Andrew R Delamater

• PhD
• Professor at Brooklyn College

-Backpropagation (BP) has been criticized for its lack of biological plausibility (Lillicrap, et al., 2020). Contrastive Hebbian Learning (CHL) is an alternative that calculates error signals locally at each unit (Detorakis, et al., 2019). -CHL assumes a symmetry in the feedback weights matrix, a novel solution with random feedback improved CHL (rC...

The American Psychological Association just released the 5th edition of this "essentials" coverage of conditioning and learning. Great for students and investigators who use conditioning techniques but don't want to get into all of the details of the underlying theory and mechanisms.

We discuss three empirical findings that we think any theory attempting to integrate interval timing with associative learning concepts will need to address. These empirical phenomena all come from studies that combine peak timing procedures with reinforcer devaluation or conditional discrimination tasks commonly employed, respectively, in interval...

In this review, we take a critical look at the methods used to document habituation and the theoretical assumptions that have been made about it. We point out problems associated with measuring habituation merely as a change over the course of repeated presentations of a stimulus. We argue that a common test procedure is essential to assess the rel...

The field of associative learning theory was forever changed by the contributions of Robert A. Rescorla. He created an organizational structure that gave us a framework for thinking about the key questions surrounding learning theory: what are the conditions that produce learning?, what is the content of that learning?, and how is that learning exp...

It is thought that goal-directed control of actions weakens or becomes masked by habits over time. We tested the opposing hypothesis that goal-directed control becomes stronger over time, and that this growth is modulated by the overall action–outcome contiguity. Despite group differences in action–outcome contiguity early in training, rats trained...

We explored the hypothesis that learning a Pavlovian negative patterning task would be facilitated when training with differential, as opposed to non-differential, reinforcing outcomes. Two groups of rats received pairings of one visual and one auditory stimulus with food reward when these stimuli were presented on separate training trials, but wit...

A conditioned flavor preference develops when hungry or thirsty rats experience a neutral flavor mixed in solution with a nutrient. In two sets of studies, we previously demonstrated that this learned preference is highly sensitive to flavor nonreinforcement (i.e., exposure to the flavor without the nutrient) either prior to (latent inhibition), du...

It is thought that goal-directed control of actions weakens or becomes masked by habits over time. We tested the opposing hypothesis that goal-directed control becomes stronger over time, and that this growth is modulated by the overall action-outcome contiguity. Despite group differences in action-outcome contiguity early in training, rats trained...

The study of animal learning developed at an extremely interesting time in the history of psychological science. Physiologists were making significant progress into understanding how reflexes could be modified to control behavior in intricate and sophisticated ways. The concepts of “excitation” and “inhibition,” for example, figured prominently int...

This is an introduction to the special issue "Perceptual Learning." This collection of studies reflects some of the interesting new discoveries being made in the study of perceptual learning. Although much headway has been made toward understanding the basic phenomena, this collection of studies makes clear that there is much that remains to be und...

This is an introduction to the special issue "Wagner Tribute." Allan R. Wagner was the first editor in chief of this journal. It is difficult to quantitatively measure the impact that a single individual has on an entire discipline, but a brief consideration of Wagner's research output provides some insight into both the breadth of his interests an...

The Journal of Experimental Psychology: Animal Learning & Cognition (JEP:ALC) has always been the most prestigious journal for researchers investigating basic mechanisms of animal learning, cognition, and behavior. It is with great humility and honor that I currently take on the role of editor. Since its inception our discipline has been deeply int...

Animals engage in intricate action sequences that are constructed during instrumental learning. There is broad consensus that the basal ganglia play a crucial role in the formation and fluid performance of action sequences. To investigate the role of the basal ganglia direct and indirect pathways in action sequencing, we virally expressed Cre-depen...

When an organism's action is based on an anticipation of its consequences, that action is said to be goal-directed. It has long been thought that goal-directed control is made possible by experiencing a strong correlation between response rates and reward rates (Dickinson, 1985). To test this idea, we designed a set of experiments to determine whet...

There is broad consensus that the basal ganglia play a crucial role in the formation and fluid performance of action sequences. To investigate the role of the basal ganglia direct and indirect pathways in action sequencing, we virally expressed Cre-dependent Gi-DREADDs in either the dorsomedial (DMS) or dorsolateral (DLS) striatum during and/or aft...

When an organism’s action is based on an anticipation of its consequences, that action is said to be goal-directed. It has long been thought that goal-directed control is made possible by experiencing a strong correlation between response rates and reward rates (Dickinson, 1985). To test this idea, we designed a set of experiments to determine whet...

The purpose of this study was to take a new approach in showing how the central nervous system might encode time at the supra-second level using recurrent neural nets (RNNs). This approach utilizes units with a delayed feedback, whose feedback weight determines the temporal properties of specific neurons in the network architecture. When these feed...

The acquired motivational impact of conditioned stimuli has been studied using the Pavlovian-to-instrumental transfer (PIT) task, where a cue paired with a reward is consistently shown to energize responses separately trained with that same reward ("specific" PIT). However, most alcohol studies have shown that alcohol-related cues elevate responses...

It is tempting to equate the automatization of an action sequence with the formation of a habit. However, the term "habit" specifically implies a failure to evaluate future consequences to guide behavior. To test if automatized sequences become habitual, we trained rats on an action sequence task for either 20 or 60 d and then conducted reward deva...

When discrete localizable stimuli are used during appetitive Pavlovian conditioning, "sign-tracking" and "goal-tracking" responses emerge. Sign-tracking is observed when conditioned responding is directed toward the CS, whereas goal-tracking manifests as responding directed to the site of expected reward delivery. These behaviors seem to rely on di...

Four experiments compared the effect of forward and backward conditioning procedures on the ability of conditioned stimuli (CSs) to elevate instrumental responding in a Pavlovian-to-instrumental transfer (PIT) task. Two responses were each trained with one distinct outcome (R1->O1, R2->O2), either concurrently (Experiment 1) or separately (Experime...

Two experiments with Long-Evans rats examined the potential independence of learning about different features of food reward, namely, "what" reward is to be expected and "when" it will occur. This was examined by investigating the effects of selective reward devaluation upon responding in an instrumental peak timing task in Experiment 1 and by expl...

In this work, we present: (1) a facilitation effect in Negative Patterning (NP) learning due to Differential Outcome Effect (DOE), and (2) results from simulations with a connectionist model created by Delamater (2012) that shows two solutions to NP: a competitive and a configural solution.

Three experiments with male and female rats were conducted to examine the effects of Pavlovian extinction training on Pavlovian-to-instrumental transfer (PIT) in a task in which the unconditioned stimulus (US) was presented at an early time point within an extended conditioned stimulus (CS). Two instrumental responses were trained with different re...

Three experiments with rats compared the relative ease with which different sets of visual or temporal cues could participate in Pavlovian learning. In Experiment 1, 1 group was trained to discriminate between visual cues (Light vs. Dark), whereas the other group learned to discriminate between temporal cues (early [10 s] vs. late [90 s]). Both gro...

Three experiments explored the utility of considering mechanisms of occasion setting for understanding patterning and biconditional discriminations − two more complex conditional discriminations in which the stimulus-outcome relations of occasion setting are embedded. In Experiment 1, rats were trained in an appetitive conditioning task with either...

Psychologists generally accept that simple associative learning processes are among those that are fundamental in enabling organisms to extract meaning about predictive event relationships in the environment, and in controlling adaptive modes of behavior. This chapter concerns with the issue of identifying critical conditions for Pavlovian learning...

The present study examined factors that affect temporal averaging in rats when discriminative stimuli are compounded following separate training indicating the availability of reward after different fixed intervals (FI) on a peak procedure. One group of rats, Group Differential, learned that a flashing light stimulus signaled that one type of food...

One experiment with rats used Pavlovian-to-instrumental transfer (PIT) tests to explore potential competitive interactions between Pavlovian and instrumental processes during instrumental learning. Two instrumental response-outcome relations (e.g., left lever – grain pellets, right lever – sucrose pellets) were first trained in distinct contexts fo...

One of the major achievements of the last century of research in experimental psychology is the identification of a coherent set of theories and principles to characterize the nature of simple forms of associative learning. Major advances are also currently being made at a rapid pace in the neurobiology of associative learning, and, interestingly,...

The Pavlovian-to-instrumental transfer (PIT) paradigm probes the influence of Pavlovian cues over instrumentally learned behavior. The paradigm has been used extensively to probe basic cognitive and motivational processes in studies of animal learning. More recently, PIT and its underlying neural basis have been extended to investigations in humans...

The present review examines key psychological concepts in the study of experimental extinction and implications these have for an understanding of the underlying neurobiology of extinction learning. We suggest that many of the signature characteristics of extinction learning (spontaneous recovery, renewal, reinstatement, rapid reacquisition) can be...

Three experiments investigated the role of the dorsal hippocampus (DH) in renewal of conditioned and then extinguished magazine approach responding in rats. Experiments 1 and 2 found no effect of muscimol inactivation of the DH during testing on ABA and ABC renewal, respectively. However, subjects from these studies were subsequently found to be im...

Four experiments examined the roles of the basolateral amygdala and orbitofrontal cortex in the formation of sensory-specific associations in conditioned flavor preference and conditioned magazine approach paradigms using unconditioned stimulus (US) devaluation and selective Pavlovian-instrumental transfer procedures in Long Evans rats. Experiment...

This paper reviews a variety of studies designed to examine the effects of extinction upon control by specific stimulus-outcome (S-O) associations in Pavlovian conditioning. Studies conducted with rats in a magazine approach conditioning paradigm have shown that control by specific S-O associations is normally unaffected by extinction treatments, a...

A significant problem in the study of Pavlovian conditioning is characterizing the nature of the representations of events that enter into learning. This issue has been explored extensively with regard to the question of what features of the unconditioned stimulus enter into learning, but considerably less work has been directed to the question of...

Pavlovian learning tasks have been widely used as tools to understand basic cognitive and emotional processes in humans. The present studies investigated one particular task, Pavlovian-to-instrumental transfer (PIT), with human participants in an effort to examine potential cognitive and emotional effects of Pavlovian cues upon instrumentally train...

Two experiments with thirsty rats explored the harmful effects of non-reinforced exposures to a flavor cue in the control by sensory-specific flavor-sucrose associations in a conditioned flavor preference paradigm. Experiment 1 demonstrated that rats learned to prefer a flavor cue that was consistently paired with sucrose over one that was paired w...

Three experiments with rats explored the differential outcome effect (DOE) using a pavlovian magazine approach conditioning preparation. Experiment 1 compared groups trained on a biconditional discrimination (AX+, AY-, BX-, BY+) with differential or nondifferential outcomes, and Experiment 2 examined this using an ambiguous occasion setting task (e...

In two experiments, we examined the effect of reversal learning on the status of initially learned associations. In Experiment 1, thirsty rats were first taught to associate one flavor with sucrose and another flavor with Polycose. These relations were then reversed in a subsequent phase. One of the nutrients was then devalued by being paired with...

Previous research has reported a role for the neurotransmitter gamma-aminobutyric acid (GABA) in the extinction and renewal of conditioned fear. Here, the authors examine whether GABA is involved in the acquisition, extinction, renewal, spontaneous recovery, and latent inhibition of appetitive conditioning. Using Long-Evans rats, systemic injection...

We tested the hypothesis that sensitization to heroin enhances appetitive motivational processes involving food reward. In Experiment 1, sixteen rats were exposed to positive pairings of a light stimulus and food for 4 consecutive daily sessions. Then, the rats received either saline or heroin (2 mg/kg) injections before placement in activity monit...

Four experiments examined the effects of varying the conditioned stimulus-unconditioned stimulus (CS-US) interval (and US density) on learning in an appetitive magazine approach task with rats. Learning was assessed with conditioned response (CR) measures, as well as measures of sensory-specific stimulus-outcome associations (Pavlovian-instrumental...

A wide variety of associative learning tasks have been employed to assess the functional role of the orbitofrontal cortex (OFC) and related structures in learning. Many of these tasks were designed to assess the learning of highly specific associations between Pavlovian conditioned stimuli (or instrumental responses) and the sensory properties of r...

The nature of the reward representation in Pavlovian conditioning has been of perennial interest to students of associative learning theory. We consider the view that it consists of a range of different attributes, each of which may be governed by different learning rules. We investigated this issue through a series of experiments using a time-sens...

In a series of 4 experiments, the effects of extinction on flavor preferences conditioned by mixing flavor cues with a nutrient were examined. In each experiment it was observed that rats preferred a flavor cue that had not undergone extinction to one that had. In addition, this preference was reversed in subjects trained thirsty (Experiments 1 and...

Experiments with different temporal relations between the conditioned stimulus (CS) and the unconditioned stimulus (US) in conditioning assessed whether US devaluation effects can be obtained after nutrient-conditioned flavor preference learning. One flavor (CScarb) was paired with a carbohydrate, Polycose; a 2nd flavor (CSprot) was paired with a p...

This paper reviews the behavioural and neuroscience literatures on extinction in Pavlovian conditioning with a view towards finding possible points of contact between these two often independent lines of investigation. Recent discoveries at the behavioural level indicate (1) that conditioned stimulus (CS)-unconditioned stimulus (US) associations sp...

In the present experiments, the outcome specificity of learning was explored in an appetitive Pavlovian backward conditioning procedure with rats. The rats initially were administered Pavlovian backward training with two qualitatively different unconditioned stimulus conditioned-stimulus (US-CS) pairs of stimuli (e.g., pellet --> noise or sucrose -...

The effects of dopamine D1 (SCH23390) and D2 (raclopride) receptor antagonists on the acquisition and expressions of flavor preferences conditioned by the postingestive actions of sucrose were investigated. Food-restricted rats were trained in one-bottle sessions to associate one flavored saccharin solution (CS+) with intragastric (i.g.) infusions...

The present study examined the effects of D(1) and D(2) antagonists on flavor-preference conditioning by the sweet taste of sucrose. All sessions were conducted under sham-feeding conditions to minimize post-ingestive influences. The rats were trained in alternating, one-bottle sessions to sham-feed a 16% sucrose solution containing one novel flavo...

The effects of naltrexone on the expression and acquisition of flavor preferences conditioned by the postingestive actions of carbohydrates were investigated. Food-restricted rats (Experiment 1) were given one-bottle training with one flavored saccharin solution (CS+) paired with intragastric (IG) infusions of 16% sucrose, and another flavored sacc...

The present experiments explored the importance of training with a common antecedent or consequence for common coding in symbolic matching-to-sample tasks with human subjects using reversal and transfer tests. Experiment 1 assessed common coding following training in many-to-one (MTO) and one-to-many (OTM) symbolic matching-to-sample tasks by compa...

Opioid and dopamine systems are both implicated in the response to sweet solutions. Our laboratory previously reported that the opioid antagonist, naltrexone, reduced the intake of sweet solutions, yet had little or no effect on sucrose-conditioned flavor preferences in sham-feeding rats. The present study examined the role of dopamine D(1) and D(2...

Two experiments investigated the role of the opioid system in sucrose-reinforced conditioned place preferences (CPPs) in rats. Experiment 1 examined the effects of a general opioid antagonist, naltrexone, on the expression of a CPP acquired in the absence of the drug. Subjects were trained to associate one compartment of a two-compartment chamber w...

Relatively little is known about the neurochemical and pharmacological mechanisms involved in flavor preference learning. The present study examined the ability of the opioid antagonist, naltrexone to alter the acquisition and expression of flavor preferences conditioned by the sweet taste of sucrose. This was accomplished by adding a novel flavor...

Three experiments used appetitive conditioning with rats to examine the involvement of elemental and configural processes in positive and negative patterning discriminations. The first experiment demonstrated that negative and, to some extent, positive patterning discriminations were learned more rapidly when these discriminations consisted of stim...

Three experiments used rats to examine the acquired equivalence or distinctiveness of cues occurring when 2 auditory and 2 visual stimuli were associated with either the same or with different reinforcing outcomes (A1+, A2+, V1*, and V2* vs. A1+, A2*, V1+, and V2*). Subsequent single modality discrimination learning (e.g., A1+, A2-) was assessed in...

In two experiments, the possibility of outcome-selective reinstatement of conditioned responding was examined. Evidence for outcome-selective reinstatement of previously extinguished appetitively conditioned magazine responses by rats was observed in both Pavlovian (Experiment 1) and discriminated instrumental conditioning (Experiment 2) procedures...

Pavlovian-to-instrumental transfer tests were used to assess the sensitivity of Pavlovian stimulus-outcome (S-O) associations to various extinction treatments in four appetitive conditioning experiments with rats. In Experiment 1, simple nonreinforcement of a stimulus was shown to have little impact on the ability of that stimulus to display outcom...

The outcome-selective effects of presenting intertrial unconditioned stimuli (USs) in a rat appetitive conditioning paradigm were examined in two experiments. In both experiments, two stimuli were paired with different outcomes, while one of these outcomes was also presented in the intertrial interval (A+, B*, +). Two measures of learning, stimulus...

Arrogance and combativeness is a sure path to resistance and has doubtless been responsible for more than a few of the difficulties the field of behavior analysis and science in general have encountered. On the other hand an inappropriate humility is a sure course toward being ignored and our science disregarded. More humility of the sort espoused...

The present experiments investigated how fluid aversions conditioned with LiCl may differ from those conditioned with shock. In the first experiment, different groups received a saccharin/vanilla fluid either paired with an injection of LiCl or paired with tongue shocks. Following aversive conditioning, rats then received the saccharin/vanilla flui...

Tastes elicit a set of palatability-dependent orofacial and somatic responses in rats. We investigated whether discrete auditory conditioned stimuli that signal the availability or onset of unconditioned taste stimuli (sucrose, quinine) can control orofacial responses in the absence of those unconditioned stimuli. In Experiment 1, one auditory stim...

Several assays were used in assessing conditioned inhibition within a taste aversion procedure. Following Pavlovian conditioned inhibition training, in which one taste was followed by an injection of LiCl on A+ trials, but was followed by access to a second flavored solution on AX− trials, retardation-of-acquisition and summation tests failed to in...

Three rats were given access to a running wheel during spaced food deliveries. As the interpellet interval increased, the overall amount of running increased, the rate of running neither systematically increased nor decreased, and the locus of maximal running occurred later in the interpellet interval. Both the overall amount and the temporal distr...

Lashley and Rosellini (1980) have recently suggested that schedule-induced polydipsia (SIP) is determined by the occurrence of absolute periods within schedules of periodic food delivery which are associated with a low probability of food delivery, that is, CS− periods. To assess this hypothesis, SIP was examined in the present experiments under th...

In the interests of full disclosure, I have to say up front that my association with Dr. Delamater goes way back and is such that none of my comments can be viewed as impartial. He began as an undergraduate student in my laboratory (many years ago) and despite this training has become an accomplished learning theorist examining the nature of associ...

Thesis (M.A.)--Dalhousie University, 1984. Includes bibliography.

Thesis (Ph. D.)--Dalhousie University, 1990. Includes bibliographical references.