Instrumental Learning in Toads (&lt;i&gt;Bufo arenarum&lt;/i&gt;):Reinforcer Magnitude and the Medial Pallium

Papini, Mauricio R.; Muzio, Rubén N.; Segura, Enrique T.

doi:10.1159/000113259

Cited by 61 publications

(49 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The pigeon's operant performance after the shift was directly related to the magnitude of reinforcement before the shift and not inversely related as predicted by frustration theory (Amsel, 1992). This is not an uncommon outcome in analogous experiments with lower vertebrates, but it is a different pattern of results from that typically obtained with mammalian species (Papini, Muzio, & Segura, 1995).…”

Section: Discussionmentioning

confidence: 55%

Role of nonreinforcement in the fixed-interval performance of pigeons

Papini

Hollingsworth

1998

Psychon Bull Rev

Self Cite

View full text Add to dashboard Cite

Fixed-interval (F1) schedules have been used extensively to study timing abilities. In F1 schedules, animals typically show higher response rates immediately after nonreinforced (N) cycles rather than reinforced (R) cycles (the reinforcement-omission effect), and they exhibit the highest rate approximately at the time when the reinforcer is scheduled to occur (peak performance). The present experiments were designed to determine the extent to which factors other than timing contribute significantly to these two learning phenomena. Pigeons were trained in an F116-sec schedule in which half the cycles were R and half were N. When successive cycles were separated by a 2-sec interval, responding early in the F1 interval was higher after an N cycle than after an R cycle. This reinforcementomission effect was eliminated when the interval between cycles was increased to 12 sec, because of an increase in performance after R cycles. In addition, timing of the 16-sec interval was assessed by interpolating 32-sec test cycles (all N cycles) at two rate5-€ither 1 test cycle every other session, or 25 test cycles per session. Peak performance, presumably indexing the animal's ability to time the 16-sec interval, emerged only with 25 test cycles per day, but not with 1 test cycle every other day, despite extensive training with the target, 16-sec-Iong interval. These results suggest that transient demotivation and time-based discrimination contribute significantly to the reinforcement-omission effect and peak performance, respectively. 84Arranging a regular distribution of reinforcers in time, as in a fixed-interval (FI) schedule of reinforcement, is a procedure that has been used extensively to study the timing abilities of organisms (Lejeune & Wearden, 1991). It has long been recognized that unexpected nonreinforced (N) cycles are followed by higher response rates than reinforced (R) cycles are (Staddon & Innis, 1966). This phenomenon, referred to as the reinforcementomission effect, has been linked to a variety of mechanisms, including the role of reinforcement in resetting the internal clock used to estimate the duration of the interval (Mellon, Leak, Fairhurst, & Gibbon, 1995). However, as Mellon et al. noted, when the reinforcement and other associated cues are omitted, animals face what is essentially a longer FI cycle. This situation approaches the conditions of the peak procedure, in which an unusually long test cycle is interpolated with shorter training cycles to assess the animal's ability to estimate the duration of the short interval. Animals exhibit peak performance-that is, a maximum response rate in the long test cycle at approximately the time within the interval when reinforcement is usually scheduled to occur (S. Roberts, 1981). In the present experiments, we examined the contribution of factors other than timing to these learning phenomena.The research reported in this paper was partially supported by TCU/RF Grant 5-23832 to M.R.P. Requests for reprints may be sent to M. R. Papini, Department of Psychology...

show abstract

Section: Discussionmentioning

confidence: 55%

Role of nonreinforcement in the fixed-interval performance of pigeons

Papini

Hollingsworth

1998

Psychon Bull Rev

Self Cite

View full text Add to dashboard Cite

show abstract

“…Available evidence from spaced-trial experiments with osteichthyes fish, amphibians, and reptiles indicates that only the allocentric effects of SN are present in these animals [see Papini et al, 1995;Bitterman, 2000]. Thus, for example, a shift from a large to a small reward magnitude is followed by an adjustment of performance without deterioration, that is, without SNC.…”

Section: Surprising Nonreward In Fish Amphibians and Reptilesmentioning

confidence: 99%

Comparative Psychology of Surprising Nonreward

2003

Self Cite

View full text Add to dashboard Cite

The surprising or unexpected omission of an appetitive reinforcer has at least two effects: An allocentric effect according to which the organism updates knowledge about the environment, and an egocentric effect that allows the organism to learn about its own emotional reaction to the change. This egocentric effect (traditionally called frustration) is correlated to activation of the hypothalamic-pituitary-adrenal axis, can be modulated by treatment with anxiolytics, and is expressed in terms of behavioral changes that have an emotional component (e.g., agonistic behavior). It is hypothesized that all vertebrates share the mechanisms underlying the allocentric effect, but only mammals possess the mechanisms underlying the egocentric effect. It is further argued that frustrative mechanisms evolved in early mammals from those underlying fear conditioning.

show abstract

“…11; see vOB y LS y vMP Y A Y R) [Hoffmann, 1973;Kicliter and Northcutt, 1975;Northcutt and Royce, 1975;Northcutt and Kicliter, 1980;Neary and Wilczynski, 1980]. Previous 14 C-2DG studies have shown that activity in the ventral medial pallium is associated with conditioning [see Finkenstädt, 1989;Finkenstädt et al, 1985;Merkel-Harff and Ewert, 1991;Papini et al, 1995;Ewert et al, 1994bEwert et al, , 1999. The increase in glucose utilization in the ventral medial pallium might also result from the action of APO as a positive reinforcer [e.g.…”

Section: Apo-induced Facilitation Of Snappingmentioning

confidence: 99%

Apomorphine Alters Prey-Catching Patterns in the Common Toad: Behavioral Experiments and <sup>14</sup>C-2-Deoxyglucose Brain Mapping Studies

Glagow

Ewert²

1999

Brain Behav Evol

View full text Add to dashboard Cite

Previous studies on the dopaminergic modulation of visuomotor functions in amphibians showed that the dopamine agonist apomorphine (APO) alters prey-catching strategies. After systemic administration of APO in common toads Bufo bufo, prey-oriented turning and locomotion was attenuated whereas snapping toward prey was facilitated in a dose dependent manner. With systemic APO administration, toads which had previously been hunting, that is pursuing prey, behaved in a waiting position, that is sitting motionless and waiting for prey. This suggests that APO facilitates the ingestive component and inhibits the orientational and locomotory components of prey capture. To help unravel the cerebral sites of action of APO, the present study employs the ¹⁴C-2-deoxyglucose method to compare the rate of local glucose utilization in 41 brain structures. The retinal projection fields – e.g. superficial optic tectum, pretectal nuclei, and anterior dorsal thalamic nucleus – showed an elevation in glucose utilization due to APO-induced increases in retinal output. The medial tectal layers and the ventral striatum, both involved in visuomotor functions related to prey-oriented turning and locomotion, displayed APO-induced decreases in glucose utilization. APO-induced increases in glucose utilization were observed in the medial reticular formation and the hypoglossal nucleus which participate in the motor pattern generation of snapping. APO-induced increases in glucose utilization were also detected in the nucleus accumbens and the ventral tegmentum (mesolimbic system) as well as in the ventromedial pallium (‘primordium hippocampi’) and the septum, both of which belonging to the limbic system. These structures contribute to motivational level control and may be responsible for the APO-induced elevation of the snapping rate. Various other structures revealed APO-induced increases in glucose utilization. These structures include the olfactory bulb, lateral pallium, suprachiasmatic nucleus, nucleus of the periventricular organ, and the nucleus of the solitary tract. The lateral amygdala displayed APO-induced decreases in glucose utilization. The APO-induced alterations in local cerebral glucose utilization are evaluated with reference to the distribution of dopaminergic structures, and this is compared with similar data obtained in the rat by other authors. A neural network explaining the APO-induced behavioral syndrome in the common toad is discussed.

show abstract

Instrumental Learning in Toads (<i>Bufo arenarum</i>):Reinforcer Magnitude and the Medial Pallium

Cited by 61 publications

References 16 publications

Role of nonreinforcement in the fixed-interval performance of pigeons

Role of nonreinforcement in the fixed-interval performance of pigeons

Comparative Psychology of Surprising Nonreward

Apomorphine Alters Prey-Catching Patterns in the Common Toad: Behavioral Experiments and <sup>14</sup>C-2-Deoxyglucose Brain Mapping Studies

Contact Info

Product

Resources

About