Semantic priming in nonproductive schizophrenia the present study stems from some recent russian research on schizophrenia. We employed robust linear regression to compare n400 and behavioral priming effects across 36 monozygotic twin pairs 6 pairs concordant. The studies are placed in the context of current models of information processing. Type of receptive language deficit in schizophrenia and dyslexia memory research during the past decade has been largely directed to identifying unique systems of memory e. Previous investigations of semantic priming in schizophrenic subjects have provided tentative support for the hypothesis of increased facilitation in schizophrenia. Impairments in probabilistic prediction and bayesian learning. Excessive attractor instability accounts for semantic priming in schizophrenia itamar lerner1, shlomo bentin2, oren shriki3 1interdisciplinary center for neural computation, the hebrew university of jerusalem, israel, 2department of psychology and interdisciplinary center for neural. Semantic memory deficits are thought to underlie core symptoms of schizophrenia, including delusions, thought disorder and alogia. With a longer isi of 500 ms, an indirect semantic priming effect was obtained in. There was no support for altered semantic priming in schizophrenia as a whole. Weckowicz university of alberta, edmonton, canada a group of 10 nonproductive schizophrenics i. Impairments in probabilistic prediction and bayesian. When maintained, semantic priming effects can last for several seconds or longer due to veiled verbal working memory controlled processes, and without need for conscious awareness of the activated information.
Semantic priming has been studied using the n400 eventrelated potential erp component, and prior research showing reduced n400 amplitude in sz in. Semantic priming paradigms show utility in assessing the role of deficits in semantic memory network access in the pathology of schizophrenia. Schizophrenia is characterised by disturbances in language and thought. To investigate semantic memory in patients with schizophrenia with and without thought disorder. Compared to control, semantic priming in schizophrenics is characterized by reduced priming effects at long primetarget stimulus onset.
The literature regarding semantic priming in schizo. Background increased semantic priming is an influential theory of thought disorder in schizophrenia. An eventrelated brain potential study of direct and. Excessive attractor instability accounts for semantic priming. Facilitation was defined as the accuracy of target word recognition for the related word. The task involved the presentation of related, neutral, and unrelated word pairs. Increased semantic priming or semantic hyperpriming is currently one of the most influential theories of thought disorder, the incoherent speech seen in some. Abnormal semantic priming has been reported in schizophrenia patients in various studies that have used different measures and experimental. Performance on these tasks is thought to be a correlate of the speed of information running through human semantic association networks. Emotional priming of facial affect identification in. Shenton a,b a clinical neuroscience division, laboratory of neuroscience, boston va health care systembrockton division. May 01, 2010 semantic priming has long been used to investigate how concepts and ideas are related at the level of language, and has become a convenient tool for assessing conceptual and semantic dysfunction in cognitive disorders, including schizophrenia. Semantic priming tasks have been used to study semantic associative impairments in schizophrenia sz, possibly contributing to psychotic symptoms such as thought disorder and unusual thought content.
In contrast to normal comparison subjects, schizophrenia patients have exhibited less or no semantic priming, consistent with low activation of related items by primes 710. Many cognitive psychologists and cognitive scientists are trying to understand this process. Direct and indirect semantic priming with neutral and emotional. Semantic priming effects in schizophrenia request pdf. Semantic priming refers to the facilitated processing of a target stimulus when it is preceded by a semantically related stimulus or context. These cognitive abnormalities are presumed to underlie a number of thought disorder symptoms in patients diagnosed with schizophrenia. Studies were identified initially through pubmed, and then medline, psycinfo and embase, using the keywords schizophrenia, priming and semantic priming. This hypothesized core deficit includes both disturbance in the processing of rapid, sequential information and disruptions to patterns of brain activation and synchronization.
These timing deficits may alter the way associative connections are formed andor accessed in semantic memory. This study used the n400 component of the eventrelated potential as a brainbased method of assessing direct and indirect semantic priming in schizophrenia. Some studies have revealed stronger semantic priming effects for schizophrenia subjects than for healthy controls manschreck et al. Whether the thought disorder observed in schizophrenia involves deficits in semantic. N400 is elicited by words that are not primed by the preceding context and provides a direct measure of the neural mechanisms underlying semantic priming. If a related word is first we process it better than if an unrelated word comes first. The influence of working memory load on semantic priming. Increased semantic priming is an influential theory of thought disorder in schizophrenia. Direct and indirect semantic priming with neutral and. Increased semantic priming in patients with thought disorder was supported, but this was significant only in comparison with normal controls and not in comparison with patients without thought disorder. Pdf the brief psychiatric rating scale semantic scholar. The current psychopathology of the schizophrenia group was rated using the scale for the assessment of negative symptoms sans and the scale for the assessment of positive symptoms saps andreasen and olsen, 1982. It is hoped that if we can understand how people recognize written.
May 20, 2020 in schizophrenia, both behavioral 19 and neural 20 semantic priming effects are reduced under experimental conditions that encourage controlled processing in contrast with the preserved, or increased, semantic priming effect observed in some patients under more automatic conditions. Diagnostic and statistical manual of mental disorders. A twin study anuradhasharma,1 heinrichsauer,2 holgerhill,3 claudiakaufmann,4 stephanbender,5 andmatthiasweisbrod1,6 1researchgroupneurocognition,departmentofgeneralpsychiatry,centreforpsychosocialmedicine, heidelberguniversity,heidelberg,germany. Former models of semantic priming in schizophrenia have addressed only limited aspects of the above findings. Papers reporting semantic priming studies in patients with schizophrenia were searched electronically from 1988 the year of the publication of the first study3 to april 2007. Nestor a,c, olga valdman a,b, margaret niznikiewicz a, kevin spencer a, robert w. Although computational models simulating this breakdown exist, studies have yet to investigate this phenomena using functional mri fmri coupled with an auditory lexicaldecision semantic priming paradigm. The study of semantic priming in schizophrenia has led to diverse results. Priming and formal thought disorder in schizophrenia.
Aims to investigate semantic memory in patients with schizophrenia with and without thought. Priming production neural evidence for enhanced automatic. The enhanced automatic indirect semantic priming effect in. To investigate this further, we examined priming in 42 schizophrenics and 28 normal controls on a lexical decision task involving three different primetarget conditions all at 700 ms stimulus onset asynchrony soa. First, because it only manipulates the semantic relationship between the prime and the target, it primarily probes disturbances within semantic memory itself. In schizophrenia, both behavioral 19 and neural 20 semantic priming effects are reduced under experimental conditions that encourage controlled processing in contrast with the preserved, or increased, semantic priming effect observed in some patients under more automatic conditions. Behavioral and brain measures n400 of semantic priming. Extralexicalrefers to processes originating outside of the semantic store. A twin study anuradhasharma,1 heinrichsauer,2 holgerhill,3 claudiakaufmann,4 stephanbender,5 andmatthiasweisbrod1,6 1researchgroupneurocognition,departmentofgeneralpsychiatry,centreforpsychosocialmedicine. Semantic priming paradigms have been frequently employed to investigate language function in schizophrenia. Although the automatic semantic priming paradigm has yielded important insights, it has two major limitations. Affective semantic priming in patients with schizophrenia. Data were pooled from 36 studies comparing patients with schizophrenia and normal controls in semantic priming tasks. The influence of working memory load on semantic priming tom heyman, bram van rensbergen, and gert storms university of leuven keith a.
Abnormal activation of semantic networks characterizes schizophrenia and can be studied using the n400 eventrelated potential erp. In the past decade, the semantic priming paradigm has been used to assess structural and functional aspects of the semantic memory network of people with schizophrenia. Affective semantic priming was examined in normal controls and patients with schizophrenia using a lexical decision task with four affective categories of related word pairs. N400 was elicited using an incidental semantic priming paradigm, in which semantic relatedness and word frequency were varied, and a letter probe task. Greater priming is thought to reflect greater activation of the target by the prime. Shenton a,b a clinical neuroscience division, laboratory of neuroscience, boston va health care systembrockton division, department of psychiatry, harvard medical school, boston, ma, united states. Semantic priming has been studied using the n400 eventrelated potential erp component, and prior research showing reduced n400. Semantic priming effects in schizophrenia bentham science. American psychiatric associationdiagnostic and statistical manual of mental. Results demonstrated a striking and reliable effect of affective category upon semantic priming.
The semantic priming effect is the reaction time advantage that is achieved by priming a target to which a participant is responding with a semantically or associatively related word. Semantic priming has long been used to investigate how concepts and ideas are related at the level of language, and has become a convenient tool for assessing conceptual and semantic dysfunction in cognitive disorders, including schizophrenia. Indirect semantic priming in schizophrenic patients sciencedirect. Pdf metaanalysis of semantic priming in schizophrenia. Investigation of the associative network in schizophrenia using the semantic priming paradigm. Excessive attractor instability accounts for semantic. Multimodal neuroimaging evidence for looser lexico. Semantic priming in nonproductive schizophrenia sciencedirect. These mechanisms include strategic pro cesses such as expectancy effects and semantic matching e. Several studies, focusing on hyper priming, postulated that the enhanced effects in schizophrenics arise from either excessive activation in semantic memory of patients or excessive synaptic pruning leading to reduced connectivity between cortical areas. Activation of semantic networks is indexed by the n400 effect. However, studies to date have had conflicting findings. The semantic priming sp paradigm has been used extensively to assess semantic memory function. Semantic priming in thought disordered schizophrenic patients.
Language disorder in schizophrenia as a developmental. Semantic priming describes the phenomenon of increasing the speed with which a string of letters the target is recognized as a word lexical decision task. An eventrelated brain potential study of direct and indirect. Yet how our brainmind accomplishes this seemingly simple task remains unclear. An examination of spreading activation using word pronunciation and multiple soas. We used a twin study design to investigate whether n400 effect abnormalities reflect genetictrait liability or are related to psychopathological processes in schizophrenia. Traditionally, semantic priming studies in schizophrenia have used reduction in reaction times in primed trials as an index of semantic priming e. Neely u977,investigated semantic priming by varying the time available to subjects between the priming event and the target array. These ratings were completed on the same day as the semantic priming task was administered by an experienced clinical research psychologist cb. Information about the openaccess article abnormal n400 semantic priming effect may reflect psychopathological processes in schizophrenia. A neuropsychological hallmark of schizophrenia is a breakdown in semantic association networks that often impacts language and formal thought. Behavioral and brain measures n400 of semantic priming in.
Schizophrenic n 21, bipolar n 18, and normal control subjects n 21 were compared on a word recognition measure of semantic priming. Feigenberg 1969, 1971, 1972, 1974 has proposed a theory of schizophrenia based on his cognitive model of probabilistic prognosis or prediction. Priming, as will be discussed later in this thesis, refers to the finding that the presentation of a certain stimulus e. Automatic semantic priming abnormalities in schizophrenia. Semantic priming of category relations in schizophrenia. N400 to lexical ambiguity and semantic incongruity in. Onifer 1980 presented subjects with a sentence aurally and a letter string visually and instructed them to report whether the letter string was a word or a nonword. Neuroimaging of semantic processing in schizophrenia. Facilitation of word recognition by semantic priming in. Semantic priming, schizophrenia and the ketamine model of.
One explanation for such an imbalance is that semantic associations between individual words are hyperactive in patients with schizophrenia, leading to increased semantic priming between individual words m. Excessive attractor instability accounts for semantic priming in. Evidence is accumulating that suggests that semantic networks are abnormal in schizophrenia. Jul 23, 2012 former models of semantic priming in schizophrenia have addressed only limited aspects of the above findings.
Semantic priming in schizophrenia university of hertfordshire. Evidence of semantic processing abnormalities in schizotypy. Semantic priming, schizophrenia and the ketamine model of psychosis ana stefanovic this thesis. Research suggests that in schizophrenia semantic representations are disorganized and that spreading activation processes may be abnormal spitzer, 1997. Pdf semantic priming in word pronunciation was examined at 5 stimulus onset asynchronies soas in 75 medicated and 25 unmedicated people with.
Multimodal neuroimaging evidence for looser lexicosemantic. Abnormal n400 semantic priming effect may reflect psychopathological processes in schizophrenia. Pdf crossmodal semantic priming in schizophrenia simon. After years of practice, most adults are able to read and understand text effortlessly. In a priming experiment, responses to a target word are consistently accelerated following a semantically associated cue word versus a semantically unrelated cue word, and this phenomenon is referred to as a priming effect meyer and schvaneveldt, 1971.
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