TY - JOUR
T1 - On the indicators for perceiving empty sets as zero
AU - Zaks-Ohayon, Rut
AU - Pinhas, Michal
AU - Tzelgov, Joseph
N1 - Publisher Copyright:
© 2020 The Author(s)
PY - 2021/2
Y1 - 2021/2
N2 - The question whether human beings process empty sets as zero has received little research attention. In this study, we used the distance and end effects as indicators for treating empty sets as a numerical entity that represents an absence of quantity. In a series of experiments, participants performed a magnitude comparison task. They were presented with empty sets and other numerosities from 1 to 9, presented as dot arrays. We manipulated task instructions relevant to the target (i.e., “choose the target that contains more/less dots” in Experiment 1) or the given numerical range mentioned in the instructions (i.e., 0–9 or 1–9 in Experiment 2) to create conditions in which an empty set would be perceived as the smallest value of the experimental numerical range. The results revealed distance effects for comparisons to empty sets, irrespective of task instructions. In Experiment 3, we manipulated the response mode. Two groups of participants responded to target location, one group with a key-press and the other vocally, while the third group responded vocally to target color. The results revealed distance effects for comparisons to empty sets only when responding to target location, regardless of the response mode, indicating that spatial features should be primed in order to perceive an empty set as a numerical entity. These findings show that perceiving an empty set as nothing or as zero depends on the context in which it is presented.
AB - The question whether human beings process empty sets as zero has received little research attention. In this study, we used the distance and end effects as indicators for treating empty sets as a numerical entity that represents an absence of quantity. In a series of experiments, participants performed a magnitude comparison task. They were presented with empty sets and other numerosities from 1 to 9, presented as dot arrays. We manipulated task instructions relevant to the target (i.e., “choose the target that contains more/less dots” in Experiment 1) or the given numerical range mentioned in the instructions (i.e., 0–9 or 1–9 in Experiment 2) to create conditions in which an empty set would be perceived as the smallest value of the experimental numerical range. The results revealed distance effects for comparisons to empty sets, irrespective of task instructions. In Experiment 3, we manipulated the response mode. Two groups of participants responded to target location, one group with a key-press and the other vocally, while the third group responded vocally to target color. The results revealed distance effects for comparisons to empty sets only when responding to target location, regardless of the response mode, indicating that spatial features should be primed in order to perceive an empty set as a numerical entity. These findings show that perceiving an empty set as nothing or as zero depends on the context in which it is presented.
KW - An empty set
KW - Distance effect
KW - End effect
KW - Magnitude comparison
KW - Nonsymbolic number representation
KW - Zero
UR - http://www.scopus.com/inward/record.url?scp=85099523804&partnerID=8YFLogxK
U2 - 10.1016/j.actpsy.2020.103237
DO - 10.1016/j.actpsy.2020.103237
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C2 - 33360323
AN - SCOPUS:85099523804
SN - 0001-6918
VL - 213
JO - Acta Psychologica
JF - Acta Psychologica
M1 - 103237
ER -