Inhibitory effect of forward mask on target stimuli recognition: The influence of mask-target categorical compatibility N Gerasimenko, S Kalinin, A Slavutskaya, E Mikhailova |
|---|
Department of Sensory Physiology, IHNA & NP RAS, Russian Federation
|
| In the behavioral and EEG experiments we have investigated the impact of information provided by forward masking stimuli on recognition of the target ones. Thirty-eight healthy subjects had to recognize the complex images of two categories (animals and objects) in situations where the target and masking stimulus (SOA=50 ms) belonged to the same or different categories (categorial “compatible” or “incompatible” pairs). It was found that forward masking evoked reduced accuracy and increased RT of recognition. These effects were more pronounced for compatible pairs compared to incompatible ones. It should be emphasized that the impairment was more marked for animals as compared to objects. Mask-target compatibility was also accompanied by an increase in RT dispersion and its interquartile range, suggesting that compatibility affects the central decision component of recognition. This assumption is partly supported by reduced amplitude of N200 and P300 waves of visual ERPs mostly in frontal and parietal cortical areas. We suggest that forward mask is not perceived passively, but its processing may suppress target processing, and the greater the similarity of the stimulus and mask the more pronounced inhibitory interaction. |
| Up Home |
|---|