Operant conditioning and behavioral analyses using a minicomputer.

An operant conditioning and data analysis software system was developed for use on a PDP-12A minicomputer. The operant software functions in quasi time-sharing fashion to control and acquire data from any peripheral device that operates in the binary mode. In addition to independently running different experiments in near simultaneous fashion, the program also provides information on the current status of each experiment using a cathode ray-tube display. Response data from each experimental subject is stored on magnetic tape and analyzed, off-line, by the data analysis portion of the software system. A discussion of the operation of this system is given for one possible application: visual discrimination training.     

A new paradigm for operant conditioning of Drosophila melanogaster

A freely walking single fly (Drosophila melanogaster) can be conditioned to avoid one side of a small test chamber if the chamber is heated whenever the fly enters this side. In a subsequent memory test without heat it keeps avoiding the heat-associated side. The memory mutants dunce ¹ and rutabaga ¹ successfully avoid the heated side but show no avoidance in the memory test. Wildtype flies can be trained to successively avoid alternating sides in a reversal conditioning experiment. Every single fly shows strong avoidance and a positive memory score. The new conditioning apparatus has several advantages: (1) Statistically significant learning scores can be obtained for individual flies. (2) Learning scores are obtained fully automatically without interference of the experimenter. (3) The procedure is fast, robust and requires little handling. Therefore the apparatus is suitable for largescale mutant screening. (4) Animals are not attached to a hook and thus can easily be used for breeding.Abbreviations dnc dunce gene - PI performance Index - rut rutabaga gene - S.E.M. standard error of mean     

A technique for the operant conditioning to differentiate signals during reinforcement delay in primates

A new technique of training the primates to differentiate signals immediately during execution of the instrumental act (pushing the lever) was proposed. The technique makes it possible to study the processes of decision making during activation of the executive (motor) brain systems.     

Hearing in honeybees: operant conditioning and spontaneous reactions to airborne sound

Summary Airborne sound signals emitted by dancing bees (Apis mellifera) play an essential role in the bees' dance communication. It has been shown earlier that bees can learn to respond to airborne sounds in an aversive conditioning paradigm. Here we present a new training paradigm. A Y-choice situation was used to determine the frequency range and amplitude thresholds of hearing in bees. In addition, spontaneous reactions of bees to airborne sound were observed and used to determine thresholds of hearing. Both methods revealed that bees are able to detect sound frequencies up to about 500 Hz. The hearing threshold is 100–300 mm/s peak-to-peak velocity and is roughly constant over the range of detectable frequencies. The amplitude of the signals emitted in the dance language is 5 to 10 times higher, so we can conclude that bees can easily detect the dance sounds.     

The development of an operant conditioning training program for new world primates at the Bronx Zoo

This article describes the development of an operant conditioning training program for 17 species of New World primates at the Bronx Zoo. To apply less invasive techniques to husbandry protocols, the study introduced behaviors-hand feeding, syringe feeding, targeting, scale and crate training, and transponder reading-for formal training to 86 callitrichids and small-bodied cebids housed in 26 social groups. Individual responses to training varied greatly, but general patterns were noted among species. With the exception of lion tamarins, tamarins responded more rapidly than marmosets, Bolivian gray titi monkeys, and pale-headed saki monkeys in approaching trainers and learning behaviors. Marmosets, in comparison to most tamarins, had longer attention spans. This meant that fewer, lengthier sessions were productive whereas shorter, more frequent sessions were most successful for tamarins. Among the cebids, pale-headed saki monkeys needed relatively few sessions to perform basic and advanced behaviors whereas Bolivian gray titi monkeys were less responsive and progressed at a deliberate pace. Marked changes in the animals' behavior during daily husbandry procedures, their voluntary participation in training activities, and the disappearance of aggressive threats toward care staff indicated that training reduced stress and improved the welfare of the animals. During daily training displays, zoo visitors experienced interactive animals while learning the importance of low-stress animal husbandry.     

A case study employing operant conditioning to reduce stress of capture for red-bellied tamarins (Saguinus labiatus)

Traditional techniques used to capture New World monkeys, such as net capture, can induce high levels of acute stress detrimental to welfare. Alternatively, training nonhuman animals via operant conditioning to voluntarily participate in husbandry and/or veterinary practices is accepted as a humane process that can reduce stress and improve welfare. This study details the use of operant conditioning using positive reinforcement training (PRT) and target training to train a family of 5 captive red-bellied tamarins (Saguinus labiatus) in a wildlife park to voluntarily enter a transportation box and remain calm for 1 min after 54 training sessions. Observations of 2 unrelated net-capture processes provided measures of locomotion and vocalizations as indicators of stress behavior that were compared with those of the trained tamarins. Net-captured monkeys exhibited rapid erratic locomotion and emitted long, high-frequency vocalizations during capture whereas the trained tamarins exhibited minimal locomotion and emitted only 4 brief vocalizations (root mean square 35 dB) during capture. This indicates that the use of PRT considerably reduced potential for stress and improved welfare during the capture and containment of the tamarins.     

Attempt to modify rate and duration of licking in rats by operant conditioning

Lick-rate in rats is said to be constant for a given animal, despite variations of internal and external stimuli. On the other hand, small changes can be observed due to changes in the construction of the licking device. However, variations do not exceed 20%.In an attempt to gain operant control over the ILI (interlick interval — the time between two lick-onsets) the delivery of reinforcement (20 μl water) was made dependent on the emission of ILIs of a predetermined length longer than during baseline licking. It could be observed that rats could not shift the peak of their ILI distribution within the reinforced range but — to increase the number of reinforcements — they increased the scatter of the ILI distribution or developed a “harmonic” peak at double ILI length. When the animals were forced in a second experiment to prolong the lick-duration (time of tongue-spout contact) to obtain water, they failed if the restriction from the drinking spout made a closer approach impossible.It is argued that the ability to obtain reinforcement under both schedules is due to postural changes of the animal. The mechanisms controlling licking seem to be relatively constant, which allows good coordination with other behaviours which have to be performed during drinking, such as breathing and swallowing. It can be concluded that the amount of water consumed by rats is controlled by the length of time spent in licking and not by changing the lick-rate.     

BEAGLE: an application programming interface and high-performance computing library for statistical phylogenetics

Phylogenetic inference is fundamental to our understanding of most aspects of the origin and evolution of life, and in recent years, there has been a concentration of interest in statistical approaches such as Bayesian inference and maximum likelihood estimation. Yet, for large data sets and realistic or interesting models of evolution, these approaches remain computationally demanding. High-throughput sequencing can yield data for thousands of taxa, but scaling to such problems using serial computing often necessitates the use of nonstatistical or approximate approaches. The recent emergence of graphics processing units (GPUs) provides an opportunity to leverage their excellent floating-point computational performance to accelerate statistical phylogenetic inference. A specialized library for phylogenetic calculation would allow existing software packages to make more effective use of available computer hardware, including GPUs. Adoption of a common library would also make it easier for other emerging computing architectures, such as field programmable gate arrays, to be used in the future. We present BEAGLE, an application programming interface (API) and library for high-performance statistical phylogenetic inference. The API provides a uniform interface for performing phylogenetic likelihood calculations on a variety of compute hardware platforms. The library includes a set of efficient implementations and can currently exploit hardware including GPUs using NVIDIA CUDA, central processing units (CPUs) with Streaming SIMD Extensions and related processor supplementary instruction sets, and multicore CPUs via OpenMP. To demonstrate the advantages of a common API, we have incorporated the library into several popular phylogenetic software packages. The BEAGLE library is free open source software licensed under the Lesser GPL and available from http://beagle-lib.googlecode.com. An example client program is available as public domain software.     

Percentage reward in an operant analogue to foraging

Pigeons (Columba livia) responding on an operant, conditioning analogue to foraging could either accept or reject a variable-interval 20-s schedule which always led to food or a variable-interval 5-s schedule which led to food on only a percentage of trials. The probability of accepting the certain alternative increased as the percentage of food trials for the uncertain alternative decreased. The probability of accepting the uncertain alternative increased with the percentage of food trials for this alternative. Subjects receiving all of their food in the experiment (‘closed economy’) and those requiring supplementation (‘open economy’) preferred whichever alternative provided the higher overall mean rate of reinforcement.     

Skill-based conditioning games as an alternative to traditional conditioning for rugby league players

This study investigated the effects of skill-based conditioning games and traditional conditioning for improving speed, agility, muscular power, and maximal aerobic power in rugby league players. Sixty-nine subelite rugby league players performed either a skill-based conditioning games program (N = 32) or a traditional conditioning (i.e., running activities with no skill component) program (N = 37). Each player participated in a 9-week in-season training program, performed over 2 competitive seasons. Players performed 2 organized field-training sessions each week. Players underwent measurements of speed (10-m, 20-m, and 40-m sprint), muscular power (vertical jump), agility (L run), and maximal aerobic power (multi-stage fitness test) before and after the training period. Skill-based conditioning games induced a significant improvement (p < 0.05) in 10-m, 20-m, and 40-m speed, muscular power, and maximal aerobic power, whereas traditional conditioning activities improved 10-m speed and maximal aerobic power only. No significant differences (p > 0.05) were detected between the traditional conditioning and skill-based conditioning games groups for changes in 10-m speed, agility, and maximal aerobic power. Both groups won 6 of 8 matches played within the training period, resulting in a win-loss ratio of 75%. However, on average, the skill-based conditioning games group scored more points in attack (p < 0.05) and had a greater (p < 0.05) points differential than the traditional conditioning group. The results of this study demonstrate that skill-based conditioning games offer an effective method of in-season conditioning for rugby league players. In addition, given that skills learned from skill-based conditioning games are more likely to be applied in the competitive environment, their use may provide a practical alternative to traditional conditioning for improving the physiological capacities and playing performance of rugby league players.     

A minicomputer system for display and rate analysis in vectorcardiography

A system has been constructed for recording vectorcardiographic signal with a FM taperecorder. Off-line AD-conversion and analysis of rates and magnitudes of partial vectors are made with a minicomputer. The reason for studying particularly initial vectorrates is that according to our hypothesis these contain valuable information for classification of certain cardiac arrythmias according to supraventricular or ventricular impulse focus. Preliminary results confirm the hypothesis.In vectorcardiography one difficulty is to give an easily comprehensible presentation of the vectorloop. In this study a method for ‘3-dimensional’ display has been developed, using a graphic display processor and varying intensities of the beam.The system is to a high degree man-machine interactive.     

Motmot, an open-source toolkit for realtime video acquisition and analysis

Background  

Video cameras sense passively from a distance, offer a rich information stream, and provide intuitively meaningful raw data. Camera-based imaging has thus proven critical for many advances in neuroscience and biology, with applications ranging from cellular imaging of fluorescent dyes to tracking of whole-animal behavior at ecologically relevant spatial scales.     

Learning an operant conditioning task differentially induces gliogenesis in the medial prefrontal cortex and neurogenesis in the hippocampus

Circuit modification associated with learning and memory involves multiple events, including the addition and remotion of newborn cells trough adulthood. Adult neurogenesis and gliogenesis were mainly described in models of voluntary exercise, enriched environments, spatial learning and memory task; nevertheless, it is unknown whether it is a common mechanism among different learning paradigms, like reward dependent tasks. Therefore, we evaluated cell proliferation, neurogenesis, astrogliogenesis, survival and neuronal maturation in the medial prefrontal cortex (mPFC) and the hippocampus (HIPP) during learning an operant conditioning task. This was performed by using endogenous markers of cell proliferation, and a bromodeoxiuridine (BrdU) injection schedule in two different phases of learning. Learning an operant conditioning is divided in two phases: a first phase when animals were considered incompletely trained (IT, animals that were learning the task) when they performed between 50% and 65% of the responses, and a second phase when animals were considered trained (Tr, animals that completely learned the task) when they reached 100% of the responses with a latency time lower than 5 seconds. We found that learning an operant conditioning task promoted cell proliferation in both phases of learning in the mPFC and HIPP. Additionally, the results presented showed that astrogliogenesis was induced in the medial prefrontal cortex (mPFC) in both phases, however, the first phase promoted survival of these new born astrocytes. On the other hand, an increased number of new born immature neurons was observed in the HIPP only in the first phase of learning, whereas, decreased values were observed in the second phase. Finally, we found that neuronal maturation was induced only during the first phase. This study shows for the first time that learning a reward-dependent task, like the operant conditioning, promotes neurogenesis, astrogliogenesis, survival and neuronal maturation depending on the learning phase in the mPFC-HIPP circuit.