An outdoor 3-D visual tracking system for the study of spatial navigation and memory in rhesus monkeys

Previous studies of the navigational abilities of nonhuman primates have largely been limited to what could be described by a human observer with a pen and paper. Consequently, we have developed a system that uses a pair of cameras to automatically obtain the three-dimensional trajectory of rhesus monkeys performing an outdoor spatial navigation and memory task. The system provides trajectories, path length, speed, and other variables that would be impossible for an unaided observer to note. From trajectory data, we computed and validated a path-length measurement. We use this measurement to compare the navigation abilities of several animals. In addition, we provide quantitative data on the accuracy of a method for automatic behavior detection. Currently, the system is being used to examine the sex differences in spatial navigation of rhesus monkeys. We expect that measures derived from the trajectory data will reveal strategies used by animals to solve spatial problems.     

On relations among perceptual and cognitive measures of information processing

Tests of visual information processing and verbal information processing were administered to 178 Ss. Intercorrelations showed low positive relationships between two sets of two cognitive measures each, the Sentence Completion Test (Schroder, Driver, & Streufert, 1967) and the Interpersonal Topical Inventory (Tuckman, 1965), and the Interpersonal Topical Inventory and the Polarity Scale (1965), and a high negative correlation between preference for highly complex and for moderately complex visual stimuli. Factor analysis showed three reliable major factors. There was little evidence for a relationship between perceptual and cognitive processing characteristics, which indicates some danger for general theorists.     

The determination of successive principal components without computation of tables of residual correlation coefficients

A procedure is presented for determining the successive principal components of a correlation matrix where it is not necessary to compute the successive tables of residual correlations. The original correlation matrix is bordered with a new row and column for each principal component that is determined.This paper is one of a series of reports on the development of multiple factor analysis in the study of primary human abilities which have been supported by research grants from the Carnegie Corporation of New York and the facilities of the Psychometric Laboratory, which have been provided by the Social Science Research Committee of The University of Chicago.     

A semi-analytical method of factorial rotation to simple structure

A factorial rotational method is presented which represents a compromise between the use of subjective judgment characteristic of graphical methods and the routine application of analytical methods. At present the analytical methods seem to be inadequate for the discovery of a simple structure, while graphical methods require more subjective judgment. The method herein presented locates the axes for subgroups of tests by an analytical method. The judgments used in the selection of subgroups are based on graphic data concerning interrelation of the factors.     

Some mathematical notes on three-mode factor analysis

The model for three-mode factor analysis is discussed in terms of newer applications of mathematical processes including a type of matrix process termed the Kronecker product and the definition of combination variables. Three methods of analysis to a type of extension of principal components analysis are discussed. Methods II and III are applicable to analysis of data collected for a large sample of individuals. An extension of the model is described in which allowance is made for unique variance for each combination variable when the data are collected for a large sample of individuals.     

The effects of social vigilantism and masculine honor beliefs on perceptions of confrontation during the COVID-19 pandemic

Varying opinions about the COVID-19 pandemic inspire different behaviors (e.g., mask-wearing), and confrontation may result between people with differing viewpoints. Individual differences associated with belief superiority (e.g., Social Vigilantism; SV) and/or pride (e.g., Masculine Honor Beliefs; MHB) likely related to third-person perceptions of pandemic confrontations. In this study (N = 237; US sample), we used vignettes in a 2 (Mask: Yes/No) ×  2(Confrontation Response: Vocal Defense/Walked Away) between-groups design to examine how SV and MHB predict perceptions of (1) responses to public confrontation about (not) wearing a mask and (2) the person being confronted. In general, mask-wearing and walking away from confrontation were perceived more positively. Higher SV was associated with more positive perceptions of seemingly morally-justified responses to confrontation (e.g., walking away when confronted for not wearing a mask, vocally defending oneself when confronted for wearing a mask). Contrarily, higher MHB were associated with more positive perceptions of non-mask-wearing. This research provides insight about how individual differences in SV and MHB relate to nuances in pandemic confrontations, and responses to confrontations, about (non)mask-wearing.     

Unique Events: The Underdetermination of Explanation

The paper explicates unique events and investigates their epistemology. Explications of unique events as individuated, different, and emergent are philosophically uninteresting. Unique events are topics of why-questions that radically underdetermine all their potential explanations. Uniqueness that is relative to a level of scientific development is differentiated from absolute uniqueness. Science eliminates relative uniqueness by discovery of recurrence of events and properties, falsification of assumptions of why-questions, and methodological simplification e.g. by explanatory methodological reduction. Finally, an overview of contemporary philosophical disputes that hinge on issues of uniqueness emphasizes its philosophical significance.     

Estimating the spatial Nyquist of the human EEG

The discrete sampling of the brain’s electrical field at the scalp surface with individual recording sensors is subject to the same sampling error as the discrete sampling of the time series at any one sensor with analog-to-digital conversion. Unlike temporal sampling, spatial sampling is intrinsically discrete, so that the post hoc application of analog anti-aliasing filters is not possible. However, the skull acts as a low-pass spatial filter of the brain’s electrical field, attenuating the high spatial frequency information. Because of the skull’s spatial filtering, a discrete sampling of the spatial field with a reasonable number of scalp electrodes is possible. In this paper, we provide theoretical and experimental evidence that adequately sampling the human electroencephalograph (EEG) across the full surface of the head requires a minimum of 128 sensors. Further studies with each of the major EEG and event-related potential phenomena are required in order to determine the spatial frequency of these phenomena and in order to determine whether additional increases in sensor density beyond 128 channels will improve the spatial resolution of the scalp EEG.     

Maximum validity of a test with equivalent items

It is assumed that a scale of true scores on a function exists and that the probability of answering an item correctly is a curve of the type of the integral of the normal curve. The product moment correlation between the test score and true score is derived for a normal distribution of subjects and a test composed of equivalent items. Numerical examples demonstrate that the maximum correlation between test scores and true scores occurs for a one hundred item test when the point correlation between items is less than three tenths.