1
|
Kucwaj H, Ociepka M, Gajewski Z, Chuderski A. Captured by associations: Semantic distractibility during analogical reasoning in schizophrenia. Schizophr Res Cogn 2023; 31:100274. [DOI: 10.1016/j.scog.2022.100274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Revised: 11/09/2022] [Accepted: 11/16/2022] [Indexed: 11/21/2022] Open
|
2
|
Almeida VN, Radanovic M. Semantic priming and neurobiology in schizophrenia: A theoretical review. Neuropsychologia 2021; 163:108058. [PMID: 34655651 DOI: 10.1016/j.neuropsychologia.2021.108058] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Revised: 10/06/2021] [Accepted: 10/07/2021] [Indexed: 12/11/2022]
Abstract
In this theoretical review we bridge the cognitive and neurobiological sciences to shed light on the neurocognitive foundations of the semantic priming effect in schizophrenia. We review and theoretically evaluate the neurotransmitter systems (dopaminergic, GABAergic and glutamatergic) and neurobiological underpinnings of behavioural and electrophysiological (N400) semantic priming in the pathology, and the main hypotheses on their geneses: a disinhibition of the semantic spread of activation, a disorganised semantic storage or noisy lexical-semantic associations, a psychomotor artefact, an artefact of relatedness proportions, or an inability to mobilise contextual information. We further assess the literature on the endophenotype of Formal Thought Disorder from multiple standpoints, ranging from neurophysiology to cognition: considerations are weaved on neuronal (PV basket cell, SST, VIP) and receptor deficits (DRD1, NMDA), neurotransmitter imbalances (dopamine), cortical and dopaminergic lateralisation, inter alia. In conclusion, we put forth novel postulates on the underlying causes of controlled hypopriming, automatic hyperpriming, N400 reversals (larger amplitudes for close associations), indirect versus direct hyperpriming, and the endophenotype of lexical-semantic disturbances in schizophrenia.
Collapse
Affiliation(s)
- Victor N Almeida
- Faculdade de Letras, Universidade Federal de Minas Gerais (UFMG), Av. Pres. Antônio Carlos, 6627 - Pampulha, Belo Horizonte, MG, 31270-901, Brazil.
| | - Marcia Radanovic
- Laboratório de Neurociências (LIM-27), Faculdade de Medicina, Departamento e Instituto de Psiquiatria, Hospital das Clínicas HCFMUSP, Universidade de São Paulo, Brazil
| |
Collapse
|
3
|
Sharpe V, Weber K, Kuperberg GR. Impairments in Probabilistic Prediction and Bayesian Learning Can Explain Reduced Neural Semantic Priming in Schizophrenia. Schizophr Bull 2020; 46:1558-1566. [PMID: 32432697 PMCID: PMC7846190 DOI: 10.1093/schbul/sbaa069] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
It has been proposed that abnormalities in probabilistic prediction and dynamic belief updating explain the multiple features of schizophrenia. Here, we used electroencephalography (EEG) to ask whether these abnormalities can account for the well-established reduction in semantic priming observed in schizophrenia under nonautomatic conditions. We isolated predictive contributions to the neural semantic priming effect by manipulating the prime's predictive validity and minimizing retroactive semantic matching mechanisms. We additionally examined the link between prediction and learning using a Bayesian model that probed dynamic belief updating as participants adapted to the increase in predictive validity. We found that patients were less likely than healthy controls to use the prime to predictively facilitate semantic processing on the target, resulting in a reduced N400 effect. Moreover, the trial-by-trial output of our Bayesian computational model explained between-group differences in trial-by-trial N400 amplitudes as participants transitioned from conditions of lower to higher predictive validity. These findings suggest that, compared with healthy controls, people with schizophrenia are less able to mobilize predictive mechanisms to facilitate processing at the earliest stages of accessing the meanings of incoming words. This deficit may be linked to a failure to adapt to changes in the broader environment. This reciprocal relationship between impairments in probabilistic prediction and Bayesian learning/adaptation may drive a vicious cycle that maintains cognitive disturbances in schizophrenia.
Collapse
Affiliation(s)
| | - Kirsten Weber
- Department of Neurobiology of Language, Max Planck Institute for Psycholinguistics, Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition and Behavior, Radboud University, Nijmegen, The Netherlands
| | - Gina R Kuperberg
- Department of Psychology, Tufts University, Medford, MA
- Department of Psychiatry, Massachusetts General Hospital, Boston, MA
| |
Collapse
|
4
|
Kuperberg GR, Delaney-Busch N, Fanucci K, Blackford T. Priming production: Neural evidence for enhanced automatic semantic activity preceding language production in schizophrenia. NEUROIMAGE-CLINICAL 2017; 18:74-85. [PMID: 29387525 PMCID: PMC5789757 DOI: 10.1016/j.nicl.2017.12.026] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/26/2017] [Revised: 11/27/2017] [Accepted: 12/19/2017] [Indexed: 10/25/2022]
Abstract
Introduction Lexico-semantic disturbances are considered central to schizophrenia. Clinically, their clearest manifestation is in language production. However, most studies probing their underlying mechanisms have used comprehension or categorization tasks. Here, we probed automatic semantic activity prior to language production in schizophrenia using event-related potentials (ERPs). Methods 19 people with schizophrenia and 16 demographically-matched healthy controls named target pictures that were very quickly preceded by masked prime words. To probe automatic semantic activity prior to production, we measured the N400 ERP component evoked by these targets. To determine the origin of any automatic semantic abnormalities, we manipulated the type of relationship between prime and target such that they overlapped in (a) their semantic features (semantically related, e.g. "cake" preceding a < picture of a pie >, (b) their initial phonemes (phonemically related, e.g. "stomach" preceding a < picture of a starfish >), or (c) both their semantic features and their orthographic/phonological word form (identity related, e.g. "socks" preceding a < picture of socks >). For each of these three types of relationship, the same targets were paired with unrelated prime words (counterbalanced across lists). We contrasted ERPs and naming times to each type of related target with its corresponding unrelated target. Results People with schizophrenia showed abnormal N400 modulation prior to naming identity related (versus unrelated) targets: whereas healthy control participants produced a smaller amplitude N400 to identity related than unrelated targets, patients showed the opposite pattern, producing a larger N400 to identity related than unrelated targets. This abnormality was specific to the identity related targets. Just like healthy control participants, people with schizophrenia produced a smaller N400 to semantically related than to unrelated targets, and showed no difference in the N400 evoked by phonemically related and unrelated targets. There were no differences between the two groups in the pattern of naming times across conditions. Conclusion People with schizophrenia can show abnormal neural activity associated with automatic semantic processing prior to language production. The specificity of this abnormality to the identity related targets suggests that that, rather than arising from abnormalities of either semantic features or lexical form alone, it may stem from disruptions of mappings (connections) between the meaning of words and their form.
Collapse
Affiliation(s)
- Gina R Kuperberg
- Department of Psychology, Tufts University, United States; Department of Psychiatry and the Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, United States.
| | | | | | | |
Collapse
|
5
|
Brown M, Kuperberg GR. A Hierarchical Generative Framework of Language Processing: Linking Language Perception, Interpretation, and Production Abnormalities in Schizophrenia. Front Hum Neurosci 2015; 9:643. [PMID: 26640435 PMCID: PMC4661240 DOI: 10.3389/fnhum.2015.00643] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2015] [Accepted: 11/12/2015] [Indexed: 12/27/2022] Open
Abstract
Language and thought dysfunction are central to the schizophrenia syndrome. They are evident in the major symptoms of psychosis itself, particularly as disorganized language output (positive thought disorder) and auditory verbal hallucinations (AVHs), and they also manifest as abnormalities in both high-level semantic and contextual processing and low-level perception. However, the literatures characterizing these abnormalities have largely been separate and have sometimes provided mutually exclusive accounts of aberrant language in schizophrenia. In this review, we propose that recent generative probabilistic frameworks of language processing can provide crucial insights that link these four lines of research. We first outline neural and cognitive evidence that real-time language comprehension and production normally involve internal generative circuits that propagate probabilistic predictions to perceptual cortices - predictions that are incrementally updated based on prediction error signals as new inputs are encountered. We then explain how disruptions to these circuits may compromise communicative abilities in schizophrenia by reducing the efficiency and robustness of both high-level language processing and low-level speech perception. We also argue that such disruptions may contribute to the phenomenology of thought-disordered speech and false perceptual inferences in the language system (i.e., AVHs). This perspective suggests a number of productive avenues for future research that may elucidate not only the mechanisms of language abnormalities in schizophrenia, but also promising directions for cognitive rehabilitation.
Collapse
Affiliation(s)
- Meredith Brown
- Department of Psychiatry–Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, CharlestownMA, USA
- Department of Psychology, Tufts University, MedfordMA, USA
| | - Gina R. Kuperberg
- Department of Psychiatry–Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, CharlestownMA, USA
- Department of Psychology, Tufts University, MedfordMA, USA
| |
Collapse
|
6
|
Thermenos H, Whitfield-Gabrieli S, Seidman L, Kuperberg G, Juelich R, Divatia S, Riley C, Jabbar G, Shenton M, Kubicki M, Manschreck T, Keshavan M, DeLisi L. Altered language network activity in young people at familial high-risk for schizophrenia. Schizophr Res 2013; 151:229-37. [PMID: 24176576 PMCID: PMC3987706 DOI: 10.1016/j.schres.2013.09.023] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/03/2013] [Revised: 09/20/2013] [Accepted: 09/23/2013] [Indexed: 01/01/2023]
Abstract
BACKGROUND Abnormalities in language and language neural circuitry are observed in schizophrenia (SZ). Similar, but less pronounced language deficits are also seen in young first-degree relatives of people with SZ, who are at higher familial risk (FHR) for the disorder than the general population. The neural underpinnings of these deficits in people with FHR are unclear. METHODS Participants were 43 people with FHR and 32 comparable controls. fMRI scans were collected while participants viewed associated and unrelated word pairs, and performed a lexical decision task. fMRI analyses conducted in SPM8 examined group differences in the modulation of hemodynamic activity by semantic association. RESULTS There were no group differences in demographics, IQ or behavioral semantic priming, but FHR participants had more schizotypal traits than controls. Controls exhibited the expected suppression of hemodynamic activity to associated versus unrelated word pairs. Compared to controls, FHR participants showed an opposite pattern of hemodynamic modulation to associated versus unrelated word pairs, in the left inferior frontal gyrus (IFG), right superior and middle temporal gyrus (STG) and the left cerebellum. Group differences in activation were significant, FWE-corrected for multiple comparisons (p<0.05). Activity within the IFG during the unrelated condition predicted schizotypal symptoms in FHR participants. CONCLUSIONS FHR for SZ is associated with abnormally increased neural activity to semantic associates within an inferior frontal/temporal network. This might increase the risk of developing unusual ideas, perceptions and disorganized language that characterize schizotypal traits, potentially predicting which individuals are at greater risk to develop a psychotic disorder.
Collapse
Affiliation(s)
- H.W. Thermenos
- Harvard Medical School, Boston, MA, USA,Massachusetts Mental Health Center Division of Public Psychiatry, Boston, MA, USA,Department of Psychiatry, Beth Israel Deaconess Medical Center, Boston, MA, USA,Department of Psychiatry, Massachusetts General Hospital, Boston, MA, USA,Corresponding author at: Athinoula A. Martinos Center for Biomedical Imaging, Building 149, 2nd Floor (Room 2602E), 13th Street, Charlestown, MA 02129, USA. Tel.: +1 617 726 6043; fax: +1 617 726 4078. (H.W. Thermenos)
| | - S. Whitfield-Gabrieli
- McGovern Institute for Brain Research and Poitras Center for Affective Disorders Research, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - L.J. Seidman
- Harvard Medical School, Boston, MA, USA,Massachusetts Mental Health Center Division of Public Psychiatry, Boston, MA, USA,Department of Psychiatry, Beth Israel Deaconess Medical Center, Boston, MA, USA,Department of Psychiatry, Massachusetts General Hospital, Boston, MA, USA
| | - G. Kuperberg
- Harvard Medical School, Boston, MA, USA,Department of Psychiatry, Massachusetts General Hospital, Boston, MA, USA,Tufts University, Department of Psychology, Medford, MA, USA
| | - R.J. Juelich
- Department of Psychiatry, Massachusetts General Hospital, Boston, MA, USA
| | - S. Divatia
- Department of Psychiatry, Massachusetts General Hospital, Boston, MA, USA
| | - C. Riley
- Department of Psychiatry, Massachusetts General Hospital, Boston, MA, USA
| | - G.A. Jabbar
- Harvard Medical School, Boston, MA, USA,VA Boston Healthcare System, Brockton, MA 02301, USA
| | - M.E. Shenton
- Harvard Medical School, Boston, MA, USA,VA Boston Healthcare System, Brockton, MA 02301, USA,Department of Psychiatry and Radiology, Brigham and Women's Hospital, Boston, MA, USA
| | - M. Kubicki
- Harvard Medical School, Boston, MA, USA,Department of Psychiatry and Radiology, Brigham and Women's Hospital, Boston, MA, USA
| | - T. Manschreck
- Harvard Medical School, Boston, MA, USA,Corrigan Mental Health Center, Fall River, MA, USA
| | - M.S. Keshavan
- Harvard Medical School, Boston, MA, USA,Massachusetts Mental Health Center Division of Public Psychiatry, Boston, MA, USA,Department of Psychiatry, Beth Israel Deaconess Medical Center, Boston, MA, USA
| | - L.E. DeLisi
- Harvard Medical School, Boston, MA, USA,VA Boston Healthcare System, Brockton, MA 02301, USA
| |
Collapse
|
7
|
Jamadar S, O’Neil KM, Pearlson GD, Ansari M, Gill A, Jagannathan K, Assaf M. Impairment in semantic retrieval is associated with symptoms in schizophrenia but not bipolar disorder. Biol Psychiatry 2013; 73:555-64. [PMID: 22985694 PMCID: PMC3581745 DOI: 10.1016/j.biopsych.2012.07.027] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2011] [Revised: 07/04/2012] [Accepted: 07/05/2012] [Indexed: 10/27/2022]
Abstract
BACKGROUND The Semantic Object Retrieval Task (SORT) requires participants to indicate whether word pairs recall a third object. Schizophrenia individuals (SZ) tend to report associations between nonassociated word pairs; this overretrieval is related to formal thought disorder (FTD). Since semantic memory impairments and psychosis are also found in bipolar disorder (BP), we examined whether SORT impairments and their relationship to symptoms are also present in BP. METHODS Participants (n = 239; healthy control subjects [HC] = 133; BP = 32; SZ = 74) completed SORT while undergoing functional magnetic resonance imaging (fMRI) scanning. RESULTS Retrieval accuracy negatively correlated with negative symptoms and no-retrieval accuracy negatively correlated with FTD severity in SZ but not BP. Retrieval versus no-retrieval trials activated a distributed fronto-parieto-temporal network; bilateral inferior parietal lobule (IPL) activity was larger in HC versus SZ and HC versus BP, with no difference in SZ versus BP. Right IPL activity positively correlated with positive and general psychosis symptoms in SZ but not BP. CONCLUSIONS SZ reported more associations between unrelated word pairs than HC; this overretrieval increased with FTD severity. Schizophrenia individuals were also more likely to fail to find associations between related word pairs; this underretrieval increased with negative symptom severity. fMRI symptom correlations in IPL in SZ are consistent with arguments that IPL abnormality relates to loosening of associations in SZ. By comparison, BP showed intermediate impairments on SORT, uncorrelated with symptoms, suggesting that the relationship between SORT performance, fMRI activity, and psychotic symptoms is schizophrenia-specific.
Collapse
Affiliation(s)
- Sharna Jamadar
- Olin Neuropsychiatry Research Center, Institute of Living, Hartford, Connecticut 06106, USA.
| | - Kasey M. O’Neil
- Olin Neuropsychiatry Research Center, Institute of Living, Hartford CT, USA
| | - Godfrey D. Pearlson
- Olin Neuropsychiatry Research Center, Institute of Living, Hartford CT, USA,Departments of Psychiatry and Neurobiology, Yale University, New Haven CT, USA
| | - Mahvesh Ansari
- Olin Neuropsychiatry Research Center, Institute of Living, Hartford CT, USA
| | - Adrienne Gill
- Olin Neuropsychiatry Research Center, Institute of Living, Hartford CT, USA
| | | | - Michal Assaf
- Olin Neuropsychiatry Research Center, Institute of Living, Hartford CT, USA,Departments of Psychiatry and Neurobiology, Yale University, New Haven CT, USA
| |
Collapse
|
8
|
Semantic priming in remitted patients with bipolar disorder. J Behav Ther Exp Psychiatry 2013; 44:48-52. [PMID: 22922076 DOI: 10.1016/j.jbtep.2012.07.014] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2011] [Revised: 07/26/2012] [Accepted: 07/31/2012] [Indexed: 11/22/2022]
Abstract
BACKGROUND AND OBJECTIVES Semantic priming disturbances are increasingly recognized as a feature of schizophrenia, and increased priming has been suggested to constitute a "cognitive correlate" of positive formal thought disorder (FTD). The present study aimed to investigate semantic priming in patients with bipolar disorder (BD). METHODS A primed lexical decision task with strongly related (STR), weakly related (WR), or unrelated (UR) prime-target pairs (SOA = 250 ms) was administered to fourteen remitted patients with BD and twelve control subjects matched on key demographic variables. FTD was measured by means of the Scale for Thought, Language and Communication (TLC). RESULTS Control subjects showed a robust (59.6 ms) and statistically significant priming effect for STR words, while priming for UR words was non-significant. In patients there was no evidence of priming in either condition. In patients, there were no significant correlations between priming magnitude and TLC scores. However, the only patient with a positive score on the TLC disorganization factor exhibited evidence of hyperpriming. LIMITATIONS The present patient sample exhibited very low TLC scores, and no direct comparison to patients with schizophrenia was possible. CONCLUSIONS The finding of decreased priming in patients with BD raises the possibility that semantic processing abnormalities in BD are of a different nature than those encountered in schizophrenia. Due to the small size and very low TLC scores of the present patient sample, no definite conclusions can be drawn as to the relationship of formal thought disorder and semantic processing abnormalities in BD.
Collapse
|
9
|
Bazan A. From sensorimotor inhibition to freudian repression: insights from psychosis applied to neurosis. Front Psychol 2012; 3:452. [PMID: 23162501 PMCID: PMC3498871 DOI: 10.3389/fpsyg.2012.00452] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2012] [Accepted: 10/09/2012] [Indexed: 11/13/2022] Open
Abstract
First, three case studies are presented of psychotic patients having in common an inability to hold something down or out. In line with other theories on psychosis, we propose that a key change is at the efference copy system. Going back to Freud's mental apparatus, we propose that the messages of discharge of the motor neurons, mobilized to direct perception, also called "indications of reality," are equivalent to the modern efference copies. With this key, the reading of the cases is coherent with the psychodynamic understanding of psychosis, being a downplay of secondary processes, and consequently, a dominance of primary processes. Moreover, putting together the sensorimotor idea of a failure of efference copy-mediated inhibition with the psychoanalytic idea of a failing repression in psychosis, the hypothesis emerges that the attenuation enabled by the efference copy dynamics is, in some instances, the physiological instantiation of repression. Second, we applied this idea to the mental organization in neurosis. Indeed, the efference copy-mediated attenuation is thought to be the mechanism through which sustained activation of an intention, without reaching it - i.e., inhibition of an action - gives rise to mental imagery. Therefore, as inhibition is needed for any targeted action or for normal language understanding, acting in the world, or processing language, structurally induces mental imagery, constituting a subjective unconscious mental reality. Repression is a special instance of inhibition for emotionally threatening stimuli. These stimuli require stronger inhibition, leaving (the attenuation of) the motor intentions totally unanswered, in order to radically prevent execution which would lead to development of excess affect. This inhibition, then, yields a specific type of motor imagery, called "phantoms," which induce mental preoccupation, as well as symptoms which, especially through their form, refer to the repressed motor fragments.
Collapse
Affiliation(s)
- Ariane Bazan
- Centre de Recherche en Psychologie Clinique, Psychopathologie et Psychosomatique, Faculté des Sciences Psychologiques et de l’Education, Université Libre de Bruxelles (ULB)Brussels, Belgium
| |
Collapse
|
10
|
Badgaiyan RD. Nonconscious processing and a novel target for schizophrenia research. OPEN JOURNAL OF PSYCHIATRY 2012; 2. [PMID: 24404419 DOI: 10.4236/ojpsych.2012.224047] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Analysis of the pattern of altered cognition observed in schizophrenia provides better insight into neurocognitive deficits. It reveals a potential novel target for schizophrenia research. To understand this target we reviewed the findings of neuroimaging studies on implicit [nonconscious] memory. These studies have consistently reported attenuated activity in the area V3A of the extrastriate cortex during retrieval of studied items. It was suggested that the attenuation limits the pool of information available for further cognitive processing. Therefore, if V3A is functionally damaged, individuals will have access to a larger pool of information for cognitive processing. Since cognitive tasks that are not dependent on attention [attention independent] process a larger pool of information more efficiently, performance in these tasks is likely to improve after V3A is damaged. Conversely, tasks that are dependent on attentional resources are more efficient in processing smaller pool of information. Performance in these tasks therefore is expected to deteriorate if a large pool of information is made available following V3A damage. A review of cognitive performance in schizophrenia suggests that patients perform at above normal level in attention independent priming tasks and perform at subnormal level in attention dependent episodic and working memory tasks. These findings indicate possible impairment of V3A activity. It could therefore be a potentially important unstudied target for schizophrenia research, particularly because a number of investigators have reported that the activity in this area is altered in schizophrenia.
Collapse
Affiliation(s)
- Rajendra D Badgaiyan
- Department of Psychiatry; State University of New York at Buffalo, New York, USA ; Department of Psychiatry, VA Medical Center, Buffalo, New York, USA
| |
Collapse
|
11
|
Lerner I, Bentin S, Shriki O. Excessive attractor instability accounts for semantic priming in schizophrenia. PLoS One 2012; 7:e40663. [PMID: 22844407 PMCID: PMC3402492 DOI: 10.1371/journal.pone.0040663] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2012] [Accepted: 06/11/2012] [Indexed: 11/23/2022] Open
Abstract
One of the most pervasive findings in studies of schizophrenics with thought disorders is their peculiar pattern of semantic priming, which presumably reflects abnormal associative processes in the semantic system of these patients. Semantic priming is manifested by faster and more accurate recognition of a word-target when preceded by a semantically related prime, relative to an unrelated prime condition. Compared to control, semantic priming in schizophrenics is characterized by reduced priming effects at long prime-target Stimulus Onset Asynchrony (SOA) and, sometimes, augmented priming at short SOA. In addition, unlike controls, schizophrenics consistently show indirect (mediated) priming (such as from the prime ‘wedding’ to the target ‘finger’, mediated by ‘ring’). In a previous study, we developed a novel attractor neural network model with synaptic adaptation mechanisms that could account for semantic priming patterns in healthy individuals. Here, we examine the consequences of introducing attractor instability to this network, which is hypothesized to arise from dysfunctional synaptic transmission known to occur in schizophrenia. In two simulated experiments, we demonstrate how such instability speeds up the network’s dynamics and, consequently, produces the full spectrum of priming effects previously reported in patients. The model also explains the inconsistency of augmented priming results at short SOAs using directly related pairs relative to the consistency of indirect priming. Further, we discuss how the same mechanism could account for other symptoms of the disease, such as derailment (‘loose associations’) or the commonly seen difficulty of patients in utilizing context. Finally, we show how the model can statistically implement the overly-broad wave of spreading activation previously presumed to characterize thought-disorders in schizophrenia.
Collapse
Affiliation(s)
- Itamar Lerner
- Interdisciplinary Center for Neural Computation, The Hebrew University of Jerusalem, Jerusalem, Israel
- * E-mail: (OS); (IL)
| | - Shlomo Bentin
- Department of Psychology and Interdisciplinary Center for Neural Computation, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Oren Shriki
- Section on Critical Brain Dynamics, National Institute of Mental Health, Bethesda, Maryland, United States of America
- * E-mail: (OS); (IL)
| |
Collapse
|
12
|
Pfeifer S, Schiller NO, van Os J, Riedel WJ, Vlamings P, Simons C, Krabbendam L. Electrophysiological correlates of automatic spreading of activation in patients with psychotic disorder and first-degree relatives. Int J Psychophysiol 2012; 84:102-12. [DOI: 10.1016/j.ijpsycho.2012.01.017] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2011] [Revised: 01/06/2012] [Accepted: 01/13/2012] [Indexed: 10/14/2022]
|
13
|
Disorganization and reality distortion in schizophrenia: a meta-analysis of the relationship between positive symptoms and neurocognitive deficits. Schizophr Res 2010; 121:1-14. [PMID: 20579855 PMCID: PMC3160271 DOI: 10.1016/j.schres.2010.05.033] [Citation(s) in RCA: 113] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/20/2009] [Revised: 05/23/2010] [Accepted: 05/26/2010] [Indexed: 11/22/2022]
Abstract
BACKGROUND Factor analytic studies have shown that in schizophrenia patients, disorganization (e.g., conceptual disorganization and bizarre behavior) is a separate dimension from other types of positive symptoms such as reality distortion (delusions and hallucinations). Although some studies have found that disorganization is more strongly linked to neurocognitive deficits and poor functional outcomes than reality distortion, the findings are not always consistent. METHODS A meta-analysis of 104 studies (combined n=8015) was conducted to determine the magnitude of the relationship between neurocognition and disorganization as compared to reality distortion. Additional analyses were conducted to determine whether the strength of these relationships differed depending on the neurocognitive domain under investigation. RESULTS The relationship between reality distortion and neurocognition was weak (r=-.04; p=.03) as compared to the moderate association between disorganization and neurocognition (r=-.23; p<.01). In each of the six neurocognitive domains that were examined, disorganization was more strongly related to neurocognition (r's range from -.20 to -.26) than to reality distortion (r's range from .01 to -.12). CONCLUSIONS The effect size of the relationship between neurocognition and disorganization was significantly larger than the effect size of the relationship between neurocognition and reality distortion. These results hold across several neurocognitive domains. These findings support a dimensional view of positive symptoms distinguishing disorganization from reality distortion.
Collapse
|
14
|
Kern RS, Hartzell AM, Izaguirre B, Hamilton AH. Declarative and nondeclarative memory in schizophrenia: What is impaired? What is spared? J Clin Exp Neuropsychol 2010; 32:1017-27. [PMID: 20446142 DOI: 10.1080/13803391003671166] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
The study's aim was to assess a broad range of declarative and nondeclarative memory functions in schizophrenia to identify areas of impairment versus relative preservation. Participants included 40 schizophrenia outpatients and 30 demographically comparable community residents. All participants were administered a battery assessing declarative memory (verbal learning, working memory, semantic memory, remote memory, verbal retention) and nondeclarative memory (procedural learning, priming). To control for order effects, the battery was divided into three parts of approximately equal length with order of administration counterbalanced across study participants. The results showed persons with schizophrenia to be significantly impaired relative to community residents in verbal learning, working memory, semantic memory, remote memory, and priming. In contrast, the two groups were comparable in verbal retention and procedural learning. In the schizophrenia group, priming ability best discriminated past year's vocational status. In sum, the findings indicate a specific pattern of impairment and preservation of memory functioning in schizophrenia. Skill (procedural) learning and retention of learned, declarative verbal information across a delay appear intact, while all other areas measured appear impaired.
Collapse
Affiliation(s)
- Robert S Kern
- David Geffen School of Medicine, UCLA Semel Institute for Neuroscience and Human Behavior, Los Angeles, CA, USA.
| | | | | | | |
Collapse
|
15
|
Abstract
Contextual recall in humans relies on the semantic relationships between items stored in memory. These relationships can be probed by priming experiments. Such experiments have revealed a rich phenomenology on how reaction times depend on various factors such as strength and nature of associations, time intervals between stimulus presentations, and so forth. Experimental protocols on humans present striking similarities with pair association task experiments in monkeys. Electrophysiological recordings of cortical neurons in such tasks have found two types of task-related activity, "retrospective" (related to a previously shown stimulus), and "prospective" (related to a stimulus that the monkey expects to appear, due to learned association between both stimuli). Mathematical models of cortical networks allow theorists to understand the link between the physiology of single neurons and synapses, and network behavior giving rise to retrospective and/or prospective activity. Here, we show that this type of network model can account for a large variety of priming effects. Furthermore, the model allows us to interpret semantic priming differences between the two hemispheres as depending on a single association strength parameter.
Collapse
|
16
|
Han SD, Wible CG. Neuroimaging of semantic processing in schizophrenia: a parametric priming approach. Int J Psychophysiol 2009; 75:100-6. [PMID: 19765623 DOI: 10.1016/j.ijpsycho.2009.09.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2008] [Revised: 05/07/2009] [Accepted: 05/15/2009] [Indexed: 11/28/2022]
Abstract
The use of fMRI and other neuroimaging techniques in the study of cognitive language processes in psychiatric and non-psychiatric conditions has led at times to discrepant findings. Many issues complicate the study of language, especially in psychiatric populations. For example, the use of subtractive designs can produce misleading results. We propose and advocate for a semantic priming parametric approach to the study of semantic processing using fMRI methodology. Implications of this parametric approach are discussed in view of current functional neuroimaging research investigating the semantic processing disturbance of schizophrenia.
Collapse
Affiliation(s)
- S Duke Han
- Department of Behavioral Sciences, Rush University Medical Center, Chicago, IL 60612, USA.
| | | |
Collapse
|
17
|
Kreher DA, Goff D, Kuperberg GR. Why all the confusion? Experimental task explains discrepant semantic priming effects in schizophrenia under "automatic" conditions: evidence from Event-Related Potentials. Schizophr Res 2009; 111:174-81. [PMID: 19386472 PMCID: PMC2680451 DOI: 10.1016/j.schres.2009.03.013] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/27/2008] [Revised: 03/06/2009] [Accepted: 03/08/2009] [Indexed: 11/29/2022]
Abstract
The schizophrenia research literature contains many differing accounts of semantic memory function in schizophrenia as assessed through the semantic priming paradigm. Most recently, Event-Related Potentials (ERPs) have been used to demonstrate both increased and decreased semantic priming at a neural level in schizophrenia patients, relative to healthy controls. The present study used ERPs to investigate the role of behavioral task in determining neural semantic priming effects in schizophrenia. The same schizophrenia patients and healthy controls completed two experiments in which word stimuli were identical, and the time between the onset of prime and target remained constant at 350 ms: in the first, participants monitored for words within a particular semantic category that appeared only in filler items (implicit task); in the second, participants explicitly rated the relatedness of word-pairs (explicit task). In the explicit task, schizophrenia patients showed reduced direct and indirect semantic priming in comparison with healthy controls. In contrast, in the implicit task, schizophrenia patients showed normal or, in positively thought-disordered patients, increased direct and indirect N400 priming effects compared with healthy controls. These data confirm that, although schizophrenia patients with positive thought disorder may show an abnormally increased automatic spreading activation, the introduction of semantic decision-making can result in abnormally reduced semantic priming in schizophrenia, even when other experimental conditions bias toward automatic processing.
Collapse
Affiliation(s)
- Donna A. Kreher
- Department of Psychology, Tufts University, Medford, MA 02155
| | - Donald Goff
- Department of Psychiatry, Massachusetts General Hospital, Boston and Charlestown, MA 02129
| | - Gina R. Kuperberg
- Department of Psychology, Tufts University, Medford, MA 02155,Department of Psychiatry, Massachusetts General Hospital, Boston and Charlestown, MA 02129
| |
Collapse
|
18
|
Effects of sentence context on lexical ambiguity resolution in patients with schizophrenia. Neuropsychologia 2009; 47:1079-87. [DOI: 10.1016/j.neuropsychologia.2008.12.031] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2008] [Revised: 11/19/2008] [Accepted: 12/23/2008] [Indexed: 11/17/2022]
|
19
|
Lavigne F, Darmon N. Dopaminergic neuromodulation of semantic priming in a cortical network model. Neuropsychologia 2008; 46:3074-87. [DOI: 10.1016/j.neuropsychologia.2008.06.019] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2008] [Revised: 05/24/2008] [Accepted: 06/27/2008] [Indexed: 12/22/2022]
|
20
|
Doughty OJ, Done DJ, Lawrence VA, Al-Mousawi A, Ashaye K. Semantic memory impairment in schizophrenia--deficit in storage or access of knowledge? Schizophr Res 2008; 105:40-8. [PMID: 18657951 DOI: 10.1016/j.schres.2008.04.039] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/16/2007] [Revised: 04/18/2008] [Accepted: 04/28/2008] [Indexed: 10/21/2022]
Abstract
This study evaluates whether patients with schizophrenia have a degraded memory store for semantic knowledge. 20 patients with a chronic history of schizophrenia and evidence of cognitive impairment were selected, since the literature indicates that this subgroup is most likely to manifest a degraded semantic knowledge store. Their profile of semantic memory impairments was compared to that of a group of Alzheimer's Dementia (AD) patients (n=22), who met neuropsychological criteria for degraded semantic store. Both groups were matched for Performance IQ. 15 elderly healthy controls were also included in the study. The AD and schizophrenia groups produced substantially different profiles of semantic memory impairment. This is interpreted as indicating that the semantic impairments in this subgroup of patients with schizophrenia do not result from a degraded store. This is corroborated by an analysis of the data using other neuropsychological criteria for determining degraded store. We conclude that there is little evidence for a classic degradation of semantic knowledge in schizophrenia, and it appears that impairments result from an inability to use semantic knowledge appropriately, particularly when selection of salient semantic relations is required.
Collapse
|
21
|
Kreher DA, Holcomb PJ, Goff D, Kuperberg GR. Neural evidence for faster and further automatic spreading activation in schizophrenic thought disorder. Schizophr Bull 2008; 34:473-82. [PMID: 17905785 PMCID: PMC2632424 DOI: 10.1093/schbul/sbm108] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
It has been proposed that the loose associations characteristic of thought disorder in schizophrenia result from an abnormal increase in the automatic spread of activation through semantic memory. We tested this hypothesis by examining the time course of neural semantic priming using event-related potentials (ERPs). ERPs were recorded to target words that were directly related, indirectly related, and unrelated to their preceding primes, while thought-disordered (TD) and non-TD schizophrenia patients and healthy controls performed an implicit semantic categorization task under experimental conditions that encouraged automatic processing. By 300-400 milliseconds after target word onset, TD patients showed increased indirect semantic priming relative to non-TD patients and healthy controls, while the degree of direct semantic priming was increased in only the most severely TD patients. By 400-500 milliseconds after target word onset, both direct and indirect semantic priming were generally equivalent across the 3 groups. These findings demonstrate for the first time at a neural level that, under automatic conditions, activation across the semantic network spreads further within a shorter period of time in specific association with positive thought disorder in schizophrenia.
Collapse
Affiliation(s)
- Donna A Kreher
- Department of Psychology, University of Massachusetts, Amherst, MA 01003, USA.
| | | | | | | |
Collapse
|
22
|
Han SD, Nestor PG, Wible CG. GRAND ROUNDS: fMRI of Lexical-Semantic Priming in a Chronic Schizophrenia Patient. ACTA ACUST UNITED AC 2006; 13:51-7. [PMID: 16594871 DOI: 10.1207/s15324826an1301_7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
A neuropsychological hallmark of schizophrenia is a breakdown in semantic association networks that often impacts language and formal thought. Although computational models simulating this breakdown exist, studies have yet to investigate this phenomena using functional MRI (fMRI) coupled with an auditory lexical-decision semantic priming paradigm. Thus, this serves to functionally map brain activation to word pairs that differed with respect to a concept called "connectivity" in a patient with schizophrenia and a demographically matched control adult. Analyses revealed a striking difference with respect to the expected stepwise modulation of activation, with the control participant showing significantly greater areas of modulation than the participant with schizophrenia in regions classically implicated in language. Although the results are tentative because of the nature of this investigation (single-case study), they further support the characterization of schizophrenia as a breakdown in lexical-semantic association networks and represent one of the first fMRI studies of semantic priming in schizophrenia informed by a computer model.
Collapse
Affiliation(s)
- S Duke Han
- Department of Psychiatry, University of California San Diego, San Diego, California, USA.
| | | | | |
Collapse
|
23
|
Rossell SL, David AS. Are semantic deficits in schizophrenia due to problems with access or storage? Schizophr Res 2006; 82:121-34. [PMID: 16386407 DOI: 10.1016/j.schres.2005.11.001] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2005] [Revised: 10/25/2005] [Accepted: 11/05/2005] [Indexed: 11/27/2022]
Abstract
Semantic processing deficits are central to cognitive abnormalities in schizophrenia. Such semantic deficits may be related to either poor access or poor storage of semantic knowledge. 32 schizophrenia patients and 32 matched normal controls performed five semantic processing tasks that examined item-specific consistency over time, the word frequency effect and semantic priming. A subgroup of patients performed tasks on three separate occasions. It is generally assumed that a storage deficit is signalled by item-specific consistent performance, an exaggerated effect of word frequency, and the occurrence of hyperpriming; an access deficit is signalled by the absence of these effects. The data demonstrated item-specific consistency, a frequency effect and significant hyperpriming. The pattern is consistent with a storage deficit of semantic memory in schizophrenia.
Collapse
Affiliation(s)
- Susan L Rossell
- Macquarie Centre for Cognitive Science (MACCS), Macquarie University, Sydney, NSW 2109, Australia.
| | | |
Collapse
|
24
|
Quelen F, Grainger J, Raymondet P. An investigation of semantic priming in schizophrenia using a new priming paradigm. Schizophr Res 2005; 80:173-83. [PMID: 16140505 DOI: 10.1016/j.schres.2005.07.020] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/13/2005] [Revised: 07/11/2005] [Accepted: 07/14/2005] [Indexed: 11/26/2022]
Abstract
In the present study, twenty schizophrenic patients and twenty healthy controls were tested in a new priming paradigm that allows a clear distinction to be made between automatic, perceptual priming effects and effects related to decision bias. Participants had to identify briefly presented masked target words preceded by clearly visible primes that were semantically related to the target or not. Target presentation duration corresponded to a pre-determined perceptual threshold for each participant, and a two-alternative forced-choice methodology was used. Equivalent amounts of semantic priming were found in schizophrenic patients compared with healthy controls. However, for the schizophrenic patients, a positive correlation was found between the size of automatic perceptual priming effects and formal thought disorders, as measured by Andreasen's Thought, Language and Communication (TLC) scale. The new paradigm tested in the present study overcomes some of the limitations of prior research on semantic priming in schizophrenia, and provides further evidence suggesting that an increased spreading of activation in the semantic network could partly underlie formal thought disorders in schizophrenia.
Collapse
Affiliation(s)
- Florence Quelen
- Laboratoire de Psychologie Cognitive, CNRS et Université de Provence, Centre St Charles, Bâtiment 9, Case D, 3 place Victor Hugo, 13331 Marseille Cedex 3, France
| | | | | |
Collapse
|
25
|
Narr KL, Green MF, Capetillo-Cunliffe L, Toga AW, Zaidel E. Lateralized Lexical Decision in Schizophrenia: Hemispheric Specialization and Interhemispheric Lexicality Priming. JOURNAL OF ABNORMAL PSYCHOLOGY 2003; 112:623-32. [PMID: 14674874 DOI: 10.1037/0021-843x.112.4.623] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Reports of left-hemisphere dysfunction and abnormal interhemispheric transfer in schizophrenia are mixed. The authors used a unified paradigm, the lateralized lexical decision task, to assess hemispheric specialization in word recognition, hemispheric error monitoring, and interhemispheric transfer in male, right-handed participants with schizophrenia (n=34) compared with controls (n=20). Overall, performance and error monitoring were worse in patients. However, patients like controls showed left-hemisphere superiority for lexical processing and right-hemisphere superiority for error monitoring. Only patients showed selective-interhemispheric lexicality priming for accuracy, in which performance improved when the lexical status of target and distractor stimuli presented to each hemifield was congruent. Results suggest that schizophrenia is associated with impaired monitoring and with increased interhemispheric automatic information transfer rather than with changed hemispheric specialization for language or error monitoring.
Collapse
Affiliation(s)
- Katherine L Narr
- Department of Neurology, University of California, Los Angeles, Los Angeles, CA 90095-1769, USA.
| | | | | | | | | |
Collapse
|