A comparison of three training programs with the same workload on overhead throwing velocity with different weighted balls

The purpose of this study was to determine if different throwing programs based upon velocity (throwing with a regular sized soccer ball), resistance (throwing with heavy medicine ball), or a combination of both with the same workload would enhance 2-handed overhead throwing velocity with different ball weights. Sixty-eight high-school students (16.5 ± 1.8 years, 57.8 ± 12 kg, 164 ± 9 cm), divided into 3 groups, participated in the study. The training programs were matched on total workload, which resulted in the velocity-training group performing 6 series of 14 reps per session with soccer balls, whereas the resistance-training group performed 3 series of 6 throws with a 3-kg medicine ball, and the combination-training group threw 9 times with a 3-kg medicine ball and 3 series of 14 reps with a soccer ball per session. Throwing velocity with a soccer ball, a 1- and 3-kg medicine ball was tested before and after a training period of 6 weeks with 2 sessions per week. A significant (p ≤ 0.05) increase in throwing velocity was found after the 6-week training period with the soccer ball (6.9%) and the 1-kg medicine ball (2.8%), but not with the 3-kg medicine ball (-2.5%). In contrast, no group interaction was found with the different balls indicating that velocity, resistance, or a combination as a form of training increased the throwing velocity. Different types of training with the same total workload can increase the throwing velocity in a similar way, which shows that workload is of importance in designing training programs and comparing training with each other. Therefore, those that train high-school soccer players could implement any one of these 3 6-week programs to increase 2-handed overhead soccer throw-in velocity. This could allow the throw-in to be harder or potentially thrown farther if the right trajectory is used.     

Learning and long- and short-term memory in cockroaches

Intact cockroaches, headless insects and isolated segments of the animal were trained to avoid electric shocks, contingent upon an electric signal which was applied a fraction of a second prior to the shocks. The results showed that all the intact insects learned to avoid the shocks in approximately ten sessions, on a schedule of two daily sessions and ten trials per session. The retention of the learned responses was further tested; it showed that there was no decrement of avoidance reactions till the end of insect life in the experimental conditions. Furthermore, this retention of the learned behaviour was not affected by the severance of the head nor even by the isolation of a single ganglion, once the behaviour had been established.The learning ability of the headless animals, and of the isolated segments, was different. There is evidence that both types of preparations demonstrated some degree of learning, but a majority of them failed to reach the criterion of 100 per cent avoidances in a training schedule, exactly the same as for the intact cockroach. Nevertheless, if the headless insects were given a mass training of fourteen sessions per day, all of them reached the criterion. The retention of the isolated segment was found to be less than 1 day long, and that of the headless insects lasted at most 2 or 3 days after the last training session.It is interpreted that long-term memory can be established in the intact animals and, once it has been accomplished, the acquired behaviour can be retained by the lower portions of the central nervous system.     

Positive reinforcement training in rhesus macaques—training progress as a result of training frequency

Positive reinforcement training (PRT) efficiency was examined as a function of training frequency in 33 pair‐ or triple‐housed female rhesus macaques. The animals were trained three times a week, once a day or twice a day, using PRT and a clicker as a secondary reinforcer. All animals were trained on 30 sessions, with an average of 5 min per training session per animal. The behaviors, trained in succession, were Targeting (reliably touching and following a Target); Collaborating (dominant animals allowing subordinates to train while stationing); Box‐training (accepting being enclosed in a small compartment while responding to Target training) and initial Injection training. Fulfilled criteria for Targeting were obtained in 32/33 animals in a median of nine training sessions. Collaboration was obtained in 27/33 animals in a median of 15 training sessions. However, only four animals completed Box‐training during the 30 training sessions and started Injection training. When comparing training success in terms of number of training sessions, training twice a day was less efficient than the other two treatments. In terms of daily progress, our results suggest that from a management perspective, daily training is more conducive to quick training success than thrice weekly training. In addition, in this study no further advantages could be gained from training twice a day. Am. J. Primatol. 71:373–379, 2009. © 2009 Wiley‐Liss, Inc.     

Breakfast in the nook and dinner in the dining room: time-of-day discrimination in rats

Four studies were conducted which demonstrate that most (63%) male Sprague-Dawley rats can attain criterion, nine correct choices over ten consecutive trials, on a time-of-day discrimination in an elevated T-maze, but that the task is relatively difficult. The discrimination required that the rats go to one goal arm during a morning session and the other in an afternoon session. The sessions always began at the same time and were at least 6 h apart. A larger proportion of rats attained criterion and required fewer trials when the discriminative cue was a maze insert providing visual and tactile stimulation (0.72), orientation and position of the maze in the room (0.88), or the rats were required to always make the same left or right turn (0.94). Also, once criterion was attained, rats trained on time-of-day discrimination only made about 70% correct choices with continued training. Housing the rats with continuous light, all laboratory noises masked with white noise, and a random feeding schedule did not prevent them from acquiring the time-place discrimination. Testing the rats with a random number of trials during morning and afternoon sessions and with added or omitted sessions revealed that the rats did not use response or session alternation strategies to perform the discrimination. Also, the particular experimenter administering the morning or afternoon sessions did not serve as a cue for the discrimination. The relative difficulty of the task suggests that time of day does not normally function as a discriminative stimulus for choices, but probably as a contextual stimulus. Further, performance of the task in the absence of time-of-day cues suggests that the discrimination is based on event memory combined with an internal timing mechanism.     

The effects of the distribution of training on learning feedback-assisted cardiac acceleration

In order to test a hypothesis derived from a motor skills learning model of cardiac acceleration control, groups of subjects were given biofeedback training for four sessions to learn cardiac acceleration under four different training schedules: (1) all sessions in one day, (2) daily sessions, (3) sessions every other day, and (4) weekly sessions. Ability to accelerate heart rate both with and without feedback was determined at each session. Also ability to accelerate heart rate without feedback was determined 1 week after the last training session as a measure of retention. Although there was highly significant (p less than.0001) evidence of heart rate control both with and without feedback, there were no differences in degree of control attributable to distribution of training sessions. There was, however, a trend (p less than .10) for subjects trained under the most distributed training schedule (weekly) to show more retention than subjects trained under a less distributed schedule (daily).     

Voluntary heart rate deceleration: A critical evaluation

This experiment was designed as a test of the view that the human heart rate (HR) deceleration response can be brought under voluntary control, when some form of exteroceptive feedback is available. Sixteen female volunteers were randomly assigned to two groups. The first group received instructions to decrease their HR plus a continuous negative (failure) binary feedback, while the second group received only the instructions. Each subject was given four sessions of HR deceleration training. Two identical tests were presented, one before and the other after the series of training sessions. These tests were divided into two parts. In the first part, subjects attempted to decrease their HR while undergoing an ischemic arm pain stress. In the second part, subjects performed a 40-trial HR discrimination task. The results indicate that all subjects decrease HR during both rest and voluntary control periods within each training session, but there are no significant group differences, no improvement in HR deceleration control over the four training sessions, and no difference in performance between rest and voluntary control periods. Similarly HR, blood pressure (BP), and the HR×BP product levels during the ischemic stress condition and the HR discrimination performance do not show group differences. It is suggested that the HR deceleration response may not meet the criteria generally applied to the definition of a voluntary response.     

Fine structural changes in uterine smooth muscle and fibroblasts in response to estrogen

The fine structure of the estrogen-primed uterus was examined in two series of rats, with emphasis upon the alterations in smooth muscle cells and fibroblasts. The first series of animals were mature animals that were sacrificed at diestrus or estrus. The second series consisted of prepubertal rats (57–70 g) that received subcutaneous injections of estradiol-17 β in 20% alcohol. Four groups of animals received the hormone twice daily for 3 days for a total dose of 0.06, 0.6, 6.0, or 60.0 µg, respectively. An estrogenic response was observed in all groups as indicated by an increase in uterine weight. Control groups consisted of either untreated animals or animals receiving 20% alcohol. All animals were sacrificed on the 4th day. The fibroblasts and smooth muscle cells in the controls were similar to their counterparts in the mature animal in diestrus. They were small, contained relatively little rough endoplasmic reticulum, and the connective tissue cells appeared like fibrocytes. All of the estrogen-treated animals were similar in appearance and were comparable to their counterparts in the mature animal in estrus. Both the smooth muscle cells and the fibroblasts were increased in size, demonstrated a marked enlargement and dilation of ergastoplasmic cisternae, and contained increased numbers of attached and free cytoplasmic ribosomes. The presence of an extensive rough endoplasmic reticulum in the smooth muscle cells of the stimulated uterus is in marked contrast to the appearance of these cells in other tissues. These observations correlate with previous biochemical studies by other workers, in which estrogens have been shown to promote the synthesis of uterine RNA, collagen, and noncollagenous protein, and suggest that smooth muscle cells may participate in the synthesis of connective tissue proteins.     

Influence of rest interval lengths on hypotensive response after strength training sessions performed by older men

The purpose of this study was to compare the postexercise hypotensive response after different rest intervals between sets (1 and 2 minutes) in normotense older men. Seventeen older men (67.6 ± 2.2 years) with at least 1 year of strength training experience participated. After determination of 10 repetition maximum (10RM) loads for exercises, subjects performed 2 different strength training sessions. On the first day, volunteers performed 3 sets of 10 repetitions per exercise at 70% 10RM, with 1 or 2 minutes' rest interval between sets depending on random assignment. On the second day, the procedures were similar but with the other rest interval. There was no difference in systolic and diastolic blood pressure between rest intervals at any time point measure. Before 1- and 2-minute sessions, the systolic blood pressure values were 122.7 ± 6.0 and 123.2 ± 3.7 mm Hg, and diastolic blood pressure values were 80.5 ± 5.6 and 82.0 ± 3.7 mm Hg, respectively. Both 1 and 2 minute sessions still presented reduced values for systolic blood pressure after 60 minutes (102.9 ± 6.9 and 106.7 ± 5.4 mm Hg, respectively), while the diastolic blood pressure presented significant reductions for 50 minutes after a 1 minute session (12.1 to 5.6 mm Hg) and for 60 minutes after the 2 minute session (13.3 to 6.5 mm Hg). Additionally, the systolic and diastolic blood pressure effect size data demonstrated higher magnitudes at all time point measures after the 2-minute rest sessions. These results suggest a poststrength training hypotensive response for both training sessions in normotense older men, with higher magnitudes for the 2-minute rest session. Our findings suggest a potentially positive health benefit of strength training.     

Cytoplasmic changes in level and distribution of glucose-6-phosphatase activities from rat liver during diethylnitrosamine-induced carcinogenesis.

Glucose-6-phosphatase (EC 3.1.3.9) activities were determined in isolated microsomes, cytoplasmic smooth and rough membranes, ribosomes and free cytosol from rat liver undergoing carcinogenesis by diethylnitrosamine (DENA) and compared with cytoplasmic fractions isolated in parallel from healthy animals from the same age.With continuous administration of a low dose of DENA (2.6 mg/kg rat per day for 20 weeks in the drinking water) livers of carcinogen treated rats became heavier than the control livers but the body weight decreased. About 70% of total glucose-6-phosphatase activity could be detected in the microsomal fraction. While there was no significant difference in this activity in both animal groups up to the 4th week, glucose-6-phosphatase of cancerous liver showed a distinct decrease of activity compared with normal liver.During cancer induction this enzyme became more soluble, confirmed by the observation that it was detached from firmer structures of cytoplasm as rough membranes and polysomes and translocated to smooth membranes and the soluble cytoplasmic fraction successively. The corresponding increase in glucose-6-phosphatase activity in the 105 000 g supernatant appears to be due to the loss of enzyme activity in a distinct cytoplasmic membrane fraction. These data strongly suggest that in parallel with alteration of cytoplasmic membrane structures during carcinogen feeding glucose-6-phosphatase is detached from heavier components of the cytoplasm while total activity decreased. Possible mechanisms of these findings are discussed.     

Implementation of Motor Imagery during Specific Aerobic Training Session in Young Tennis Players

The aim of this study was to investigate the effects of implementing motor imagery (MI) during specific tennis high intensity intermittent training (HIIT) sessions on groundstroke performance in young elite tennis players. Stroke accuracy and ball velocity of forehand and backhand drives were evaluated in ten young tennis players, immediately before and after having randomly performed two HIIT sessions. One session included MI exercises during the recovery phases, while the other included verbal encouragements for physical efforts and served as control condition. Results revealed that similar cardiac demand was observed during both sessions, while implementing MI maintained groundstroke accuracy. Embedding MI during HIIT enabled the development of physical fitness and the preservation of stroke performance. These findings bring new insight to tennis and conditioning coaches in order to fulfil the benefits of specific playing HIIT sessions, and therefore to optimise the training time.     

Facial Expression Training Optimises Viewing Strategy in Children and Adults

This study investigated whether training-related improvements in facial expression categorization are facilitated by spontaneous changes in gaze behaviour in adults and nine-year old children. Four sessions of a self-paced, free-viewing training task required participants to categorize happy, sad and fear expressions with varying intensities. No instructions about eye movements were given. Eye-movements were recorded in the first and fourth training session. New faces were introduced in session four to establish transfer-effects of learning. Adults focused most on the eyes in all sessions and increased expression categorization accuracy after training coincided with a strengthening of this eye-bias in gaze allocation. In children, training-related behavioural improvements coincided with an overall shift in gaze-focus towards the eyes (resulting in more adult-like gaze-distributions) and towards the mouth for happy faces in the second fixation. Gaze-distributions were not influenced by the expression intensity or by the introduction of new faces. It was proposed that training enhanced the use of a uniform, predominantly eyes-biased, gaze strategy in children in order to optimise extraction of relevant cues for discrimination between subtle facial expressions.     

Acute effects of verbal feedback on upper-body performance in elite athletes

Argus, CK, Gill, ND, Keogh, JWL, and Hopkins, WG. Acute effects of verbal feedback on upper-body performance in elite athletes. J Strength Cond Res 25(12): 3282-3287, 2011-Improved training quality has the potential to enhance training adaptations. Previous research suggests that receiving feedback improves single-effort maximal strength and power tasks, but whether quality of a training session with repeated efforts can be improved remains unclear. The purpose of this investigation was to determine the effects of verbal feedback on upper-body performance in a resistance training session consisting of multiple sets and repetitions in well-trained athletes. Nine elite rugby union athletes were assessed using the bench throw exercise on 4 separate occasions each separated by 7 days. Each athlete completed 2 sessions consisting of 3 sets of 4 repetitions of the bench throw with feedback provided after each repetition and 2 identical sessions where no feedback was provided after each repetition. When feedback was received, there was a small increase of 1.8% (90% confidence limits, ±2.7%) and 1.3% (±0.7%) in mean peak power and velocity when averaged over the 3 sets. When individual sets were compared, there was a tendency toward the improvements in mean peak power being greater in the second and third sets. These results indicate that providing verbal feedback produced acute improvements in upper-body power output of well-trained athletes. The benefits of feedback may be greatest in the latter sets of training and could improve training quality and result in greater long-term adaptation.     

Reduction of instrumental discrimination performance by post-conditioning devaluation of discriminative stimulus: the effects of novelty in reinforcing outcome and extended training

In three experiments the effects of post-conditioning pairings of a discriminative stimulus (Sd) with an illness-inducing agent (lithium chloride, LiCl) on subsequent discrimination performance in extinction and consumption of reinforcing outcome were investigated. Rats were trained to choose a correct lever to obtain food pellets, with a light presented on a bulb just above the correct lever serving for the Sd on each trial. After achievement of a criterion of the discrimination, animals received paired or unpaired presentations of the Sds and LiCl injection. In Experiment 1, in which a familiar outcome was given throughout the discrimination training, Sd-LiCl pairings did not reduce either lever-press performance during presentation of the Sds or amount of consumption of outcomes. On the other hand, in Experiment 2 where a novel outcome was introduced in the final two sessions of the discrimination training, subsequent Sd devaluation reduced lever-press performance during presentations of the Sds. Similar findings were obtained in Experiment 3, in which animals were given extended discrimination training with introduction of novel outcomes in the final two sessions. These findings suggest that a representation of the outcome, evoked by presentation of the Sd, and illness were associated in the course of Sd-LiCl pairings but only when a novel outcome was used.     

Automatic imitation in budgerigars

A fully automated procedure, involving computer-controlled stimulus presentation and computer-recorded response measurement, was used for the first time to study imitation in non-human animals. After preliminary training to peck and step on a manipulandum, budgerigars were given a discrimination task in which they were rewarded with food for pecking during observation of pecking and for stepping during observation of stepping (Compatible group), or for pecking while observing stepping and for stepping while observing pecking (Incompatible group). The Incompatible group, which had to counter-imitate for food reward, showed weaker discrimination performance than the Compatible group. This suggests that, like humans, budgerigars are subject to 'automatic imitation'; they cannot inhibit online the tendency to imitate pecking and/or stepping, even when imitation of these behaviours interferes with the performance of an ongoing task. The difference between the two groups persisted over 10 test sessions, but the Incompatible group eventually acquired the discrimination, making more counter-imitative than imitative responses in the final sessions. These results are consistent with the associative sequence learning model, which suggests that, across species, the development of imitation and the mirror system depends on sensorimotor experience and phylogenetically ancient mechanisms of associative learning.     

Endocrine and behavioral traits in low-avoidance Sprague-Dawley rats

In the present series of experiments, we have examined the endocrine profile of two stable colonies of Sprague-Dawley rats, here labeled Stock A, and Stock B, differing markedly in their ability to acquire a conditioned avoidance response. On separate occasions, the animals were subjected to five daily sessions (approximately 20 trials per 15 min session) of conditioned avoidance training, measurements of startle reactivity to an auditory stimulation and open-field spontaneous locomotor activity observations. The experiments were concluded by taking blood samples for later analysis of plasma glucose and plasma levels of the following hormones: insulin, gastrin, CCK, glucagon, somatostatin, oxytocin and corticosterone. The low-performing Stock B animals were characterized by [1] being more reactive to sensory stimulation: higher startle amplitude and shorter startle latency; [2] having higher plasma insulin and corticosterone levels, whereas plasma gastrin and oxytocin were significantly lowered and a strong tendency for a decrease also in plasma CCK. There were no differences in spontaneous locomotor activity between the two substrains. Taking total variability in avoidance performance into account, there was a statistically significant positive correlation between plasma oxytocin, as well as gastrin, levels and avoidance performance. The evidence obtained here, and in other laboratories, suggests that the Stock B animals display hormonal changes indicative of a submissive-defensive reaction pattern. Thus, the avoidance acquisition deficits displayed by the present Sprague-Dawley stocks A and B, are in all probability caused by emotional reactions when challenged with external stimuli requiring active responding.     

Effect of stress on the Schultz-Dale reaction in guinea pig aorta.

The smooth muscle of thoracic aorta from guinea pig sensitized with egg albumin (EA) produced an anaphylactic contraction when it was exposed to EA. Experiments were performed to evaluate stress effects on the anaphylactic contraction in guinea pig aortic rings. Two types of stressors were used as immunosuppressor stimuli: physical restraint and shaking of the animals. Both stressors diminished the amplitude of the Schultz-Dale contraction in aortic rings from sensitized guinea pig. The shake stress stimulus interrupted several times during each session induced higher immunosuppression in animals in which the active sensitization and the stress sessions began the same day. Severe restraint stress, prior to active immunization, also suppressed significantly the anaphylactic response. The Schulz-Dale reaction in guinea pig aorta seems to be a valuable technique to study the stress effects on the anaphylactic response.     

Fine structure of the epineural connective tissue sheath of the subesophageal ganglion in Helix aspersa

Summary The epineural connective tissue sheath investing the subesophageal ganglion of Helix aspersa consists of a superficial region and a deeper region. The superficial region contains masses of globular cells intermingled with smooth muscle cells and nerve fibers all embedded in a connective tissue matrix. The histochemical and fine structural features of the globular cells show seasonal changes. During autumn to winter glycogen accumulates in their cytoplasm; this accumulation is accompanied by the appearance of dense, cytoplasmic globules which fuse together and ultimately form large pools of granular material. All the organelles and cytoplasm are displaced towards the cell periphery. Various cell-membrane invaginations containing dense material are prominent but there is no direct evidence to link these structures with the uptake of metabolites for glycogenesis. In winter there is a concentration of homogeneous, membrane-bound inclusions in the vicinity of the Golgi bodies. It is suggested that these inclusions constitute a lipid store. They decrease in number during summer. The globular cells do not bear any intimate relation to neurons and there is no reason to include these cells in the neuroglia. The muscle cells often weave around the globular cells but there is no direct contact. Nerve fibers innervate at least some of the muscle cells. The connective tissue consists of large and small diameter fibers suggesting that maturation of the fibrous components of the intercellular matrix is taking place in the superficial regions of the epineural sheath.This work has been supported by the Australian Research Grants Committee.     

How rats process spatiotemporal information in the face of distraction

How rats process spatiotemporal information in the face of distraction was assessed. Rats were trained on a time-place learning task in which the location of food availability depended on the amount of time elapsed since the beginning of the training session. In each training session each of four levers provided food pellets for 5 min on an intermittent schedule. In probe sessions interspersed with the final training sessions, the rats were presented with a second highly preferred food source-a piece of cheese-at various times into the session. Rats choose the correct lever after the cheese distraction, but it appeared that their internal clock had stopped during the cheese consumption period. Thus rats' internal clock, like that of pigeons, displays the properties of 'stop', 'reset', and 'restart'. Rat-pigeon differences in timing processes may be restricted to circadian or time of day timing. Present results also suggest that rats process spatial and temporal information separately.     

Spontaneous light or dark preference in albino mice?

The present experiment examined spontaneous visual choice behaviour and acquisition of a positively reinforced visual discrimination task in Swiss albino mice. In experiment I animals were given 4 consecutive trials in which they could freely enter either a dimly illuminated or a darkened arm of a Y-maze; the position of the light stimulus was randomized across trials. D groups and L groups were tested during the dark and the light period of the day respectively. Results revealed a significant spontaneous preference for the illuminated arm of the maze, independent of the testing period. It is suggested that the dim light has a reinforcing value because it provides additional information about a novel environment. In a second experiment an appetitive visual discrimination task was carried out in the same Y-maze. After a pretraining period, half the animals were reinforced in the illuminated arm and half were reinforced in the darkened one, on five consecutive days. On the first test session all groups of animals chose the illuminated arm significantly more frequently, whereas light/dark choices reached chance level on the last test session. Discrimination learning was not acquired and a behavioural analysis revealed an increasing tendency to a side preference across testing.     

Stimulus specificity in the acquisition and extinction of conditioned taste aversion

An experiment evaluated whether the acquisition and extinction of conditioned taste aversion in the rat is stimulus-specific by testing the degree of response transfer between sweet and salty tastes. Animals in the paired-same and paired-different groups received a presentation of a gustatory CS and a cyclophosphamide injection US. Nonconditioned control groups received unpaired CS /US presentations or the CS followed by a vehicle injection. Taste avoidance was evaluated in three nonreinforced test sessions. In the paired-same, unpaired and vehicle groups, all test sessions were conducted with the same flavor as originally used in training, whereas the paired-different group was tested with a novel flavor on the first and second sessions and with the originally trained flavor in last session. Stimulus specific acquisition was apparent in the first test session, when the animals in the group paired-same exhibited lower fluid intake than the other three groups. Evidence of specificity of extinction was apparent in the last test session, when animals in the group paired-different exhibited lower fluid intake than the other three groups. These results provide further evidence of stimulus specificity in acquisition and extinction of conditioned taste aversion, supporting the associative interpretation of these phenomena.