Year: 2000
Type: review
Abstract: Lawrence Williams, Ph.D., is Associate Professor in the Primate Research Laboratory of the Department of Comparative Medicine, University of South Alabama, Mobile, Alabama. Martha Glasgow, M.S., is a Ph.D. candidate in the Department of Ecology, Evolution, and Organismal Biology, Tulane University, New Orleans, Louisiana. Lawrence Williams, Ph.D., is Associate Professor in the Primate Research Laboratory of the Department of Comparative Medicine, University of South Alabama, Mobile, Alabama. Martha Glasgow, M.S., is a Ph.D. candidate in the Department of Ecology, Evolution, and Organismal Biology, Tulane University, New Orleans, Louisiana. Squirrel monkeys have been a valuable animal model in biomedical research ( Abee 2000 ). They have been utilized in a wide variety of study areas including, but not limited to, atherosclerosis, neuroscience, pharmacology, psychiatry, toxicology, and vision research. A quick search of on-line databases MEDLINE and PSYCHINFO indicates that approximately 200 articles have been published in the last 10 yr that have used behavioral testing of squirrel monkeys. Analysis of experimental manipulations of Saimiri behavior has been an important tool. Depending on the level of analysis needed, several different behavioral testing protocols have been used successfully in biomedical research using squirrel monkeys. If a predicted effect is on the whole organism, other than studying the natural behavior of an animal, investigating its interaction with social partners and its environment has been most appropriate. If the effects of interest are more limited, more specific tests of the squirrel monkey’s motor performance, cognitive ability, or reflex actions may enable an investigator to isolate the consequence of the experimental intervention. The purpose of this article is to review how behavior has been employed using squirrel monkeys in biomedical research. We describe three general types of behavioral analysis: natural behavior, conditioned behavior, and neurobehavioral assessment profiles. Natural behavior refers to data collected on squirrel monkeys as they move about the environment. This type of analysis includes studies of animals in seminatural and captive laboratory environments as well as field studies. Although an investigator can arrange particular situations in all three study types, a key difference between behavioral analysis and conditioned tests is usually in the investigator’s direct supply of rewards or punishments (“conditions”) in the latter. Conditioned behavior tests (cognitive, classical, and instrumental paradigms) are used to investigate the squirrel monkey’s ability to learn or react to environmental stimuli. Classical conditioning entrains reflexive behavior to stimuli that do not normally elicit it. Cognitive and instrumental conditioning relies on animal tendencies to maximize rewards and minimize punishment in an effort to examine its ability to perform a motor skill or learn a task. In all cases, the experimenter is setting the experimental conditions and supplying the rewards and punishments that influence the animal’s actions. Neurobehavioral assessment profiles are used to measure a subject’s reflexes, motor abilities, and emotionality in contrived situations. No rewards or punishments are given, and the animal is tested in highly structured situations. The ability of an animal to visually track a specific stimulus and the reaction of an animal to a visual cliff are examples of the types of assessments made. In the sections below, we provide a brief review of particular terminology and methodologies associated with several behavioral paradigms. We then provide several examples of how the paradigm has been applied to the squirrel monkey. These examples are intended to inform the reader of the value of studying squirrel monkey behavior. Naturalistic observations are made on animals without imposing experimentally contrived rewards or punishments. During behavioral observations, the subject animal is observed for the presence or absence of a particular response or set of responses. If the response is present, then the number of times it occurs (frequency or rate) or the length of time it occurs (duration) can be recorded. Ethograms may be used to operationally define a set of responses produced by the subject animals. Their use provides a consistent frame of reference both within and between study protocols, ensuring that behavioral responses are scored consistently across time. Natural behavior of an animal falls into three categories or types of responses: behavioral events, behavioral states, and behavioral stereotypes. Many behavioral events are acts or responses that may appear to be instantaneous. Although such responses have a finite duration, they may be so brief and consistent that they may be viewed as instantaneous. Responses that may be described as “slap, grab, or hit” are distinct acts that can be reported as a frequency or rate, such as slaps per hour. Other types of responses, such as “sitting in contact with another animal” or “huddling,” are behavioral states that can last a relatively long time. A state may be briefly interrupted as individuals adjust their positions, but the duration of a bout of sitting together may be, for example, minutes or hours long. Although frequency data may be collected on such states, a duration measure may be more desirable. It may be expressed as minutes per hour huddled together, percentage of time in contact, or other similar measures of duration. Sequences of responses may be difficult to analyze but may be important when examining patterns of responses such as behavioral stereotypes. One can record all items in an ethogram during data collection and then analyze for the frequencies of combinations. Such combinations are assessed as significant if they occur more often than one would predict from the individual frequencies of the two items. An alternative is to predefine the combinations or sequences of interest and then to regard and record such sequences as a single instance. In Jeanne Altmann’s (1974) review of observational techniques, four methods for collecting naturalistic data are listed: ad libitum scoring, focal animal observations, instantaneous scans of a group, and one-zero samples. The most simple method, ad libitum scoring, is to observe an animal or group for the presence or absence of a response and to record all occurrences. Animals are not observed for set periods of time so it is impossible to summarize the data in terms of frequency or hourly rate. Because no one can watch everywhere at once, Altmann criticizes ad libitum data collection, especially with a large battery of response categories applied to multiple subjects, as being inherently inaccurate. Nevertheless, an accepted use of this methodology is to develop an ethogram or categorized list of observed animal responses. Focal animal observations comprise another observational method that enables the observer to record the onset and cessation of behavioral states and the time of occurrence of actions with small durations for a large number of behavioral categories. This technique requires that the observer collect data on only one animal at time. Data involving other animals in the study that do not interact directly with the focal subject are disregarded. The advantage, of course, is that the observer gathers information on the frequencies, durations, and sequences for many more behavioral categories than the other techniques can provide. Instantaneous scans of a group assess behavior states like sleeping by attending to the subjects’ behavior at preselected times. The percentage of time spent in a behavioral category or response can be calculated by dividing the number of scans in which the subject is seen asleep by the total number of snapshots. Such point samples of an animal’s behavioral state can be extrapolated to estimate the amount of time the subject spends in a particular behavioral category. Instantaneous scans must be performed at intervals that exceed the duration of most instances of the behavior of interest to ensure independence of sampling. One-zero samples ( Altmann 1974 ) comprise a form of data collection that involves recording whether a response occurs within a predetermined time frame. For example, if an animal scratches itself one or 10 times within a predetermined time block, the animal receives a score of one. If the animal does not scratch itself at all, it receives a score of zero. Altmann (1974) has criticized the one-zero scoring method, stating that it provides data that are not related to frequency or duration but are an indeterminate index of both. Although this type of dichotomous data may be useless in measuring frequency and duration, it may be used to calculate probabilities, which are comparatively useful quantitative measurements. The research investigator must choose among techniques according to the properties of the variables of interest. Fragaszy and colleagues (1992) compared focal animal and group scan methods of data collection in the field conditions for capuchin and squirrel monkeys. They found that focal animal and group scan data similar and for and all of which are behavioral They that focal animal and group scans is a useful to collect the most data in the amount of time. the data collection methods the about squirrel monkey behavior have been made. In the squirrel monkeys most types of both and and and ( and ). 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Source: ILAR Journal
DOI: 10.1093/ilar.41.1.26
Authors: L. Williams, M. Glasgow
Institutions: University of South Alabama, Tulane University
Language: English
Topic: Primate Behavior and Ecology
Subfield: Social Psychology
Field: Psychology
Domain: Social Sciences
Open Access status: bronze
OpenAlex ID: W2171504283