J. R. Royce

Factor Analytic Studies Of Human Brain Damage: I. First And Second-Order Factors And Their Brain Correlates

This report is concerned with identifying the first and second-order cognitive factors underlying a battery of 49 measures taken from 22 brain damage tests. The test scores from 176 brain damaged patients between 16 and 65 years of age were intercorrelated and subjected to first-order alpha factoring followed by promax rotation to oblique simple structure. Ten of the 13 first-order factors extracted were interpretable, six of them being perceptual in nature and four being of a more conceptual nature. The perceptual factors include: perceptual organization, perceptual-motor speed, pattern recognition, temporal resolution, spatial orientation, and figure-ground identification. The conceptual factors include verbal comprehension, memory, and two abstraction factors. A second-order alpha factoring was performed on the matrix of correlations among the 13 primaries. Three of the five second-order factors extracted were interpretable. They were identified as perceptual integration (subsuming the first-order factors of perceptual organization, perceptual-motor speed, and temporal resolution), verbal memory (subsuming verbal comprehension and memory), and visualization (subsuming spatial orientation and figure-ground identification). Although factor interpretations were based primarily on the patterns of high loading variables, they were also influenced by lesion effects observed in this and related studies. About half the interpretable factors are relatively localized (i.e., confined to one or two lobes of one hemisphere), with the other half more diffuse (i.e., multi-lobed, combined with laterality or bilaterality). The more localized factors include the right hemisphere factors of perceptual-motor speed, temporal resolution, and spatial orientation, and the left hemisphere factors of verbal comprehension, memory, and verbal memory. The more neurally diffuse factors include the second-order factors and such broad gauged first-order factors as abstraction I and II, and pattern recognition. Furthermore, same lobe, bilaterally hemispheric effects were rare, and only four factors (memory, verbal memory, visualization, and abstraction I) were correlated with sub-cortical lesions.

Behavior genetic analysis of mouse emotionality. III. The diallel analysis.

A total of 775 pure-strain and F1 mice were obtained from a 6×6 diallel mating plan. Previous factor analysis of 42 measures of emotionality identified 14 behavioral factors, ten of which were interpretable. Haymans analysis of variance and analysis of diallel crosses were applied to each of the factors. In general, the findings indicate that the mode of inheritance for emotionality factors is polygenic and in the direction of complete dominance. However, a major point of this investigation is that the mode of inheritance of highly complex behavior such as emotionality depends on the factor in question. For example, the breakdown of dominance effects by factor was as follows: partial dominance—Motor Discharge, Food Motivation, Tunneling-2, and Activity Level (males); complete dominance—Audiogenic Reactivity, Underwater Swimming (males), and Activity Level (females); overdominance—Acrophobia, Territorial Marking (males). Additional findings include directional dominance for Underwater Swimming and Audiogenic Reactivity, and significant sex differences for eight of the 14 factors.

Optimal Stimulus Parameters In Avoidance Conditioning Of Inbred Strains Of Mice.

Highly inbred mice of fast and slow conditioning strains (N = 228) were trained in avoidance conditioning and 180 were continued to extinction. The principal goal was to determine optimal stimulus conditions for fast learning, small variances, and maximal strain differences. Conclusions are: a) the major effect of change in CS-US and intertrial intervals occurs, respectively, for intervals less than 3 sec. and 60 sec.; b) change in amperage (150-400 pa) or voltage (250-400 v.) caused no significant differences; c) strain differences in extinction occurred after nearly optimal conditioning, and d) strain differences were altered considerably as stimulus conditions became optimal. Optimal levels of parameters are: 3 sec. CS-US interval, 120-sec. intertrial interval, and 400 v. (220 K ohm impedance circuit).

Behavior genetic analysis of mouse emotionality, ii. Stability of factors across genotypes.

Three emotionally divergent strains of mice (SWR/J, A/HeJ, and SJL/J) were mated to produce three populations: a pure strain population (N = 90), an F1 population (N = 120), and an F2 population (N = 96). All Ss were tested on a battery of measures of emotionality. Each population was factored separately by principal components factoring with varimax and promax rotations. Factorial invariance was assessed quantitatively by congruence coefficients. Eight of the resultant factors were found to be replicable across populations. These were autonomic balance, motor discharge, territorial marking, acrophobia, tunneling-1, tunneling-2, underwater swimming, and audiogenic reactivity. Of the eight factors, motor discharge was most distinct in each population and tunneling-1 was least distinct.

Evidence for a territorial marking factor of mouse emotionality

The interpretation of an invariant factor of mouse emotionality as “territorial marking” was tested. Ninety mice from two emotionally divergent strains, SJL/J and SWR/J, were obtained from the Jackson Laboratory. At 33 days of age, they were placed in separate cages and at 60 days of age they were run through a battery of tests consisting of 19 measures of emotionality. Scores were factor analyzed by alpha factoring, followed by varimax and then promax rotations. Factor scores were computed for all Ss on territorial marking and correlated with scores on nine tests of dominance and aggressiveness. The interpretation of Factor 1, territorial marking, was borne out by the correlations with social measures.

Factors of Mouse Emotionality at the Second Order, Third Order, and Fourth Order

Data which had previously yielded 15 factors at the first order were reanalyzed to produce six second-order, three third-order and one fourth-order factors. Broad behavioral patterns were discovered which indicate that escape, avoidance, emotionality, and motor reactivity are the primary manifestations of affectivity in a variety of test situations. In spite of difficulties in distinguishing between dimensions at different strata, this investigation constitutes an important contribution to the empirical basis for hierarchical organization of the affective domain.

Invariance of Factors of Mouse Emotionality With Changed Experimental Conditions

Six factors of mouse emotionality (autonomic balance, motor discharge, acrophobia, territoriality, tunneling-1, and tunneling-2) were compared across three separate studies. Each study included 19 measures from five tests of emotionality: open field, straightaway, pole, cell, and hole-in-wall. However, conditions of testing differed significantly in each study. In the first study, the measures taken were part of a large test battery. In the second study, a reduced test battery included only the 19 measures. In the third study, this reduced battery was used again, but subjects were injected with psychoactive drugs prior to testing. In addition to these changes, different genotypes were used across studies. Subjects in the first study were tested as part of a 6 × 6 diallel table. In the second and third studies, two emotionally contrasted strains (SWR and SJL) were tested. Each population was refactored by alpha factoring with varimax, followed by promax rotations. Factors obtained were compared by quantitative means using S-index and r[SUBc] coefficients of factor matching. Although support was obtained for the invariance of all six factors, the results indicate invariance as being strongest for motor discharge and acrophobia and weakest for tunneling-1 and tunneling-2 factors.

FACTORS OF EMOTIONALITY RELATED TO ALCOHOL CONSUMPTION IN LABORATORY MICE

Fifty mice from four genotypes were tested on a factor analyzed battery of measures of emotionality. This was followed by testing of alcohol consumption. The factors were related to alcohol consumption by a stepwise regression procedure. Among the five best predictors, Factor B, interpreted as a disorganization factor and Factor C, interpreted as an audiogenic reactivity factor, were most consistently related to alcohol consumption.

Effect of magnesium pemoline on avoidance conditioning and intertrial activity in two strains of inbred mice.

Magnesium pemoline was found to have a differential effect on behavior depending upon genotype. The drug resulted in increased activity and reduced avoidance scores for the fast-conditioning C3H strain of mice, whereas it significantly increased avoidance scores and activity for the slow-conditioning ST/bJ strain. The effect of magnesium pemoline on behavior is discussed in terms of an inverted-U relationship between reactivity and learning.