Prism Adaptation Modulates The Small Number Preferences

The processing of numbers has been the focus of psychologists for long years.Researchers found that healthy subjects prefer small numbers weakly and stably in many tasks,such as number bisection,number detection and temporal order judgement etc.The mechanisms of this phenomenon are still in dispute.A large number of studies show that there are close connections between number and space,we speculate that the reason why healthy people prefer small number has something to do with the spatial presentation of numbers.Prism adaptation(PA)is initial used to treat the neglect patients,then it becomes a method to control the spatial attention of subjects.Lots of researchers have found sensorimotor and even high-level cognitive changes taking place after PA.The main point of present study is to instigate whether the spatial attention shifted by PA can affect the small number preferences in different tasks.We adopted simple number detection task,temporal order judgement(TOJ)task and synchrony judgement(SJ)task as pre-and post-task in three studies,respectively.Between each pair of pre-and post-tasks,we inserted the PA as a mediator,the difference value of small number preferences in pre-and post-task should reveal by which way the shift of spatial attention influences the small number preferences.Our results show that only in the simple number detection task the LEFT PA affects the small number preference,PA has no influence on small number preferences found in TOJ task and SJ task.The results indicate that small number preferences have relationship with the spatial representation of number.The spatial cognition altered by PA can affect the number cognition,but this effect is task-specific,implying that the PA has limit impact on the tasks which ask for more judgement and decision.