First Day Of Training Research Articles

The control of dustbathing by pecking in young chicks

Young chicks have to learn what dust is for dustbathing. Therefore, early pecking experience with non-nutritious substrates may be significant for later identification of substrates for dustbathing. In this study, pecking experience was controlled in 12 pairs of chicks housed in wire cages by presentation of peat and yellow sand in a small box that allowed pecking, but not dustbathing in it. Five-minute tests were carried out on Days 39 and 16-17, whereas on Days 10-15, they were 'trained' to dustbathe by being allowed to peck for 30 min while on a glass plate in front of the pecking box. Pecking increased from Day 3 to 9, scratching from Day 3 to 5, and peat was clearly preferred over yellow sand. At that stage, the substrates were swallowed, i.e. treated as food. Chicks with a high dustbathing performance during training days readily performed dustbathing from the first day of training, and they performed little spontaneous vacuum-dustbathing on Days 16-17 on the wire floor of their cage as compared with the chicks we failed to train, who were more likely to engage in vacuum-dustbathing after the training period. Accordingly, in these chicks access to peat and sand for pecking (and ingestion) controlled dustbathing behaviour by Day 10. The results of a dustbathing choice test over Days 17-19, in which the chicks were allowed full opportunity to dustbathe in the substrates, confirmed this conclusion.

The effects of pregnenolone on acquisition and retention of a food search task

Two experiments were undertaken in which the effects of semichronic administration of the precursor steroid, pregnenolone, were examined in a food search task. In both experiments male rats were required to find a food reward in a designated hole in an arena with 16 equally spaced holes. Hormone administration began 8 days before the onset of training. Training was given on an every-other-day schedule for five sessions. Animals were deprived of food for 18 h before training or testing. Retention testing occurred 10 days after acquisition and this was followed by 2 days of training using a different hole for the reward. The two experiments differed only in the method of hormone administration. In one experiment the rats received an implanted (sc) slow release pellet containing pregnenolone before training. In the second experiment the animals received ip injections of pregnenolone sulfate before and during initial training and then had the slow release pellet implanted between acquisition and retention. Significant enhancement of retention was found during the middle trials of the retention test when the treated and control groups from the two experiments were combined. No differences were found during acquisition training in either experiment. On the first day of training the animals to find the reward in a new location, the group injected with pregnenolone sulfate and later implanted with pregnenolone slow-release pellets exhibited performance superior to that of their matched control group.

An examination of the relations between hippocampal long-term potentiation, kindling, afterdischarge, and place learning in the water maze.

Two approaches were used to study the relations between the acquisition of place learning in the Morris water maze and long-term potentiation (LTP), kindling, and afterdischarge (AD). In the first, the possibility of behavioral LTP in the dentate gyrus field potential evoked by stimulation of the perforant path was evaluated in rats that showed robust place learning in the water maze. There was no effect of place learning on the field potential, and field potential measures did not correlate with place learning acquisition measures. In the second approach, the effect of bilateral saturation of LTP on subsequent place learning in the water maze task, begun within 5 minutes of the last LTP session, was evaluated. The effect of kindled seizures evoked bilaterally from the perforant path, or of a single unilateral AD, on acquisition of the water maze task (begun within 10 minutes) were also evaluated. Bilateral LTP saturation did not affect place learning, and the bilateral LTP group learned as readily as controls. In contrast, the kindled and AD groups were severely impaired in their performance of the place learning task. A second day of training in the water maze without any further electrical stimulation indicated that these groups had acquired considerable information on the first day of maze training and were not distinguishable from controls on the second day of training. This indicated that the deficit in these groups on the first day of training was temporary and likely resulted from a temporary perturbation of normal brain function due to the seizures. The results indicate that bilateral saturation of LTP in the dentate gyrus does not affect place learning in the water maze. They also indicate that recent hippocampal seizures, but not kindling, disrupt place learning in this task.

Stimulation of 5-HT 1A receptors in the dorsal hippocampus impairs acquisition and performance of a spatial task in a water maze

8-Hydroxy-2-(di- n-propylamino)tetralin (8-OH-DPAT), a potent 5-HT 1A receptor agonist, was infused in the dorsal hippocampus of rats and its effect on acquisition and performance of a 2-platform spatial discrimination task was studied using a water maze. The infusion (0.5 μl/min) of 2 but not 0.4 μg 8-OH-DPAT in the CA1 region of the dorsal hippocampus impaired rats' accuracy with no effect on latency (except day 3). At 5 μg 8-OH-DPAT impaired rats' accuracy and significantly increased choice latencies from day 2 to day 5 of the training period. The dose of 2 μg significantly increased the errors of omissions on the first day of training and animals which had received 5 μg 8-OH-DPAT made significantly more errors of omission on the first and second days of training. Intrahippocampal administration of 1 μg spiroxatrine, a 5-HT 1A receptor antagonist, antagonized the effect of 5 μg 8-OH-DPAT on accuracy and choice latency with no significant effect on the errors of omission on days 1 and 2 of training. Infusion of 2 and 5 μg 8-OH-DPAT in the dorsal hippocampus also impaired accuracy in well-trained rats. The results suggest that stimulation of 5-HT 1A receptors in the CA1 region of the dorsal hippocampus causes an impairment of spatial discrimination in rats.

Sex-dependent effects of neonatally administered morphiceptin and d-Ala– d-Leu-enkephalin on maze learning in rats

Newborn rats were injected (ip) with morphiceptin [72.7 micrograms/kg (a mu-type opioid receptor agonist)], D-alanine2-D-leucine5-enkephalin [79.4 micrograms/kg (a delta-receptor agonist)], or saline for 7 days after birth. Testing on a complex maze on Day 25 revealed a significant sex-dependent facilitation of performance by the opioid peptides. Peptide-treated females performed better than the males on the first day of training as measured by errors. Opioid treatment increased mortality, as three times as many peptide-treated animals died in comparison to the saline control group. Peptide treatment did not affect locomotor activity measured in an open field. Weight at Day 24 was also affected by the peptide treatment, females and males injected with the opioids being lighter and heavier, respectively, than the control group.

Conditioned orienting and defensive responses in the developing rat

Infant rats (16, 21, and 26 days old) received 3 days of classical conditioning training to Tone/Shock pairings using heart rate as the index of conditioning. The youngest group (16 days old) showed no evidence of conditioning at any stage of acquisition. In the 21- and 26-day-olds, response to the conditioned stimulus (CS) was a deceleration in heart rate during the first day of training. By day 3, the conditioned response (CR) shifted to cardioacceleration. The data were interpreted as offering strong support for a two-stage model of information processing in the infant rat, comprised of a conditioned orienting response in the first stage and a conditioned defensive response in the second.

CHANGES IN RESIDENT NEONATAL ETHICAL ATTITUDES ASSOCIATED WITH PEDIATRIC TRAINING

We previously demonstrated that Pediatric level 3 residents (PL3's) expressed attitudes of greater reluctance to resuscitate certain high risk infants than did Pediatric level 1 residents (PL1's) tested on the first day of training. We have followed our original group of PL1's at yearly intervals throughout residency training. Cumulative Guttman scaling procedures were employed to construct an attitude scale to measure the willingness of residents to resuscitate infants in a variety of clinical circumstances. A dynamic model of attitude change was tested using correlation and regression procedures. Residents demonstrated significantly increasing reluctance to resuscitate high risk infants over the first year of training compared to the first day of training (p<0.01), and again over the second year compared to the attitudes expressed at the end of the first year (p<0.01). This reluctance to resuscitate infants was accentuated by marriage (p<.005), but not by age, gender, or religious preference. There were no significant changes during the third year. These longitudinally acquired data support our original cross-sectional data demonstrating an association of Pediatric training and attitudes concerning neonatal resuscitation. These attitude changes are greatest during the first 2 years of training and may be accentuated by other personal factors.

A survey of learners coming to mental handicap nursing

FOR NEARLY HALF a century, recruitment and wastage of learners : have remained a fertile and favourite ground for detailed investigations. Today, with available data, it is possible to produce a profile of a typical nurse learner who stays and leaves during her training. But in a rapidly changing society, both culturally and materially, with specialisation as the central feature, is there a need to look afresh at the recruits coming into different types of nursing? This article, a culmination of several years of observations and experience, is an attempt to obtain a picture of the newly recruited learners (both student and pupil nurses) into mental handicap nursing in the South Ockenden School of Nursing. At the beginning of 1981, two sets of student and pupil nurses were asked to complete a simple questionnaire of 11 questions on their first day of training. At the same time, a profile of these learners' background was completed separately.

The Effect of Command Preexposure on Instruction-Following Behavior in Severely Retarded Adolescents

Repeated nonreinforced preexposure of a stimulus subsequently used as a conditioned or discriminative stimulus typically results in a decrement in performance of infrahumans and humans in classical and instrumental conditioning tasks. The naturalistic or applied significance of this “latent inhibition” phenomenon has not been investigated. This study examined the effects of repeated presentations of verbal commands on the acquisition of instruction-following behavior in two severely retarded girls. Each received 200 preexposures of one command followed by instruction-following training on both the preexposed and a nonpreexposed command. This procedure was repeated for three different pairs of commands for each girl. Commands were given in French and preexposed and nonpreexposed commands were counterbalanced across subjects. Mean percentage of unassisted responses to preexposed commands was 35.9 percentage points less than to nonpreexposed commands on the first day of training. The results suggest that latent inhibition may be a viable phenomenon in applied settings.

Failure of mice to demonstrate spatial memory in the radial maze

The radial maze performances CD-1 mice and S-1 (Berkeley strain) rats were compared. Rats readily learned to solve the maze. In contrast, mice gave no indication of improved performance beyond that exhibited during the first days of training. Several interpretations of this finding are discussed. These data provide evidence against the hypothesis that rodents readily solve this maze because the reinforcement contingencies are consonant with those that naturally occur when foraging for food. It was concluded that one cannot be certain that radial maze performance necessarily reflects specific innate foot-search behaviors of animals until more investigations are carried out on food-search behaviors in the field, variables that affect search behaviors, and how these factors directly influence radial maze performance.

Correlation between the rate of avoidance conditioning and the brain catecholamine level in rats.

1. The number of mistakes made by animals on the first day of formation of an avoidance reaction correlates with a low DA level in the whole brain and with a high NA level in the cortex + corpus striatum. 2. The number of mistakes on the first day of training does not depend on the level of spontaneous motor activity, and mistakes characterize the actual learning process.

Increased self-administration of d-amphetamine after destruction of 5-hydroxytryptaminergic neurons

Rats will initiate self-administration of d-amphetamine and achieve a stable injection rate within 7–10 days. Animals injected intraventricularly with 5,7-dihydroxytryptamine, which selectively destroys 5-hydroxytryptamine-containing neurons, consistently self-injected larger amounts of d-amphetamine from the first day of training, but the acquisition of a stable rate of drug self-administration was not altered. Bilateral microinjection of 5,7-dihydroxytryptamine into nucleus accumbens failed to alter either the acquisition of d-amphetamine self-administration or the maintenance of a stable rate of injection.

Influence of shaping procedures and schedules of reinforcement on performance in the two-bar drug discrimination task: a methodological report.

Rats were trained to discriminate phenobarbital (50 mg/kg) vs saline in a two-bar, thirst-motivated operant drug discrimination task. Presses on bar 1 were reinforced when the rat was drugged and presses on bar 2 when not drugged. Several shaping procedures and schedules of reinforcement were compared to determine which would allow drug discriminations to be learned most rapidly, and which would result in the higherst asymptotic accuracy of discrimination. The discrimination was learned more rapidly when differential drug conditions were used from the very first day of training than when shaping on both bars was completed before the differential drug conditions were introduced. Variable interval (VI), fixedratio (FR), and differential reinforcement of low rate (DRL) schedules were tested as well as several more complex schedules. Asymptotic accuracy of discrimination was highest when FR, interlocking FR 10/FI90″, or DRL 16″ schedules were used; accuracy was intermediate when a tandem VI 20″/FR 10 schedule was used; accuracy was relatively low when a VI 20″ schedule was employed. When the optimal shaping procedure and schedule of reinforcement were used, highly accurate drug discriminations were learned much more rapidly than has previously been reported. The results are discussed with reference to control of differential responding by contextual and discriminative stimuli.

Elimination of enuresis without a conditioning apparatus: An extension by office instruction of the child and parents

A new and effective method of training enuretic children without a conditioning apparatus has relied on a special trainer during the first day of training. The present study determined whether a single office session would suffice to teach the parents to conduct training themselves. Forty-four enuretic children 3 to 15 years of age were treated. The results were similar to those obtained when using the special trainer. All of the children stopped bedwetting. A median of four accidents occurred before achieving 2 weeks of dryness. Bedwetting was reduced to 18% on the first day and decreased progressively to 4% at the 1-year follow-up. Relapses were infrequent (7%), and none of the children “dropped out.” The new method appears to be very effective when taught in a single, usual office counseling situation without the need for a special trainer.

Effects of Drive upon Habit Strength and Resistance to Extinction

In Exp. 1 rats were given 5 training trials per day for 8 days in a straight runway under both low and high drive, with the drive state of each subject altered each day. Subjects were subdivided and given 20 extinction trials under either low or high drive. Exp. 2 replicated the training conditions of Exp. 1, but, in addition, lengthened training sessions to 18 days and extinguished each subject under both low and high drive. Combined results showed residual effects of intensity of drive state on the first day of training upon later training trials; however, with additional training the effect dissipated. Data were interpreted as supportive of the position that drive contributes to habit strength.

Behavioral transfer in praying mantis by injection of brain homogenate

Adult female mantids Stagmatoptera biocellata were trained not to attack a black star in movement. Brain extracts of these trained donors were transferred by injection to naive mantids (i.e. the Experimental Group) which then showed a number of strikes significantly smaller than that reached during preinjection testing. Recipients that received extracts from untrained donors (i.e. the Control Group) did not present such a difference in performance. The Experimental Group, unlike the Control Group, evinced a further reduction in number of attacks by training, in spite of the fact that they had not had the proper experimental conditions to learn not to attack. The authors interpret these results simply as induction of specific behavior rather than as chemical transfer of learning. The influence of a general depressive effect during the first day of training is discussed.

Haloperidol-induced disruption of conditioned avoidance responding: Attenuation by prior training or by anticholinergic drugs

Rats injected daily with haloperidol (0.15 mg/kg) failed to acquire a one-way active avoidance response over a 9 day period (10 traisl/day). When these animals were subsequently tested without haloperidol, on the first drug-free day they performed as well as animals given saline throughout the training period and significantly better than naive saline-treated animals on the first day of training. The performance of rats were trained for two days before receiving haloperidol was only partly blocked by the drug, while animals trained for 9 days before drug administration were immune to the disruptive effects. Three anticholinergic (muscarinic) drugs, atropine (10 mg/kg), scopolamine (1 mg/kg) and benztropine (2 mg/kg) significantly reversed the effect of haloperidol on the acquisition of the avoidance response. These results are similar to those observed after bilateral destruction of the dipaminergic nigroneostriatal projection and support the view that this system is critically involved in the acquisition of learned instrumental responses. The nature of the avoidance deficit produced by these treatments is discussed with reference on the possibility that they selectively block the initiation of voluntary motor responses. According to this hypothesis, the failure of these treatments to disrupt escape responding may be due to the fact that the unconditioned stimulus generates reflexive motor responses (flinch, jump, etc.) which are sufficient to begin the motoric sequences that cannot be initiated voluntarily in response to the conditioned stimulus.

Post-Shock Discriminations in the Acquisition of Free-Operant Avoidance By Rats

Acquisition of free-operant avoidance was studied during 5 days of training in 36 rats. The response-shock interval was 20 sec, and an escape response was required in shock. Temporal discriminations of the response-shock interval were indicated by rising conditional probability of response functions for some of the animals on Days 4 and 5 of training. No Ss showed temporal discriminations in their over-all interresponse time distributions before Day 4. However, as early as the first day of training, discriminations were obtained with some Ss when responding directly after shock was considered separately. These early post-shock discriminations appeared only for Ss that eventually became efficient avoiders. However, many Ss learned to avoid without showing a temporal discrimination.

Hippocampal unit activity during classical aversive and appetitive conditioning.

Rats were trained with a tone being followed by either food or electric shock, on alternate days. Unit activity during application of the conditioned stimulus was recorded from the dorsal hippocampus. The results indicate differentiation of the hippocampal system. Dentate units respond by augmentation to a conditioned stimulus which leads to food and by inhibition to the same stimulus when it precedes electric shock. The hippocampus proper responds by augmentation in both situations. The intensity of the hippocampal response to the conditioned stimulus on the first day of training is higher if the unconditioned stimulus is food than if it is electric shock. These data cast light on the functions of the dorsal dentate-hippocampal connections and the hippocampus proper during aversive and appetitive conditioning.

恐怖動因と補強価の転換性

According to N. E. Miller, fear is a learnable drive, and therefore, is defined as response-produced stimulus. Confronting danger situation, animal responds to it with the muscle tension and this tense response becomes stimulus in the organism which works as a drive or cue for further instrumental response.Ordinarily drive state is controled on a certain level (e.g. 23hrs. hunger drive), and cue is given a certain distinctiveness. There is established a univocal relationship between them. However the drive state has oscillation in itself. A response produces oscillation in a drive state and the varied drive state produces further instrumental responses. We postulate that the reinforcing value which the stimulus context carries, is reversible from rewarding to punishing, and vice versa, in accordance with the variability of the drive state that occurs with the lapse of time.Experiment I. In order to test the hypothesis of the reversibleness of reinforcing value in the stimulus context, three kinds of stimulus contexts, that is, buzzer-shock (black wall): buzzer-shock (white), buzzer-shock (black): shock (white), shock (black): shock (white) were used in a shuttle box. Number of avoidance responses is shown in Table 1. When animal runs to white side, the white side is rewarding, but this side becomes gradually punishing as time goes by, then he returns to the black side.Experiment II. In order to find the effect of the variability of the drive state which occurs with the lapse of time, animal was trained on avoidance in buzzer-shock: shock, or the unequal reinforcingstimulus context. The results are shown in the Tables 2, 3, 4. On the first day of training, animal stayed for 19.22min. out of 40.00min. on the black side, and on the last day of training, they stayed for 28.51min.. Animal may be said to prefer to stay more on the fear-reducing side than on the tense side. This is supported by the relative reinforcement theory of C. C. Perkins, Jr., though his theory does not necessarily require the drive concept.Experiment III. Fear works adaptably to any abrupt change of the stimulus context. After the completion of the avoidance training in buzzershock: shock stimuluss context, an extinction trial was introduced. The original black wall was suddenly replaced by an inserted white wall, and the original white by the inserted black one. The original and inserted stimuli were alternately presented for one min. each, and duration of stay on both sides was measured. As Fig. 1 shows, animal responds to the inserted black side with an adaptable avoidance. The curve for the duration of stay on the black side goes up until no difference is seen between the 9th inserted trial and the 10th original trial. In addition to this, a striped wall was used as an inserted wall. Almost the same result is shown in Fig. 2.