Overshadowing, but not relative validity, between the elements of an outcome during human associative learning.

Overshadowing and relative validity constitute two phenomena that inspired the development of the Rescorla-Wagner model in 1972. They demonstrate that cues will interact with one another for an association with the presence or absence of an outcome. Here, three experiments sought to explore whether these two effects extended to outcomes using a food allergist paradigm with human participants. In Experiment 1 (overshadowing) participants received trials in which a cue was followed by a compound of two outcomes (A-O1O2). Test trials revealed that participants learned less about the A-O2 association than they did between a control cue C, which had been paired with O2 in isolation (C-O2) in training - thus demonstrating an outcome overshadowing effect. In Experiment 2 (relative validity) participants received true discrimination trials, in which A was paired with an O1O3 compound and B was paired with an O2O3 compound, and pseudo discrimination trials, in which C and D were paired on 50% of the trials with an O4O6 compound and on the remaining trials with an O5O6 compound. Consequently, O3 is less well predicted by A and B relative to O1 and O2, whereas O6 is equally well predicted by C and D relative to O4 and O5. Despite the relative validity of A and B for O3 being less than the relative validity of C and D for O6, the ratings of A and B for O3 were the same as C and D for O6. This failure to observe an outcome relative validity effect was reproduced in Experiment 3, which replicated Experiment 2, but with an adjustment made to the number of training trials given to participants. These results are discussed in terms of a real-time development of the Rescorla-Wagner model provided by Wagner (1981).

Thinking outside of the box II: Disrupting the cognitive map.

A number of influential spatial learning theories posit that organisms encode a viewpoint independent (i.e. allocentric) representation of the global boundary shape of their environment in order to support spatial reorientation and place learning. In contrast to the trial and error learning mechanisms that support domain-general processes, a representation of the global-shape of the environment is thought to be encoded automatically as part of a cognitive map, and without interference from other spatial cues. To date, however, this core theoretical assumption has not been appropriately examined. This is because previous attempts to address this question have failed to employ tasks that fully dissociate reorientation based on an allocentric representation of global-shape from egocentric reorientation strategies. Here, we address this issue in two experiments. Participants were trained to navigate to a hidden goal on one side of a virtual arena (e.g. the inside) before being required to find the same point on the alternative side (e.g. the outside). At test, performing the correct search behaviour requires an allocentric representation of the global boundary-shape. Using established associative learning procedures of overshadowing and blocking, we find that search behaviour at test is disrupted when participants were able to form landmark-goal associations during training. These results demonstrate that encoding of an allocentric representation of boundary information is susceptible to interference from landmark cues, and is not acquired through special means. Instead, the results suggest that allocentric representations of environmental boundaries are acquired through the same kind of error-correction mechanisms that support domain-general non-spatial learning.

Thinking outside of the box: Transfer of shape-based reorientation across the boundary of an arena.

The way in which human and non-human animals represent the shape of their environments remains a contentious issue. According to local theories of shape learning, organisms encode the local geometric features of the environment that signal a goal location. In contrast, global theories of shape learning suggest that organisms encode the overall shape of the environment. There is, however, a surprising lack of evidence to support this latter claim, despite the fact that common behaviours seem to require encoding of the global-shape of an environment. We tested one such behaviour in 5 experiments, in which human participants were trained to navigate to a hidden goal on one side of a virtual arena (e.g. the inside) before being required to find the same point on the alternative side (e.g. the outside). Participants navigated to the appropriate goal location, both when inside and outside the virtual arena, but only when the shape of the arena remained the same between training and test (Experiments 1a and 1b). When the arena shape was transformed between these stages, participants were lost (Experiments 2a and 2b). When training and testing was conducted on the outside of two different-shaped arenas that shared local geometric cues participants once again explored the appropriate goal location (Experiment 3). These results provide core evidence that humans encode a global representation of the overall shape of the environments in, or around, which they navigate.

A developmental trajectory of latent inhibition.

Latent inhibition is said to occur when learning about the relationship between a cue and an outcome proceeds more readily when the cue is novel relative to when the cue has been rendered familiar through mere preexposure. Previous studies suggest that latent inhibition, while evident in 4- to 5-year-old children, is attenuated or even absent in older children. There are, however, acknowledged shortcomings associated with previous demonstrations of this effect, which we attempted to overcome using a letter prediction task that has been employed in recent studies of latent inhibition in adults. One hundred and seventy-five 4- to 14-year-old children and 175 young adults completed a letter prediction task, with a latent inhibition manipulation embedded within it. Using developmental trajectory analysis we found, contrary to other studies, an increase in the magnitude of latent inhibition as children age, with the effect becoming significant when children were around 6.7 years of age. Model comparison revealed that a linear function best described the relationship between latent inhibition and age. We discuss these findings in the context of theories of learning and attention, and consider the role of concurrent task type as a factor that determines the developmental trajectory of latent inhibition. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Overshadowing and associability change: examining the contribution of differential stimulus exposure.

In two appetitive conditioning experiments with rats, we investigated the mechanisms responsible for demonstrations of the superior associability of overshadowed conditioned stimuli (CSs) relative to control CSs. In Experiment 1, we investigated whether previous demonstrations were a consequence of differences in the relationship between the CSs and the unconditioned stimulus (US) or of differences in the conditions of exposure to the CSs. Rats received trials with X, Y, and an AB compound, but no delivery of the US (X-, Y-, AB-). A subsequent AY-, AX+, BY + test discrimination revealed that the AY/BY component of the discrimination was solved more readily than the AY/AX component--suggesting the contribution of an exposure effect. In Experiment 2, we better equated the conditions of exposure between A and Y by using AB+, XY+, X- training in Stage 1. In Stage 2, instrumental responses were rewarded during an AY compound. A final test revealed that Y took better control of instrumental responding than did A. The results of these experiments are discussed in terms of classical and contemporary theories of learning and attention.

Schizotypy dimensions do not predict overshadowing.

When two cues are presented together and reliably predict an outcome (AB-O1) an "overshadowing" effect is typically observed. That is, the relationship between these cues and the outcome is learned about less well than a cue presented on its own with an outcome (e.g., C - O1). The current study sought to explore the relationship between overshadowing and the positive and negative dimensions of schizotypy. A total of 256 participants completed an overshadowing procedure embedded within a causal judgement task and the Short Oxford-Liverpool Inventory of Feelings and Experiences (O-LIFE) which measured the different dimensions of schizotypy. A unilateral overshadowing effect was observed, however, none of the dimensions of schizotypy predicted the magnitude of this effect. These results are the first to demonstrate this finding using an appropriately powered sample and reveal that a tendency to experience symptoms of schizophrenia does not impact upon the overshadowing effect.

Modeling attention in associative learning: two processes or one?

Certain studies of associative learning show that attention is more substantial to cues that have a history of being predictive of an outcome than to cues that are irrelevant. At the same time, other studies show that attention is more substantial to cues whose outcomes are uncertain than to cues whose outcomes are predictable. This has led to the suggestion of there being two kinds of attention in associative learning: one based upon a mechanism that allocates attention to a cue on the basis of its predictiveness, the other based upon a mechanism that allocates attention to a cue on the basis of its prediction error (e.g., Le Pelley, Quarterly Journal of Experimental Psychology, 57B, 193-243, 2004). As an alternative, it has been demonstrated that the effects of both predictiveness and uncertainty can be accounted for with only one kind of attention: one that emphasizes the role of prediction (Esber & Haselgrove, Proceedings of the Royal Society B, 278, 2553-2561, 2011). Here, we consider the alternative: whether the effects of predictiveness and uncertainty can be reconciled with a model of learning that emphasizes the role of prediction error (Pearce, Kaye, & Hall, 1982). Simulations of this model reveal that, in many cases, it too is able to account for the influence of predictiveness and uncertainty in associative learning.

The role of prediction in learned predictiveness.

Learning permits even relatively uninteresting stimuli to capture attention if they are established as predictors of important outcomes. Associative theories explain this "learned predictiveness" effect by positing that attention is a function of the relative strength of the association between stimuli and outcomes. In three experiments we show that this explanation is incomplete: learned overt visual-attention is not a function of the relative strength of the association between stimuli and an outcome. In three experiments, human participants were exposed to triplets of stimuli that comprised (a) a target (that defined correct responding), (b) a stimulus that was perfectly correlated with the presentation of the target, and (c) a stimulus that was uncorrelated with the presentation of the target. Participants' knowledge of the associative relationship between the correlated or uncorrelated stimuli and the target was always good. However, eye-tracking revealed that an attentional bias toward the correlated stimulus only developed when it and target-relevant responding preceded the target stimulus. We propose a framework in which attentional changes are modulated during learning as a function the relative strength of the association between stimuli and the task-relevant response, rather than an association between stimuli and the task-relevant outcome. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Increasing Condom Use and STI Testing: Creating a Behaviourally Informed Sexual Healthcare Campaign Using the COM-B Model of Behaviour Change.

Sexually transmitted infections (STIs) are a major public health challenge. Although theoretically informed public health campaigns are more effective for changing behaviour, there is little evidence of their use when campaigns are commissioned to the commercial sector. This study describes the implementation of the COM-B model to a sexual health campaign that brought together expertise from academics, sexual healthcare, and marketing and creative professionals. Insights were gathered following a review of the relevant academic literature. Barriers and facilitators to condom use and STI testing were explored with the use of the COM-B model and the Behaviour Change Wheel in a workshop attended by academics, behavioural scientists, healthcare experts and creative designers. Feedback on the creative execution of the campaign was obtained from healthcare experts and via surveys. Barriers to psychological capability, automatic and reflective motivation, and social opportunity were identified as targets for the campaign, and creative solutions to these barriers were collaboratively devised. The final sexual health campaign was rated positively in its ability to change attitudes and intentions regarding the use of condoms and STI testing. This study describes the implementation of the COM-B model of behaviour change to a public sexual health campaign that brought together academics, public and commercial sector expertise. The barriers and facilitators identified in this collaborative process represent potential targets for future public health communication campaigns.

The developmental trajectories of children's reorientation to global and local properties of environmental geometry.

The way in which organisms represent the shape of their environments during navigation has been debated in cognitive, comparative, and developmental psychology. While there is evidence that adult humans encode the entire boundary shape of an environment (a global-shape representation), there are also data demonstrating that organisms reorient using only segments of the boundary that signal a goal location (a local-shape representation). Developmental studies offer unique insights into this debate; however, most studies have used designs that cannot dissociate the type of boundary-shape representation that children use to guide reorientation. Thus, we examined the developmental trajectories of children's reorientation according to local and global boundary shape. Participants aged 6-12 years were trained to find a goal hidden in one corner of a virtual arena, after which they were required to reorient in a novel test arena. From 10.5 years, children performed above chance when the test arena permitted reorientation based only on local-shape (Experiment 2), or only global-shape (Experiment 3) information. Moreover, when these responses were placed into conflict, older children reoriented with respect to global-shape information (Experiment 4). These age-related findings were not due to older children being better able to reorient in virtual environments per se: when trained and tested within the same environment (Experiment 1), children performed above chance from 6 years. Together, our results suggest (a) the ability to reorient on the basis of global- and local-shape representations develops in parallel, and (b) shape-based information is weighted to determine which representation informs reorientation. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Latent inhibition, aberrant salience, and schizotypy traits in cannabis users.

Aberrant salience processing may underlie the link between cannabis and psychosis, as posited in individuals with schizophrenia or high schizotypy. We investigated the relative effects of cannabis use, schizotypy status, and self-reported aberrant salience experiences on salience processing, measured using a latent inhibition (LI) task (Granger et al., 2016), in a non-clinical population. A university sample of 346 participants completed the Schizotypal Personality Questionnaire (SPQ), Aberrant Salience Inventory (ASI) the modified Cannabis Experience Questionnaire (CEQmv) and the LI task. Regression models and parallel (Bayesian and frequentist) t-tests or ANOVA (or non-parametric equivalents) examined differences in LI based on lifetime or current cannabis use (frequent use during previous year), as well as frequency of use. Mann-Whitney U tests assessed differences in SPQ and ASI scores based on current cannabis use. Neither lifetime nor current cannabis use was associated with significant change in LI scores. Current cannabis use was associated with both higher 'Disorganised' and 'Cognitive-perceptual' SPQ dimension scores and higher total and sub-scale ASI scores. No association was observed between LI score and SPQ total and dimension scores. Higher scores on 'Senses sharpening' and the 'Heightened cognition' ASI subscales predicted decreased LI scores. These data support previous findings of no association between cannabis use and abnormality in other associative learning tasks in young non-clinical populations, and elaborate the previously demonstrated association between self-reported cannabis use, schizotypy and aberrant salience. The association between dimensions of ASI and LI performance suggests this task may have potential as an experimental measure of aberrant salience.

Reconciling the influence of predictiveness and uncertainty on stimulus salience: a model of attention in associative learning.

Theories of selective attention in associative learning posit that the salience of a cue will be high if the cue is the best available predictor of reinforcement (high predictiveness). In contrast, a different class of attentional theory stipulates that the salience of a cue will be high if the cue is an inaccurate predictor of reinforcement (high uncertainty). Evidence in support of these seemingly contradictory propositions has led to: (i) the development of hybrid attentional models that assume the coexistence of separate, predictiveness-driven and uncertainty-driven mechanisms of changes in cue salience; and (ii) a surge of interest in identifying the neural circuits underpinning these mechanisms. Here, we put forward a formal attentional model of learning that reconciles the roles of predictiveness and uncertainty in salience modification. The issues discussed are relevant to psychologists, behavioural neuroscientists and neuroeconomists investigating the roles of predictiveness and uncertainty in behaviour.

Resilient allocentric reorientation following transfer from the inside to the outside of an arena.

In two virtual spatial-navigation experiments, participants were trained to find a hidden goal that was located adjacent to one of the right-angled corners of a cross-shaped virtual environment. The location of the goal was defined solely with respect to the geometry of the environmental structure. Training trials started from a single central start location (Experiment 1) or from multiple start locations over 2, 4, or 16 training trials (Experiment 2). Following training, participants were placed onto the outside of the same environment and asked to again find the hidden goal (which, unbeknown to participants, was removed) during a single test trial. The results from both experiments revealed that participants spent more time searching in regions on the outside of the environment that were closest to the location where the hidden goal was positioned during the previous training stage. In contrast, participants spent very little time searching in regions whose visual appearance matched those regions that contained the hidden goal during training. These results reproduce the findings from previous research which supports the idea of an allocentric encoding of the shape of the environment during navigation and further implies that this encoding is relatively resilient to manipulations that might be expected to undermine it.

High Schizotypy Predicts Emotion Recognition Independently of Negative Affect.

Introduction: Deficits in Emotion Recognition (ER) contribute significantly to poorer functional outcomes in people with schizophrenia. However, rather than reflecting a core symptom of schizophrenia, reduced ER has been suggested to reflect increased mood disorder co-morbidity and confounds of patient status such as medication. We investigated whether ER deficits are replicable in psychometrically defined schizotypy, and whether this putative association is mediated by increased negative affect. Methods: Two hundred and nine participants between the ages of 18 and 69 (66% female) were recruited from online platforms: 80% held an undergraduate qualification or higher, 44% were current students, and 46% were in current employment. Participants were assessed on psychometric schizotypy using the O-LIFE which maps onto the same symptoms structure (positive, negative, and disorganised) as schizophrenia. Negative affect was assessed using the Depression Anxiety and Stress Scale (DASS-21). Emotion Recognition of both positive and negative emotions was assessed using the short version of the Geneva Emotion Recognition Task (GERT-S). Results: Negative schizotypy traits predicted poorer ER accuracy to negative emotions (ß = -0.192, p = 0.002) as predicted. Unexpectedly, disorganised schizotypy traits predicted improved performance to negative emotions (ß = 0.256, p = 0.007) (primarily disgust). Negative affect was found to be unrelated to ER performance of either valence (both p > 0.591). No measure predicted ER accuracy of positive emotions. Positive schizotypy traits were not found to predict either positive or negative ER accuracy. However, positive schizotypy predicted increased confidence in decisions and disorganised schizotypy predicted reduced confidence in decisions. Discussion: The replication of ER deficits in non-clinical negative schizotypy suggests that the association between negative symptoms and ER deficits in clinical samples may be independent of confounds of patient status (i.e., anti-psychotic medication). The finding that this association was independent of negative affect further suggests ER deficits in patients may also be independent of mood disorder co-morbidity. This association was not demonstrated for the positive symptom dimension of the O-LIFE, which may be due to low levels of this trait in the current sample.

Effects of 7.5% Carbon Dioxide and Nicotine Administration on Latent Inhibition.

Stratified medicine approaches have potential to improve the efficacy of drug development for schizophrenia and other psychiatric conditions, as they have for oncology. Latent inhibition is a candidate biomarker as it demonstrates differential sensitivity to key symptoms and neurobiological abnormalities associated with schizophrenia. The aims of this research were to evaluate whether a novel latent inhibition task that is not confounded by alternative learning effects such as learned irrelevance, is sensitive to (1) an in-direct model relevant to psychosis [using 7.5% carbon dioxide (CO2) inhalations to induce dopamine release via somatic anxiety] and (2) a pro-cognitive pharmacological manipulation (via nicotine administration) for the treatment of cognitive impairment associated with schizophrenia. Experiment 1 used a 7.5% CO2 challenge as a model of anxiety-induced dopamine release to evaluate the sensitivity of latent inhibition during CO2 gas inhalation, compared to the inhalation of medical air. Experiment 2 examined the effect of 2 mg nicotine administration vs. placebo on latent inhibition to evaluate its sensitivity to a potential pro-cognitive drug treatment. Inhalation of 7.5% CO2 raised self-report and physiological measures of anxiety and impaired latent inhibition, relative to a medical air control; whereas administration of 2 mg nicotine, demonstrated increased latent inhibition relative to placebo control. Here, two complementary experimental studies suggest latent inhibition is modified by manipulations that are relevant to the detection and treatment of schizophrenia. These results suggest that this latent inhibition task merits further investigation in the context of neurobiological sub-groups suitable for novel treatment strategies.

Interactions between the elements of an outcome in human associative learning.

When a cue is established as a reliable predictor of an outcome (A-O1), this cue will typically block learning between an additional cue and the same outcome if both cues are subsequently trained together (AB-O1). Three experiments sought to explore whether this effect extends to outcomes and was investigated using the food allergist paradigm in human participants. In all 3 experiments, an outcome facilitation effect was observed. That is, prior learning about an element of an outcome compound (A-O1) facilitated learning about a novel outcome when (A-O2) these outcomes were presented together (A-O1 O2) relative to a control stimulus that first received C-O3 trials prior to C-O1 O2 trials. In Experiment 2, however, participants were also presented with an additional set of control trials, which were presented during Stage II only and reliably predicted the outcome compounds. At test, participants displayed more learning about these additional control trials relative to the blocked outcomes, thus displaying an outcome blocking effect alongside an outcome facilitation effect. In Experiment 3, a one-trial outcome blocking procedure was used to distinguish theoretical accounts of these findings. This procedure revealed an outcome facilitation effect but not an outcome blocking effect. These results can be understood in terms of an account derived from Wagner's (1981) model. The implications of these findings are discussed. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Learned changes in outcome associability.

When a cue reliably predicts an outcome, the associability of that cue will change. Associative theories of learning propose this change will persist even when the same cue is paired with a different outcome. These theories, however, do not extend the same privilege to an outcome; an outcome's learning history is deemed to have no bearing on subsequent new learning involving that outcome. Two experiments were conducted which sought to investigate this assumption inherent in these theories using a serial letter-prediction task. In both experiments, participants were exposed, in Stage 1, to a predictable outcome ('X') and an unpredictable outcome ('Z'). In Stage 2, participants were exposed to the same outcomes preceded by novel cues which were equally predictive of both outcomes. Both experiments revealed that participants' learning towards the previously predictable outcome was more rapid in Stage 2 than the previously unpredicted outcome. The implications of these results for theories of associative learning are discussed.

Crossing boundaries: Global reorientation following transfer from the inside to the outside of an arena.

In 2 spatial navigation experiments, human participants were asked to find a hidden goal (a WiFi signal) that was located in 1 of the right-angled corners of a kite-shaped (Experiment 1) or a cross-shaped (Experiment 2) virtual environment. Goal location was defined solely with respect to the geometry of the environment. Following this training, in a test conducted in extinction, participants were placed onto the outside of the same environments and asked to locate the WiFi signal. The results of both experiments revealed that participants spent more time searching in regions on the outside of the environments that were closest to where the WiFi signal was located during training. These results are difficult to explain in terms of analyses of spatial navigation and reorientation that emphasize the role of local representational encoding or view matching. Instead, we suggest that these results are better understood in terms of a global representation of the shape of the environment. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Web-based indicated prevention of common mental disorders in university students in four European countries - Study protocol for a randomised controlled trial.

BACKGROUND: Mental disorders and their symptoms are highly prevalent in the university student population, and the transition from secondary to tertiary education is associated with a rise in mental health problems. Existing web-based interventions for the prevention of common mental disorders in student populations often focus on just one disorder and have not been designed specifically for students. There is thus a need for transdiagnostic, student-specific preventative interventions that can be widely disseminated. This two-arm, parallel group randomised controlled trial aims to evaluate the effectiveness and cost-effectiveness of a web-based transdiagnostic mental health problem prevention programme (PLUS) across several universities in four countries. METHOD: Students (N = 5550) will be recruited through a variety of channels and asked to complete a personality assessment to determine whether they are at high risk for developing common mental disorders. Students at high risk will be randomly allocated to either PLUS or a control intervention, which provides practical support around issues commonly experienced at university. Students at low risk will be allocated to the control intervention. Both intervention groups will be assessed at baseline, 4 weeks, 3 months, 6 months and 12 months after randomisation. Depression and generalised anxiety, assessed using the Patient Health Questionnaire and the Generalised Anxiety Disorder scales, will form the primary outcomes in this study. Secondary outcome measures include alcohol and drug use, eating behaviour, self-esteem, and quality of life. The cost-effectiveness of the intervention will also be evaluated. CONCLUSIONS: This study will contribute to understanding the role of transdiagnostic indicated web-based interventions for the prevention of common mental disorders in university students. It will also be one of the first studies to investigate the cost-effectiveness of such interventions. TRIAL REGISTRATION: This trial was registered in the ISRCTN register (ISRCTN15570935) on 12th February 2016.