Journals of Gerontology:PSYCHOLOGICAL SCIENCES,2020,Vol.75,No.4 those with bigger feet have higher intelligence.But when were functionally normal using the screening criteria of Fang controlling for et al.(2014).To ensure reliable asse ment of ACE-R,olde correlation were redu the use of IOR-OT in ing cognitive functionsinolder individuals.To the best of Sun Yat-Sen Universiry. our knowl dge,however,no research has been conducted directh Apparatus and procedure OR-OT cognitive functions in older individuals.Specifically,we The part hhrghrmforanedhe a sound attenuate given a posne eripheral cueing task and an ACE-R assess ate ment within half a day.The order of the ACE-R and Posner general cognitive functioning in older adults:the later one's .200 IOR-OT i its Chinese translation version Hodges (2013),translated on,thi by Xiong,Liu Yang and edited by Zhou). The Posner peripheral cueing task was similar to that of stand what is"normal"in cognitive aging and can help tal.(2003).Parti define what is“abn in future studies (e.g..Petersen. with a 1.024 768 resolution (32 cm19 cm Res were made on an external numeric kevpad.Participants were asked to stare at a fixation cross at the center of the creen.I e of cach t is sh wn In l Study 1 nd on each trial a white oss fixation(0.5° en lor-OT and general cognitive functions in older adults We adopted a Posner peripheral cue play and these remained on the screen until a response was with six SOAs tim oxes w of the initial dis observer showed an IOR effect of at least 10 ms,the pr play,a bigger and concentric white box (the cue,1.4 sent study innovatively evaluates IOR-OT for each individ. 1.4)app red at the outer o one of the two horizonta ual using a quadratic polynomial fitting approach boxes for 50 ms.In 80 of the trials,a (th the cent one of th T Method c0 uld be50.100.250,500,750,0r1,000ms;these S0A randomly selected with withir Th older adults (56-85 =70.39,1 rget w as the cue alid(valid m the from the community in Zhuhai,China.They had an averag 12.79(SD ties The remaining 20%of trials served as catch trials in 2.8 range:6- 16)years of edu tion.For repl cating the Cn the to respond as acc (18-23 vears.mean age=20.59.8males)were also recruited. wa presente o0 ms Yat-Sen Un 139 (including 7 catch trials)with five short breaks.Twelve d younger participants were practice trials were given before the formal study. fluent in Chinese.All participants reported normal or cor Data prepro cessing For the ACE-R evaluation,the total score of each partic known genera In the Posne r peripheral cucing task and had an ACE-R score not which means they RTs bevond SD above or below a given participant's mearthose with bigger feet have higher intelligence. But when controlling for age, the correlation between foot size and intelligence would disappear. The correlation between IOR-OT and general cognitive functions among a group of older adults would support the use of IOR-OT in assess￾ing cognitive functions in older individuals. To the best of our knowledge, however, no research has been conducted to explore their relationship. The main purpose of this research was to directly explore the relationship between IOR-OT and the general cognitive functions in older individuals. Specifically, we used the Posner peripheral cueing task to measure individu￾al’s IOR-OT and the ACE-R to evaluate cognitive functions of older adults. Based on the inhibitory deficit theory, we expect to find a negative association between IOR-OT and general cognitive functioning in older adults: the later one’s IOR-OT is, the worse are his/her general cognitive func￾tions. In addition, this research focuses on the assessment of cognitive function in healthy older adults. The data from cognitively normal older adults allow us to better under￾stand what is “normal” in cognitive aging and can help define what is “abnormal” in future studies (e.g., Petersen, 2004; Sperling et al., 2011). Study 1 The main purpose of Study 1 is to directly explore the rela￾tionship between IOR-OT and general cognitive functions in older adults. We adopted a Posner peripheral cueing task with six SOAs to characterize the time course of IOR. Unlike previous studies (e.g., Castel et  al., 2003), which defined individual IOR-OT as the first SOA where each observer showed an IOR effect of at least 10 ms, the pre￾sent study innovatively evaluates IOR-OT for each individ￾ual using a quadratic polynomial fitting approach. Method Participant Thirty-three older adults (56–85 years, mean age = 70.39, 11 males) participated in Study 1. Older adults were recruited from the community in Zhuhai, China. They had an average 12.79 (SD = 2.88; range: 6–16) years of education. For repli￾cating the age difference in the time course of IOR reported in previous studies (i.e., Castel et al., 2003), 22 younger adults (18–23 years, mean age = 20.59, 8 males) were also recruited. The younger adults were undergraduate students from Sun Yat-Sen University and had an average 14.32 (SD = 1.39) years of education. All older and younger participants were recruited as paid volunteers. Informed consent was obtained from all participants before the study. All participants were fluent in Chinese. All participants reported normal or cor￾rected-to-normal vision. None of the participants suffered any known general psychiatric or neurological disease. All older participants self-reported no obvious behavioral impairment and had an ACE-R score not less than 85, which means they were functionally normal using the screening criteria of Fang et al. (2014). To ensure reliable assessment of ACE-R, older participants were required to have at least 6 years of educa￾tion (i.e., primary school education). The study was approved by the Ethics Committee of the Department of Psychology, Sun Yat-Sen University. Apparatus and procedure The participants performed the tasks in a sound attenuated room with bright illumination. All older participants were given a Posner peripheral cueing task and an ACE-R assess￾ment within half a day. The order of the ACE-R and Posner peripheral cueing task administration was counterbalanced across participants. The measurement of ACE-R was in strict accordance with the standards (Hodges, 2007; and its Chinese translation version Hodges (2013), translated by Xiong, Liu & Yang and edited by Zhou). The Posner peripheral cueing task was similar to that of Castel et al. (2003). Participants were seated 60 cm in front of a 14-inch color monitor of an IBM Thinkpad laptop, with a 1,024 × 768 resolution (32 cm × 19 cm). Responses were made on an external numeric keypad. Participants were asked to stare at a fixation cross at the center of the screen. The sequence of each trial is shown in Figure 1. Full contrast stimuli (white or green) were presented on a black background. On each trial, a white cross fixation (0.5° × 0.5°) and two white boxes (1° × 1°) served as an initial dis￾play and these remained on the screen until a response was made. The boxes were centered 5° from the fixation cross and located horizontally to the left and right of the fixation. About 1,000–1,200 ms after the presence of the initial dis￾play, a bigger and concentric white box (the cue, 1.4° × 1.4°) appeared at the outer of one of the two horizontal boxes for 50 ms. In 80% of the trials, a green circle (the target, 0.7°) was presented at the center of one of the two boxes for 2,000 ms or until response. The cue-target SOA could be 50, 100, 250, 500, 750, or 1,000 ms; these SOAs were randomly selected with equal probabilities within blocks of trials. The location of the target was either same as the cued location (valid trial) or different from the cued location (invalid trial), randomized with equal probabili￾ties. The remaining 20% of trials served as catch trials in which no target was presented. The participants were asked to respond as accurately and quickly as possible if the tar￾get was presented. A 500 ms blank display was presented after a response. The entire session consisted of 360 trials (including 72 catch trials) with five short breaks. Twelve practice trials were given before the formal study. Data preprocessing For the ACE-R evaluation, the total score of each partici￾pant was calculated. In the Posner peripheral cueing task, the RTs of noncatch trials were computed and analyzed. RTs beyond 3 SD above or below a given participant’s mean Journals of Gerontology: PSYCHOLOGICAL SCIENCES, 2020, Vol. 75, No. 4 755 Downloaded from https://academic.oup.com/psychsocgerontology/article/75/4/753/5033575 by Southern Medical University user on 04 May 2022