Implicit learning of non-spatial sequences in schizophrenia

Marvel, Cherie L.; Schwartz, Barbara L.; Howard, Darlene V.; Howard, James H.

doi:10.1017/s1355617705050861

Cited by 21 publications

(26 citation statements)

References 35 publications

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“…These results are consistent with studies finding no deficit in implicit learning in schizophrenia (Kéri et al, 2000;Danion et al, 2001;Marvel et al, 2005; for review see: Gold et al, 2009). In contrast with studies that assay explicit statistical learning and inference using more cognitive tasks (i.e.…”

Section: Acquisition Of Visual Prior Expectationssupporting

confidence: 88%

Acquisition of visual priors and induced hallucinations in chronic schizophrenia

Valton

Karvelis

Richards

et al. 2018

Preprint

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Prominent theories suggest that symptoms of schizophrenia stem from learning deficiencies resulting in distorted internal models of the world. To further test these theories, we here use a visual statistical learning task known to induce rapid implicit learning of the stimulus statistics (Chalk et al., 2010). In this task, participants are presented with a field of coherently moving dots and need to report the presented direction of the dots (estimation task) and whether they saw any dots or not (detection task). Two of the directions were more frequently presented than the others. In controls, the implicit acquisition of the stimuli statistics influences their perception in two ways: 1-motion directions are perceived as being more similar to the most frequently presented directions than they really are (estimation biases); 2-in the absence of stimuli, participants sometimes report perceiving the most frequently presented directions (a form of hallucinations). Such behaviour is consistent with probabilistic inference, i.e. combining learnt perceptual priors with sensory evidence. We investigated whether patients with chronic, stable, treated schizophrenia (n=20) differ from controls (n=23) in the acquisition of the perceptual priors and/or their influence on perception. We found that, although patients were slower than controls, they showed comparable acquisition of perceptual priors, correctly approximating the stimulus statistics.This suggests that patients have no statistical learning deficits in our task. This may reflect our patients relative wellbeing on antipsychotic medication. Intriguingly, however, patients made significantly fewer hallucinations of the most frequently presented directions than controls and fewer prior-based lapse estimations. This suggests that prior expectations had less influence on patients' perception than on controls when stimuli were absent or below perceptual threshold.

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Section: Acquisition Of Visual Prior Expectationssupporting

confidence: 88%

Acquisition of visual priors and induced hallucinations in chronic schizophrenia

Valton

Karvelis

Richards

et al. 2018

Preprint

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“…However, an inability to become sensitive to the abstract quality of the spatial relations may explain why these high-generation patients failed to show a continued increase in trial type differences across blocks, as controls did. Using a similar probabilistic sequence learning paradigm, Marvel et al (2005) also found that trial type differences in the schizophrenia group leveled off early in testing and did not change across sessions. Taken together, these studies indicate that patients may have a limit, not on how quickly they learn sequential regularities but rather on the level of sensitivity they develop with extended exposure (i.e., their asymptote).…”

Section: Discussionmentioning

confidence: 85%

The neural correlates of implicit sequence learning in schizophrenia.

Marvel¹,

Turner²,

O'Leary³

et al. 2007

Neuropsychology

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Twenty-seven schizophrenia spectrum patients and 25 healthy controls performed a probabilistic version of the serial reaction time task (SRT) that included sequence trials embedded within random trials. Patients showed diminished, yet measurable, sequence learning. Postexperimental analyses revealed that a group of patients performed above chance when generating short spans of the sequence. This high-generation group showed SRT learning that was similar in magnitude to that of controls. Their learning was evident from the very 1st block; however, unlike controls, learning did not develop further with continued testing. A subset of 12 patients and 11 controls performed the SRT in conjunction with positron emission tomography. High-generation performance, which corresponded to SRT learning in patients, correlated to activity in the premotor cortex and parahippocampus. These areas have been associated with stimulus-driven visuospatial processing. Taken together, these results suggest that a subset of patients who showed moderate success on the SRT used an explicit stimulus-driven strategy to process the sequential stimuli. This adaptive strategy facilitated sequence learning but may have interfered with conventional implicit learning of the overall stimulus pattern.

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“…Since response time becomes slower and more variable with age, the time between successive event onsets is longer and more variable for old than young people. The focus of the present study is healthy aging, but similar arguments apply to other populations that show impaired sequence learning such as Parkinson's and Huntington's disease patients (Helmuth et al, 2000;Willingham et al, 1996), early dementia patients (Negash et al, 2006), schizophrenics (Marvel et al, 2005) and dyslexics (J. H. Howard, Jr, et al, 2006;Vicari et al, 2005).…”

Section: Introductionmentioning

confidence: 68%

Event Timing and Age Deficits in Higher-Order Sequence Learning

Howard

Dennis

et al. 2007

Aging, Neuropsychology, and Cognition

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Recent studies have reported age deficits in learning sequences that contain subtle sequential regularities (e.g., Curran (1997) Psychological Research, 60(1-2), 24; D. V. Howard et al. (2004) Psychology and Aging, 19(1), 79; Howard, J. H. Jr, & Howard, D. V. (1997). Psychology and Aging, 12(4), 634). This finding is of potential theoretical interest, but the contribution of sequence event timing to this deficit has not been investigated. This study used an alternating serial reaction time task to examine implicit sequence learning in young adults when event timing mimicked that experienced by older adults in previous research. We varied the response-to-stimulus interval directly in Experiment 1 and indirectly by degrading the stimuli to influence response time in Experiment 2. Results indicate that these "aged" young adults learned the higher-order sequence structure implicitly, but they learned less than young controls and more than old adults on some measures of implicit learning in both experiments. In addition, these two different experimental manipulations produced distinct patterns of deficits despite having nearly identical effects on event sequence timing. These findings suggest that event timing alone cannot explain the age deficits observed in high-order implicit sequence learning.

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Implicit learning of non-spatial sequences in schizophrenia

Cited by 21 publications

References 35 publications

Acquisition of visual priors and induced hallucinations in chronic schizophrenia

Acquisition of visual priors and induced hallucinations in chronic schizophrenia

The neural correlates of implicit sequence learning in schizophrenia.

Event Timing and Age Deficits in Higher-Order Sequence Learning

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