Response learning confounds assays of inhibitory control on detour tasks

Animal Cognition - The ability to inhibit prepotent actions towards rewards that are made inaccessible by transparent barriers has been considered to reflect capacities for inhibitory control (IC)....     

Visual-reinforcer color-and operant behavior in Siamese fighting fish

Male Siamese Fighting Fish (Betta splendens) were conditioned to emit an operant response sequence reinforced by presentation of a model of a male Siamese Fighting Fish in aggressive display. Operant response rate varied as a function of the color of the model with respect to the color of the subject.     

Serotonin blockade delays learning performance in a cooperative fish

Animals use learning and memorizing to gather information that will help them to make ecologically relevant decisions. Neuro-modulatory adjustments enable them to make associations between stimuli and appropriate behavior. A key candidate for the modulation of cooperative behavior is serotonin. Previous research has shown that modulation of the serotonergic system spontaneously affects the behavior of the cleaner wrasse Labroides dimidiatus during interactions with so-called ‘client’ reef fish. Here, we asked whether shifts in serotonin function affect the cleaners’ associative learning abilities when faced with the task to distinguish two artificial clients that differ in their value as a food source. We found that the administration of serotonin 1A receptor antagonist significantly slowed learning speed in comparison with saline treated fish. As reduced serotonergic signaling typically enhances fear, we discuss the possibility that serotonin may affect how cleaners appraise, acquire information and respond to client-derived stimuli via manipulation of the perception of danger.     

Individual behavior in learning of an artificial grammar

Artificial grammar learning (AGL) is a widely used experimental paradigm that investigates how syntactic structures are processed. After a familiarization phase, participants have to distinguish strings consistent with a set of grammatical rules from strings that violate these rules. Many experiments report performance solely at a group level and as the total number of correct judgments. This report describes a systematic approach for investigating individual performance and a range of different behaviors. Participants were exposed to strings of the nonfinite grammar A ⁿ B ⁿ . To distinguish grammatical from ungrammatical strings, participants had to pay attention to local dependencies while comparing the number of stimuli from each class. Individual participants showed substantially different behavioral patterns despite exposure to the same stimuli. The results were replicated across auditory and visual sensory modalities. It is suggested that an analysis that looks at individual differences grants new insights into the processes involved in AGL. It also provides a solid basis from which to investigate sequence-processing abilities in special populations, such as patients with neurological lesions.     

Social learning in Cartilaginous fish (stingrays Potamotrygon falkneri)

Social learning is considered one of the hallmarks of cognition. Observers learn from demonstrators that a particular behavior pattern leads to a specific consequence or outcome, which may be either positive or negative. In the last few years, social learning has been studied in a variety of taxa including birds and bony fish. To date, there are few studies demonstrating learning processes in cartilaginous fish. Our study shows that the cartilaginous fish freshwater stingrays (Potamotrygon falkneri) are capable of social learning and isolates the processes involved. Using a task that required animals to learn to remove a food reward from a tube, we found that observers needed significantly (P < 0.01) fewer trials to learn to extract the reward than demonstrators. Furthermore, observers immediately showed a significantly (P < 0.05) higher frequency of the most efficient “suck and undulation” strategy exhibited by the experienced demonstrators, suggesting imitation. Shedding light on social learning processes in cartilaginous fish advances the systematic comparison of cognition between aquatic and terrestrial vertebrates and helps unravel the evolutionary origins of social cognition.     

A technique for measuring thermoregulatory behavior in the fish

Apparatus and procedure are described for studying thermoregulatory behavior in fish. Results obtained with rainbow trout suggest that the described apparatus has several advantages over previously utilized devices.     

Two visual mechanisms underlying the behavior of fish

Summary Studies of motion-detection by fish reveal two separate processes, which are hypothetically linked to different kinds of behavior. Furthermore, studies of interocular transfer with mirror-image shape discriminations also indicate two distinct mechanisms for the representation of visual directions. From these two kinds of experiment, it seems that visual processes subserving orientation of the fish to a moving object should be clearly distinguished from processes by which the fish evaluates the identity or activity of the object.

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Zusammenfassung Untersuchungen der Bewegungswahrnehmung von Fischen zeigen zwei verschiedene Prozesse auf, die mit zwei verschiedenen Verhaltensweisen in Beziehung gesetzt werden. Eine Analyse des interokularen Transfers mit Unterscheidung spiegelbildlicher Formen läßt außerdem erkennen, daß zwei verschiedene Mechanismen für die Repräsentation visueller Richtungen verantwortlich sind. Aus diesen Experimenten wird geschlossen, daß jene visuellen Prozesse, welche der Orientierung des Fisches in bezug auf ein sich bewegendes Objekt dienen, scharf unterschieden werden sollten von denen, durch welche der Fisch die Identität oder Aktivität des Objektes beurteilt.

     

Factors in the learning behavior of the albino rat

The table of intercorrelations published by Dr. R. L. Thorndike in theGenetic Psychology Monographs, 1935,17, No. 1, has been reanalyzed into ten factors. Rotation of the reference vectors resulted in a configuration which, for all practical purposes, may be said to show a simple structure and (except for one variable on one factor) a positive manifold. Five of the factors can be interpreted with some confidence, one only with considerable caution; three factors are specific to the apparatus employed, and for the one remaining factor, no interpretation is attempted; it appears to be a residual plane.     

Caudal fin branding fish for individual recognition in behavior studies

Caudal fin branding is an inexpensive technique for marking and identifying small, fragile fish. A modified tip on a hand-held soldering pencil is used to cauterize small holes in the caudal fin membrane. The technique is simple to use, appears to cause little trauma to the fish, and lasts for at least several weeks.