Apomorphine: Effects on the timing and sequencing of pecking behavior in chicks

Machlis, Lee E.

doi:10.1016/0091-3057(80)90235-x

Cited by 19 publications

(8 citation statements)

References 29 publications

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“…However three books devoted specifically to quantitative methods in ethology (COLGAN 1978; HAZ- LETT 1977;LEHNER 1979) each contain at least one example of a Pooled data set. We note parenthetically that one of us has two refereed publications (MACHLIS 1977(MACHLIS , 1980) that contain statistical analyses of Pooled data sets).…”

Section: How Prevalent Is Pooling?mentioning

confidence: 99%

The Pooling Fallacy: Problems Arising when Individuals Contribute More than One Observation to the Data Set

Machlis

Dodd

Fentress

1985

Zeitschrift für Tierpsychologie

293

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and Summary In ethological studies it is common practice to obtain multiple observations on each individual in a sample and to Pool these observations into one data set for statistical analysis. In this paper we argue that this procedure reflects a fundamental error in the logic underlying random sampling since it implicitly assumes that the purpose of data gathering in ethology is to obtain large “samples of behaviour” rather than samples of behaviour from a large number of individuals. That is, it is assumed that the reliability of estimates of population parameters can be increased by obtaining additional observations on individuals already in the sample rather than by increasing the number of individuals observed. Using a Monte Carlo simulation we show that when such Pooled data sets are analysed statistically, the probability of rejecting a true null hypothesis is almost always substantially greater than the stated alpha level. Zusammenfassung In ethologischen Untersuchungen ist es üblich, von jedem Individuum einer Stichprobe mehrere Meßwerte zu gewinnen und für die statistische Analyse die Werte aller Individuen zu einer einzigen Stichprobe zu vereinigen („pooling”). Diesem Verfahren liegt, wie in der vorliegenden Arbeit gezeigt wird, ein fundamentaler Irrtum bezüglich der zufälligen Stichprobenauswahl zugrunde, da implizit davon ausgegangen wird, man müsse große Stichproben der Verhaltensweisen anstatt Stichproben des Verhaltens möglichst vieler Individuen sammeln. Damit wird angenommen, daß Populationsparameter zuverlässiger geschätzt werden können, wenn man mehr Beobachtungen am bereits in der Stichprobe vertretenen Individuen macht als wenn man zusätzliche Individuen beobachtet. Mit einer Monte–Carlo–Simulation wird gezeigt, daß die statistische Analyse solcher zusammengesetzter („pooled”) Stichproben fast immer eine wesentlich großere als die angegebene Irrtumswahrscheinlichkeit für („type I error”) ergibt.

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Section: How Prevalent Is Pooling?mentioning

confidence: 99%

The Pooling Fallacy: Problems Arising when Individuals Contribute More than One Observation to the Data Set

Machlis

Dodd

Fentress

1985

Zeitschrift für Tierpsychologie

293

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“…However, in rodents these substances elicit a number of different stereotyped reactions and locomotory responses that apparently index somewhat different sensItIzation v,ariants (Moller et a/., 1987;Mattingly and Gotsick, 1989;Willner et a/., 1992;Mattingly et af., 1997;Tirelli and Heidbreder, 1999;Battisti et a/., 1999Battisti et a/., ,2000. In birds 9:Po elicits a prolonged bout of repetitive pecking and almost no other motor activities (Cheng and Long, 1974;Brunelli et a/., 1975;Machlis, 1980;Delius, 1985).…”

Section: Introductionmentioning

confidence: 99%

Haloperidol blocks the acquisition but not the retrieval of a conditioned sensitization to apomorphine

Acerbo

Godoy

Delius

2003

Behavioural Pharmacology

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The dopamine agonist apomorphine (apo) elicits stereotyped pecking bouts in pigeons, a response which increases with successive apo injections. The present study sought, first, to confirm the hypothesis that this sensitization arises through a Pavlovian conditioning driven by both external and internal cues; and, secondly, to advance the hypothesis that during this learning the dopaminergic activation only initiates a process that probably ends in glutamatergic synapse modifications. The conditioned nature of the sensitization to apo was examined in two separate experiments that compared context contingent and context uncontingent apo treatments. The role of dopaminergic mechanisms in the acquisition, maintenance and retrieval of sensitization-conditioned pecking was examined by administering the dopamine antagonist haloperidol (hal) either before, during or after apo sensitization treatments. A contingency between context and apo was found to be essential for the acquisition and retrieval of apo-sensitized pecking. A pretreatment with hal did not curtail a subsequent sensitization to apo. When hal was co-administrated with apo it suppressed the initial pecking response to apo and blocked the acquisition of sensitized responding. A pecking response normally observed when apo-sensitized pigeons are challenged with saline (sal) in the same cage in which they were sensitized, was also absent. When hal was co-administered with apo after the sensitization was complete this led at first to an only partial apo response suppression. When treated with hal in the same cage, already sensitized pigeons responded much as if they had been challenged with sal. The sensitization induced by apo was thus blocked by hal co-administered during acquisition, but during the maintenance or retrieval phase hal did not impair a previously sensitized responding. It is concluded that when pigeons are sensitized to apo, dopaminergic mechanisms are implicated in initiating the neural modifications that underlie the conditioned sensitization, but that they themselves are not importantly altered.

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“…When apomorphine (between about 0.2 mg and 2 mg/kg bodyweight) is intramuscularly administered, pigeons and other birds (except occasional genetically non-responsive individuals) exhibit an about 30-min to 2-h long, dose dependant bout of repetitive pecking activity. The pecks are stereotypically and idiosyncratically directed at contrasting cage details (cross-welds, rivet heads, coloured dots) but sometimes also directed at features of their own integument (feathers, toes; Brunelli et al 1975;Machlis 1980). Although the pecking may also be directed at grains, these are rarely swallowed since apomorphine has an anorectic side-effect (Deviche 1984).…”

Section: Introductionmentioning

confidence: 99%

Discriminative learning occasioned by the administration of a dopamine agonist

Keller

Delius

2001

Psychopharmacology

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Rationale: The repeated administration of psychostimulants usually brings about a progressive increment of the behavioral responses that they induce. We examined to what extent this sensitization is due to an associative learning process. Objectives: The dopamine agonist apomorphine elicits stereotyped pecking in pigeons, a response that increases with successive intramuscular injections. We tested whether this sensitized pecking would be discriminatively directed at environmental stimuli that had been present during the sensitization phase. Methods: In a preliminary experiment we identified a pair of stimulus compounds that attracted an equal number of apomorphine peck responses. During discrimination training naive pigeons were exposed on 5 days to both a cage furnished with one of these stimuli after having been injected with apomorphine and to a cage furnished with the other stimuli after having been injected with saline. Then the birds were administered apomorphine (or saline) and tested in a cage that offered both compound stimuli simultaneously. A discrimination reversal training and renewed tests followed. Results:The tests under apomorphine and saline showed that the pecking by the pigeons was virtually exclusively aimed at the specific environmental stimuli under which the sensitization to apomorphine had taken place. This discriminative stimulus control was reversed after the pigeons had been retrained with converse stimulus compound allocations. Conclusions: The sensitized apomorphine pecking of pigeons was subject to close control by environmental stimuli. The results thus support the hypothesis that the sensitization to psychostimulants may be due to a conditioning process. The conditioning occasioned by apomorphine injections in birds could be a useful model for the study of sensory-motor learning processes.

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Apomorphine: Effects on the timing and sequencing of pecking behavior in chicks

Cited by 19 publications

References 29 publications

The Pooling Fallacy: Problems Arising when Individuals Contribute More than One Observation to the Data Set

The Pooling Fallacy: Problems Arising when Individuals Contribute More than One Observation to the Data Set

Haloperidol blocks the acquisition but not the retrieval of a conditioned sensitization to apomorphine

Discriminative learning occasioned by the administration of a dopamine agonist

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