130,875 research outputs found
Multi-modal discrimination learning in humans: evidence for configural theory
No full textHuman contingency learning was used to compare the predictions of configural and elemental theories. In three experiments, participants were required to learn which indicators were associated with an increase in core temperature of a fictitious nuclear plant. Experiments 1 and 2 investigated the rate at which a triple-element stimulus (ABC) could be discriminated from either single-element stimuli (A, B, and C) or double-element stimuli (AB, BC, and AC). Experiment 1 used visual stimuli, whilst Experiment 2 used visual, auditory, and tactile stimuli. In both experiments the participants took longer to discriminate the triple-element stimulus from the more similar double-element stimuli than from the less similar single-element stimuli. Experiment 3 tested for summation with stimuli from either single or multiple modalities and summation was found only in the latter. Thus the pattern of results seen in Experiments 1 and 2 was not dependent on whether the stimuli were single- or multi-modal nor was it dependent on whether the stimuli could elicit summation. This pattern of results is consistent with the predictions of Pearce’s (1987) configural theory
The effectiveness of environmental enrichment on reducing stereotypic behaviour in two captive vicugna (Vicugna vicugna)
No full textEnvironmental enrichment by increasing foraging behaviour and providing food item choice are widely practised and generally accepted as effective methods for reducing stereotypic behaviour in captive animals. In this study, the effectiveness of increasing foraging patch choice and food item choice on reducing motor stereotypy in two captive vicugna were examined. For the purposes of the study, first, browse was added to the vicugna's enclosure as an additional forage item and, second, the vicugna's normal feed was divided: half being provided in the indoor quarters and half in the outdoor yard. The results revealed that providing browse as an additional forage item increased the observed stereotypic behaviour; however, dividing the vicugna's feed, and therefore increasing forage patch choice, decreased stereotypy. This study was limited because of the small sample size and because the area in which the vicugna were performing stereotypic behaviour was partially visually obscured. However, this study has implications for animal welfare because it highlights the need to evaluate the suitability of foraging enrichment items, and suggests that more research into accommodating the adaptive foraging behaviour of this species in captivity may be necessary
Impaired instrumental choice in crib-biting horses (Equus caballus)
No full textHorses displaying an oral stereotypy were tested on an instrumental choice paradigm to examine differences in learning from non-stereotypic counterparts. The paradigm was specifically applied in order to examine learning that requires maintenance of response-outcome judgements. The stereotypic horses were found not to choose a more immediate reinforcer over three learning sessions. This suggests an initial behavioural correlate for dorsomedial striatum dysregulation in the stereotypy phenotype
Control of rodent and human spatial navigation by room and apparatus cues
No full textA growing body of literature indicates that rats prefer to navigate in the direction of a goal in the environment (directional responding) rather than to the precise location of the goal (place navigation). This paper provides a brief review of this literature with an emphasis on recent findings in the Morris water task. Four experiments designed to extend this work to humans in a computerized, virtual Morris water task are also described. Special emphasis is devoted to how directional responding and place navigation are influenced by room and apparatus cues, and how these cues control distinct components of navigation to a goal.Experiments 1 and 2 demonstrate that humans, like rats, perform directional responses when cues from the apparatus are present, while Experiment 3 demonstrates that place navigation predominates when apparatus cues are eliminated. In Experiment 4, an eyetracking system measured gaze location in the virtual environment dynamically as participants navigated from a start point to the goal.Participants primarily looked at room cues during the early segment of each trial, but primarily focused on the apparatus as the trial progressed, suggesting distinct, sequential stimulus functions. Implications for computational modeling of navigation in the Morris water task and related tasks are discussed
Training engagement and the development of behaviour problems in the dog: a longitudinal study
No full textCanine behaviour problems have serious welfare implications for dog and owner. Canine behavioural development can be divided into eight stages. Of these, the first year is most critical as it is the period when most social and environmental learning occurs, learned behaviour patterns become established and problem behaviours are most likely to become apparent (Lund et al, 1996). Whilst experiences during the socialisation period are of great importance, dogs may regress and become fearful if exposure to socio-environmental stimuli is not maintained (Dehasse, 1994; Fox, 1978) as both social and environmental learning continue throughout the juvenile period and adolescence. There is evidence of second phase of heightened sensitivity to fear arousing stimuli at the age of 6 months, around the onset of sexual maturity (Fox, 1972; Serpell and Jagoe, 1995), known as the ‘secondary sensitive’ or ‘secondary socialisation’ period. As with the onset of sexual maturity, the exact timing of this phase is variable between breeds and individuals. It may be that some do not go through this ‘secondary sensitive period’ until later adolescence or that it lasts for a greater or lesser part of the adolescent period (Dehasse, 1994; McBride et al. 1995).The present longitudinal study investigated the relationship between behaviour and early experience and management, including training engagement throughout the first year (Thompson et al, in prep.).51 owners completed questionnaires at the time of first vaccination (A), 6 months (B), 9 months (C) and 12 months (D) of age. Behaviour was assessed using the Canine Behaviour and Research Questionnaire (Hsu and Serpell, 2003), and responses produced scores on 6 subscales which had been validated by the current authors for this age group (<1 year).Results showed that dogs attending ‘puppy socialisation/training classes’ or ‘puppy parties/socialisation groups’ prior to 6 months of age had significantly lower total problem behaviour scores than dogs attending other training formats or receiving no training. Dogs attending ‘young dogs classes’ between 6 and 9 months of age also showed a significant reduction in total problem behaviour. Six C-BARQ subscales were used: attachment/attention seeking (AAS); non-social fear (NSF); dog-directed aggression or fear (DDAF); owner directed aggression (ODA); stranger-directed fear (SDF) and separation-related problems (SRP). Analysis revealed differential effects of both the age at which the dog was trained and the type and methods of training used. In summary, results indicate that professional training is beneficial in reducing the incidence of problems behaviour and is most effective when engaged in prior to 6 months of age. Furthermore, class formats providing a combination of obedience training, troubleshooting advice and intra-specific socialisation are most effective in producing well balanced dogs.<br/
MeSH term explosion and author rank improve expert recommendations
No full textInformation overload is an often-cited phenomenon that reduces the productivity, efficiency and efficacy of scientists. One challenge for scientists is to find appropriate collaborators in their research. The literature describes various solutions to the problem of expertise location, but most current approaches do not appear to be very suitable for expert recommendations in biomedical research. In this study, we present the development and initial evaluation of a vector space model-based algorithm to calculate researcher similarity using four inputs: 1) MeSH terms of publications; 2) MeSH terms and author rank; 3) exploded MeSH terms; and 4) exploded MeSH terms and author rank. We developed and evaluated the algorithm using a data set of 17,525 authors and their 22,542 papers. On average, our algorithms correctly predicted 2.5 of the top 5/10 coauthors of individual scientists. Exploded MeSH and author rank outperformed all other algorithms in accuracy, followed closely by MeSH and author rank. Our results show that the accuracy of MeSH term-based matching can be enhanced with other metadata such as author rank
Differential place and response learning in horses displaying an oral stereotypy
No full textSignificant similarities exist between the neural and behavioural features of environmentally and drug-induced stereotypy. For example, exposure to dopamine agonists, such as amphetamine, induces stereotypy and causes alterations in midbrain neurophysiology similar to those observed following chronic stress. An additional behavioural feature of these neural
29 changes in the drug-induced phenotype is an enhanced rate of switching from response-outcome (R-O) to stimulus-response (S-R) learning. The aim of the current experiment was to examine O and S-R learning in horses displaying environmentally-induced oral stereotypies. This was achieved by employing variations of a place-response paradigm. In Experiment 1, we found that crib-biting horses displayed ‘response’ learning after 20-learning trials, whereas non-crib-biting controls tended to display ‘place’ learning throughout the experiment. In Experiment 2, we used a modified version of the place-response paradigm, where the subjects were introduced to the maze from different start points and forced always to turn the same way. We found that the crib biters acquired the task at a faster rate suggesting again that this group were displaying ‘response’ learning. Finally, in Experiment 3, we carried out an arena test to ensure that crib biters were capable of ‘place’ learning. These results are the first to show that horses displaying an oral stereotypy, a behavioural phenotype previously associated with stress-induced perturbations of the basal ganglia, preferentially use ‘response’ learning. The findings are discussed in relation to the search for an aetiological model of stereotypy
The relative influence of place and direction in the Morris water task
No full textThe present study evaluated the generality of directional responding (Hamilton, Akers, Weisend, & Sutherland, 2007) in the Morris water task and attempted to identify methods that would yield a preference for navigation to the precise spatial location of an escape platform in the room. Four experiments evaluated the effects of training with the pool in a fixed location by repositioning the pool for a no-platform probe trial such that the absolute spatial location of the platform and the relative location of the platform within the pool (to which a directional response would occur) were in opposite quadrants. Two experiments attempted to explicitly train navigation to an absolute location in the room by repositioning the pool
during training while keeping the platform at the same location in the room. A preference for directional responding over navigation to the precise location of the platform was observed across a wide range of conditions including when rats were given extensive training (240 trials; Experiment 1), only given
platform placement experience in the absence of active swim training (Experiment 2), trained to navigate to multiple platform locations in a moving platform variant of the task (Experiment 3), and when animals were trained to navigate to a particular location regardless of the position of the apparatus in the room
(Experiments 4 - 5). A preference for navigation to the absolute spatial location of the platform was observed only when the salience of the pool was reduced by filling it to the top with water (Experiment 6)
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Comparison of tethering and group-pen housing for sled dogs
No full textThe experiment investigated whether there would be a difference in behaviour between the effects of long-term tethering without exercise, long-term tethering with exercise and group pen housing on sled dogs. Siberian husky sled dogs from a commercial sled-dog kennel (n=9), were exposed to four different housing conditions and filmed to record behaviours for analysis. Filming took place at the sled dog kennel. The conditions consisted of six-months with no-exercise/tethered (Condition A), exercise (daily running)/tethered (Condition B), four weeks no-exercise/tethered (Condition C) and no exercise/un-tethered in group pens with 3 dogs per pen (Condition D). The dogs were returned to baseline (Condition A) after three months in group pen housing to control for order effects. Subjects were then filmed after a two-week habituation period. The tethered housing conditions (A,B and C) produced evidence of more repetitive behaviours and fewer social behaviours than the un-tethered housing condition. Although un-tethering subsequently reduced rebound and repetitive behaviours, the variable of tethering without exercise (conditions A and C) revealed the greatest difference in behaviour. Long term tethering with no exercise produced agonistic behaviours indicative of frustrative non-reward heightened by the intermittent delivery of the reward of exercise. Increased aggression vigorously directed at neighbouring dogs and an overall increase in vigilance was the direct consequence of the frustration of non- reward. Un-tethering significantly reduced interdog aggression (p=.05), but the dogs remained vigilant. Therefore, long-term tethering without exercise or with the intermittent reward of exercise produces an increase in frustrative maladaptive behaviours such as aggression and increased vigilance
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