Attentional gain is modulated by probabilistic feature expectations in a spatial cueing task: ERP evidence

Several theoretical and empirical studies suggest that attention and perceptual expectations influence perception in an interactive manner, whereby attentional gain is enhanced for predicted stimuli. The current study assessed whether attention and perceptual expectations interface when they are fully orthogonal, i.e., each of them relates to different stimulus features. We used a spatial cueing task with block-wise spatial attention cues that directed attention to either left or right visual field, in which Gabor gratings of either predicted (more likely) or unpredicted (less likely) orientation were presented. The lateralised posterior N1pc component was additively influenced by attention and perceptual expectations. Bayesian analysis showed no reliable evidence for the interactive effect of attention and expectations on the N1pc amplitude. However, attention and perceptual expectations interactively influenced the frontally distributed anterior N1 component (N1a). The attention effect (i.e., enhanced N1a amplitude in the attended compared to the unattended condition) was observed only for the gratings of predicted orientation, but not in the unpredicted condition. These findings suggest that attention and perceptual expectations interactively influence visual processing within 200 ms after stimulus onset and such joint influence may lead to enhanced endogenous attentional control in the dorsal fronto-parietal attention network

Impact of lower- vs. upper-hemifield presentation on automatic colour-deviance detection: a visual mismatch negativity study

The automatic processing of deviances from the temporal context of the visual environment has become an important topic in visual cognitive sciences, which is often investigated using the visual mismatch negativity (vMMN). This event-related potential (ERP) component is elicited by an irregular stimulus (e.g., a red disc) presented in a series of stimuli (e.g., green discs) comprising a temporal regularity (e.g., colour repetition). We determined the influence of lower- vs. upper-hemifield presentation of the irregular stimulus on the vMMN while using whole-field stimulus displays controlling for sustained shifts in spatial attention. Deviances presented in the lower hemifield elicited a larger vMMN than the ones presented in the upper hemifield at a latency of 200–280 ms. However, this asymmetry was preceded by deviance-related hemifield effects already emerging at an earlier latency (110–150 ms), where upper-hemifield deviances elicited a positive potential but lower-hemifield deviances did not. With variable resolution electromagnetic tomography (VARETA) early deviance-related activity was localised to retinotopically organised regions of the visual cortex (BA 17/18) and vMMN-sources were localised to the middle/superior occipital gyrus, to higher areas along the temporal visual stream, but also to BA 17/18. We argue that the upper/lower-hemifield vMMN asymmetry relies at least partially on the hemifield-dependent differential sensitivity of early deviance-related activity generated in retinotopically organised regions of the visual cortex. However, a superior automatic processing of deviances presented in the lower visual hemifield may also contribute to the effect

Behavioral and evoked potential measures of distraction in 5-year-old children born preterm

Executive and attention dysfunctions are common in very preterm children. We studied their involuntary attention process by using behavioral measurements and auditory event-related potentials (AERP) with a distraction paradigm at age five years. The active task was to distinguish between two animal sounds. As an irrelevant feature the sounds were presented from frequent (standard) or infrequent (deviant, 11%) direction from two loudspeakers. Of the 28 preterm children, only 75% could accomplish the task, whereas all full-term children (n = 15) could. When distinguishing the animal sounds, the reaction times were longer to the sounds from the deviant than from the standard direction in both groups, indicating involuntary distraction. The hit rates for the sounds from standard and deviant directions were similar in both groups. AERP amplitudes in the P1 interval and in the P3a interval elicited by standard and deviant stimuli were smaller in the preterm than in the control children. Deviants elicited P3a (indicating attentional orienting) and reorienting negativity (indicating attentional reorienting after distraction) in both groups. Comparable involuntary attentional orienting, distraction, and reorienting suggest similar maturation processes in 5-year-old preterm and full-term children. However, smaller AERP amplitudes in P1 and P3a interval suggest altered processing of auditory stimuli in those born preterm. As one-fourth of the preterm children could not accomplish the paradigm, less demanding paradigms should be used in studying children with increased distractibility. (C) 2010 Elsevier B.V. All rights reserved