Disrupted attentional learning in high schizotypy: Evidence of aberrant salience

Why creatives don't find the oddball odd: Neural and psychological evidence for atypical salience processing

Creativity has previously been linked with various attentional phenomena, including unfocused or broad attention. Although this has typically been interpreted through an executive functioning framework, such phenomena may also arise from atypical incentive salience processing. Across two studies, we examine this hypothesis both neurally and psychologically. First we examine the relationship between figural creativity and event-related potentials during an audio-visual oddball task, finding that rater creativity of drawings is associated with a diminished P300 response at midline electrodes, while abstractness and elaborateness of the drawings is associated with an altered distribution of the P300 over posterior electrodes. These findings support the notion that creativity may involve an atypical attribution of salience to prominent information. We further explore the incentive salience hypothesis by examining relationships between creativity and a psychological indicator of incentive salience captured by participants' ratings of enjoyment (liking) and their motivation to pursue (wanting) diverse real world rewards, as well as their positive spontaneous thoughts about those rewards. Here we find enhanced motivation to pursue activities as well as a reduced relationship between the overall tendency to enjoy rewards and the tendency to pursue them. Collectively, these findings indicate that creativity may be associated with atypical allocation of attentional and motivational resources to novel and rewarding information, potentially allowing more types of information access to attentional resources and motivating more diverse behaviors. We discuss the possibility that salience attribution in creatives may be less dependent on task-relevance or hedonic pleasure, and suggest that atypical salience attribution may represent a trait-like feature of creativity.

The effect of schizotypy on spatial learning in an environment with a distinctive shape

In two experiments, participants completed the Oxford-Liverpool Inventory of Feelings and Experiences measuring schizotypal traits across four dimensions (unusual experiences, cognitive disorganization, introvertive anhedonia, and impulsive non-conformity). They then took part in a virtual navigation task where they were required to learn about the position of a hidden goal with reference to geometric cues of a rectangular arena or rely on colored wall panels to find the hidden goal in a square-shaped arena. Unusual experience and cognitive disorganization were significant predictors of the use of geometric cues, but no significant predictors were found for the use of wall panels. Implications to hippocampal function and the clinical domain are considered.

The prediction-error hypothesis of schizophrenia: new data point to circuit-specific changes in dopamine activity

Schizophrenia is a severe psychiatric disorder affecting 21 million people worldwide. People with schizophrenia suffer from symptoms including psychosis and delusions, apathy, anhedonia, and cognitive deficits. Strikingly, schizophrenia is characterised by a learning paradox involving difficulties learning from rewarding events, whilst simultaneously 'overlearning' about irrelevant or neutral information. While dysfunction in dopaminergic signalling has long been linked to the pathophysiology of schizophrenia, a cohesive framework that accounts for this learning paradox remains elusive. Recently, there has been an explosion of new research investigating how dopamine contributes to reinforcement learning, which illustrates that midbrain dopamine contributes in complex ways to reinforcement learning, not previously envisioned. This new data brings new possibilities for how dopamine signalling contributes to the symptomatology of schizophrenia. Building on recent work, we present a new neural framework for how we might envision specific dopamine circuits contributing to this learning paradox in schizophrenia in the context of models of reinforcement learning. Further, we discuss avenues of preclinical research with the use of cutting-edge neuroscience techniques where aspects of this model may be tested. Ultimately, it is hoped that this review will spur to action more research utilising specific reinforcement learning paradigms in preclinical models of schizophrenia, to reconcile seemingly disparate symptomatology and develop more efficient therapeutics.

Deletion of AMPA receptor GluA1 subunit gene (Gria1) causes circadian rhythm disruption and aberrant responses to environmental cues

Dysfunction of the glutamate α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor GluA1 subunit and deficits in synaptic plasticity are implicated in schizophrenia and sleep and circadian rhythm disruption. To investigate the role of GluA1 in circadian and sleep behaviour, we used wheel-running, passive-infrared, and video-based home-cage activity monitoring to assess daily rest-activity profiles of GluA1-knockout mice (Gria1-/-). We showed that these mice displayed various circadian abnormalities, including misaligned, fragmented, and more variable rest-activity patterns. In addition, they showed heightened, but transient, behavioural arousal to light→dark and dark→light transitions, as well as attenuated nocturnal-light-induced activity suppression (negative masking). In the hypothalamic suprachiasmatic nuclei (SCN), nocturnal-light-induced cFos signals (a molecular marker of neuronal activity in the preceding ~1-2 h) were attenuated, indicating reduced light sensitivity in the SCN. However, there was no change in the neuroanatomical distribution of expression levels of two neuropeptides-vasoactive intestinal peptide (VIP) and arginine vasopressin (AVP)-differentially expressed in the core (ventromedial) vs. shell (dorsolateral) SCN subregions and both are known to be important for neuronal synchronisation within the SCN and circadian rhythmicity. In the motor cortex (area M1/M2), there was increased inter-individual variability in cFos levels during the evening period, mirroring the increased inter-individual variability in locomotor activity under nocturnal light. Finally, in the spontaneous odour recognition task GluA1 knockouts' short-term memory was impaired due to enhanced attention to the recently encountered familiar odour. These abnormalities due to altered AMPA-receptor-mediated signalling resemble and may contribute to sleep and circadian rhythm disruption and attentional deficits in different modalities in schizophrenia.

Aberrant Learned Irrelevance in Patients with First-Episode Schizophrenia-Spectrum Disorder

Emerging evidence has indicated disrupted learned irrelevance (LIrr), a form of selective attention deficit that may contribute to psychotic symptom formation, in schizophrenia. However, previous research mostly focused on chronic patients. There is a paucity of studies on LIrr in first-episode schizophrenia-spectrum disorder (i.e., schizophrenia and schizophreniform disorder; FES), which were limited by small sample size and have produced mixed results. The current study examined a LIrr effect and its relationship with positive symptom severity in 40 briefly-medicated FES patients and 42 demographically-matched healthy controls using a well-validated computerized LIrr paradigm which has been applied in chronic schizophrenia sample. Positive symptoms were assessed by Positive and Negative Syndrome Scale (PANSS) and Psychotic Symptom Rating Scales (PSYRATS). Our results showed that controls demonstrated intact LIrr, with significantly faster learning about previously predictive (relevant) than previously non-predictive (irrelevant) cues. Lack of such normal attention bias towards predictive over non-predictive cues was observed in FES patients, indicating their failure to distinguish between relevant and irrelevant stimuli. Nonetheless, we failed to reveal any significant correlations between learning scores, in particular learning scores for non-predictive cues, and positive symptom measures in FES patients. Learning scores were also not associated with other symptom dimensions, cognitive functions and antipsychotic dose. In conclusion, our findings indicate aberrant LIrr with impaired allocation of attention to relevant versus irrelevant stimuli in briefly-medicated FES patients. Further prospective research is warranted to clarify the longitudinal trajectory of such selective attention deficit and its association with positive symptoms and treatment response in the early course of illness.

Uncertainty and predictiveness modulate attention in human predictive learning

[Correction Notice: An Erratum for this article was reported online in Journal of Experimental Psychology: General on Jan 14 2021 (see record 2021-07705-001). In the article, formatting for UK Research Councils funding was omitted. The author note and copyright line now reflect the standard acknowledgment of and formatting for the funding received for this article. All versions of this article have been corrected.] Attention determines which cues receive processing and are learned about. Learning, however, leads to attentional biases. In the study of animal learning, in some circumstances, cues that have been previously predictive of their consequences are subsequently learned about more than are nonpredictive cues, suggesting that they receive more attention. In other circumstances, cues that have previously led to uncertain consequences are learned about more than are predictive cues. In human learning, there is a clear role for predictiveness, but a role for uncertainty has been less clear. Here, in a human learning task, we show that cues that led to uncertain outcomes were subsequently learned about more than were cues that were previously predictive of their outcomes. This effect occurred when there were few uncertain cues. When the number of uncertain cues was increased, attention switched to predictive cues. This pattern of results was found for cues (1) that were uncertain because they led to 2 different outcomes equally often in a nonpredictable manner and (2) that were used in a nonlinear discrimination and were not predictive individually but were predictive in combination with other cues. This suggests that both the opposing predictiveness and uncertainty effects were determined by the relationship between individual cues and outcomes rather than the predictive strength of combined cues. These results demonstrate that learning affects attention; however, the precise nature of the effect on attention depends on the level of task complexity, which reflects a potential switch between exploration and exploitation of cues. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Hearing hooves, thinking zebras: A review of the inverse base-rate effect

People often fail to use base-rate information appropriately in decision-making. This is evident in the inverse base-rate effect, a phenomenon in which people tend to predict a rare outcome for a new and ambiguous combination of cues. While the effect was first reported in 1988, it has recently seen a renewed interest from researchers concerned with learning, attention and decision-making. However, some researchers have raised concerns that the effect arises in specific circumstances and is unlikely to provide insight into general learning and decision-making processes. In this review, we critically evaluate the evidence for and against the main explanations that have been proposed to explain the effect, and identify where this evidence is currently weak. We argue that concerns about the effect are not well supported by the data. Instead, the evidence supports the conclusion that the effect is a result of general mechanisms that provides a useful opportunity to understand the processes involved in learning and decision making. We discuss gaps in our knowledge and some promising avenues for future research, including the relevance of the effect to models of attentional change in learning, an area where the phenomenon promises to contribute new insights.

High schizotypy traits are associated with reduced hippocampal resting state functional connectivity

Altered hippocampal functioning is proposed to play a critical role in the development of schizophrenia-spectrum disorders. Previous resting state functional Magnetic Resonance Imaging (rs-fMRI) studies report disrupted hippocampal connectivity in patients with psychosis and in individuals with clinical high risk, yet hippocampal connectivity has not been investigated in people with high schizotypy traits. Here we used rs-fMRI to examine hippocampal connectivity in healthy people with low (LS, n = 23) and high levels (HS, n = 22) of schizotypal traits assessed using the Schizotypy Personality Questionnaire. Using a bilateral hippocampal seed region, we examined resting state functional connectivity (RSFC) between hippocampus and striatal, thalamic and prefrontal cortex regions of interest. Compared to LS, HS participants showed lower RSFC between hippocampus and striatum and between hippocampus and thalamus. Whilst the group effect of reduced hippocampal RSFC in striatal and thalamic regions was driven by total schizotypy scores, positive schizotypy subfactor scores were significantly positively correlated with hippocampus-caudate/thalamus RSFC. Group differences in RSFC were not observed between hippocampus and prefrontal cortex. These results demonstrate that subclinical schizotypal traits are associated with altered hippocampal connectivity in striatal and thalamic regions and provide further support that hippocampal dysconnectivity confers risk for schizophrenia spectrum disorders.

Schizotypy is associated with difficulty maintaining multiple hypotheses

Among neurocognitive accounts of delusions, there is a growing consensus that it is the certainty with which delusions are held, rather than their content that defines some beliefs as delusional. On a continuum model of psychosis, this inappropriate certainty ought to be present (albeit in an attenuated form) in healthy adults who score highly in schizotypy. It was hypothesised that this might be most evident in circumstances where the environment provides incomplete or probabilistic information, which thereby forces the participant to hold two imperfectly supported, concurrent hypotheses in mind. A cued visual search task was used to measure people's capacity to use partially predictive information (i.e., a cue that predicted the target may occur in one of the two locations) to facilitate speeded responding. As hypothesised, people's performance on the trials that required holding two hypotheses in mind concurrently was significantly and specifically associated with the positive components of schizotypy. This finding is consistent with a hyperfocusing of attention in schizophrenia, and may help explain why delusion-prone individuals have a tendency to "jump to conclusions" or be resistant to disconfirming information when faced with multiple, partially supported hypotheses.

Cannabis Use, Schizotypy and Kamin Blocking Performance

Cannabis use has been associated with increased risk for a first episode of psychosis and inappropriate assignment of salience to extraneous stimuli has been proposed as a mechanism underlying this association. Psychosis-prone (especially schizotypal) personality traits are associated with deficits in associative learning tasks that measure salience allocation. The aim of this study was to examine the relationship between history of cannabis use and Kamin blocking (KB), a form of selective associative learning, in a non-clinical sample. Additionally, KB was examined in relation to self-reported schizotypy and aberrant salience scale profiles. A cross-sectional study was conducted in 307 healthy participants with no previous psychiatric or neurological history. Participants were recruited and tested using the Testable Minds behavioural testing platform. KB was calculated using Oades' "mouse in the house task", performance of which is disrupted in schizophrenia patients. Schizotypy was measured using the Schizotypal Personality Questionnaire (SPQ), and the Aberrant Salience Inventory (ASI) was used to assess self-reported unusual or inappropriate salience. The modified Cannabis Experience Questionnaire (CEQm) was used to collect detailed history of use of cannabis and other recreational drugs. Regression models and Bayesian t-tests or ANOVA (or non-parametric equivalents) examined differences in KB based on lifetime or current cannabis use (frequent use during previous year), as well as frequency of use among those who had previously used cannabis. Neither lifetime nor current cannabis use was associated with any significant change in total or trial-specific KB scores. Current cannabis use was associated with higher Disorganised SPQ dimension scores and higher total and sub-scale values for the ASI. A modest positive association was observed between total KB score and Disorganised SPQ dimension scores, but no relationships were found between KB and other SPQ measures. Higher scores on "Senses Sharpening" ASI sub-scale predicted decreased KB score only in participants who have not engaged in recent cannabis use. These results are discussed in the context of our understanding of the effects of long-term cannabis exposure on salience attribution, as well as inconsistencies in the literature with respect to both the relationship between KB and schizotypy and the measurement of KB associative learning phenomena.

Self-perceived cognitive lapses and psychological well-being in schizotypy: Generalized and domain-specific associations

A critical link between schizotypy and schizophrenia is impoverished cognitive functioning. In the majority of studies, though: (1) cognition is examined with standard neuropsychological tasks; and (2) high-schizotypal individuals are defined according to criteria applied in the respective study sample. Taking these considerations into account, the aims of the present study were to examine: (1) differences between four pre-defined, according to normative criteria, schizotypal (paranoid, negative, disorganized and cognitive-perceptual) and one control groups in self-perceived cognitive lapses; and (2) associations between schizotypal dimensions, self-perceived cognitive lapses and psychological well-being. Two hundred and sixty-one participants were administered the Schizotypal Personality Questionnaire, the Cognitive Failures Questionnaire (CFQ) and the Flourishing Scale, which assesses psychological well-being. Negative schizotypals reported higher scores in almost all CFQ measures compared with the control group (all p values < 0.01) along with poorer psychological well-being compared with the control and the cognitive-perceptual groups (both p values < 0.001). The disorganized group had higher scores in distractibility, blunders and total CFQ scores compared with the control group (all p values < 0.001). High psychological well-being was significantly associated with low negative schizotypy and CFQ blunders along with high cognitive-perceptual schizotypy (all p values < 0.05). To summarize, negative schizotypy is associated with a profile of "generalized" self-perceived cognitive lapses while disorganized schizotypy is characterized by self-perceived cognitive slips that have previously been shown to be mediated by a fronto-parietal network. Although psychological well-being is negatively associated with social-context specific cognitive failures and negative schizotypy, it is positively associated with cognitive-perceptual schizotypy.

Learned predictiveness acquired through experience prevails over the influence of conflicting verbal instructions in rapid selective attention

Previous studies have provided evidence that selective attention tends to prioritize the processing of stimuli that are good predictors of upcoming events over nonpredictive stimuli. Moreover, studies using eye-tracking to measure attention demonstrate that this attentional bias towards predictive stimuli is at least partially under voluntary control and can be flexibly adapted via instruction. Our experiment took a similar approach to these prior studies, manipulating participants’ experience of the predictiveness of different stimuli over the course of trial-by-trial training; we then provided explicit verbal instructions regarding stimulus predictiveness that were designed to be either consistent or inconsistent with the previously established learned predictiveness. Critically, we measured the effects of training and instruction on attention to stimuli using a dot probe task, which allowed us to assess rapid shifts of attention (unlike the eye-gaze measures used in previous studies). Results revealed a rapid attentional bias towards stimuli experienced as predictive (versus those experienced as nonpredictive), that was completely unaffected by verbal instructions. This was not due to participants’ failure to recall or use instructions appropriately, as revealed by analyses of their learning about stimuli, and their memory for instructions. Overall, these findings suggest that rapid attentional biases such as those measured by the dot probe task are more strongly influenced by our prior experience during training than by our current explicit knowledge acquired via instruction.

[Oculomotor activity as an indicator of disturbances in perception and programming in patients with schizotypal disorder]

AIM

To consider the patterns of stimuli analysis and task execution in conditions of voluntary and involuntary attention in people with schizotypal disorder from the psychopathological and psychological points of view.

MATERIAL AND METHODS

A total of 40 subjects were examined including 16 patients diagnosed with schizotypal disorder, 13 with personality disorders and 11 without psychiatric pathology (controls). In the first part of the study, subjects looked upon various static images without any instructions, followed by a test with antisaccade task in vertical and horizontal directions; the last task duplicated the first, but the subjects were asked to remember the presented images as best as possible.

RESULTS

In the group of patients with schizotypal disorder, an increase in average and maximum fixation variance, its greater variation between images, and a decrease in the scanpath length were found. These differences were associated with the intentional focus of attention and several indicators of the accomplish efficiency of the antisaccade task.

CONCLUSION

The changes in fixative eye movements observed in individuals with schizotypal disorder indicate violations of information selectivity and construction of an image of future action. Assumptions about inadequacy of their perceptual strategy to the simultaneous one and the primacy of the sense-bearing (motivational) violations in the programming of saccadic activity were made.

Oculomotor capture is influenced by expected reward value but (maybe) not predictiveness

A large body of research has shown that learning about relationships between neutral stimuli and events of significance – rewards or punishments – influences the extent to which people attend to those stimuli in the future. However, different accounts of this influence differ in terms of the critical variable that is proposed to determine learned changes in attention. We describe two experiments using eye-tracking with a rewarded visual search procedure to investigate whether attentional capture is influenced by the predictiveness of stimuli (i.e., the extent to which they provide information about upcoming events) or by their absolute associative value (i.e., the expected incentive value of the outcome that a stimulus predicts). Results demonstrated a clear influence of associative value on the likelihood that stimuli will capture eye-movements, but the evidence for a distinct influence of predictiveness was less compelling. The results of these experiments can be reconciled within a simple account under which attentional prioritization is a monotonic function of the expected, subjective value of the reward that is signalled by a stimulus.

The blocking effect in associative learning involves learned biases in rapid attentional capture

Blocking refers to the finding that less is learned about the relationship between a stimulus and an outcome if pairings are conducted in the presence of a second stimulus that has previously been established as a reliable predictor of that outcome. Attentional models of associative learning suggest that blocking reflects a reduction in the attention paid to the blocked cue. We tested this idea in three experiments in which participants were trained in an associative learning task using a blocking procedure. Attention to stimuli was measured 250 ms after onset using an adapted version of the dot probe task. This task was presented at the beginning of each learning trial (Experiments 1 and 2) or in independent trials (Experiment 3). Results show evidence of reduced attention to blocked stimuli (i.e. “attentional blocking”). In addition, this attentional bias correlated with the magnitude of blocking in associative learning, as measured by predictive-value judgments. Moreover, Experiments 2 and 3 found evidence of an influence of learning about predictiveness on memory for episodes involving stimuli. These findings are consistent with a central role of learned attentional biases in producing the blocking effect, and in the encoding of new memories.

Altered balance of excitatory and inhibitory learning in a genetically modified mouse model of glutamatergic dysfunction relevant to schizophrenia

The GluA1 AMPAR subunit (encoded by the Gria1 gene) has been implicated in schizophrenia. Gria1 knockout in mice results in recently experienced stimuli acquiring aberrantly high salience. This suggests that GluA1 may be important for learning that is sensitive to the temporal contiguity between events. To test this, mice were trained on a Pavlovian trace conditioning procedure in which the presentation of an auditory cue and food were separated by a temporal interval. Wild-type mice initially learnt, but with prolonged training came to withhold responding during the trace-conditioned cue, responding less than for another cue that was nonreinforced. Gria1 knockout mice, in contrast, showed sustained performance over training, responding more to the trace-conditioned cue than the nonreinforced cue. Therefore, the trace-conditioned cue acquired inhibitory properties (signalling the absence of food) in wild-type mice, but Gria1 deletion impaired the acquisition of inhibition, thus maintaining the stimulus as an excitatory predictor of food. Furthermore, when there was no trace both groups showed successful learning. These results suggest that cognitive abnormalities in disorders like schizophrenia in which gluatamatergic signalling is implicated may be caused by aberrant salience leading to a change in the nature of the information that is encoded.