Subitizing is the ability to appraise a number of small quantities(up to four)rapidly and precisely.This system,however,can be impaired by distractors presented along with targets to be enumerated.To better understand...Subitizing is the ability to appraise a number of small quantities(up to four)rapidly and precisely.This system,however,can be impaired by distractors presented along with targets to be enumerated.To better understand whether this limitation arises in perceptual circuits or in the response selection stage,we investigated whether subitizing can endure in simultaneous comparison tasks.Participants were asked to compare the number of dots in two sets on the left and right sides of the screen,presented either simultaneously or sequentially.For comparing within the numerosity range(6-32 dots),both the error rate and reaction time increased steadily as the ratio between the two numbers compared approached“1.”Namely,a phenomenon labeled the ratio effect was revealed.For comparison with small numbers(<5),the sequential comparison task was errorless despite the ratio,suggesting the feature of subitizing.Individual efficiency(measured by the inverse efficiency score[IES])did not correlate between number ranges in sequential comparison,suggesting that distinct mechanisms were involved.However,we found that in simultaneous tasks,error rate and efficiency showed an increase as the ratios of the two numbers compared approached“1.”This is similar to the ratio effect revealed in the comparison for moderate numbers.Individual efficiency within these two ranges correlated,indicating that the enumeration within these two ranges was based on a single mechanism.These results suggest that subitizing cannot process sets in parallel,and numerosity takes the job whenever subitizing fails.展开更多
基金supported by the Funds of the National Natural Science Foundation of China(Grant 32060192,31500879)from European Research Council(ERC)under the European Union’s Horizon 2020 research and innovation programme(Grant Agreement 832813-GenPercept)from Italian Ministry of Education,University,and Research under the PRIN2017 programme(2017SBCPZY-“Temporal context in perception:serial dependence and rhythmic oscillations”).
文摘Subitizing is the ability to appraise a number of small quantities(up to four)rapidly and precisely.This system,however,can be impaired by distractors presented along with targets to be enumerated.To better understand whether this limitation arises in perceptual circuits or in the response selection stage,we investigated whether subitizing can endure in simultaneous comparison tasks.Participants were asked to compare the number of dots in two sets on the left and right sides of the screen,presented either simultaneously or sequentially.For comparing within the numerosity range(6-32 dots),both the error rate and reaction time increased steadily as the ratio between the two numbers compared approached“1.”Namely,a phenomenon labeled the ratio effect was revealed.For comparison with small numbers(<5),the sequential comparison task was errorless despite the ratio,suggesting the feature of subitizing.Individual efficiency(measured by the inverse efficiency score[IES])did not correlate between number ranges in sequential comparison,suggesting that distinct mechanisms were involved.However,we found that in simultaneous tasks,error rate and efficiency showed an increase as the ratios of the two numbers compared approached“1.”This is similar to the ratio effect revealed in the comparison for moderate numbers.Individual efficiency within these two ranges correlated,indicating that the enumeration within these two ranges was based on a single mechanism.These results suggest that subitizing cannot process sets in parallel,and numerosity takes the job whenever subitizing fails.
