Sex difference in open field activity after learning in mice

Sex difference in open field activity after learning as studied. Both Swiss albino female and male mice increased their activity after maze learning. However, the learning induced open field activity increase of the males was significantly higher than that of the females. The males were also initially more active than the females. No significant sex difference in maze learning error scores was found.     

Open field activity after learning in mice

The possible increase of open field activity after learning in mice was examined in five experiments, where the following factors were assessed: (1) and (2) the duration of an open field activity increase (3) the influence of the familiarity of the environment (4) the influence of floor texture during activity measurements and (5) the result of motor activation per se compared to the result of learning. The results indicate that the activity increase lasted 60 min. The phenomenon was related to the learning paradigm used and to the familiarity of the environment and was affected by floor texture. Motor activation per se did not activate the mice as much as the learning of a task. It is suggested that an open field activity increase in mice after learning is associated both with the strain due to the acquisition of a new response and with the strain due to the activity measurement.     

Several types of learning increase open field activity in mice

Experimental and control groups of mice were initially matched on the basis of their open field activity. Experimental groups were trained in one of six types of learning tasks: (1) active avoidance conditioning with light and sound signals as conditioned stimuli and electric shocks as uncoditioned stimulus, (2) learning of a linear 5-point maze, (3) learning of a T-maze, (4) passive avoidance conditioning, (5) learning of non-aggressive behavior, and (6) learning of aggressive behavior. In all cases, learning was associated with a significant increase of the open field activity over that of the untrained but otherwise similarly treated control mice. This effect was most marked during the learning phase and disappeared when the acquired behavior had become firmly established. It is suggested that several types of learning are associated with an increase of arousal level, possibly mediated by the activation of central catecholamine neurons.     

Open field activity after learning and stress in mice

Open field activity after maze Iearning light-sound stress and attacking stress was studied in mice. The results from the present experiments indicated that these procedures affected the open field activity in various ways. Maze learning caused an increase in activity compared to the control group, whereas attacking stress decreased and light-sound stress did not affect activity. The results were discussed in terms of different coping strategies.     

Mice selectively bred for an open field activity increase after maze learning

A unidirectional selective breeding experiment performed over six generations resulted in a line of mice (S6), which differed from the maintained unselected Swiss albino strain, called normal (N) strain, in the following respects: S6 mice increased their open field activity after maze learning significantly more than N mice. S6 mice ambulated more and exhibited more thigmotactic behaviour in a circular open field than N mice. S6 mice were superior than N mice in regard to maze learning capacity. Finally, S6 mice were interpreted as significantly less emotional according to their defecation, more responsive to novelty according to their urine pattern and more aggressive than N mice.     

A qualitative aspect of learning-sensitive open field ambulation in mice

Maze training was shown to affect qualitative aspects of the learning-sensitive open-field (OF) ambulation in male Swiss albino mice. The changes in thigmotactic (wall-seeking) behaviour were most pronounced when significant signs of learning occurred, usually on the third day of training. Also daily changes in thigmotaxis from before to after training were found. Mice not subjected to maze training exhibited a different thigmotactic pattern of behaviour. The present series of experiments indicated that separate starting-points (centre or wall) influenced the thigmotactic behaviour as opposed to the shape of the OF (circular or square).     

Home-cage open-field ambulation after maze learning in mice

The present paper indicates that it is with appropriate methods, i.e., maze learning and a not-previously used home-cage open-field, possible to observe a learning-induced ambulation increase in a familiar environment lacking novel cues. This finding is at variance with an earlier one achieved by electromagnetic recordings indicating a decrease in activity in the home-cage after passive avoidance conditioning.     

Automatic analysis of altered gait in arylsulphatase A-deficient mice in the open field

In current research with laboratory animals, observing their dynamic behavior or locomotion is a laborintensive task. Automatic continuous monitoring can provide quantitative data on each animal’s condition and coordination ability. The objective of the present work is to develop an automated mouse observation system integrated with a conventional open-field test for motor function evaluation. Data were acquired from 86 mice having a targeted disruption of the arylsulphatase A (ASA) gene and having lowered coordinated locomotion abilities as a symptom. The mice used were 36 heterozygotes (12 females) and 50 knockout mice (30 females) at the age of 6 months. The mice were placed one at a time into the test setup, which consisted of a Plexiglas cage (53× 34.5 × 26 cm) and two fluorescent bulbs for proper illumination. The transparent cage allowed images to be captured from underneath the cage, so image information could be obtained about the dynamic variation of the positions of the limbs of the mice for gait reconstruction. Every mouse was recorded for 10 min. Background subtraction and color filtering were used to measure and calculate image features, which are variables that contain crucial information, such as the mouse’s position, orientation, body outline, and poßible locations for the mouse’s paws. A set of heuristic rules was used to prune implausible paw features and label the remaining ones as front/hind and left/right. After we had pruned the implausible paw features, the paw features that were consistent over subsequent images were matched to footprints. Finally, from the measured footprint sequence, eight parameters were calculated in order to quantify the gait of the mouse. This automatic observation technique can be integrated with a regular open-field test, where the trajectory and motor function of a free-moving mouse are measured simultaneously.     

Individual differences in performance and learning of visual anticipation in expert field hockey goalkeepers

The study of anticipation in truly expert performers can provide insight into how they cope with extreme time constraints. The purpose of this dual-experiment paper was to investigate individual differences; in anticipation of the penalty corner drag-flick, its trainability, and transfer of improvement to field settings. Australian international and national male field-hockey goalkeepers participated. In experiment 1, international and national goalkeepers (n = 11) completed a penalty corner drag-flick temporal occlusion task that presented; defensive runner positioning at the penalty spot, drag-flicker kinematics, and ball flight. Results indicated seven goalkeepers integrated runner contextual and drag-flicker kinematic information to anticipate above chance. The cause of individual differences was independent pick-up of run and kinematic cues that presented greater opportunity to integrate sources for anticipation. In experiment 2, a sub-sample of goalkeepers participated and received temporal occlusion training or no training. Results indicated individualized improvement in anticipation across video, field, and competition assessments for those that received the intervention, but not controls. Improvements on video test were retained for six months. An individual differences approach can identify deficiencies in anticipation, which can be improved through perceptual training that transfers to motor responses. This contributes to theoretical and practical knowledge to develop anticipation skill.     

Age-related differences in memory after attending to distinctiveness or similarity during learning

Episodic memory is vulnerable to age-related change, with older adults demonstrating both impairments in retrieving contextual details and susceptibility to interference among similar events. Such impairments may be due in part to an age-related decline in the ability to encode distinct memory representations. Recent research has examined how manipulating stimulus properties to emphasize distinctiveness can reduce age-related deficits in memory. However, few studies have addressed whether learning strategies that differentially encourage distinctiveness processing attenuate age-related differences in episodic memory. In the present study, participants engaged in two incidental encoding tasks emphasizing either distinctiveness or similarity processing. Results demonstrated higher rates of recollection for stimuli studied under the distinctiveness task than the similarity task in younger but not older adults. These findings suggest a declining capacity for distinctiveness processing to benefit memory in older adults, and raise the possibility that strategies that enhance gist-based encoding may attenuate age-related memory deficits.     

Strain and sex differences on olfactory discrimination learning in C57BL/6J and DBA/2J inbred mice (Mus musculus)

In this study, the authors explored potential strain and sex differences in nonspatial cognitive ability. Beginning around 90 days of age, male and female C57BL/6J (C57) and DBA/2J (DBA) inbred mice (Mus musculus) were tested on a task of simple odor discrimination learning with 3 repeated reversals. Males learned the task more readily than females, and DBA mice learned the task more readily than C57 mice. All differences became evident after repeated testing. Similarity of perseveration measures indicated the differences were not due to inhibitory deficits. Instead, a phase analysis localized differences to a transitional period of reversal learning. Females increased transitional errors that more likely indicated adaptive sampling strategies than memory failures. C57 females used this strategy indiscriminately, but DBA females sampled as a function of environmental uncertainty.     

Subordinate male mice show long-lasting differences in spatial learning that persist when housed alone

In the wild, house mice live in social groups, whereas in the laboratory male mice are often singly housed. Environmental enrichment such as that provided by social housing has been argued to improve the cognitive performance of laboratory animals in experimental tests. The aim of the present study was to test the cost of aggressive social interactions on learning in male CD-1 mice. We found that subordinate mice from more aggressive dyads showed spatial learning impairment, measured as alternation on a T-maze. Learning impairments in subordinates have hitherto been presumed attributable to the animals' exposure to, and relative standing within, the social group. By contrast, the impairment we observed could not have been the result of recent social defeat because it persisted weeks later when the mice were housed alone. Elevated urinary corticosterone predicted later subordination, though paradoxically these abnormally high levels were reduced by pair housing.     

Variations in working memory capacity predict individual differences in general learning abilities among genetically diverse mice

Up to 50% of an individuals' performance across a wide variety of distinct cognitive tests can be accounted for by a single factor (i.e., "general intelligence"). Despite its ubiquity, the processes or mechanisms regulating this factor are a matter of considerable debate. Although it has been hypothesized that working memory may impact cognitive performance across various domains, tests have been inconclusive due to the difficulty in isolating working memory from its overlapping operations, such as verbal ability. We address this problem using genetically diverse mice, which exhibit a trait analogous to general intelligence. The general cognitive abilities of CD-1 mice were found to covary with individuals' working memory capacity, but not with variations in long-term retention. These results provide evidence that independent of verbal abilities, variations in working memory are associated with general cognitive abilities, and further, suggest a conservation across species of mechanisms and/or processes that regulate cognitive abilities.     

Gender differences in adult word learning

In prior work, women were found to outperform men on short-term verbal memory tasks. The goal of the present work was to examine whether gender differences on short-term memory tasks are tied to the involvement of long-term memory in the learning process. In Experiment 1, men and women were compared on their ability to remember phonologically-familiar novel words and phonologically-unfamiliar novel words. Learning of phonologically-familiar novel words (but not of phonologically-unfamiliar novel words) can be supported by long-term phonological knowledge. Results revealed that women outperformed men on phonologically-familiar novel words, but not on phonologically-unfamiliar novel words. In Experiment 2, we replicated Experiment 1 using a within-subjects design, and confirmed gender differences on phonologically-familiar, but not on phonologically-unfamiliar stimuli. These findings are interpreted to suggest that women are more likely than men to recruit native-language phonological knowledge during novel word-learning.     

Age differences in visual statistical learning

Recent work has shown that older adults' lessened inhibitory control leads them to inadvertently bind co-occurring targets and distractors. Although this hyper-binding effect may lead to the formation of more superfluous associations, and thus greater interference at retrieval for older adults, it may also lead to a greater knowledge of information contained within the periphery of awareness. On the basis of evidence that younger adults only show learning for statistical regularities contained within attended information, we asked whether older adults may also show learning for regularities contained within to-be-ignored information. Older and younger adults viewed a series of red and green pictures and performed a 1-back task on one of the colors. Unbeknownst to participants, both color streams were organized into triplets that occurred sequentially. Implicit memory for the triplets from both the attended and ignored streams was tested using a speeded detection task. Replicating previous work, younger adults demonstrated more learning for the attended triplets than the unattended triplets. Older adults, however, demonstrated similar learning for both the attended and ignored triplets, suggesting that contrary to popular belief, they may actually know more than younger adults about the world around them, including how seemingly irrelevant events co-occur. (PsycINFO Database Record (c) 2012 APA, all rights reserved).     

An analysis of response,direction, and place learning in an open field and T maze

Rats were trained to locate food in a response, direction, or place problem on an open field located at 2 positions. In Experiment 1, both the response and direction groups solved the problem. The place group failed to solve the task in approximately 300 trials. Experiment 2 demonstrated that rats need distinguishable start points to solve a place problem when neither a response nor a direction solution is available. Findings from Experiment 3 suggest that a combination of path traveled and distinct cues help to differentiate start points. Experiment 4 replicated the findings using a T maze. These results suggest "place" solutions are difficult for rats. The data are discussed with respect to conditional learning and modern spatial mapping theory.