Six white rats were reinforced continuously for one, three, six, or nine successive barpresses at the end of fixed intervals of 1 min [schedule mix FI 1 CRF (n)]. Schedule-induced drinking became controlled by the onset of the FI in that drinking rarely occurred when food was available on CRF. Drink durations were predictable but were not related to “meal size” over the range of...
Extinction in a free-operant avoidance situation was defined as removing the effectiveness of the response in delaying shocks rather than the removal of shocks. This was identified as a procedure more consistent with those used in appetitive reward studies involving extinction. In the present study, orderly extinction was found in four out of five albino rats where the R-S...
The present study was conducted to ascertain whether the visual patterning or the intensity of environmental light in early life is the critical factor in inducing reported behavioral and physiological changes in adult animals (cf Singh et al, 1967). After weaning, littermate female rats were raised in either total darkness, facing a black-and-white striped or a flat-white...
The influences of central applications of adrenergic and cholinergic stimulating and blocking agents to the cat thalamus on successive visual discrimination performance were investigated. Applications of both noradrenaline and the adrenergic blocking agent ethobutamoxane improved discrimination performance by reducing nonreinforced responding. Conversely, injections of both the...
Fourteen mice served as Ss in a test of the odor hypothesis. All Ss received 104 acquisition trials administered in a double-alternation sequence of reward and nonreward. The results indicated that the mice were able to learn the double-alternation sequence when odor cues were maximized and unable to do so when odor cues were minimized. These results are seen as being comparable...
The training, extinction, and retraining performance of three groups of rats with large rewards (11 45-mg), small (45-mg) rewards, and small (45-mg) rewards with intertrial feedings (10 45-mg) was investigated in a runway. The results were in accord with the generalization that asymptotic performance is directly related to the magnitude of reward and differed from results...
Rats under physical restraint were presented a CS that was previously paired with either shock onset or electric shock termination, or at random intervals before and after shock onset (control). The group exposed to the CS previously paired with shock onset had significantly more gastric lesions than did the other two groups, which did not differ. These results support the...
Eighteen male and 18 female hooded rats were trained to perform a two-turn task in a temporal circular maze to evaluate the effects of different training schedules on acquisition rate. Ss were randomly allocated to the two Es (HM and CSC), and also to one of three training schedules: (1)4 × (2G 2F), i.e., four repetitions of two guided trials followed by two free trials; (2) 2...
A total of 132 rats were employed in two experiments designed to investigate the effect of an extraneous stimulus (light) presented at different stages of extinction. The animals were initially trained with either a CRF or VI food-reinforcement schedule. Presenting the light early in extinction led to inhibition in the CRF animals and disinhibition in the VI Ss. Later in...
Electrophysiological recordings of sleep in adult rats blinded prior to weaning were significantly different from those recorded in littermates blinded after weaning. Behavior on an open-field test failed to indicate any significant differences between these two groups. Thus, it appears that an early reduction of external sensory input can modify brain activity during sleep.
Cebus monkeys were subjected to differential classical, differential avoidance, or differential classical-avoidance eyelid conditioning. Conditioning performance was analyzed in terms of both response probability and eyeblink magnitude. The response-probability analysis failed to reveal either acquisition or discrimination under any treatment condition. The magnitude analysis...
C57BL/6J mice were tested at either 50 or 100 days of age under one of two illumination levels in the open field for 10 consecutive days. Analysis of activity scores revealed a reliable Age by Illumination interaction, indicating that illumination had different effects at the two ages. Overall defecation scores formed an inverted U-shaped function over test days, with defecation...
Twelve Mongolian gerbils were given daily tests of their preference for their own familiar vs other novel litter environments. The gerbils showed a striking preference for the home environment which gradually declined over 6 days of testing. The home litter preference was reinstated following aversiye stimulation. The data are discussed in terms of habituation, dishabituation...
Rats were given discriminated conditioned-suppression training. After the discrimination was well established, further trials were administered during which the signal for nonshock (CS-) was compounded with the signal for shock (CS+) during selected portions of CS+ presentation. Shocks continued to be delivered following CS+. It was shown that CS- reduced suppression in a readily...
Two studies using partial or consistent large (500 mg) and small (45 mg) reward are presented. In both studies, after extended reward acquisition, differences are negligible or nonexistent. Results from the partial reward groups indicate extinction differences also disappear after extended training. These results do not seem to be in line with usual assumptions regarding the...
The effect of 0.5-M hydroxylamine injected intracranially on a passive-avoidance task was followed in mice. Hydroxylamine administered 24 h before the acquisition trial or earlier had no effect on performance of animals. Hydroxylamine injected 2 h before the acquisition trial impaired the performance of animals tested 24, 48, 72 h, or 1 week later. Hydroxylamine injected 1, 2, or...
Fifteen female guinea pigs were observed with their offspring for Days 1–28 postpartum. The larger the litter (one to four animals), the greater the percentage of nursing time. With the exception of the four-animal litters, the smaller the litter, the greater the weight of the young. Finally, there was no relationship between litter size and the number of positive or negative...
Five groups of mice received 0, 30, 90, 270, or 810 mg/kg body weight of agroclavine, a drug chemically similar to LSD. Over 5 consecutive days smaller dosage levels either enhanced or produced little change in wheel-running activity, while higher dosages produced a decrement.
Seven rats were given 1-min buzzer presentations during Sidman avoidance (Experiment 1). Four of these Ss with a classical conditioning history (light-shock pairings) were also given light presentations alone and light-buzzer presentations during avoidance (Experiment 2). The buzzer presentations increased avoidance rates (unconditioned acceleration) and the light-buzzer compound...
One group of pigeons. Group TL1-L2, were rewarded for pecking a lighted response key in the presence of a tone and were not rewarded for pecking a less bright response key in the presence of noise. A second group of pigeons. Group (L1-L2)(TL1-L2), were similarly treated after first being given extensive pretraining with noise and the brighter light on positive trials and noise...
Two experimental groups (E1 and E2) were first trained in a runway before being transferred to a T-maze in which they received the same number of acquisition trials as a control group (C), which had no prior runway training. Group E2 differed from Group E1 in that it received extinction trials in the runway before being transferred to the T-maze. None of the three groups received...
In a double-runway apparatus using shock escape as the reinforcement, Lambert & Hammond (in press) showed that the Amselian frustration effect (FE) manifests itself as a marked slowing down in the second runway, when an expected relief from shock is not forthcoming. The present experiment was performed to determine if an animal builds up a particular expectancy of timeout from...
Guinea pigs were given shuttlebox avoidance training with one of three different shock intensities. Low shock produced the most rapid acquisition and highest final performance. In a second session, 48 h after the first, there was a marked and immediate increase in performance of low- and medium-shock animals. These results are attributed to the interference of performance by...
The acquisition and transfer performance of six cats with hippocampal-pyriform ablations was compared with that of seven normal animals. All animals were trained on a successive, go/no-go, auditory-brightness discrimination (Task 1). Ss were tested for transfer to the auditory and/or brightness cues of Task 1 by training them on similar discriminations using only the brightness...