Seasonal variation of sexually dimorphic spatial learning implicates mating system in the intertidal Cocos Frillgoby (Bathygobius cocosensis)

Animal Cognition - Spatial learning is an important cognitive function found across a multitude of species. Natural selection can enhance specific cognitive abilities depending on species ecology...     

The dissociation of repetition priming and recognition memory in language/learning-disabled children.

Recent research has found that the performance of learning-disabled and non-disabled children is dissociated on explicit and implicit tests of memory (Lorsbach & Worman, 1989). The current study further examined this phenomenon by comparing language/learning-disabled (L/LD) and nondisabled children (NLD) on tasks measuring primed picture-naming and item recognition. Included within the design of the experiment was the manipulation of both presentation format (pictures or words) and retention interval (immediate or 1 day). Children were initially presented with pictures and words. Performance was measured both immediately and following a 1-day retention interval on a picture naming task, an item recognition task, and a supplementary measure of memory for presentation format. The magnitude of facilitation associated with primed picture-naming was found to be independent of item recognition performance. In addition, the effects of population (L/LD and NLD) and retention interval (immediate test or 1 day) each produced dissociations between the magnitude of naming facilitation and item recognition performance. Results were discussed in terms of their implications for our understanding of the nature of memory difficulties in L/LD children.     

Two tests of all-or-none learning and retention

A number of recent experiments have seemed to imply that the basic associations of learning are formed in an all-or-none manner. However, the evidence provided by these experiments has been essentially indirect since the presence of an association has been assessed by an all-or-none method, viz. simple recall. By allowing the subject more than one attempt at recall or recognition more direct evidence can be obtained. All-or- none learning implies that the probability of success during further attempts will be at the chance level. The experiments described show that this is not the case for the stimulus materials used. On the other hand the uncertainty in bits during further attempts was a fairly high proportion of the uncertainty expected on the all-or-none hypothesis. For this reason the results may indicate only a minor breakdown of the hypothesis. In a retention test administered after a week, fewer first-attempt successes were achieved than in the immediate test but, despite this, the uncertainty after a first- attempt failure was about the same as in the immediate test. The experiments also incorporated a second test of the all-or-none hypothesis. This involved comparing 2-choice and 4-choice recognition scores and recognition scores with recall scores. After corrections for guessing, these scores should be identical, if the hypothesis is correct. Results of this corrected-comparisons test tended to support those of the further-attempts test.     

Developmental characteristics of figure drawings made by boys and girls ages five through eleven

526 children from the ages of 5 yr. through 11 yr. (257 boys and 269 girls) responded when asked to draw the figure of a man. Of the 68 characteristics investigated the girls' responses were significantly different from the boys' on 41 items (60%) while boys' responses were significantly different on 28 items (41%). Although there were significant differences in some responses they were not necessarily indicative of higher levels of performance. Given the number of boys and girls participating and the number of significant differences, the over-all significant difference was 0. There were, however, many significant differences found in the drawings made by boys and girls ages 5, 6 and 9 yr.     

Relative durations of conditioned stimulus and intertrial interval in conditioned suppression.

The effects of the relative durations of the conditional stimulus and the intertrial interval on bar pressing during a conditioned-suppression procedure were examined as a function of two additional variables--type of operant baseline schedule and rate of shock presentation. In Experiment 1, response suppression was compared across components of a multiple fixed-ratio, random-ratio, fixed-interval, random-interval schedule, at relative conditioned-stimulus/intertrial-interval durations of 1/1, 1/4, and 1/9. In Experiment 2, relative conditioned-stimulus/intertrial-interval duration (1/5, 3/3, or 5/1) was manipulated across groups, while shock frequency (2, 6, or 10 shocks/hr) was manipulated within groups. In both experiments, suppression during the signal was virtually complete at all relative durations. Responding was also suppressed during the intertrial interval, but that suppression varied as a function of experimental manipulations. In Experiment 1, intertrial-interval response rates were higher when relative signal duration was 1/9 than when it was 1/1, although both relative signal duration and shock frequency, which covaried, could have contributed to the difference. In Experiment 2, the patterning of response rates between successive shocks was affected by relative duration, absolute rates during the intertrial interval varied as a function of shock frequency, and differences between suppression during the signal and suppression during the intertrial interval were affected by both relative duration and shock frequency. The data support an analysis based upon relationships between shock-correlated and intertrial-interval stimuli and, as assessed by the relative-delay-to-reinforcement metric, are comparable to results that have been reported from experiments using similar manipulations under the autoshaping paradigm.     

Distributed and massed practice: from laboratory to classroom

The benefit to memory of spacing presentations of material is well established but lacks an adequate explanation and is rarely applied in education. This paper presents three experiments that examined the spacing effect and its application to education. Experiment 1 demonstrated that spacing repeated presentations of items is equally beneficial to memory for a wide range of ages, contrary to some theories. Experiment 2 introduced ‘clustered’ presentations as a more relevant control than massed, reflecting the fact that massed presentation of material is uncommon in education. The scheduling of clustered presentations was intermediate between massed and distributed, yet recall was no different than for massed. Experiment 3, a classroom‐based study, demonstrated the benefit of distributed over clustered teaching of reading through modification of the scheduling of everyday lessons. Thus, the effectiveness of teaching may be improved by increasing the degree to which lessons are distributed. Copyright © 2004 John Wiley & Sons, Ltd.