This study examined object permanence in Sumatran orangutans (Pongo abelii), Western lowland gorillas (Gorilla gorilla gorilla), and black-and-white-ruffed lemurs (Varecia variegata) at Zoo Atlanta. A literature review reveals two main issues with object permanence research in non-human primates. One of the issues is that it is difficult to make valid comparisons between different species because very few studies have been conducted using appropriate controls. Thus, one of the goals of this study was to conduct control trials for all tasks in the traditional object permanence test battery, in order to reliably assess and compare performance in the species under study. The second issue is concerned with the finding that all of the non-human primate species tested so far have failed one of the more difficult tasks in the test battery, namely the non-adjacent double invisible displacement task. It has been hypothesized that this performance limitation is a result of the manner in which the task is presented. Thus, the second goal of this study was to modify the existing methodology and present the task to gorillas and orangutans in locomotive space to see if performance improves. This is the first study to present this task to non-human primate species in locomotive space. This study found that orangutans were the only species to reliably pass most tasks in the traditional object permanence test battery. Black-and-white ruffed lemurs failed most visible and invisible displacement tasks. Owing to the small sample size of gorillas in this study, further research is required before any firm conclusions can be made about the ability of this species to solve visible and invisible displacement tasks in the traditional object permanence test battery. Presenting the boxes in locomotive space to gorillas and orangutans did not improve performance on the non-adjacent double invisible displacement task. Further research is required to resolve the question of whether this performance limitation is a result of the manner in which the task was presented.

Thesis (M.S.)--University of Michigan, 1993.

Many animals socially learn, but very few do so through teaching, where an individual modifies its behaviour in order to facilitate learning for another individual. Teaching behaviour is costly, but can confer numerous advantages, such as high fidelity transmission of information or an increase in the rate of social learning. In many putative cases of teaching, it is not known whether the pupil learns from the modified behaviour. This thesis addresses this issue in three cases of potential teaching behaviour. In particular, it investigates whether the role of food transfers in wild golden lion tamarins is to teach which foods are good to eat (Chapter 5). There was little evidence that novel foods were transferred more than familiar foods, and this was not due to the juveniles attempting to obtain novel foods more than familiar ones, or by adults discarding novel foods more than familiar ones. Transfers were however more successful when donors had previously ingested the food type transferred. Successful food transfers also had a positive correlation with foraging choices once juveniles were older, suggesting they learned from food transfers. In golden lion tamarins, this thesis also examined whether juveniles learned from food-offering calls which substrates were good to forage on (Chapter 6). Juveniles that experienced playback of food-offering calls ate more on a novel substrate, than juveniles that did not experience those playbacks, both immediately as the calls were being played, and in the long term, six months after the playbacks. This suggests that juveniles learned from the playbacks. Finally, this thesis attempted to replicate previous findings showing that hens modify their behaviour when chicks feed from seemingly unpalatable food, and explored whether chicks learned what food to eat based on the maternal display (Chapter 7). The experiment failed to find evidence for teaching behaviour, but results were not inconsistent with previous findings. Moreover, there was little evidence that chicks learned from their mother, quite to the contrary, hens seemed to acquire their foraging decisions based on their chicks' choices.

I tested two pairs of captive chimpanzees (Pan troglodytes) in the informed forager paradigm: a subordinate saw the location of hidden bait, and then searched with a naïve dominant. This paradigm has tested what subjects know about others' states of knowledge, but my focus was to determine how subjects used different movement types and different gaze types to modify their competitive tactics. In particular, I investigated whether chimpanzees follow opponents' gaze to gain information. Learning more about how primates use visual information to predict others' behaviour can shed light on the continuing debate over to what degree apes possess theory of mind capacities. Previous published studies in this paradigm included narratives of ignorant competitors exploiting informed subjects by following their movement and gaze, and informed subjects avoided this exploitation by walking away from hidden food. The subordinate's behaviour can be considered tactical deception, which is a good place to seek strong evidence of second-order intentionality. Analyses with descriptive statistics, however, fail to capture the complexity of these interactions, which range from single decision-making points to larger patterns of following and misleading. I introduced a novel method of statistical analysis, cross correlations, that enabled me to examine behavioural patterns quantitatively that previous authors have only been able to describe in narrative form. Though previous studies on chimpanzees' understanding of gaze found that they were unable to use (human-given) gaze cues to locate hidden food, the subjects I tested followed their conspecific opponent's gaze, and used information gained from the gaze interaction to modify their own movement towards the hidden bait. Dominants adjusted their physical following of the subordinates as the interaction progressed, which reflected their changed states of knowledge. Subordinates used their movement and gaze differentially to manipulate dominants' behaviour, by withholding information and by recruiting towards a less-preferred bait.

Indiana University-Purdue University Indianapolis (IUPUI) / Alcohol consumption produces a complex array of effects that can be divided into two types: the explicit pharmacological effects of ethanol (which can be quite separate temporally from time of intake) and the more temporally “relevant” effects (primarily olfactory and taste) that bridge the time from intake to the onset of the pharmacological effects. Dissociating these effects is essential to untangling the neurologic underpinnings of alcohol abuse and dependence. Intravenous self-administration of ethanol allows for controlled and precise dosing, bypasses first order absorption kinetics allowing for a faster onset of pharmacologic effects, and eliminates the confounding “non-pharmacological” effects associated with oral consumption. Intravenous self-administration of ethanol has been reliably demonstrated in both mouse and human experimental models; however, consistent intravenous self-administration of pharmacologically relevant levels of ethanol remains elusive in the rat. Previous work has demonstrated reliable elevated intravenous ethanol self administration using a compound reinforcer of oral sucrose and intravenous ethanol. The present study sought to elucidate the role of each component of this reinforcer complex using a multiple schedule study design. Male P rats had free access to both food and water during all intravenous self-administration sessions and all testing was performed in conjunction with the onset of the dark cycle. Once animals achieved stable operant responding on both levers for an orally delivered 1% sucrose solution (1S) on a FR4 schedule, surgery was conducted to implant an indwelling jugular catheter. Animals were habituated to the attachment of infusion apparatus and received twice daily sessions for four days to condition each lever to its associated schedule. Animals were then trained to respond on a multiple FR4-FR4 schedule composed of alternating 2.5 minute components. During one component only oral 1S was presented, while in the second component a compound reinforcer of oral 1S + IV 20% ethanol was presented (25 mg/kg/injection). Both levers were extended into the chamber during the session, with the active lever/schedule alternating as the session progressed across components. Average ethanol intake was 0.47 ± 0.04 g/kg. A significant increase in sucrose only reinforcers and sucrose lever error responding was found suggesting that sucrose not ethanol is responsible for driving overall responding. The current findings suggest that the existing intravenous ethanol self-administration methodology remains aversive in the rat.

The purpose of this thesis was to develop methodology by which treatments for the cognitive impairments in Huntington's disease (HD) could be tested. As such, the thesis focused mainly on evaluating rats with quinolinic acid (QA) lesions of the striatum, as this manipulation mimics some aspects of the neural damage in Huntington's disease, to try to identify cognitive deficits of HD resulting from cell loss in the striatum. In the first part (Chapters 3-5), the role of the striatum in implicit memory was investigated. Chapter 3 compared the performance of rats and humans on a reaction time task that evaluated implicit memory by presenting visual stimuli with differing probabilities which change over time. Although rats made higher percentage of incorrect responses and late errors, both groups showed a similar pattern of reaction times. Chapter 4 investigated whether implicit memory (the computation of probabilities to predict the location of a stimulus) was affected by selective blockade of dopaminergic transmission at the D1 or D2 receptors by SCH-23390 and raclopride, respectively. Reaction times were slower with SCH-23390 and raclopride, but only SCH-23390 reduced errors to the least probable target location. Chapter 5 used the same task to evaluate implicit memory in rats with QA lesions of the dorsomedial striatum (DMS). Implicit memory was not affected by lesions of the DMS, which suggested that once a task that requires implicit memory has been learned, the DMS was not involved in sustaining the performance of the task. The second part of this thesis (Chapter 6), explored the contribution of the DMS in habit formation. DMS lesioned rats did not show habitual responding, and were not impaired in learning a new goal-directed behaviour. The third part (Chapters 7 and 8), investigated the role of the dorsal striatum in reversal learning, attentional set-formation, and set-shifting. Dorsal striatum lesioned rats were not impaired in reversal learning, but had a diminished shift-cost, which suggested that dorsal striatum lesions disrupted the formation of attentional sets. These results showed that although QA lesions of the dorsal striatum mimic some aspects of the neural damage in HD, they did not result in the same cognitive deficits observed in patients with HD, at least using the tasks presented in this thesis. However, other animal models of HD could be evaluated using the different tasks presented in this thesis to continue the search of a reliable animal model of HD in which treatments for the disease could be evaluated.

Indiana University-Purdue University Indianapolis (IUPUI) / Alcoholism inheritance rates have been estimated as high as 60% in a human population. Many significant features of alcohol dependence have been replicated in rodent animal models of alcoholism, however not in totality. These animal models include inbred preferring (iP) and nonpreferring (iNP) rat types. Congenic rats have been engineered from the iP and iNP strains whereby a P congenic rat has in its genome a well-chosen chromosomal portion taken from an NP rat (P.NP) and, reciprocally, an NP congenic rat has acquired the analogous DNA from a P rat (NP.P). In this case, a quantitative trait locus (QTL) from chromosome 4 is the donor genetic material for the congenic rats. It is of great interest to further study this chromosome 4 QTL because it has been found to control a significant portion of ethanol consumption behavior in iP and iNP rats. This study aimed to behaviorally profile the iP, iNP and reciprocal congenic rats. As a result of the behavioral profiling of these genetically related groups, some conclusions could be made regarding which behaviors appear to be controlled by the chromosome 4 donor DNA.This study primarily utilized the Multivariate Concentric Square Field apparatus (MCSF) to characterize behavioral profiles for the inbred and congenic rats. The Open field (OF) and Elevated plus maze (EPM) supported this effort. The MCSF is valuable in that it allows for the animals to interact within an environment that has ethological value. The 12 different zones that make up the field are characterized by some functional quality in terms of type and duration of behavior performed, etc. The behavioral data is aggregated and finally represented in terms of five functional categories, the elements of the behavioral profile: general activity, exploratory activity, risk assessment, risk taking, and shelter seeking. The study hypotheses were shaped by prior research suggesting that iPs should display lower general activity and risk taking strategy than iNPs in the MCSF. Inbred Ps should be more active in the OF and spend more time in the center of the EPM. Generally, it is expected that the iP QTL confer behavioral phenotypes to the iNP strain that deviate toward a "P" behavioral phenotype and reciprocally, the iNP QTL confer behavioral phenotypes to the iP strain that deviate toward an "NP" behavioral phenotype. The results showed that iP rats performed more risk assessment and risk taking behavior and less shelter seeking and anxiety-like behavior than iNP rats. It followed that P.NP congenic rats significantly downgraded their risk assessment and risk taking behavior when compared to iP rats. This decrease can be attributed to the chromosome 4 QTL donated from the iNP breed. All together this study concludes that risk assessment and risk taking behavior in the iP rats is controlled by the same DNA region that, in part, determines voluntary intake of ethanol consumption. Further fine mapping of the QTL region should help in discovering if the same DNA sequences that influence ethanol intake also significantly influence risk behavior.