Inhibitory stimuli are slow to acquire excitatory properties when paired with the outcome in a retardation test. However, this pattern is also seen after simple nonreinforced exposure: latent ...inhibition. It is commonly assumed that retardation would be stronger for a conditioned inhibitor than for a latent inhibitor, but there is surprisingly little empirical evidence comparing the two in either animals or humans. Thus, retardation after inhibitory training could in principle be attributable entirely to latent inhibition. We directly compared the speed of excitatory acquisition after conditioned inhibition and matched latent inhibition training in human causal learning. Conditioned inhibition training produced stronger transfer in a summation test, but the two conditions did not differ substantially in a retardation test. We offer two explanations for this dissociation. One is that learned predictiveness attenuated the latent inhibition that otherwise would have occurred during conditioned inhibition training, so that retardation in that condition was primarily due to inhibition. The second explanation is that inhibitory learning in these experiments was hierarchical in nature, similar to negative occasion-setting. By this account, the conditioned inhibitor was able to negatively modulate the test excitor in a summation test, but was no more retarded than a latent inhibitor in its ability to form a direct association with the outcome.
Consumption of sugar-sweetened beverages (SSBs) forms the primary source of added sugar intake and can increase the risk of metabolic disease. Evidence from studies in humans and rodents also ...indicates that consumption of SSBs can impair performance on cognitive tests, but that removing SSB access can ameliorate these effects.
The present study used an unblinded 3-group parallel design to assess the effects of a 12-week intervention in which young healthy adults (mean age = 22.85, SD = 3.89; mean BMI: 23.2, SD = 3.6) who regularly consumed SSBs were instructed to replace SSB intake with artificially-sweetened beverages (
= 28) or water (
= 25), or (c) to continue SSB intake (
= 27).
No significant group differences were observed in short-term verbal memory on the Logical Memory test or the ratio of waist circumference to height (primary outcomes), nor in secondary measures of effect, impulsivity, adiposity, or glucose tolerance. One notable change was a significant reduction in liking for strong sucrose solutions in participants who switched to water. Switching from SSBs to 'diet' drinks or water had no detectable impact on cognitive or metabolic health over the relatively short time frame studied here. This study was prospectively registered with the Australian New Zealand Clinical Trials Registry (ACTRN12615001004550; Universal Trial Number: U1111-1170-4543).
Our prior experiences shape the way that we prioritize information from the environment for further processing, analysis, and action. We show in three experiments that this process of attentional ...prioritization is critically modulated by the degree of uncertainty in these previous experiences. Participants completed a visual search task in which they made a saccade to a target to earn a monetary reward. The color of a color-singleton distractor in the search array signaled the reward outcome(s) that were available, with different degrees of variance (uncertainty). Participants were never required to look at the colored distractor, and doing so would slow their response to the target. Nevertheless, across all experiments, participants were more likely to look at distractors associated with high outcome variance versus low outcome variance. This pattern was observed when all distractors had equal expected value (Experiment 1), when the difference in variance was opposed by a difference in expected value (i.e., the high-variance distractor had a low expected value, and vice versa: Experiment 2), and when high- and low-variance distractors were paired with the maximum-value outcome on an equal proportion of trials (Experiment 3). Our findings demonstrate that experience of prediction error plays a fundamental role in guiding "attentional exploration," wherein priority is driven by the potential for a stimulus to reduce future uncertainty through a process of learning, as opposed to maximizing current information gain.
Public Significance Statement
Uncertainty is a ubiquitous feature of our experience of the world and may represent a common currency in neural processing. This study demonstrates that our attention is involuntarily drawn to unreliable sources of information even when more reliable or rewarding options are available, highlighting the role of uncertainty as a fundamental motivating force in attentional control. This drive to explore the unknown has broad implications for the way that we gather information from the environment. For instance, prioritizing stimuli whose consequences are currently unknown may be a central way that our attention system facilitates learning: by focusing on uncertain stimuli now, we can learn more about them, reducing our uncertainty when we encounter them again in the future. These findings could also shed light on attentional processes linked to anxiety and gambling, where individual differences in responses to uncertainty may play a central role.
Inhibitory Summation as a Form of Generalization Chow, Julie Y. L.; Lee, Jessica C.; Lovibond, Peter F.
Journal of experimental psychology. Animal learning and cognition,
04/2022, Letnik:
48, Številka:
2
Journal Article
Recenzirano
Inhibitory learning after feature negative training (A+/AB-) is typically measured by combining the Feature B with a separately trained excitor (e.g., C) in a summation test. Reduced responding to C ...is taken as evidence that B has properties directly opposite to those of C. However, in human causal learning, transfer of B's inhibitory properties to another excitor is modest and depends on individual differences in inferred causal structure. Here we ask whether instead of opposing processes, a summation test might instead be thought of in terms of generalization. Using an allergist task, we tested whether inhibitory transfer would be influenced by similarity. We found that transfer was greater when the test stimuli were from the same semantic category as the training stimuli (Experiments 1 and 2) and when the test excitor had previously been associated with the same outcome (Experiment 3). We also found that the similarity effect applied across all self-reported causal structures. We conclude it may be more helpful to consider transfer of inhibition as a form of conceptual generalization rather than the arithmetic summation of opposing processes.
One of the many strengths of the Rescorla and Wagner (1972) model is that it accounts for both excitatory and inhibitory learning using a single error-correction mechanism. However, it makes the ...counterintuitive prediction that nonreinforced presentations of an inhibitory stimulus will lead to extinction of its inhibitory properties. Zimmer-Hart and Rescorla (1974) provided the first of several animal conditioning studies that contradicted this prediction. However, the human data are more mixed. Accordingly, we set out to test whether extinction of an inhibitor occurs in human causal learning after simultaneous feature negative training with a conventional unidirectional outcome. In 2 experiments with substantial sample sizes, we found no evidence of extinction after presentations of the inhibitory stimulus alone in either a summation test or causal ratings. By contrast, 2 "no-modulation" procedures that contradicted the original training contingencies successfully reversed inhibition. These results did not differ substantially as a function of participants' self-reported causal structures (configural/modulation/prevention). We hypothesize that inhibitory learning may be intrinsically modulatory, analogous to negative occasion-setting, even with simultaneous training. This hypothesis would explain why inhibition is reversed by manipulations that contradict modulation but not by simple extinction, as well as other properties of inhibitory learning such as imperfect transfer to another excitor.
Influential models of causal learning assume that learning about generative and preventive relationships are symmetrical to each other. That is, a preventive cue directly prevents an outcome from ...occurring (i.e., "direct" prevention) in the same way a generative cue directly causes an outcome to occur. However, previous studies from our lab have shown that many participants do not infer a direct prevention causal structure after feature-negative discrimination (A+/AB-) with a unidirectional outcome (Lee & Lovibond, 2021). Melchers et al. (2006) suggested that the use of a bidirectional outcome that can either increase or decrease from baseline, encourages direct prevention learning. Here we test an alternative possibility that a bidirectional outcome encourages encoding of a
relationship in the
direction, where B directly causes a decrease in the outcome. Thus, previous evidence of direct prevention learning using bidirectional outcomes may instead be explained by some participants inferring an "Opposite Causal" structure. In two experiments, participants did indeed report an opposite causal structure. In Experiment 1, these participants showed the lowest outcome predictions when B was combined with a novel cause in a summation test, and lowest outcome predictions when B was presented alone. In Experiment 2, B successfully blocked learning to a novel cue that was directly paired with a reduction in the outcome, and this effect was strongest among participants who endorsed an Opposite Causal structure. We conclude that previous evidence of direct prevention learning using bidirectional outcomes may be a product of excitatory rather than inhibitory learning.
Teachers sometimes believe in the efficacy of instructional practices that have little empirical support. These beliefs have proven difficult to efface despite strong challenges to their evidentiary ...basis. Teachers typically develop causal beliefs about the efficacy of instructional practices by inferring their effect on students’ academic performance. Here, we evaluate whether causal inferences about instructional practices are susceptible to an
outcome density effect
using a contingency learning task
.
In a series of six experiments, participants were ostensibly presented with students’ assessment outcomes, some of whom had supposedly received teaching via a novel technique and some of whom supposedly received ordinary instruction. The distributions of the assessment outcomes was manipulated to either have frequent positive outcomes (high outcome density condition) or infrequent positive outcomes (low outcome density condition). For both continuous and categorical assessment outcomes, participants in the high outcome density condition rated the novel instructional technique as effective, despite the fact that it either had no effect or had a
negative
effect on outcomes, while the participants in the low outcome density condition did not. These results suggest that when base rates of performance are high, participants may be particularly susceptible to drawing inaccurate inferences about the efficacy of instructional practices.
Beliefs about cause and effect, including health beliefs, are thought to be related to the frequency of the target outcome (e.g., health recovery) occurring when the putative cause is present and ...when it is absent (treatment administered vs. no treatment); this is known as contingency learning. However, it is unclear whether unvalidated health beliefs, where there is no evidence of cause–effect contingency, are also influenced by the subjective perception of a meaningful contingency between events. In a survey, respondents were asked to judge a range of health beliefs and estimate the probability of the target outcome occurring with and without the putative cause present. Overall, we found evidence that causal beliefs are related to perceived cause–effect contingency. Interestingly, beliefs that were not predicted by perceived contingency were meaningfully related to scores on the paranormal belief scale. These findings suggest heterogeneity in pseudoscientific health beliefs and the need to tailor intervention strategies according to underlying causes.
When laboratory rats are given repeated access to an activity wheel, the amount that they run steadily increases. This suggests an analogy with drug dependency in animals and humans, in that this is ...marked by both increasing intakes of the drug and increasing motivation to obtain the drug (craving). This analogy was examined by measuring motivation to obtain an opportunity to run using a progressive ratio (PR) schedule, whereby the number of lever presses required to release a brake on an activity wheel was increased progressively. Each of two experiments included two groups of rats that differed in running experience. In Experiment
1
, both groups were given 17 wheel-running sessions before they were given the PR test, with sessions for the
short
group lasting only 30 min, while those for the
long
group lasted 4.5 hrs. In Experiment
2
, both groups were given 3-hr wheel sessions, with the
short
group given only four such sessions and the
medium
groups given 12 such sessions prior to their PR test. In both experiments, the PR tests revealed that motivation to run was greater when the rats had not had an opportunity to run for at least 24 hrs prior to the test than when they had run the previous day. However, neither experiment produced evidence that motivation to run increased with the amount of previous running. Given only limited support for the analogy between running and drug addiction, steady increases in running may instead reflect circadian adaptation and/or increases in fitness.
People tend to overestimate the efficacy of an ineffective treatment when they experience the treatment and its supposed outcome co-occurring frequently. This is referred to as the
effect. Here, we ...attempted to improve the accuracy of participants' assessments of an ineffective treatment by instructing them about the scientific practice of comparing treatment effects against a relevant base-rate, i.e., when no treatment is delivered. The effect of these instructions was assessed in both a trial-by-trial contingency learning task, where cue administration was either decided by the participant (Experiments 1 & 2) or pre-determined by the experimenter (Experiment 3), as well as in summary format where all information was presented on a single screen (Experiment 4). Overall, we found two means by which base-rate instructions influence efficacy ratings for the ineffective treatment: 1) When information was presented sequentially, the benefit of base-rate instructions on illusory belief was mediated by reduced sampling of cue-present trials, and 2) When information was presented in summary format, we found a
effect of base-rate instruction on reducing causal illusion. Together, these findings suggest that simple instructions on the scientific method were able to decrease participants' (over-)weighting of cue-outcome coincidences when making causal judgements, as well as decrease their tendency to over-sample cue-present events. However, the effect of base-rate instructions on correcting illusory beliefs was incomplete, and participants still showed illusory causal judgements when the probability of the outcome occurring was high. Thus, simple textual information about assessing causal relationships is partially effective in influencing people's judgements of treatment efficacy, suggesting an important role of scientific instruction in debiasing cognitive errors.
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