Negative priming in schizophrenia: effects of masking and prime presentation time

The negative priming paradigm: An update and implications for selective attention

“…Park and colleagues (1996) noted regular spatial NP in chronic outpatients, but no NP in acutely psychotic inpatients. Interestingly, deficits in NP were associated with the length (and masking) of stimulus presentation and with the length of response stimulus intervals (Moritz et al, 2001;Salo et al, 2002) prompting Moritz and colleagues to suggest that reduced NP may be due to perceptual deficits rather than deficits in inhibition. This assumption is difficult to maintain, however, since reduced NP has been reported in studies with large RSIs (Park et al, 1996;Sturgill & Ferraro, 1997;Zimmermann et al, 2006) and with long or response-dependent stimulus representation (Fuller et al, 2000;MacQueen et al, 2003;Park et al, 1996;Sturgill & Ferraro, 1997).…”

Attentional window in schizophrenia and schizotypal personality: Insight from negative priming studies

“…NP was reduced for schizophrenic patients in the 100ms-with-mask condition but not in the other three conditions (Moritz et al, 2001). They concluded that the attenuation of NP for schizophrenia patients is observed only under special experimental conditions and is caused by an inability to perceive a briefly presented stimulus (Moritz et al, 2001). However, backward masking should affect both ignored repetition and control trials.…”

“…Moritz et al (2000) and Moritz, Ruff, Wilke, Andresen, Krausz, & Naber (2001) have examined different aspects of the NP paradigms to determine the contribution of perceptual versus attentional deficits to NP by investigating the potential effects of backward masking, prime and probe presentation time, and stimulus-onsetasynchrony (SOA). Moritz et al, (2000) manipulated the response-to-stimulus interval (RSI) to determine if the NP effect was intact in schizophrenia but was maintained for a shorter period than healthy controls.…”

“…In a subsequent study, Moritz et al, (2001) tested the hypothesis that NP deficit in schizophrenic patients may stem from perceptual problems that prevent the patients from seeing the target. They used the visual backward masking paradigm in which an informational target stimulus is presented, followed after an interstimulus interval by a masking stimulus that interferes with or interrupts target identification.…”

“…This technique can effectively prevent observers from perceiving the target. Moritz et al, (2001) examined the effects of using a mask in between prime and probe trials with the hypothesis that backward masking could trigger a perceptual deficit for schizophrenic patients as opposed to tapping an inhibition deficit. This study used a short and long presentation times (100ms and 250ms) with and without a mask.…”