The symmetrical maze: An automated closed-field test series for rats

An automated “intelligence” test for rats is described. Supporting data indicate that this maze-problem series is sensitive to hypothyroidism-induced learning deficit and sex differences. Comparisons between this new problem set and the Rabinovitch-Rosvold (1951) closed-field tests are presented with respect to difficulty, internal consistency, and test-retest reliability.     

Further evidence that mice learn a win-shift but not a win-stay contingency under water-escape motivation

Previous research (C. Locurto, C. Emidy, & S. Hannan, 2002) indicated that mice quickly learned a water-escape task under a win-shift contingency but did not exceed chance-level performance under a win-stay contingency. We examined the robustness of this conclusion in two experiments by varying procedural and temporal aspects of that earlier experiment. Results of both experiments indicated that the preference for win-shift learning in mice under water-escape motivation could not be attributed to procedural or design features of that earlier study and were independent of the influence of intertrial interval, normally a variable that produces strong effects on learning. In neither experiment did subjects exposed to a win-stay contingency perform at above-chance levels.     

The effects of intelligence test preparation

The first goal of this study was to investigate the effects of reading a book concerning intelligence tests and the effects of a specific test-training programme on numerical and verbal intelligence tests. The second goal was to investigate to what extent the acquisition of test-specific problem-solving strategies affects the ability to solve items on different, but comparable tests (transfer). In the experimental design two factors were included: practice (pretest or no pretest) and (level of) preparation (none, book, or training), so there were six conditions. Each condition consisted of about 26 subjects, who had been randomly assigned to one of the conditions. The results showed a strong effect of preparation, especially for the numerical intelligence test and to a lesser degree for the verbal intelligence test. No practice or pretest effects were found. Positive transfer was demonstrated for the numerical test. The results for the verbal test were less clear. The implications for the predictive and construct validity are discussed.     

The comparability of intelligence test results: Group- and individual-level comparisons of seven intelligence tests

A significant body of research has demonstrated that IQs obtained from different intelligence tests substantially correlate at the group level. Yet, there is minimal research investigating whether different intelligence tests yield comparable results for individuals. Examining this issue is paramount given that high-stakes decisions are based on individual test results. Consequently, we investigated whether seven current and widely used intelligence tests yielded comparable results for individuals between the ages of 4–20 years. Results mostly indicated substantial correlations between tests, although several significant mean differences at the group level were identified. Results associated with individual-level comparability indicated that the interpretation of exact IQ scores cannot be empirically supported, as the 95% confidence intervals could not be reliably replicated with different intelligence tests. Similar patterns also appeared for the individual-level comparability of nonverbal and verbal intelligence factor scores. Furthermore, the nominal level of intelligence systematically predicted IQ differences between tests, with above- and below-average IQ scores associated with larger differences as compared to average IQ scores. Analyses based on continuous data confirmed that differences appeared to increase toward the above-average IQ score range. These findings are critical as these are the ranges in which diagnostic questions most often arise in practice. Implications for test interpretation and test construction are discussed.     

The multiple selection vocabulary test (MSVT-B)--an accelerated intelligence test]

A new accelerated intelligence test is presented which is known as the multiple selection vocabulary test B. This is a very objective and reliable test measuring the general level of intelligence. The time of testing will be about three to five minutes in the case of persons that are free of any psychiatric disorders. Test results will be only negligibly influenced by psychic and mental disorders.     

Problems with the slosson intelligence test for preschool children

The Slosson Intelligence Test (SIT) was administered to 92 preschool children. Because of the considerably above average performance of the group on the SIT, the Stanford-Binet Intelligence Scale was administered to a sample of the group and the results compared to the results on the SIT. The differences between the two sets of scores was highly significant, and as a result the SIT appears to over estimate the performance of average preschool children.     

Those cheating rats: male and female rats use odor trails in a water-escape "working memory" task.

Three-month-old Sprague-Dawley rats were trained on a working memory win-stay (spatial delayed matching-to-sample) water-escape task with the escape platform location the same for all subjects on a given trial, a procedure that maximizes the buildup of an odor trail to the escape platform. In subsequent tests during which the location of the escape platform varied randomly between subjects, the rats, especially the females, while continuing to perform above chance level, made increased errors. Varying the platform location between subjects eliminated odor trail as a nonambiguous cue for locating the escape platform. In a second experiment females performed better than males on a reference memory odor trail discrimination task which involved following the path of like-gender "pathmaker" rats to the escape platform. The relatively poor use of odor trails by the males was associated with a high frequency of choosing a preferred choice section or returning to the choice section selected first on the immediately preceding trial (perseveration). Collectively, the two experiments demonstrate that rats can use either working memory or odor trails to locate an escape platform in a water maze, and that they, especially females, will use odor trails in a working memory task if odor trails are available. Clearly, the location of the escape platform should be varied randomly between subjects in tests of working memory.