Biomedical subjects

Ralph R Miller

Publications and source records attributed to Ralph R Miller.

At least 19 recordsLinked to original sources

PubMed2004

The role of cognition in classical and operant conditioning.

For the past 35 years, learning theorists have been providing models that depend on mental representations, even in their most simple, deterministic, and mechanistic approaches. Hence, cognitive involvement (typically thought of as expectancy) is assumed for most instances of classical and operant conditioning, with current theoretical differences concerning the level of cognition that is involved (e.g., simple association vs. rule learning), rather than its presence. Nevertheless, many psychologists not in the mainstream of learning theory continue to think of cognitive and conditioning theories as rival families of hypotheses. In this article, the data pertaining to the role of higher-order cognition in conditioning is reviewed, and a theoretical synthesis is proposed that provides a role for both automatic and cognitively mediated processes.

Cognition↗

PubMed2004

Temporal coding in conditioned inhibition: analysis of associative structure of inhibition.

Two experiments with rats as subjects were conducted to investigate the associative structure of temporal control of conditioned inhibition through posttraining manipulation of the training excitor-unconditioned stimulus (US) temporal relationship. Experiment 1 found that following simultaneous Pavlovian inhibition training (i.e., A --> US/XA-no US) in which a conditioned stimulus (CS A) was established as a delay excitor, maximal inhibition was observed on a summation test when CS X was compounded with a delay transfer CS. Furthermore, posttraining shifts in the A-US temporal relationship from delay to trace resulted in maximal inhibition of a trace transfer CS. Experiment 2 found complementary results to Experiment 1 with an A-US posttraining shift from serial to simultaneous. These results suggest that temporal control of inhibition is mediated by the training excitor-US temporal relationship.

Animals↗

PubMed2004

Outcome pre- and postexposure effects: retention interval interacts with primacy and recency.

Effects of outcome-alone pretraining and posttraining exposure were investigated in conditioned suppression experiments conducted within a sensory preconditioning preparation with rats. Experiment 1 found that interference by outcome postexposure was stronger than that by outcome preexposure, suggesting a recency effect. Experiment 2 found that after a long retention interval, outcome preexposure produced more interference than outcome postexposure, suggesting a shift from recency to primacy with increasing retention interval. Experiment 3 showed that presentation of a priming stimulus that had been embedded within the earlier phase of treatment also caused a shift from recency to primacy. These results suggest that, at least in a sensory preconditioning paradigm, retrievability of outcome-alone exposure memory is an important determinant of any outcome-alone exposure effect.

Animals↗

PubMed2004

Comparing excitatory backward and forward conditioning.

Three Pavlovian lick suppression studies with rats were conducted to compare the role of the conditioning context in excitatory backward and forward conditioning. The experiments explored the possibility that excitatory backward conditioning, but not forward conditioning, is mediated by the context. That is, in excitatory backward conditioning, the conditioning context may function as an excitatory mediator, which supports second-order conditioning of the target cue. This possibility contrasts with traditional accounts, which suggests that common processes underlie excitatory backward and forward conditioning. Experiment 1 found that conditioned responding following backward conditioning was attenuated as a result of posttraining extinction of the training context, but the same manipulation elevated responding after forward conditioning. Experiments 2 and 3 found that posttraining and pretraining associative inflation of the context (presenting unsignalled USs) increased conditioned responding to the target of a backward conditioning procedure but either had no effect or reduced responding to the target of a forward conditioning procedure. Thus, excitatory backward and forward conditioning appear to differ in their dependence on the status of the conditioning context.

Analysis of Variance↗

PubMed2004

The basic laws of conditioning differ for elemental cues and cues trained in compound.

The cue-duration effect (i.e., longer cues result in less conditioned responding than shorter cues) was examined as a function of whether cues were trained alone or in compound. Compound (AX) or elemental (X) cues of either long or short duration were paired with the unconditioned stimulus. In testing with X alone, the cue-duration effect was observed with elementally trained cues, but not with compound cues. Instead, stronger responding resulted from training with long compound cues relative to short compound cues (i.e., a reversed cue-duration effect). Moreover, an overshadowing effect (i.e., decreased responding due to compound conditioning) was observed when conditioning was conducted with a short cue, but compound conditioning resulted in enhanced responding when it was conducted with a long cue (i.e., reversed overshadowing). These findings are consistent with other recent demonstrations that some laws of learning that apply to elementally trained cues do not similarly apply to cues trained in compound.

Animals↗

PubMed2004

Interference and time: a brief review and an integration.

Contemporary theories of associative learning have been preoccupied with the phenomenon of stimulus competition (attenuated responding to a target stimulus-outcome association if another stimulus trained together with the target is a better or more reliable predictor of the outcome). In recent years, reports of associative interference between associations trained separately have challenged associative learning theories, which provide no mechanism to account for this type of interference. Moreover, the ever-growing reports of temporal relationships between stimuli being a variable that determines the occurrence of stimulus competition and associative interference call for a reformulation of associative theory that can account for both interference and temporal learning effects. Here, we briefly review some of the central findings in stimulus competition, associative interference, and temporal learning, as well as a recently-proposed integration of these three seemingly disparate families of phenomena.

Animals↗

PubMed2004

Trial number and compound stimuli temporal relationship as joint determinants of second-order conditioning and conditioned inhibition.

Two conditioned lick suppression experiments with rats used feature-negative training (A-footshock trials intermixed with nonreinforced XA presentations) to analyze the role of the number of XA compound presentations and the temporal relationship of the elements within the compound (simultaneous or serial) as determinants of the resulting behavioral control. Second-order conditioning (i.e., excitatory behavioral control by X) was observed to decline as the number of XA compound trials was increased. This decline was more rapid if X and A were presented simultaneously, as opposed to serially (i.e., X before A; Experiment 1). Conditioned inhibition to X, as assessed by a summation test (Experiment 1) and a retardation test (Experiment 2), increased with the number of XA trials and did so more quickly for simultaneous than for serial pairings of X and A. The results help to clarify previously discrepant findings regarding factors that promote excitation versus inhibition with this protocol.

Animals↗

PubMed2004

Interaction of retention interval with CS-preexposure and extinction treatments: symmetry with respect to primacy.

Imposition of a retention interval between cue-outcome pairings and testing can alleviate the retardation of conditioned responding induced by pretraining exposure to the cue (i.e., the CS-preexposure effect). However, recent studies have reported an enhanced effect of CS-preexposure treatment with longer retention intervals (De la Casa & Lubow, 2000, 2002; Lubow & De la Casa, 2002). In a series of conditioned barpress suppression studies with rats, we examined the effects of imposing a retention interval just prior to testing following either CS-preexposure (cue alone before cue-outcome pairings) or extinction (cue alone after cue-outcome pairings) treatments. Experiment 1 replicated in a different preparation recent reports of CS-preexposure treatment effects increasing with longer retention intervals. Experiment 2 showed that spontaneous recovery of stimulus control of behavior after extinction can be obtained with the same parameters as those used to observe the augmented effect of CS-preexposure treatment. In Experiment 3, both the augmented effect of CS-preexposure treatment and spontaneous recovery from extinction were found when we used, in place of a retention interval, an associative priming manipulation.

Animals↗

PubMed2004

Signaling a change in cue-outcome relations in human associative learning.

In three experiments, we assessed the role of signals for changes in the consequences of cues as a potential account of the renewal effect. Experiment 1 showed recovery of responding following extinction when acquisition, extinction, and test phases occurred in different contexts. In addition, extinction treatment in multiple contexts attenuated context-induced response recovery. In Experiment 2, we used presentations of an extraneous stimulus (ES), instead of context shifts, and found that responding recovered from extinction only when the ES was presented both between acquisition and extinction and between extinction and test. In Experiment 3, we used a reversal learning design in which, during training, two cues were first paired with different outcomes, then paired with the alternative outcomes, and finally paired again with the original outcomes. In this experiment, presentation, just prior to testing, of an ES that had previously been presented between the different phases produced an expectation of reversal in the meaning of the cues.

Adolescent↗

PubMed2003

Backward conditioning: mediation by the context.

The information acquired in backward conditioning (i.e., outcome-->cue) was assessed in 3 Pavlovian lick-suppression experiments with water-deprived rats as subjects. Experiment 1 confirmed previous research that few outcome-->cue pairings made the cue into a conditioned excitor and additionally showed that massive posttraining extinction of the training context attenuated a backward-trained cue's excitatory value. Experiment 2 found that many outcome-->cue pairings made the cue into a conditioned inhibitor and that the same context manipulation attenuated this inhibitory value. Experiment 3 confirmed the observations of Experiments 1 and 2 and demonstrated that these effects of context extinction were specific to backward-trained cues conditioned in the extinguished context. These results are interpreted in terms of cue-->context and context-->outcome associations.

Animals↗

PubMed2003

Proactive interference between cues trained with a common outcome in first-order Pavlovian conditioning.

The nature of interference between cues (X, A) trained apart with a common outcome (O; an unconditioned stimulus) was explored by assessing proactive interference in first-order Pavlovian conditioning (i.e., A-O, X-O, resulting in attenuated responding to X). Three lick-suppression studies were conducted with water-deprived rats. Posttraining extinction of the interfering cue (A) attenuated proactive interference (Experiment 1), which mirrors the observation that extinction of the competing cue can reduce competition between cues trained together (e.g., recovery from overshadowing). Proactive interference was also attenuated with manipulations known to attenuate interference between outcomes trained apart (e.g., counterconditioning), namely reminder cues (Experiment 2) and renewal (Experiment 3). The findings suggest that similar processes underlie interference between cues trained apart, between cues trained together, and between outcomes trained apart.

Animals↗

PubMed2003

Latent inhibition in human adults without masking.

Latent inhibition refers to attenuated responding to Cue X observed when the X-outcome pairings are preceded by X-alone presentations. It has proven difficult to obtain in human adults unless the preexposure (X-alone) presentations are embedded within a masking (i.e., distracting) task. The authors hypothesized that the difficulty in obtaining latent inhibition with unmasked tasks is related to the usual training procedures, in which the preexposure and conditioning experiences are separated by a set of instructions. Experiment 1 reports latent inhibition without masking in a task in which preexposure and conditioning occur without interruption. Experiments 2 and 3 demonstrate that this attenuation in responding to target Cue X does not pass a summation test for conditioned inhibition and is context specific, thereby confirming that it is latent inhibition. Experiments 3 and 4 confirm that introducing instructions between preexposure and conditioning disrupts latent inhibition.

Adult↗

PubMed2003

Interaction between preexposure and overshadowing: further analysis of the extended comparator hypothesis.

Three experiments with rats used conditioned suppression of barpress to test predictions of the extended comparator hypothesis, which assumes that the effectiveness of (first-order) comparator stimuli in modulating responding to a target conditioned stimulus (CS) is itself modulated by other (second-order) comparator stimuli. Experiment 1 demonstrated that both pretraining exposure to the target CS alone (i.e., CS-preexposure effect, also known as latent inhibition) and pretraining exposure to a compound of the target CS and nontarget CS (i.e., compound-CS-preexposure effect) counteract overshadowing, and that posttraining deflation (i.e., extinction) of the overshadowing stimulus attenuates responding to the target CS when overshadowing is preceded by a CS-preexposure treatment (i.e., yields a CS-preexposure effect), but not when overshadowing is preceded by a compound-CS-preexposure treatment. Experiment 2 examined the consequences of posttraining associative inflation of the overshadowing stimulus or the preexposure companion stimulus following conjoint compound-CS-preexposure and overshadowing treatment. Experiment 3 examined the consequences of posttraining inflation of the overshadowing stimulus or the context following conjoint CS-alone preexposure and overshadowing treatment. The results support the expression-focused comparator view in contrast to recent acquisition-focused models of retrospective reevaluation.

Animals↗

PubMed2003

Temporal integration and temporal backward associations in human and nonhuman subjects.

Two experiments are reported that demonstrate temporal integration of independently acquired temporal relationships, including backward associations, in both human (Experiment 1) and nonhuman (rats, Experiment 2) subjects. The experiments were designed and analyzed in the framework of the temporal coding hypothesis (e.g., Matzel, Held, & Miller, 1988; Savastano & Miller, 1998) as a strategy toward illuminating the use of temporal information and assessing the existence of temporal backward associations. Both experiments provided evidence of retrieval of associations to an event that was expected to occur prior to the moment in time at which a stimulus was presented (i.e., backward associations). In addition, Experiment 1 constitutes the first controlled demonstration of temporal integration by human subjects.

Adult↗

PubMed2003

Timing in retroactive interference.

Retroactive interference is conventionally viewed as attenuated retrieval of a target association due to the training of a second association between training and testing of the target association. In three experiments in which water-deprived rats were used as subjects, we manipulated the durations of the time between cue termination and outcome onset (Experiment 1), the durations of the target and the interfering cues (Experiment 2), and the durations of the outcome used during target and interfering training (Experiment 3). Greater interference was consistently observed between associations bearing a high degree of similarity in their temporal structure, which suggests that interference occurs between complex representations that encode not only the physical attributes of the stimuli, but also their temporal characteristics.

Animals↗

PubMed2003

Massive preexposure and preexposure in multiple contexts attenuate the context specificity of latent inhibition.

Latent inhibition, which refers to attenuated responding to a conditioned stimulus (CS) after CS-unconditioned stimulus (CS-US) pairings as a result of CS-alone presentations prior to the pairings, is often attenuated if preexposure and conditioning occur in different contexts (i.e., it is context specific). Here we report two conditioned lick suppression experiments, using rat subjects, that examined whether manipulations known to attenuate the context specificity of extinction could also eliminate the context specificity of latent inhibition. Context specificity of latent inhibition was eliminated when the CS was preexposed in multiple contexts (Experiment 1) and when the CS was massively pre-exposed in the training context alone (Experiment 2). These results and their practical implications are discussed in the framework of contemporary theories of latent inhibition.

Animals↗

PubMed2003

Trial spacing is a determinant of cue interaction.

Four conditioned lick suppression experiments with rats examined the effect of trial spacing on cue interaction. Experiments 1 and 2 found overshadowing to be eliminated with massed compound stimulus-outcome pairings and the usual trial spacing effect to be reversed with compound acquisition trials. Experiment 3 found that whether acquisition compound-outcome pairings were massed or spaced determined the effect of posttraining extinction treatment. Extinction of the overshadowing cue reduced responding following massed training and increased responding following spaced training. Extinction of the context decreased responding following massed training. Experiment 4 found the conditioning and devaluation results to be associative and stimulus specific. These results are in accord with the extended comparator hypothesis (J. C. Denniston, H. I. Savastano, & R. R. Miller, 2001).

Animals↗

PubMed2002

Associative deficit accounts of disrupted latent inhibition and blocking in schizophrenia.

Latent inhibition (attenuated responding to a signal due to signal-alone presentations preceding the signal-outcome pairings) and blocking (attenuated responding to Signal B due to Signal A being paired with the outcome prior to pairings of an AB compound with the outcome) are reportedly absent in acute schizophrenics. The common assumption that these phenomena reflect the normal functioning of attention and the observation that rats administered low doses of amphetamine show a similar disruption has resulted in the development of an animal model of attentional dysfunction in acute schizophrenia. Here, we selectively review the experimental and clinical literature concerning latent inhibition and blocking, their disruption in acute schizophrenia, and the current status of this model. We conclude that the construct validity of the model is compromised if latent inhibition and blocking are viewed in attentional terms because experimental data indicate both phenomena can be better understood in associative terms. We favor a framework in which disruption of latent inhibition and blocking in acute schizophrenics is viewed as an inability to compare and express stored representations (i.e. associative performance deficit). This change of perspective does not undermine the potential value of the model, but rather suggests that the nature of its validity should be reconsidered.

Animals↗