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Quigley M, Bradley A, Haselgrove M. Schizotypy dimensions do not predict overshadowing. Behav Brain Res 2023; 453:114631. [PMID: 37591412 DOI: 10.1016/j.bbr.2023.114631] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Revised: 08/10/2023] [Accepted: 08/14/2023] [Indexed: 08/19/2023]
Abstract
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.
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Affiliation(s)
- Martyn Quigley
- School of Psychology, Swansea University, United Kingdom.
| | - Alex Bradley
- School of Education and Sociology, University of Portsmouth, United Kingdom
| | - Mark Haselgrove
- School of Psychology, University of Nottingham, United Kingdom
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2
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Buhusi M, Griffin D, Buhusi CV. Brain-Derived Neurotrophic Factor Val66Met Genotype Modulates Latent Inhibition: Relevance for Schizophrenia. Schizophr Bull 2023; 49:626-634. [PMID: 36484490 PMCID: PMC10154718 DOI: 10.1093/schbul/sbac188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND AND HYPOTHESIS Latent inhibition (LI) is a measure of selective attention and learning relevant to Schizophrenia (SZ), with 2 abnormality poles: Disrupted LI in acute SZ, thought to underlie positive symptoms, and persistent LI (PLI) in schizotypy and chronic SZ under conditions where normal participants fail to show LI. We hypothesized that Brain-Derived Neurotrophic Factor (BDNF)-Met genotype shifts LI toward the PLI pole. STUDY DESIGN We investigated the role of BDNF-Val66Met polymorphism and neural activation in regions involved in LI in mice, and the interaction between the BDNF and CHL1, a gene associated with SZ. STUDY RESULTS No LI differences occurred between BDNF-wild-type (WT) (Val/Val) and knock-in (KI) (Met/Met) mice after weak conditioning. Chronic stress or stronger conditioning disrupted LI in WT but not KI mice. Behavior correlated with activation in infralimbic and orbitofrontal cortices, and nucleus accumbens. Examination of LI in CHL1-KO mice revealed no LI with no Met alleles (BDNF-WTs), PLI in CHL1-WT mice with 1 Met allele (BDNF-HETs), and PLI in both CHL1-WTs and CHL1-KOs with 2 Met alleles (BDNF-KIs), suggesting a shift to LI persistence with the number of BDNF-Met alleles in the CHL1 model of acute SZ. CONCLUSIONS Results support a role for BDNF polymorphisms in gene-gene and gene-environment interactions relevant to SZ. BDNF-Met allele may reduce expression of some acute SZ symptoms, and may increase expression of negative symptoms in individuals with chronic SZ. Evaluation of (screening for) SZ phenotypes associated with mutations at a particular locus (eg, CHL1), may be masked by strong effects at different loci (eg, BDNF).
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Affiliation(s)
- Mona Buhusi
- Interdisciplinary Program in Neuroscience, Department Psychology, Utah State University, Logan, UT, USA
| | - Daniel Griffin
- Interdisciplinary Program in Neuroscience, Department Psychology, Utah State University, Logan, UT, USA
| | - Catalin V Buhusi
- Interdisciplinary Program in Neuroscience, Department Psychology, Utah State University, Logan, UT, USA
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Dawes C, Quinn D, Bickerdike A, O'Neill C, Granger KT, Pereira SC, Mah SL, Haselgrove M, Waddington JL, O'Tuathaigh C, Moran PM. Latent inhibition, aberrant salience, and schizotypy traits in cannabis users. Schizophr Res Cogn 2022; 28:100235. [PMID: 35028297 PMCID: PMC8738960 DOI: 10.1016/j.scog.2021.100235] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2021] [Accepted: 12/27/2021] [Indexed: 11/17/2022] Open
Affiliation(s)
| | - Declan Quinn
- School of Applied Psychology, University College Cork, Cork, Ireland
| | - Andrea Bickerdike
- Department of Sport, Leisure, and Childhood Studies, Munster Technological University, Bishopstown, Cork, Ireland
| | - Cian O'Neill
- Department of Sport, Leisure, and Childhood Studies, Munster Technological University, Bishopstown, Cork, Ireland
| | - Kiri T Granger
- School of Psychology, University of Nottingham, NG7 2RD, UK
- Monument Therapeutics Ltd, Alderley Park, Congleton Road, Macclesfield SK10 4TG, UK
| | - Sarah Carneiro Pereira
- Psychological Sciences Research Institute, Université Catholique de Louvain, Louvain-la-Neuve, Belgium
| | - Sue Lynn Mah
- School of Psychology, University of Nottingham, NG7 2RD, UK
| | | | - John L Waddington
- School of Pharmacy and Biomolecular Sciences, Royal College of Surgeons in Ireland, St Stephen's Green, Dublin 2, Ireland
| | - Colm O'Tuathaigh
- Medical Education Unit, School of Medicine, University College Cork, Cork, Ireland
| | - Paula M Moran
- School of Psychology, University of Nottingham, NG7 2RD, UK
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Hills PJ, Vasilev MR, Ford P, Snell L, Whitworth E, Parsons T, Morisson R, Silveira A, Angele B. Sensory gating is related to positive and disorganised schizotypy in contrast to smooth pursuit eye movements and latent inhibition. Neuropsychologia 2021; 161:107989. [PMID: 34419489 DOI: 10.1016/j.neuropsychologia.2021.107989] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 07/30/2021] [Accepted: 08/05/2021] [Indexed: 10/20/2022]
Abstract
Since the characteristics and symptoms of both schizophrenia and schizotypy are manifested heterogeneously, it is possible that different endophenotypes and neurophysiological measures (sensory gating and smooth pursuit eye movement errors) represent different clusters of symptoms. Participants (N = 205) underwent a standard conditioned-pairing paradigm to establish their sensory gating ratio, a smooth-pursuit eye-movement task, a latent inhibition task, and completed the Schizotypal Personality Questionnaire. A Multidimensional Scaling analysis revealed that sensory gating was related to positive and disorganised dimensions of schizotypy. Latent inhibition and prepulse inhibition were not related to any dimension of schizotypy. Smooth pursuit eye movement error was unrelated to sensory gating and latent inhibition, but was related to negative dimensions of schizotypy. Our findings suggest that the symptom clusters associated with two main endophenotypes are largely independent. To fully understand symptomology and outcomes of schizotypal traits, the different subtypes of schizotypy (and potentially, schizophrenia) ought to be considered separately rather than together.
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Ashby DM, Dias C, Aleksandrova LR, Lapish CC, Wang YT, Phillips AG. Disruption of Long-Term Depression Potentiates Latent Inhibition: Key Role for Central Nucleus of the Amygdala. Int J Neuropsychopharmacol 2021; 24:580-591. [PMID: 33693669 PMCID: PMC8299826 DOI: 10.1093/ijnp/pyab011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Revised: 02/19/2021] [Accepted: 03/05/2021] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND Latent inhibition (LI) reflects an adaptive form of learning impaired in certain forms of mental illness. Glutamate receptor activity is linked to LI, but the potential role of synaptic plasticity remains unspecified. METHODS Accordingly, the present study examined the possible role of long-term depression (LTD) in LI induced by prior exposure of rats to an auditory stimulus used subsequently as a conditional stimulus to signal a pending footshock. We employed 2 mechanistically distinct LTD inhibitors, the Tat-GluA23Y peptide that blocks endocytosis of the GluA2-containing glutamate α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor, or the selective glutamate n-methyl-d-aspartate receptor 2B antagonist, Ro25-6981, administered prior to the acquisition of 2-way conditioned avoidance with or without tone pre-exposure. RESULTS Systemic LTD blockade with the Tat-GluA23Y peptide strengthened the LI effect by further impairing acquisition of conditioned avoidance in conditional stimulus-preexposed rats compared with normal conditioning in non-preexposed controls. Systemic Ro25-6981 had no significant effects. Brain region-specific microinjections of the Tat-GluA23Y peptide into the nucleus accumbens, medial prefrontal cortex, or central or basolateral amygdala demonstrated that disruption of glutamate α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor endocytosis in the central amygdala also potentiated the LI effect. CONCLUSIONS These data revealed a previously unknown role for central amygdala LTD in LI as a key mediator of cognitive flexibility required to respond to previously irrelevant stimuli that acquire significance through reinforcement. The findings may have relevance both for our mechanistic understanding of LI and its alteration in disease states such as schizophrenia, while further elucidating the role of LTD in learning and memory.
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Affiliation(s)
- Donovan M Ashby
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada
| | - Carine Dias
- Department of Psychiatry, University of British Columbia, Vancouver, BC, Canada
| | - Lily R Aleksandrova
- Department of Psychiatry, Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, Canada
| | - Christopher C Lapish
- Department of Psychology, Indiana University - Purdue University Indianapolis, Indianapolis, IN, United States
| | - Yu Tian Wang
- Department of Medicine, Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, Canada
| | - Anthony G Phillips
- Department of Psychiatry, Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, Canada
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Colagiuri B, Park J, Barnes K, Sharpe L, Boakes RA, Colloca L, Livesey EJ. Pre-Exposure, But Not Overshadowing, Inhibits Nocebo Hyperalgesia. THE JOURNAL OF PAIN 2021; 22:864-877. [PMID: 33636369 DOI: 10.1016/j.jpain.2021.02.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2020] [Revised: 11/24/2020] [Accepted: 02/11/2021] [Indexed: 12/19/2022]
Abstract
Nocebo hyperalgesia is a pervasive problem that significantly adds to the burden of pain. Conditioning is a key mechanism of nocebo hyperalgesia and recent evidence indicates that, once established, nocebo hyperalgesia is resistant to extinction. This means that preventive strategies are critical. We therefore tested whether two novel strategies - overshadowing (Experiment 1) and pre-exposure (Experiment 2) - could inhibit conditioned nocebo hyperalgesia. Overshadowing involves introducing additional cues during conditioning that should compete with and overshadow learning about the target nocebo cue. Pre-exposure involves pre-exposing the target nocebo cue in the absence of pain, which should diminish its ability to become associated with pain later. In both studies, healthy volunteers (N = 141) received exposure to a series of electrocutaneous pain stimuli with and without a sham electrode 'activated', which they were led to believe was a genuine hyperalgesic treatment. Nocebo conditioning was achieved by pairing sham activation with high pain prior to testing at equivalent pain intensity. In both studies, standard nocebo conditioning led to clear nocebo hyperalgesia relative to natural history controls. In Experiment 1, there was no evidence that overshadowing attenuated nocebo hyperalgesia. Importantly, however, Experiment 2 found that pre-exposure successfully attenuated nocebo hyperalgesia with post hoc analysis suggesting that this effect was dose-dependent. These findings provide novel evidence that pre-exposure, but not overshadowing, could be a cheap and effective way for mitigating the substantial harm caused by conditioned nocebo hyperalgesia in clinical settings. PERSPECTIVE: Nocebo hyperalgesia causes substantial patient burden with few preventive options available. Our study found novel evidence that pre-exposing treatment cues without pain, but not overshadowing them with other cues, has the capacity to inhibit conditioned nocebo hyperalgesia. Pre-exposure may therefore be an effective preventive strategy to combat nocebo hyperalgesia.
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Affiliation(s)
- B Colagiuri
- School of Psychology, University of Sydney, NSW, Australia.
| | - J Park
- School of Psychology, University of Sydney, NSW, Australia
| | - K Barnes
- School of Psychology, University of Sydney, NSW, Australia
| | - L Sharpe
- School of Psychology, University of Sydney, NSW, Australia
| | - R A Boakes
- School of Psychology, University of Sydney, NSW, Australia
| | - L Colloca
- School of Nursing, University of Maryland Baltimore, Maryland, USA
| | - E J Livesey
- School of Psychology, University of Sydney, NSW, Australia
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Walter EE, Fernandez F, Barkus E. Not all stress is created equal: Acute, not ambient stress, impairs learning in high schizotypes. Psych J 2021; 11:179-193. [PMID: 33915603 DOI: 10.1002/pchj.452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Revised: 03/12/2021] [Accepted: 03/15/2021] [Indexed: 11/08/2022]
Abstract
Learning from feedback is essential for daily functioning, with factors that impact learning having implications for healthy and clinical populations. Reinforcement learning appears impaired across the psychosis continuum, with deficits reported in patients with psychotic disorders as well as high schizotypes from the general population. Stress can impair learning, and sensitivity to stress is present along the psychosis continuum. The aim of the present study was to understand if stress impairs reinforcement learning in those at the lower end of the psychosis continuum. We investigated both naturalistic stress in everyday life using daily hassles (Study 1: n = 70; 31% male, M age = 22.67 years) and acute psychosocial stress using the Trier Social Stress Test (Study 2: n = 57; 32% male, M age = 22.43 years). In the presence of naturalistic stress, learning did not differ across schizotypes. However, under acute psychosocial stress, high schizotypes experienced impaired learning. Our results suggest trail-and-error learning is robust to the ebbs and flows of everyday stress for high schizotypes; however, acute stress is associated with decrements in learning. This indicates that the magnitude of stressors should be considered when designing cognitive and functional interventions for those along the psychosis continuum.
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Affiliation(s)
- Emma E Walter
- School of Psychology, University of Wollongong, Wollongong, New South Wales, Australia
| | - Francesca Fernandez
- Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, New South Wales, Australia
| | - Emma Barkus
- School of Psychology, University of Wollongong, Wollongong, New South Wales, Australia
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8
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Hearing hooves, thinking zebras: A review of the inverse base-rate effect. Psychon Bull Rev 2021; 28:1142-1163. [PMID: 33569719 DOI: 10.3758/s13423-020-01870-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/20/2020] [Indexed: 11/08/2022]
Abstract
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.
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9
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Granger KT, Ferrar J, Caswell S, Haselgrove M, Moran PM, Attwood A, Barnett JH. Effects of 7.5% Carbon Dioxide and Nicotine Administration on Latent Inhibition. Front Psychiatry 2021; 12:582745. [PMID: 33935819 PMCID: PMC8085318 DOI: 10.3389/fpsyt.2021.582745] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Accepted: 02/05/2021] [Indexed: 12/01/2022] Open
Abstract
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.
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Affiliation(s)
- Kiri T Granger
- Cambridge Cognition, Cambridge, United Kingdom.,School of Psychology, University of Nottingham, Nottingham, United Kingdom.,Monument Therapeutics, Cambridge, United Kingdom
| | - Jennifer Ferrar
- Cambridge Cognition, Cambridge, United Kingdom.,Alcohol & Tobacco Research Group, University of Bristol, Bristol, United Kingdom
| | - Sheryl Caswell
- Cambridge Cognition, Cambridge, United Kingdom.,Monument Therapeutics, Cambridge, United Kingdom
| | - Mark Haselgrove
- School of Psychology, University of Nottingham, Nottingham, United Kingdom
| | - Paula M Moran
- School of Psychology, University of Nottingham, Nottingham, United Kingdom
| | - Angela Attwood
- Alcohol & Tobacco Research Group, University of Bristol, Bristol, United Kingdom
| | - Jennifer H Barnett
- Cambridge Cognition, Cambridge, United Kingdom.,Monument Therapeutics, Cambridge, United Kingdom.,Department of Psychiatry, University of Cambridge, Cambridge, United Kingdom
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10
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Granger KT, Talwar A, Barnett JH. Latent inhibition and its potential as a biomarker for schizophrenia. Biomark Neuropsychiatry 2020. [DOI: 10.1016/j.bionps.2020.100025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
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11
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Orjiakor CT, Watt A, Iorfa SK, Onu DU, Okonkwo AI. Associations between schizotypal traits and antisocial behaviours in a sub-Saharan sample. Arch Psychiatr Nurs 2019; 33:138-143. [PMID: 31753219 DOI: 10.1016/j.apnu.2019.10.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Revised: 08/19/2019] [Accepted: 10/18/2019] [Indexed: 10/25/2022]
Abstract
Schizophrenic symptoms have often been associated with antisocial behaviours (ASBs). Most studies have focused on violence. The association between schizophrenia and violence is often confounded by socio demographic characteristics of patients. Overemphasis on diagnosis, rather than traits, and the traditional focus on violence may have obscured associations between psychotic features and antisocial behaviour. In this study, an analogue sample (n = 604, females = 54.4%, mean age = 21.46, SD = 5.89) completed self-report measures of schizotypy and antisocial behaviours. The aim was to identify the strength of associations between different schizotypal traits/symptoms (unusual experiences, cognitive disorganisation, impulsivity & introvertive anhedonia) and different forms of antisocial behaviour (rule breaking, physical aggression & social aggression). Differential patterns of association between genders were also considered. Traits akin to positive symptoms were more strongly associated with antisocial behaviours. Impulsive non-conformity was associated with rule breaking, physical aggression and social aggression for both males and females whilst unusual experiences traits were associated with physical and social aggression in both males and females but had only a weak (gender-nonspecific) association with rule breaking. Finally, cognitive disorganisation was not associated with any class of ASB for males but was associated with physical and social aggression in females. These specific associations could inform the development of more targeted treatment approaches for specific types of ASBs in males and females.
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Affiliation(s)
- Charles T Orjiakor
- Department of Psychology, University of Nigeria, Nsukka, Nigeria; Health Policy Research Group, Department of Pharmacology and Therapeutics, College of Medicine, University of Nigeria Enugu-Campus, Enugu, Nigeria
| | - Andy Watt
- Department of Applied Psychology, Cardiff Metropolitan University, United Kingdom
| | - Steven K Iorfa
- Department of Psychology, University of Nigeria, Nsukka, Nigeria
| | - Desmond U Onu
- Department of Psychology, University of Nigeria, Nsukka, Nigeria.
| | - Angela I Okonkwo
- Department of Psychology, University of Nigeria, Nsukka, Nigeria
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12
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Rodríguez G, Aranzubia-Olasolo M, Liberal U, Rodríguez-San Juan F, Hall G. Loss of salience as a source of latent inhibition in human associative learning. Q J Exp Psychol (Hove) 2019; 72:1047-1054. [DOI: 10.1177/1747021818777694] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Two experiments made use of a procedure known to generate latent inhibition in human associative learning. Participants received training consisting of exposure to a list of actions performed by a fictitious Mr. X. For most of his actions, an outcome was described, but some were not followed by any outcome. The last action performed by Mr. X was novel for participants in the NOVEL condition. For participants in the EXPOSED condition, Mr. X had performed that target action on repeated occasions, without it producing any outcome. After training, all participants were tested on their ability to retrieve what was the last action performed by Mr. X. In both experiments, retrieval of the target action was poorer in the EXPOSED than in the NOVEL condition. Experiment 2 also included a condition in which the target action was followed by a novel outcome and demonstrated a latent inhibition effect—poorer performance in the EXPOSED condition on a test of the association between the target event and its outcome. These results are interpreted in terms of an attention-reducing mechanism, triggered by the repeated preexposure to the target in the absence of a following event. It is argued that the attentional change involves a reduction in the effective salience of the stimulus of the target event, and thus reduces the processing necessary for encoding in memory and the ability of the event to enter into associations.
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Affiliation(s)
- Gabriel Rodríguez
- Facultad de Psicología, Universidad del País Vasco (UPV/EHU), San Sebastián, Spain
| | | | - Unai Liberal
- Facultad de Psicología, Universidad del País Vasco (UPV/EHU), San Sebastián, Spain
| | | | - Geoffrey Hall
- Department of Psychology, University of York, York, UK
- School of Psychology, University of New South Wales, Sydney, NSW, Australia
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13
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Abstract
Latent inhibition (LI) is a startlingly simple effect in which preexposure of a stimulus without consequence retards subsequent responding to a stimulus-consequence relation. The effect was first demonstrated with Pavlovian conditioning in animals and was later suggested to be a marker of human psychopathology such as schizophrenia. Individual differences in LI has supported the continued use of animal models to understand human mental health. In this review, we ask whether there is sufficient evidence to support the continued application of LI from animal models to human psychopathology because of the weak evidence for LI in humans. There is considerable variability in the methods used to assess LI, sustaining different theoretical accounts of the effects observed, which differ from the accepted accounts of LI as demonstrated in animals. The review shows that although there have been many experiments testing human LI, none provide the necessary experimental controls to support the conclusion that retarded responding is caused simply by preexposure to a stimulus, as has been demonstrated with animal models. Establishing this conflict, we set out a framework for future research.
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Abstract
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.
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Affiliation(s)
- Martyn C Quigley
- School of Psychology, The University of Nottingham, Nottingham, UK
| | | | - Mark Haselgrove
- School of Psychology, The University of Nottingham, Nottingham, UK
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15
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Pickett C, Cassaday HJ, Bibby PA. Overshadowing depends on cue and reinforcement sensitivity but not schizotypy. Behav Brain Res 2017; 321:123-129. [DOI: 10.1016/j.bbr.2016.12.031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Revised: 12/19/2016] [Accepted: 12/23/2016] [Indexed: 11/27/2022]
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Abstract
PURPOSE OF REVIEW This review summarizes recent executive functions research to better delineate the nosology of personality disorders. RECENT FINDINGS This review indicates that there are consistent impairments in executive functioning in people with personality disorders as compared with matched controls. Only five disorders were considered: borderline, obsessive-compulsive, antisocial, narcissistic, and schizotypal. Significant deficits are observed in decision-making, working memory, inhibition, and flexibility. Relevant data for the remaining personality disorders have not yet been published in relation to the executive functions. SUMMARY People with personality disorders could present a pattern of neurocognitive alterations that suggest a specific impairment of the prefrontal areas. The executive dysfunctions could partially explain the behavioral alterations in people with personality disorders.Further research should adopt broader considerations of effects of comorbidity and clinical heterogeneity, include community samples and, possibly, longitudinal designs with samples of youth.
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