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Temporal perception deficits in schizophrenia: integration is the problem, not deployment of attentions.

Su L, Wyble B, Zhou LQ, Wang K, Wang YN, Cheung EF, Bowman H, Chan RC - Sci Rep (2015)

Bottom Line: There was no difference between individuals with/without schizotypal personality disorder in temporal integration.Instead, we used both theoretical and empirical approaches to show that previous findings (using the suppression ratio to correct for the baseline difference) produced a systematic exaggeration of the attention deficits.Instead, we modulated the perceptual difficulty of the task to bring the baseline levels of target detection between the groups into closer alignment.

View Article: PubMed Central - PubMed

Affiliation: 1] Department of Psychiatry, University of Cambridge, Cambridge, UK [2] Neuropsychology and Applied Cognitive Neuroscience Laboratory, Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing, China.

ABSTRACT
Patients with schizophrenia are known to have impairments in sensory processing. In order to understand the specific temporal perception deficits of schizophrenia, we investigated and determined to what extent impairments in temporal integration can be dissociated from attention deployment using Attentional Blink (AB). Our findings showed that there was no evident deficit in the deployment of attention in patients with schizophrenia. However, patients showed an increased temporal integration deficit within a hundred-millisecond timescale. The degree of such integration dysfunction was correlated with the clinical manifestations of schizophrenia. There was no difference between individuals with/without schizotypal personality disorder in temporal integration. Differently from previous studies using the AB, we did not find a significant impairment in deployment of attention in schizophrenia. Instead, we used both theoretical and empirical approaches to show that previous findings (using the suppression ratio to correct for the baseline difference) produced a systematic exaggeration of the attention deficits. Instead, we modulated the perceptual difficulty of the task to bring the baseline levels of target detection between the groups into closer alignment. We found that the integration dysfunction rather than deployment of attention is clinically relevant, and thus should be an additional focus of research in schizophrenia.

No MeSH data available.


Related in: MedlinePlus

Curve fitting for the swaps. (a) healthy controls; (b) schizophrenia patients; (c) non-SPDs; (d) SPDs. The solid curves denote the logistic decay functions and the dashed curves denote the exponential decay functions.
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f5: Curve fitting for the swaps. (a) healthy controls; (b) schizophrenia patients; (c) non-SPDs; (d) SPDs. The solid curves denote the logistic decay functions and the dashed curves denote the exponential decay functions.

Mentions: where a and b are the decay rate and baseline parameters respectively as in the LDF. The LDF and EDF are often compared when modeling population growth/decay31. It can be seen that the two models have the same number of parameters, and hence the same complexity, with standard measures such as Bayesian Information Criterion. So, no correction for model flexibility is incorporated in comparing model fits. We fitted both functions to all the groups, and focused on selecting which best explains the data by minimizing a goodness of fit measurement MSE, i.e. mean squared error. We are interested in whether there is a qualitative rather than quantitative difference between groups, i.e. groups are different in terms of which function describes its behavior best. Here, a quantitative difference refers to differences between groups in terms of their parameters for the same function. The results of the curve fitting are shown in Fig. 5.


Temporal perception deficits in schizophrenia: integration is the problem, not deployment of attentions.

Su L, Wyble B, Zhou LQ, Wang K, Wang YN, Cheung EF, Bowman H, Chan RC - Sci Rep (2015)

Curve fitting for the swaps. (a) healthy controls; (b) schizophrenia patients; (c) non-SPDs; (d) SPDs. The solid curves denote the logistic decay functions and the dashed curves denote the exponential decay functions.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4419531&req=5

f5: Curve fitting for the swaps. (a) healthy controls; (b) schizophrenia patients; (c) non-SPDs; (d) SPDs. The solid curves denote the logistic decay functions and the dashed curves denote the exponential decay functions.
Mentions: where a and b are the decay rate and baseline parameters respectively as in the LDF. The LDF and EDF are often compared when modeling population growth/decay31. It can be seen that the two models have the same number of parameters, and hence the same complexity, with standard measures such as Bayesian Information Criterion. So, no correction for model flexibility is incorporated in comparing model fits. We fitted both functions to all the groups, and focused on selecting which best explains the data by minimizing a goodness of fit measurement MSE, i.e. mean squared error. We are interested in whether there is a qualitative rather than quantitative difference between groups, i.e. groups are different in terms of which function describes its behavior best. Here, a quantitative difference refers to differences between groups in terms of their parameters for the same function. The results of the curve fitting are shown in Fig. 5.

Bottom Line: There was no difference between individuals with/without schizotypal personality disorder in temporal integration.Instead, we used both theoretical and empirical approaches to show that previous findings (using the suppression ratio to correct for the baseline difference) produced a systematic exaggeration of the attention deficits.Instead, we modulated the perceptual difficulty of the task to bring the baseline levels of target detection between the groups into closer alignment.

View Article: PubMed Central - PubMed

Affiliation: 1] Department of Psychiatry, University of Cambridge, Cambridge, UK [2] Neuropsychology and Applied Cognitive Neuroscience Laboratory, Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing, China.

ABSTRACT
Patients with schizophrenia are known to have impairments in sensory processing. In order to understand the specific temporal perception deficits of schizophrenia, we investigated and determined to what extent impairments in temporal integration can be dissociated from attention deployment using Attentional Blink (AB). Our findings showed that there was no evident deficit in the deployment of attention in patients with schizophrenia. However, patients showed an increased temporal integration deficit within a hundred-millisecond timescale. The degree of such integration dysfunction was correlated with the clinical manifestations of schizophrenia. There was no difference between individuals with/without schizotypal personality disorder in temporal integration. Differently from previous studies using the AB, we did not find a significant impairment in deployment of attention in schizophrenia. Instead, we used both theoretical and empirical approaches to show that previous findings (using the suppression ratio to correct for the baseline difference) produced a systematic exaggeration of the attention deficits. Instead, we modulated the perceptual difficulty of the task to bring the baseline levels of target detection between the groups into closer alignment. We found that the integration dysfunction rather than deployment of attention is clinically relevant, and thus should be an additional focus of research in schizophrenia.

No MeSH data available.


Related in: MedlinePlus