Object substitution masking and the object updating hypothesis dating much older
Moreover, it did not appear that the patients’ deficit was due to issues in initial processing of the target because when using the same SOAs and using a single dot to indicate which target to identify, we found: (1) that there was no group difference in behavior; and (2) iconic decay of the target was not different between groups.
Therefore, the increased masking effects in schizophrenia patients appeared to be due to the presence of the mask and not other factors. Pubmed Abstract | Pubmed Full Text | Cross Ref Full Text Lamme, V.
These reentrant processes have even been shown to feedback to very early neural areas such as the lateral geniculate nucleus (Sillito et al., 1994). Sensory-based and higher-order operations contribute to abnormal emotional prosody processing in schizophrenia: an electrophysiological investigation.
In the current study we used electroencephalography techniques to examine successive stages and pathways of visual processing in a specialized masking paradigm, four-dot masking, which involves masking by object substitution. Pathways between early visual processing and functional outcome in schizophrenia.
Seventy-six schizophrenia patients and 66 healthy controls had event-related potentials (ERPs) recorded during four-dot masking. Additionally, the visual awareness negativity (VAN) to correct vs.
Target visibility was manipulated by changing stimulus onset asynchrony (SOA) between the target and mask, such that performance decreased with increasing SOA. incorrect responses, an index of reentrant processing, was examined for SOAs 50 and 100 ms.
Considering that the VAN is thought to reflect reentrant processing, one interpretation of the findings is that patients’ lack of VAN response and poorer performance may be related to dysfunctional reentrant processing.
Patients with schizophrenia exhibit several visual processing impairments (Green et al., 1994; Butler et al., 2003; Butler and Javitt, 2005; Rassovsky et al., 2005; Wynn et al., 2005; Silverstein and Keane, 2011), and these impairments have been tied to specific neural abnormalities, such as magnocellular pathway dysfunction, NMDA functioning, and activation in the lateral occipital complex (Butler et al., 2005; Green et al., 2009; Javitt, 2009). Pubmed Abstract | Pubmed Full Text | Cross Ref Full Text Rassovsky, Y., Green, M.