Mental Shopping Calculations: A Transcranial Magnetic Stimulation Study

Abstract

One of the most critical skills behind consumer's behavior is the ability to assess whether a price after a discount is a real bargain. Yet, the neural underpinnings and cognitive mechanisms associated with such a skill are largely unknown. While there is general agreement that the posterior parietal cortex (PPC) on the left is critical for mental calculations, and there is also recent repetitive transcranial magnetic stimulation (rTMS) evidence pointing to the supramarginal gyrus (SMG) of the right PPC as crucial for consumer-like arithmetic (e.g., multi-digit mental addition or subtraction), it is still unknown whether SMG is involved in calculations of sale prices. Here, we show that the neural mechanisms underlying discount arithmetic characteristic for shopping are different from complex addition or subtraction, with discount calculations engaging left SMG more. We obtained these outcomes by remodeling our laboratory to resemble a shop and asking participants to calculate prices after discounts (e.g., $8.80-25 or $4.80-75%), while stimulating left and right SMG with neuronavigated rTMS. Our results indicate that such complex shopping calculations as establishing the price after a discount involve SMG asymmetrically, whereas simpler calculations such as price addition do not. These findings have some consequences for neural models of mathematical cognition and shed some preliminary light on potential consumer's behavior in natural settings.

Physical Activity With Eduball Stimulates Graphomotor Skills in Primary School Students

“…It seems that using Eduball in the classroom would also require a miniaturization of these educational balls. We are currently developing a prototype of this type of mini-Eduball (the size of a tennis ball), which, by integrating cognitive activity with fine motor tasks, can offer even greater benefits than “big” Eduballs, as neural correlates of fine motor skills are much more closely related to language or numeracy neural circuits, compared to neural underpinnings of gross motor abilities ( Bidula et al, 2017 ; Klichowski and Kroliczak, 2017 , 2020 ; Przybylski and Kroliczak, 2017 ; Styrkowiec et al, 2019 ; Klichowski et al, 2020 ; Kroliczak et al, 2020 ; for the most recent evidences, see Kroliczak et al, 2021 ).…”

Corticospinal Excitability During a Perspective Taking Task as Measured by TMS-induced Motor Evoked Potentials

“…We suspect that a further use may be in terms of efficiency, though we admit this is speculative. We believe that testing other paradigms; in particular those that simulate 'real-life' situations (Klichowski & Kroliczak, 2020) such as knowing what another driver sees vs. what one sees would be a valuable line of investigation. Future studies should also examine the associate priming (Werner, von Ramin, Spruyt, & Rothermund, 2018) and we believe that a well-designed study could tease out both (the ecological significance and the degree of semantic or associative priming the two tasks have).…”

Corticospinal Excitability during a Perspective Taking Task as Measured by TMS-Induced Motor Evoked Potentials

“…We suspect that a further use may be in terms of efficiency, though we admit this is speculative. We believe that testing other paradigms, in particular those that simulate “real-life” situations [ 113 ], such as knowing what another driver sees vs. what one sees, would be a valuable line of investigation. Future studies should also examine the associate priming [ 114 ], and we believe that a well-designed study could tease out both the ecological significance and the degree of semantic or associative priming the two tasks have.…”