Search

Visual mismatch negativity (vMMN) is the electrophysiological correlate of automatic detection of unattended changes in the visual environment. However, vMMNs' relatedness to spatial attention has not been explicitly tested. Thus, the aim of the study was to investigate the effects of spatial attention on the vMMN event‐related potential component. To this end, participants were instructed to fixate and attend to task‐related stimuli. In an oddball sequence, offset stimuli were applied, i.e., from time‐to time, the two sides of permanently presented objects disappeared. Distance between the task‐related and unrelated events resulted in the typical finding of spatial attention; the amplitude of the N1 component was larger at the shorter distance between the two kinds of events. VMMN was elicited by the deviant vanishing parts, with no reliable effect of distance between the task‐field and vMMN‐related stimuli. In terms of the difference potentials, vMMN was followed by a positive posterior component in the 270–330 ms range. This positivity was much larger when the task‐field was close to vMMN‐related stimuli. The reappearance of the vanishing parts was also investigated. The reappearance of the whole objects after a deviant offset elicited vMMN but only when the task‐field was close to the oddball sequence. We concluded that infrequently vanishing parts of objects are detected automatically. However, these deviant events initiate orientation only if the objects are close to the field of task‐relevant events. Similarly, automatic registration of the rare but expected events are registered only in the visual field close to the focus of attention. [ABSTRACT FROM AUTHOR]

We investigated the effect of spatial attention on an event‐related potential signature of automatic detection of violations of statistical regularities, namely, the visual mismatch negativity (vMMN). To vary the task‐field and the location of vMMN‐related stimulation, in the attentional field the stimuli of a tracking task with a steady and a moving (target) bar were presented. The target stimuli of the task appeared either relatively close or far from a passive (task‐irrelevant) oddball or equiprobable sequence at the lower part of the screen. Stimuli of the oddball sequence were shapes tilted either 45° (standard, p = 0.8) or 135° (deviant, p = 0.2), while the equiprobable sequence consisted of additional three shapes with identical number of lines to the oddball stimuli. Deviant stimuli in close proximity to a continuously attended field elicited larger vMMN than similar stimuli farther away from the stimulus field. In the condition with a smaller distance between the field of the tracking task and the vMMN‐related field, the deviant stimuli and the vMMN was followed by a posterior positivity. According to these results, spatial attention modulates vMMN and is capable of initiating further processing of the deviant stimuli. [ABSTRACT FROM AUTHOR]