Individual differences, aging, and IQ in two-choice tasks

Department of Psychology, The Ohio State University, Columbus, OH 43210, United States.
Cognitive Psychology (Impact Factor: 5.06). 12/2009; 60(3):127-57. DOI: 10.1016/j.cogpsych.2009.09.001
Source: PubMed


The effects of aging and IQ on performance were examined in three two-choice tasks: numerosity discrimination, recognition memory, and lexical decision. The experimental data, accuracy, correct and error response times, and response time distributions, were well explained by Ratcliff's (1978) diffusion model. The components of processing identified by the model were compared across levels of IQ (ranging from 83 to 146) and age (college students, 60-74, and 75-90 year olds). Declines in performance with age were not significantly different for low compared to high IQ subjects. IQ but not age had large effects on the quality of the evidence that was obtained from a stimulus or memory, that is, the evidence upon which decisions were based. Applying the model to individual subjects, the components of processing identified by the model for individuals correlated across tasks. In addition, the model's predictions and the data were examined for the "worst performance rule", the finding that age and IQ have larger effects on slower responses than faster responses.

Download full-text


Available from: Anjali Thapar, Feb 05, 2015
  • Source
    • "Average data, often accounting for a non-accurate representation of the individual subjects, have been used in the RDM fitting quite successfully. Specifically, in more than a dozen large studies with 30 to 40 subjects per group, all parameter values obtained from fitting the model to data averaged over subjects were found close (within 1 or 2 SD of each other) to the parameter values obtained from averaging the parameters resulting from fits of the model to the data from individual subjects [51] [52] [53]. "
    [Show abstract] [Hide abstract]
    ABSTRACT: We are examining whether robust behavioral laws, initially designed to describe sensorimotor control of the upper extremity, can also describe lower extremity. Herein, we present our initial results of our research on measuring ankle reaction time (RT). We show that RT measured in ankle dorsiflexion and inversion-eversion of 7 healthy young subjects followed a γ distribution, a typical finding in upper limb response modalities. We used the mean and variance of the best fit γ distribution to find subjects with similar responses. We propose that this approach to find subjects with similar responses affords a rationale for clustering subjects with similar response to form super-subjects (SS), i.e., subjects with RTs accumulated across similar subjects. We then show that the most widely used model of RT cognitive processes, the Ratcliff diffusion model, is adequate to describe ankle RT in an SS. Results indicate that RT shows a great potential to be used as an assessment tool for our adaptive assist-as-needed robotic therapy delivered to the lower limbs of children with Cerebral Palsy.
    IEEE International Conference on Biomedical Robotics and Biomechatronics, Sao Paolo, Brazil; 08/2014
  • Source
    • "Today however, many researchers agree that elderly people slow down, at least in part, because they choose to be more cautious than young people. This means that elderly participants often choose to collect more evidence before they are willing to commit to a decision, a strategy that may result in a substantial loss of speed in return for a small gain in accuracy (Salthouse, 1979; Starns & Ratcliff, 2010; Strayer, Wickens, & Braune, 1987; Ratcliff, This research was supported by Veni and Vidi grants from the Dutch Organization for Scientific Research (NWO). We thank Roger Ratcliff for providing us with the data that are analyzed in Experiment 2. "
    [Show abstract] [Hide abstract]
    ABSTRACT: People generally slow down after they make an error, a phenomenon that is more pronounced for older individuals than it is for young individuals. Here, we examine the origin of this age-related difference in posterror slowing (PES) by applying the diffusion model to data from young and older participants performing a random dot motion task and a lexical decision task. Results show that the PES effects on response time and accuracy were qualitatively different for young and older participants. A diffusion model analysis revealed that following an error, older participants became more cautious, processed information less effectively, and spent more time on irrelevant processes. This pattern was evident in both the random dot motion task and the lexical decision task. For young participants, in contrast, the origin of the PES effect depended on the task that was performed: In the random dot motion task, the PES effect was due to time spent on irrelevant processes; in the lexical decision task, the PES effect was due to increased caution and decreased effectiveness in information processing. Overall, PES effects were much larger in the lexical decision task than in the random dot motion task. These findings indicate that PES originates from the interplay of different psychological processes whose contribution depends on both task settings and individual differences. (PsycINFO Database Record (c) 2012 APA, all rights reserved).
    Psychology and Aging 09/2012; 28(1). DOI:10.1037/a0029875 · 2.73 Impact Factor
  • Source
    • "Thus, the adoption of wider boundaries (i.e., a conservative decision criterion ) by both young children and older adults should be considered a preference rather than an inherent characteristic of the developing information-processing system. Starns and Ratcliff (2010) suggest that older adults are unwilling to make avoidable errors (such as accidentally pressing the wrong key) because they prioritize accuracy. That young children behave similarly, though, suggests that both age groups may be more self-conscious about, or less confident in, their ability to perform a new task well and so play it safe by adopting conservative speed-accuracy decision criteria. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Children (n = 130; M(age) = 8.51-15.68 years) and college-aged adults (n = 72; M(age) = 20.50 years) completed numerosity discrimination and lexical decision tasks. Children produced longer response times (RTs) than adults. R. Ratcliff's (1978) diffusion model, which divides processing into components (e.g., quality of evidence, decision criteria settings, nondecision time), was fit to the accuracy and RT distribution data. Differences in all components were responsible for slowing in children in these tasks. Children extract lower quality evidence than college-aged adults, unlike older adults who extract a similar quality of evidence as college-aged adults. Thus, processing components responsible for changes in RTs at the beginning of the life span are somewhat different from those responsible for changes occurring with healthy aging.
    Child Development 12/2011; 83(1):367-81. DOI:10.1111/j.1467-8624.2011.01683.x · 4.92 Impact Factor
Show more