ) and that humans seem to represent nonsymbolic ratio magnitudes as specific values instead of as nondescript generalized magnitudes less than one (Matthews & Chesney, ; Matthews & Lewis, ; but see Kallai & Tzelgov, ).…”

Symbolic fractions elicit an analog magnitude representation in school-age children

“…These limitations preclude directly testing for the presence of distance effects across notations. Mock et al (2018) demonstrated distance effects for both symbolic and several types of non-symbolic ratio stimuli in adults, but the range of distances between stimuli was limited, and the stimulus set had a higher frequency of lowdistance items, which limited the possibility of making inferences about distance effects. To address these limitations, Binzak et al (2019) developed a cross-notation magnitude comparison paradigm (symbolic fractions, non-symbolic line ratios and mixed symbolic-non-symbolic pairs) to measure distance effects within the same group of adults, with numerical distance carefully counterbalanced across notation conditions.…”

Mental Shopping Calculations: A Transcranial Magnetic Stimulation Study

“…While it is still unknown what subdivision of this network is the most critical for mental arithmetic, there is some agreement that such an area should be located in the posterior parietal cortex (PPC) on the left (Dehaene et al, 2004;Nieder, 2005). However, recent studies also suggest that the right PPC may exert some role in such mental operations too (Arsalidou and Taylor, 2011;Knops and Willmes, 2014;Sokolowski et al, 2017;Mock et al, 2018). Indeed, there is evidence that the more difficult/complex the arithmetic task, the more profound the engagement of the right PPC (Fehr et al, 2008;Hamid et al, 2011;Vansteensel et al, 2014;Klichowski and Kroliczak, 2017;Mock et al, 2018;cf.…”

“…Thereby, one cannot assume that in the case of sale price calculations the role of the right SMG will be the same as in the case of multi-digit mental addition or subtraction (Montefinese et al, 2017). In fact, operating on familiar numbers that are often seen on shop labels (e.g., −50% or −25%) -even though they are multi-digit, and therefore, complex -may not require right-hemisphere resources such as visual working memory to the extent than does operating on unfamiliar numbers (which put greater load on memory capacity, and consequently, require critical engagement of right SMG; Rosenberg-Lee et al, 2011;Bloechle et al, 2016;Nemati et al, 2017;Mock et al, 2018). Therefore, we hypothesized that the right, as compared to left SMG, might be less critical for calculations of sale prices characteristic for consumers' daily behavior.…”