Dissecting the cellular contributions to early visual sensory processing deficits in schizophrenia using the VESPA evoked response.
نویسندگان
چکیده
Electrophysiological research has shown clear dysfunction of early visual processing mechanisms in patients with schizophrenia. In particular, the P1 component of the visual evoked potential (VEP) is substantially reduced in amplitude in patients. A novel visual evoked response known as the VESPA (Visual Evoked Spread Spectrum Analysis) was recently described. This response has a notably different scalp topography from that of the traditional VEP, suggesting preferential activation of a distinct subpopulation of cells. As such, this method constitutes a potentially useful candidate for investigating cellular contributions to early visual processing deficits. In this paper we compare the VEP and VESPA responses between a group of healthy control subjects and a group of schizophrenia patients. We also introduce an extension of the VESPA method to incorporate nonlinear processing in the visual system. A significantly reduced P1 component was found in patients using the VEP (with a large effect size; Cohen's d=1.6), while there was no difference whatsoever in amplitude between groups for either the linear or nonlinear VESPA. This pattern of results points to a highly specific cellular substrate of early visual processing deficits in schizophrenia, suggesting that these deficits are based on dysfunction of magnocellular pathways with parvocellular processing remaining largely intact.
منابع مشابه
Visual sensory processing deficits in schizophrenia: is there anything to the magnocellular account?
Visual processing studies have repeatedly shown impairment in patients with schizophrenia compared to healthy controls. Electroencephalography (EEG) and, specifically, visual evoked potential (VEP) studies have identified an early marker of this impairment in the form of a decrement in the P1 component of the VEP in patients and their clinically unaffected first-degree relatives. Much behaviora...
متن کاملGeneration of the VESPA response to rapid contrast fluctuations is dominated by striate cortex: evidence from retinotopic mapping.
The VESPA (visual-evoked spread spectrum analysis) method derives an impulse response function of the visual system from scalp electroencephalographic (EEG) data using the controlled modulation of some feature of a visual stimulus. Recent research using VESPA responses to modulations of stimulus contrast has provided new insights into both early visual attention mechanisms and the specificity o...
متن کاملAuditory processing in schizophrenia during the middle latency period (10-50 ms): high-density electrical mapping and source analysis reveal subcortical antecedents to early cortical deficits.
INTRODUCTION Auditory sensory processing dysfunction is a core component of schizophrenia, with deficits occurring at 50 ms post-stimulus firmly established in the literature. Given that the initial afference of primary auditory cortex occurs at least 35 ms earlier, however, an essential question remains: how early in sensory processing do such deficits arise, and do they occur during initial c...
متن کاملSensory contributions to impaired emotion processing in schizophrenia.
Both emotion and visual processing deficits are documented in schizophrenia, and preferential magnocellular visual pathway dysfunction has been reported in several studies. This study examined the contribution to emotion-processing deficits of magnocellular and parvocellular visual pathway function, based on stimulus properties and shape of contrast response functions. Experiment 1 examined the...
متن کاملBrief Monocular Deprivation as an Assay of Short-Term Visual Sensory Plasticity in Schizophrenia – “The Binocular Effect”
BACKGROUND Visual sensory processing deficits are consistently observed in schizophrenia, with clear amplitude reduction of the visual evoked potential (VEP) during the initial 50-150 ms of processing. Similar deficits are seen in unaffected first-degree relatives and drug-naïve first-episode patients, pointing to these deficits as potential endophenotypic markers. Schizophrenia is also associa...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Schizophrenia research
دوره 98 1-3 شماره
صفحات -
تاریخ انتشار 2008