Increasing evidence suggests that personality structure differs between species, but the evolutionary reasons for this variation are not fully understood. We built on earlier research on New World monkeys to further elucidate the evolution of personality structure in primates. We therefore examined personality in 100 family-reared adult common marmosets (Callithrix jacchus) from 3 colonies on a 60-item questionnaire. Principal components analyses revealed 5 domains that were largely similar to those found in a previous study on captive, ex-pet, or formerly laboratory-housed marmosets that were housed in a sanctuary. The interrater reliabilities of domain scores were consistent with the interrater reliabilities of domain scores found in other species, including humans. Four domainsdmdash;conscientiousness, agreeableness, inquisitiveness, and assertiveness—resembled personality domains identified in other nonhuman primates. The remaining domain, patience, was specific to common marmosets. We used linear models to test for sex and age differences in the personality domains. Males were lower than females in patience, and this difference was smaller in older marmosets. Older marmosets were lower in inquisitiveness. Finally, older males and younger females had higher scores in agreeableness than younger males and older females. These findings suggest that cooperative breeding may have promoted the evolution of social cognition and influenced the structure of marmoset prosocial personality characteristics.
LBL-11581 Preprint Submitted to the Journal of Comparative and Physiological Psychology SHORT-TERM MEMORY IS INDEPENDENT OF BRAIN PROTEIN SYNTHESIS Hasker P. Davis, Mark R. Rosenzweig, and Oliver W. Jones September 1980 TWO-WEEK LOAN COPY This is a Library Circulating Copy which may be borrowed for two weeks. a personal retention copy, call Tech. Info. Division, Ext. 6782. Prepared for the U.S. Department of Energy under Contract W-7405-ENG-48
We propose a cognitive and neurobiological framework for creativity in nonhuman animals based on the framework previously proposed by Kaufman and Kaufman (2004), with additional insight from recent animal behavior research, behavioral neuroscience, and creativity theories. The additional information has lead to three major changes in the 2004 model-the addition of novelty seeking as a subcategory of novelty recognition, the addition of specific neurological processing sites that correspond to each of the processes, and the transformation of the model into a spectrum in which all three levels represent different degrees of the creative process (emphasis on process) and the top level, dubbed innovation, is defined by the creative product. The framework remains a three-level model of creativity. The first level is composed of both the cognitive ability to recognize novelty, a process linked to hippocampal function, and the seeking out of novelty, which is linked to dopamine systems. The next level is observational learning, which can range in complexity from imitation to the cultural transmission of creative behavior. Observational learning may critically depend on the cerebellum, in addition to cortical regions. At the peak of the model is innovative behavior, which can include creating a tool or exhibiting a behavior with the specific understanding that it is new and different. Innovative behavior may be especially dependent upon the prefrontal cortex and/or the balance between left and right hemisphere functions.
Studies of appetite in mammals emphasize that meal size is learned, but lactation and parental care constrain testing of naive individuals. Neonatal reptiles, in contrast, are self-sufficient foragers. The authors examined the effect of prey size on meal size in primivorous (at first feeding) northern watersnakes (Nerodia sipedon). When offered an excess of small prey (2%-20% of snake mass), neonates ate significantly smaller meals (M = 23.5% of snake mass) than when offered a single huge item (range = 32%-55%). The authors conclude that (a) the taking of smaller meals is not a learned effect, (b) there may be a satiety threshold for meal size rather than a target, (c) oropharyngeal stimuli may provide satiety cues, and (d) huge meals may have fitness costs.
Rhabdophis tigrinus, which typically forages on toads, has unusual nuchal glands on its dorsal neck region containing secretions chemically comparable to cardiac steroids found in toads. R. tigrinus also has several peculiar antipredator displays involving the neck region. If the nuchal gland secretions of R. tigrinus are derived from toads obtained as prey, populations of R. tigrinus that have not eaten toads over an evolutionary time scale would be expected to lose antipredator displays related to the nuchal glands. We found that laboratory-hatched R. tigrinus from a small toad-free island exhibited displays related to nuchal glands less frequently and flight responses more frequently than hatchling snakes from areas sympatric with toads. These results are consistent with the hypothesis of the dietary origin of the nuchal gland secretions and also support the genetic origin of the behavioral differences between the populations.
Developmental changes in the golden hamster pup's capacity for behavioral temperature regulation were studied. Groups of three pups aged 4-14 days were tested at room temperature (22 degrees C), on a strong gradient (34-22 degrees C), and on a mild gradient (30-22 degrees C). The proportion of time engaged in the following behaviors was recorded: contact with the warm edge (thermotaxis), active huddling, and quiet huddling. Pups tested at 22 degrees C engaged in active huddling, and their temperature dropped rapidly. Only on Day 14 were they able to maintain their temperature constant with a combination of vigorous exploration and quiet huddling. On the strong gradient, by contrast, pups were able to regulate their temperature at all ages. Young pups (4-5 days) depended on thermotaxis rather than huddling, separating when their temperature started to rise. With age, quiet huddling replaced thermotaxis as a dominant behavior. On the mild gradient, pups combined active and quiet huddling with thermotaxis, so that their temperature dropped at al slow steady rate (.1 degrees C/min). It is concluded that hamster pups have a well-developed capacity for behavioral temperature regulation. Whether they attempt to keep their temperature constant or tolerate a slow rate of drop depends on the amount of exogenous heat available, which under natural conditions would be supplied predominantly by the mother. These results suggest that the pups as well as the mother may participate in thermal regulation in the nest.
Rats were conditioned by pairing consumption of a novel sodium saccharin drinking solution with the effects of an ip injection of 75 mg/kg cyclophosphamide, an immunosuppressive drug. Five and ten days after conditioning, an experimental group of conditioned animals (Group CS) was reexposed to the saccharin drinking solution. Control animals (Group CSo) were conditioned but were not reexposed to saccharin. On Day 10, 15, or 25 after conditioning, animals were injected ip with sheep erythrocytes (SRBC), and independent subgroups were sampled for hemagglutinating antibody titer 4, 6, or 8 days later. There was a significant effect of sample time (antibody titers 4 days after immunization were lower than values observed 6 and 8 days after immunization) and a significant effect of treatment; conditioned animals reexposed to the CS had an attenuated antibody response. There were no significant differences between Group CSo and a group of placebo-treated animals, but conditioned animals reexposed to the CS had lower antibody titers than placebo-treated animals 4, 6, and 8 days after antigenic stimulation. These differences are more pervasive than those previously reported and suggest that reexposure to a CS may have long-lasting effects. More generally, these data provide further documentation of conditioned immunopharmacologic effects and the impact of behavioral factors in modifying immunologic reactivity.
Cats were trained to press a lever for food reinforcement in response to stimulation of the ventral lateral (VL) nucleus of the thalamus and the deep cerebellar nuclei. By scaling stimulus intensities relative to the appearance of a minimal amplitude evoked response in pericruciate cortex, it was possible to measure behavioral detection thresholds and correlate behavior with electrocortical activity. With stimulus rates of 25 Hz or greater, VL was the least effective stimulus site for producing detection. At stimulus rates less than 25 Hz, stimulation of the lateral or interpositus nuclei was even less effective in eliciting behavior, but at rates of 25 Hz or more, detection thresholds decreased below those for VL stimulation; cerebellar stimulation produced detection as readily as had stimulation of the ventrobasal complex in other experiments. These findings suggest that the cerebellum may modulate sensory experiences and that some portions of cerebral cortex, the pericruciate and suprasylvian regions, do not appear to be directly involved in mediating sensory detection. It is postulated that the neural detection circuits are more likely to be found in subcortical than in cerebrocortical structures.
Elevations in the concentration of plasma angiotensin II (AII) and decline in plasma aldosterone (Ald) were noted in African Green monkeys at 48 hr of water deprivation but not subsequent to an equivalent duration of food deprivation, compared with nondeprived levels. In a second experiment, drinking was initiated following treatment with AII, hypertonic saline, and the beta-adrenergic stimulator isoproterenol. Concomitant elevations in plasma AII concentrations were measured following isoproterenol injection, but not after AII or hypertonic saline injection, when compared with isotonic saline treatment. Elevations in plasma Ald levels were noted following AII injection. A third experiment evaluated dipsogenic additivity of stimuli by comparing the volumes of water consumed following isoproterenol or hypertonic saline injection with the intake resulting from combined treatment with isoproterenol and hypertonic saline. Additivity was tested under ad lib conditions and following adaptation to a daily water deprivation regimen. The results of the first two experiments generally agree with predictions based on the respective contributions by intracellular dehydration and extracellular fluid volume depletion, to thirst. However, additivity of thirst stimuli was not demonstrated in the third experiment.
New Zealand albino rabbits received sham lesions or complete, medial, lateral, or posterior septal lesions and were subjected to differential conditioning in which tones of different frequencies served as conditioned stimuli and paraorbital electric shock was the unconditioned stimulus. Electromyographic (EMG), heart rate (HR), and blood pressure (BP) conditioned responses (CRs) as well as hippocampal rhythmic slow wave activity (RSA) were recorded. Lateral or complete septal lesions enhanced the bradycardiac HR CR but had no effect on the BP depressor response. Both unconditioned and conditioned EMG responses occurred infrequently and were unaffected by any lesion. Unconditioned HR responses and somatomotor threshold determinations to unsignaled electric shock were also unaffected by the lesions. Complete septal lesions increased locomotor activity relative to sham or other septal lesions. Little hippocampal RSA was detected in animals with medial lesions, but the HR CR was unimpaired in these animals. These data implicate the septo-hippocampal circuit in classical conditioning of cardiovascular changes and further suggest that diencephalic forebrain structures may modulate forebrain processing of sensory stimulation, perhaps in terms of assessing its biological significance.
Four studies were conducted to delineate potential neural processes involved in retention of a peripherally induced postural asymmetry. In the first experiment, dorsal and ventral spinal root section following varying intervals of stimulation successfully abolished peripherally induced hindlimb asymmetry. Experiment 2 revealed that 50 min of ventral root stimulation, in the absence of central connection, was not effective in producing asymmetry persistence. In an attempt to more closely delineate the time parameters involved in peripherally induced asymmetry retention, Experiment 3 was conducted. Asymmetry was found to consistently outlast a spinal transection if 40 min of stimulation was given. Finally, possible modulatory higher brain center influences on the retention processes were demonstrated in Experiment 4. Asymmetry persistence was consistently observed in animals that received 10, 20, 30, 40, or 50 min of hindlimb stimulation if 50 min were allowed to elapse between the onset of stimulation and spinal section. These results, when coupled with the findings of earlier studies, suggest an active involvement of spinal reflex centers in the fixation process. In addition, these studies indicate that the manner in which reflex activity is altered is not crucial as long as underlying time parameters are adhered to. Finally, the present studies demonstrate that higher center influences can modulate retention of a postural asymmetry in a complex manner.
Infant rat pups (3-4 days of age) that received a single pairing of a novel odor (CS) with illness later responded to the CS with sustained accelerations in heart rate (HR); a different novel odor evoked deceleratory HR responses. Control pups responded to the CS and the second novel odor with cardiac deceleration. In a second experiment, rat pups that received three pairings of a novel odor with a cold (10 degrees C) temperature reinforcement displayed a similar pattern of HR responses, i.e., acceleration to the CS and deceleration to the novel odor. Cardiac response patterns are a useful measure of learning in infant mammals. The directional modulations of HR found in these experiments compare favorably with previous interpretations of "orienting" and "defensive" reactions derived from studies of HR responses in humans.
The reinforcing strengths of foods were assessed in rhesus monkeys before and after bilateral radio-frequency lesions of the lateral amygdala (n = 4), basolateral amygdala (n = 4), and total amygdala (n = 3). None of these lesions altered preoperative preferences between three highly palatable foods. Moreover, the lesions had no discernible effect on the animals' responses to different food rewards as measured by a progressive ratio schedule, although performance on this schedule proved sensitive to the size and type of food reward and to the degree of deprivation. The results suggest that amygdalectomy leaves a normal appreciation of at least this one class of rewards, foods. The dietary changes typically seen after amygdalectomy, such as meat eating, which were also observed in the same animals, probably reflect a loss of neophobia.
Regional brain uptake of 2-deoxy-D-[14C]glucose (2-DG) was measured in mice following training in a discriminated Y-maze avoidance task. In comparison with yoked-control animals that could not escape the footshock, the animals that were trained had decreased uptake of 2-DG in the hippocampus and increased uptake in the striatum. There was no difference in 2-DG uptake between experimental and control animals in the cortex overlying the striatum. Additional control studies showed that 2-DG uptake into the brain was not influenced by ether anesthetization or the route of 2-DG administration (iv or ip). The results of this study indicate that the metabolic activity of regional brain areas following training may reflect the involvement of these structures in learning and memory processes.
The importance of retroactive interference (RI) in memory for spatial locations was studied by using a 12-arm radial maze and a standard RI paradigm. Animals in the RI condition first learned to choose 4 of the 12 arms, followed by training to a second set of 4 arms. In the control condition for interference, rats learned the first set of arms but were not trained to approach the second set. Thereafter, animals in each interference condition were assigned to groups (hippocampal, cortical control, unoperated control), the operations were carried out, and then all animals were tested for retention of the set of arms learned first. Contrary to predictions of the cognitive map theory, O'Keefe & Nadel, 1978), RI was found in control animals. The severe memory deficit found in hippocampals was not influenced by the interference variable. In addition to impaired performance early in relearning, rats with hippocampal lesions continued to make many errors throughout the 10 wk of testing, including choices to unbaited arms and repeated entries into baited arms. However, hippocampals eventually learned not to reenter unbaited arms. These data indicate a deficit in the selection and utilization of sets of responses and are interpreted as implicating the hippocampus in retrieval processes.
Operated control rats and rats with small lesions in the medial septal region were tested for postoperative retention and transfer learning in a pulse-shaped elevated maze. Both maze problems were, in an empirical sense, spatial. Only when the rats worked on an alteration problem with start box reversals between sessions could the performance be characterized as depending on working memory. It was the working-memory conditions that sustained lesion-induced impairment on the tests of retention and transfer learning, and the lesion-induced behavioral impairment did not ameliorate during the four additional training sessions. Performance on problems that could be solved by reference-memory mechanisms was not impaired by the lesions. The small, but effective, lesions in the medial septal region were presumed to have severed a substantial number of connections comprising the major anterior input from the septum to the hippocampus but to have left intact much of the anterior hippocampal efferents. It is concluded that spatial cognitive mapping is crucially dependent on a basis capability for working memory which, in turn, depends on circuitry involving connections from septal region to hippocampus.
The effects of various neurotransmitter antagonists on suckling behavior of 3- and 4-day-old Sprague-Dawley rat pups were examined. Peripheral administration of three serotonergic antagonist, scopolamine, were observed to markedly reduce suckling behavior of neonatal rat pups. These effects appear to be centrally mediated since intracisternal administration of small doses of all of these drugs was observed to suppress suckling. The reduction in suckling induced by these antagonists did not appear to be a result of a debilitating effect of the drugs or to be due to any alteration in body temperature. In contrast, the opiate antagonist naloxone, the dopaminergic antagonist haloperidol, the alpha-noradrenergic antagonist phentolamine, and the beta-noradrenergi antagonist propranolol did not consistently produce any alteration in suckling behavior. These results suggest that the serotonergic and cholinergic systems may be functioning much earlier in ontogeny than previously suggested and may be involved in modulating suckling behavior in the early neonatal period.
