Distinguishing the Ratio Bias from Unsystematic Error: Situation and Individual‐difference Effects

People often perceive the occurrence of events to be less likely when the likelihood of the event is expressed in ratios consisting of smaller numbers versus larger numbers, an effect known as the ratio bias. This work presents a theoretical framework for the conditions that need to be met for the ratio bias to occur. In doing so, we contrast effects on the ratio bias to those on unsystematic error, which have often been confounded in previous research. We find that the ratio bias is weaker (1) when both sets of numbers are relatively large than when both sets of numbers are relatively small; (2) for scenarios involving lottery tickets than for scenarios involving drawing balls from a bin; and (3) when a physical display depicting the numbers is provided to participants. Each of these factors reduced the ratio bias without reducing unsystematic error. Additionally, we show that unsystematic error is lower among people who (1) reason on the basis of proportions rather than on the basis of the numerator and denominator individually; (2) score higher on the rational scale of the Rational–Experiential Inventory; and (3) are of higher numeracy. We use these results to distinguish causes of error generally from those on the ratio bias specifically and discuss the implications for our understanding of when the ratio bias occurs. Copyright © 2018 John Wiley & Sons, Ltd.     

The Implications of Adolescents’ Academic Word Knowledge for Achievement and Instruction

The purpose of the current study was to determine relationships between orthographic and morphological awareness of academic words and achievement across content areas. Participants (n = 256), diverse seventh and eighth graders, took three word knowledge measures; two standardized achievement measures were used as outcomes. Orthographic awareness of academic words explained variance in achievement, beyond overall breadth of vocabulary knowledge, with significant changes in R² ranging from 0.02 to 0.08. Morphological awareness of academic words explained variance in achievement, beyond overall breadth of vocabulary knowledge, with significant changes in R² ranging from 0.06 to 0.16.     

DETERMINATION AND EVALUATION OF RATE MEASUREMENTS IN THE ANALYSIS OF SPACE MEDICAL DATA

Measures of rate of change and of rate of rate of change are developed for application to physiological and psychological data. Examples are given of the use of these measures with heart-rate data for comparisons within and between subjects. It is shown that the measures provide information over and above that offered by means and variances, and that the measures appropriately reflect the impact of external variables.     

Basic Response Time Tools for Studying General Processing Capacity in Attention,Perception, and Cognition

One of the more important constructs in the study of attention, perception, and cognition is that of capacity. The authors reviewed some of the common meanings of this construct and proposed a more precise treatment. They showed how the distribution of response times can be used to derive measures of process capacity and to further illustrate how these measures can be used to address important hypotheses in cognition.     

A Comparative Study of Groups of High and Low Intelligence in Learning a Maze

In accordance with the determination of base-line heart rate and running in an activity wheel, 14 Long-Evans male rats were given ten 30 minute sessions of Immobile-Avoid conditioning followed by 30 minute sessions of Active-Avoid conditioning. Control Ss were yoked to the experimental Ss.

Experimental Ss made significantly fewer responses in the immobile-avoid period and significantly more responses in the active-avoid period than did the yoked control Ss. Heart rate was correlated with skeletal activity both for experimental and control Ss. For experimental Ss, low heart rate was concomitant with a low amount of activity in the immobile-avoid period and high heart rate was concomitant with greater skeletal activity in the active-avoid period.

These results support the position that heart rate is secondary to responses of the somatic-motor system and that heart rate during immobile-avoid or active avoid conditioning is more closely related to the level of somatic-motor activity than to the emotional stress which purportedly motivates instrumental avoidance behavior.     

The statistical properties of the Survivor Interaction Contrast

The Survivor Interaction Contrast (SIC) is a powerful tool for assessing the architecture and stopping rule of a model of mental processes (Townsend & Nozawa, 1995). Despite its demonstrated utility, the methodology has lacked a method for statistical testing until now. In this paper we briefly describe the SIC then develop some basic statistical properties of the measure. These developments lead to a statistical test for rejecting certain classes of models based on the SIC. We verify these tests using simulated data, then demonstrate their use on data from a simple cognitive task.     

Age-related declines in general cognitive abilities of Balb/C mice are associated with disparities in working memory, body weight, and general activity

A defining characteristic of age-related cognitive decline is a deficit in general cognitive performance. Here we use a testing and analysis regimen that allows us to characterize the general learning abilities of young (3-5 mo old) and aged (19-21 mo old) male and female Balb/C mice. Animals' performance was assessed on a battery of seven diverse learning tasks. Aged animals exhibited deficits in five of the seven tasks and ranked significantly lower than their young counterparts in general learning abilities (aggregate performance across the battery of tasks). Aging added variability to common core performance (i.e., general learning ability), which translated into increased variability on the individual cognitive tasks. Relatedly, general learning abilities did not differ between the two ages among the best quartile of learners (i.e., cognitive abilities were spared in a subsample of the aged animals). Additionally, working memory capacity (resistance to interference) and duration (resistance to decay) accounted for significantly more of the variability in general learning abilities in aged relative to young animals. Tests of 15 noncognitive performance variables indicated that an increase in body weight (and an associated decrease in general activity) was characteristic of those aged animals which exhibited deficient general learning abilities. These results suggest the possibility that general cognitive deficits in aged animals reflect a failure of specific components of the working memory system, and may be related to variations in body weight and an associated decrease in activity.     

Studying visual search using systems factorial methodology with target-distractor similarity as the factor

Systems factorial technology (SFT) is a theory-driven set of methodologies oriented toward identification of basic mechanisms, such as parallel versus serial processing, of perception and cognition. Studies employing SFT in visual search with small display sizes have repeatedly shown decisive evidence for parallel processing. The first strong evidence for serial processing was recently found in short-term memory search, using target-distractor (T-D) similarity as a key experimental variable (Townsend & Fifi?, 2004). One of the major goals of the present study was to employ T-D similarity in visual search to learn whether this mode of manipulating processing speed would affect the parallel versus serial issue in that domain. The result was a surprising and regular departure from ordinary parallel or serial processing. The most plausible account at present relies on the notion of positively interacting parallel channels.     

PHYSICAL ACTIVITY IN HOMES 13 TEACHING EMPATHY SKILLS TO CHILDREN WITH AUTISM

The purpose of this study was to teach empathetic responding to 4 children with autism. Instructors presented vignettes with dolls and puppets demonstrating various types of affect and used prompt delay, modeling, manual prompts, behavioral rehearsals, and reinforcement to teach participants to perform empathy responses. Increases in empathetic responding occurred systematically with the introduction of treatment across all participants and response categories. Furthermore, responding generalized from training to nontraining probe stimuli for all participants. Generalization occurred from dolls and puppets to actual people in a nontraining setting for 2 participants. Generalization was observed initially to the nontraining people and setting for the other participants, but responding subsequently decreased to baseline levels. Introduction of treatment in this setting produced rapid acquisition of target skills.