Social reinforcement in Betta splendens: A reconsideration.

Two experiments showed that conspecific images release aggressive behavior in male Siamese fighting fish with an intensity inversely related to the S-to-image distance. Exps III and IV then showed that part of this ethogram was the alternation of approach and escape maneuvers similar to the pattern of movements observed at the start of combat. Findings suggest that reinforcement procedures have neglected these species-specific tendencies. Claims that Ss work or are motivated to seek agonistic experiences were considered ambiguous. Data alleging to demonstrate a process of social reinforcement are more consistent with the hypothesis that Ss reacted to social cues that were presented intermittently. Aggression in Siamese fighting fish appeared not to be governed by response-reinforcement principles but to be modulated by the qualities of releasing stimuli (i.e., their size, shape, and distance from S). (11 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

On the predictability, sensitization, and habituation of aggression in male bettas (Betta splendens).

The winners of dyadic contests between male bettas were fish that in a 30-min prefight test spent a greater amount of time approaching a conspecific male that was confined behind clear glass. Approach duration was shown also to be a stable characteristic over periods as long as 30 days. Finally, approach durations and fight outcomes were influenced by both prior fighting and exposure to conspecifics behind glass. The nature of this influence, however, was dependent on the duration of an animal's approach duration in a 30-min pretreatment test. Fish with low approach durations were influenced far more extensively by social experiences than were animals with high approach durations. These studies are discussed with reference to theories of opponent assessment and the habituation and sensitization of aggression and in the context of some ethically phrased criticisms previously directed at investigations of aggression and predation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Socially mediated learning in male Betta splendens..

Showed, in 7 experiments, that in the absence of social stimulation male Siamese fighting fish would approach any of several visual and spatial cues that had previously been paired with the Ss' mirror images. Findings demonstrate that learned modifications of swimming mediated by social stimuli are possible in Bettas. Results suggest that Ss learned to exhibit conditioned gill-cover erection as part of a pattern of locomotion that could effectively maintain territories. Nearly all Ss learned to swim in proximity to visual and spatial cues previously presented with conspecific images. Results also suggest that territorial defense in some teleosts may be mediated by the association of social cues with visual and spatial stimuli. (26 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A failure to find socially mediated taste aversion learning in Norway rats (R. norvegicus).

Three studies with 240 Long-Evans rats investigated whether rats would avoid ingesting a diet as the result of interacting with an ill conspecific that had ingested that diet. Observer rats interacted with conspecific demonstrators immediately after demonstrators ate a novel diet and were made ill by LiCl injection. Following their interaction with demonstrators, observers were tested for aversion to their ill demonstrator's diet. Previous research has shown that (a) an observer can extract information from a demonstrator sufficient to permit identification of the demonstrator's diet and (b) a rat ill from LiCl toxicosis is an adequate UCS in a taste aversion learning paradigm. Two of the present experiments demonstrated that cues emitted by an S, reflecting the particular diet it has eaten, were an adequate CS in a toxicosis-induced aversion learning situation. Observer avoidance of a diet previously ingested by an ill demonstrator was, however, not demonstrated. Implications of the failure to find socially mediated aversion learning are discussed. (10 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Using visual reinforcement to establish stimulus control of responding of Siamese fighting fish (Betta splendens).

Stimulus control of ring swimming was studied with male Siamese fighting fish (Betta splendens) using 2-component multiple schedules in which the components were correlated with the presence or absence of air bubbles in the water. In Experiment 1, either response-independent mirror presentations or extinction was juxtaposed with immediate response-dependent mirror presentations. Rates of ring swimming generally were higher with immediate reinforcement than with either response-independent mirror presentations or extinction. In Experiment 2, different durations of response-dependent mirror presentations were juxtaposed. Generally, higher rates of ring swimming occurred with 15-s than with 0-, 1-, or 3-s durations. Results demonstrate that stimulus control of responding can be established with these fish under several conditions of differential reinforcement. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sex reversal in female Betta splendens as a function of testosterone manipulation and social influence.

In Experiment 1, female Betta given daily injections of testosterone (T) for 9 weeks acquired anatomical features characteristic of males as indicated by changes in fin length, body coloration, and gonadal morphology. These findings suggested that a potential for sex reversal exists in females of this species. In Experiment 2 we measured changes in aggressive behavior during testosterone-induced anatomical changes. Aggression decreased toward females and increased toward males as treatment with T progressed. The final displays of aggressive behavior and anatomical characteristics of fish injected with T resembled those of typical males. In Experiment 3, female Betta primed with T injections for 3 or 6 weeks and permitted to interact socially with females continued to display characteristics of sex reversal after T supplementation ceased. Sex reversal in isolated fish injected with T for 3 or 6 weeks was not sustained, and fish receiving only the control vehicle showed negligible change in both the isolated and community conditions. We discuss the results in terms of similarities with the sex change process found in isolated communities of coral reef fish. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Numerity of a socially housed hamadryas baboon (Papio hamadryas) and a socially housed squirrel monkey (Saimiri sciureus).

To extend a study conducted by E. M. Brannon and H. S. Terrace (1998, 2000), the authors trained 1 hamadryas baboon (Papio hamadryas) and 1 squirrel monkey (Saimiri sciureus) to respond to stimuli representing the numerosities 1-4 in ascending order. When tested with novel stimuli of the same numerosities, both subjects' performance appeared to be based on the numerical attributes of stimuli. Subjects were then tested on their ability to order pairs of numerosities derived from the values 1-9. Both subjects successfully ordered pairs that included the untrained numerosities 5-9 regardless of the total surface area of numerosities. Accuracy and latency of responding also showed numerical distance and magnitude effects. Numerosity was a salient cue to both subjects, suggesting that these 2 families of primates perceive ordinal relations. The outcome shows that cognitive studies of this type can be effectively conducted with socially housed animals. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Categorization learning in horses (Equus caballus).

Categorization learning was investigated in 2 horses (Equus caballus). Both horses learned to select a 2-dimensional black stimulus with an open center instead of a filled stimulus in a 2-choice discrimination task. After a criterion of 10 out of 10 correct responses in a random series for 2 consecutive sessions was reached, 15 additional pairs of open-center versus filled stimuli were tested. Each was run to criterion and then incorporated into sessions of randomly mixed problems. Both horses solved the 1st problem by simple pattern discrimination and showed evidence of categorical processing for subsequent problems. New pairs were learned with few or no errors, and correct responses on novel trials were significantly above chance. These results suggest that the horses were making their selections on the basis of shared characteristics with the training stimuli and were using categorization skills in problem solving. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Social competence is reduced in socially deprived rhesus monkeys (Macaca mulatta).

Rhesus monkeys deprived for some period from their mother have often served as a model for the effect of adverse rearing conditions on social competence in humans. Social competence is the capacity to react in a species-specific way to social interactions. The current study assesses whether early deprivation from peers also affects the rates of behavior and social competence in rhesus monkeys. This was studied in groups of rhesus monkeys with different rearing conditions: subadult females that were mother-only reared during their first year of life and subsequently housed with peers were compared with subadult females from five naturalistic social groups. Socially deprived monkeys showed higher rates of submission and stereotypic behaviors than socially reared individuals. In addition, they show socially incompetent behavior, since they react with agonistic behavior to nonthreatening social situations. The results suggest that this socially incompetent behavior is rooted in a general feeling of anxiety toward group companions. The authors hypothesize that anxiety negatively affects social information processing, which results in socially incompetent behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Prior-residence effect in Betta splendens..

Presented male Siamese fighting fish with the visual image of an aggressive male conspecific for a 150-min test, with attack behaviors monitored continually, to examine the hypothesis that a period of residency results in relatively persistent combat. A 10-day period of residency in either the test tank or its exact replica resulted in more persistent attack than 10 min of residency. Testing in water other than that in which Ss had resided for 10 days did not produce a reduction in attack. Finally, the extent of attack behavior occurring early in testing was highly and positively correlated with subsequent attack duration; that is, at the start of an encounter, and before severe physical damage has been caused, Bettas may communicate to opponents their intention to engage in persistent, injurious aggression. (19 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Respondent conditioning of self-injurious behavior in early socially deprived rhesus monkeys (Macaca mulatta).

Examined whether certain environmental events could elicit self-injurious behavior (SIB) and whether the resulting SIB could be conditioned to an antecedently presented external stimulus. Exp I showed that SIB could be elicited in 4 socially isolated rhesus monkeys by the application of brief, mild, electric footshock. In Exp II, 3 socially isolated Ss were exposed to a procedure that paired a 10-sec tone with a 1-sec electric footshock. Three control Ss received presentations of the tone alone. Results show that Ss in the experimental group began to show SIB during the tone periods, thereby providing evidence of respondent conditioning. Data expand the scope of the learning model of SIB from primarily operant interpretations to respondent conditioning as well. (15 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Social learning in the golden hamster (Mesocricetus auratus).

Investigates whether golden hamster (Mesocricetus auratus) pups can acquire a new behavior by interacting with an experienced adult conspecific. The behavior consisted of using teeth and forepaws to retrieve a piece of food dangling from a small chain. Instrumental learning techniques were used to train the demonstrators. Four groups of pups were exposed to different kinds of social experience. In the 1st group, the pups interacted with their skilled mother, in the 2nd group, they did the same with their inexperienced mother, in the 3rd group, they interacted with inexperienced littermates; and in the 4th group, the pups were tested individually. At the end of an acquisition period, the pups were tested individually to assess their performance. Results demonstrate that interacting with a skilled mother has a remarkable effect on the acquisition of a new feeding behavior by hamster pups. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Place and position learning in honeybees (Apis mellifera).

Foraging honeybees (Apis mellifera) were trained individually to choose between 2 identical targets set close together on a large table in a heterogeneous surround. Discrimination was facilitated by the introduction of a small object that was nearer to 1 target than the other. It was also facilitated by the introduction of a longer object or a curved shield that was not differentially placed with respect to the targets but designed to encourage a fixed orientation to them. The results support a distinction between place learning and position learning in honeybees. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cue learning by rufous hummingbirds (Selasphorus rufus).

The authors investigated the use by wild-living rufous hummingbirds ( Selasphorus rufus) of flower color pattern and flower position for remembering rewarded flowers. Birds were presented with arrays of artificial flowers, a proportion of which was rewarded. Once the locations were learned by the birds, the array was moved 2 m, and flower color pattern and/or rewarded positions were manipulated. The birds' ability to learn which were the rewarded flowers in this 2nd array was much more strongly affected by whether the rewarded flowers occupied the same positions as in the 1st array than by their color patterns. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Configural learning in two species of marsupial (Setonix brachyurus and Sminthopsis crassicaudata).

Four experiments examined the ability of quokkas (Setonix brachyurus) and fat-tailed dunnarts (Sminthopsis crassicaudata) to solve 2 configural tasks: transverse and negative patterning. Transverse patterning requires the simultaneous solution of 3 overlapping discrimination problems (A+B-, B+C-, C+A-). Both species could solve the nonoverlapping (elemental) version of this task (U+V-, W+X-, Y+Z-), but only dunnarts solved the transverse patterning task. Negative patterning requires conditioned responses to 2 stimuli when presented separately but not together (A+, B+, AB-). Both species formed a selective conditioned response to A+ and B+ stimuli and inhibited responding to a simple nonreinforced stimulus (C-), but only dunnarts successfully inhibited responding to the AB- compound to solve the negative patterning task. These experiments are the first to demonstrate configural learning in a marsupial. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Stages of category learning in monkeys (Macaca mulatta) and humans (Homo sapiens).

Smith and Minda (1998) and Blair and Homa (2001) studied the time course of category learning in humans. They distinguished an early, abstraction-based stage of category learning from a later stage that incorporated a capacity for categorizing exceptional category members. The present authors asked whether similar processing stages characterize the category learning of nonhuman primates. Humans (Homo sapiens) and monkeys (Macaca mulatta) participated in category-learning tasks that extended Blair and Homa’s paradigm comparatively. Early in learning, both species improved on typical items more than on exception items, indicating an initial mastery of the categories’ general structure. Later in learning, both species selectively improved their exception-item performance, indicating exception-item resolution or exemplar memorization. An initial stage of abstraction-based category learning may characterize categorization across a substantial range of the order Primates. This default strategy may have an adaptive resonance with the family resemblance organization of many natural-kind categories. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Display reinforcement in the Siamese fighting fish, Betta splendens : Aggressive motivation or curiosity?

Tested 34 adult male fish in a runway 'T'-maze apparatus. The 3 experiments compared performance (measured by swimming speed and percent choice correct) to a variety of stimuli in the goal box. The stimulus that evoked the most vigorous aggressive display (a live conspecific) supported the highest level of performance; a stimulus that evoked no display (a marble) failed to sustain operant behavior. Stimuli that induced some aggression but also some escape (live nondisplay fish) supported performance at reduced levels. These results implicate aggression and not curiosity as the primary motivating factor. They also show that the responsiveness of the stimulus is a critical aspect of reinforcement and that the level of performance is determined by escape tendencies as well as aggression. It is proposed that failure of a stimulus to provide appropriate feedback constitutes an aversive event. (19 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Spatial learning and memory in the tortoise (Geochelone carbonaria).

A single tortoise (Geochelone carbonaria) was trained in an eight-arm radial maze, with the apparatus and general procedures modeled on those used to demonstrate spatial learning in rats. The tortoise learned to perform reliably above chance, preferentially choosing baited arms, rather than returning to arms previously visited on a trial. Test sessions that examined control by olfactory cues revealed that they did not affect performance. No systematic, stereotyped response patterns were evident. In spite of differences in brain structure, the tortoise showed spatial learning abilities comparable to those observed in mammals. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Place and object learning in chicks (Gallus gallus domesticus).

Trained chicks (Gallus gallus domesticus) to discriminate between two identical boxes containing food on the basis of the positions of the boxes. Once learning was accomplished, the visual characteristics (color or size) of the boxes were changed and chicks were retrained to criterion. Results showed that chicks remembered more about visual characteristics of the boxes than about their position. The same results did not occur, however, if the change was limited only to parts of the boxes rather than to the entire object. Further experiments indicated that it was not the amount of physical change as such that produced these different results but rather the way in which animals select meaningful objects in their perceptual organization of the environment. We argue that chicks define spatial locations in terms of the relative positions of objects and that in so doing they also encode those visual characteristics that make possible perceptual segregation of distinct objects. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Experimental evidence for spatial learning in octopuses (Octopus bimaculoides).

Octopuses forage far from temporary home dens, to which they return for shelter. Spatial tasks may assess learning. Octopuses (Octopus bimaculoides) were placed in a novel arena, and their movements were tracked for 72 hr. Movements around the arena decreased across time, consistent with exploratory learning. Next, octopuses were given 23 hr to move around an arena; after a 24-hr delay, their memory of a burrow location was tested. Most remembered the location of the open burrow, demonstrating learning in 1 day. Finally, octopuses were trained to locate a single open escape burrow among 6 possible locations. Retention was tested after a week and was immediately followed by reversal training (location rotated 180). Octopuses learned the original location of the burrow, remembering it for a week. Path lengths increased significantly after reversal, gradually improving and showing relearning. Octopuses show exploratory behavior, learning, and retention of spatial information. (PsycINFO Database Record (c) 2010 APA, all rights reserved)