Many studies using N2pc as a marker of attentional capture have demonstrated topdown contingent capture for salient color singletons: Among all salient cues that are not predictive of the target location, only cues similar to searched-for target features, and thus, matching to the top-down attentional control settings capture attention. This is reflected in matching cue's elicitation of an N2pc and a cueing effect in behavior, and the absence of the corresponding effects for non-matching cues (with features dissimilar to that of the searched-for targets). Yet, with abrupt-onset cues, corresponding evidence is missing, inviting speculations about the potential of abrupt-onset cues to capture attention followed by quick suppression within the target displays. Here, we used two types of abrupt-onset cues to test if capture by such cues also adheres to the contingent-capture principle: matching abrupt-onset cues with a color similar to the top-down control settings and non-matching abruptonset cues with a color different from all searched-for targets. With the help of these cues, top-down contingent capture was supported. Only matching abrupt-onset cues elicited an N2pc and a behavioral cueing effect. Depending on the exact side conditions, non-matching cues either elicited no N2pc or a P D (i.e., evidence of active suppression). Results are discussed against the background of competing theories on attention capture by abrupt-onset cues.

Prior studies using the peripheral cueing paradigm have shown that singleton cues that do not match to the top-down search settings of the observer can impair performance in visual search when the cue appears at the target location (in valid conditions) compared with when the cue appears at a location away from the target (in invalid conditions). This pattern, the same-location cost (SLC), has recently been suggested to originate from an awareness-dependent updating of object files in working memory. It has also been argued that the processes underlying the SLC could have obscured results of prior studies by masking attentional capture effects by peripheral cues under certain conditions. Here, we investigated to which extent the object-file updating hypothesis can be generalized and delineate necessary side conditions for object-file updating to produce the SLC. In Experiments 1 to 3, we show that during search for spatial frequencies, SLCs emerged that are at odds with the object-file updating hypothesis. SLCs were not dependent on cue awareness and were, unlike SLCs with color cues and targets (Experiment 4), not entirely eliminated where feature updating was necessary in valid and invalid conditions. We conclude that some instances of the SLC can be explained by object-file updating, but, as the present study shows, other instances of the SLC are at odds with this explanation and are therefore more likely of an attentional origin. We end with a discussion of which side conditions might favor the emergence of SLCs as a result of object-file updating. (PsycINFO Database Record

In two experiments, we tested whether subliminal abrupt onset cues capture attention in a stimulus-driven way. An onset cue was presented 16 ms prior to the stimulus display that consisted of clearly visible color targets. The onset cue was presented either at the same side as the target (the valid cue condition) or on the opposite side of the target (the invalid cue condition). Because the onset cue was presented 16 ms before other placeholders were presented, the cue was subliminal to the participant. To ensure that this subliminal cue captured attention in a stimulus-driven way, the cue's features did not match the top-down attentional control settings of the participants: (1) The color of the cue was always different than the color of the non-singleton targets ensuring that a top-down set for a specific color or for a singleton would not match the cue, and (2) colored targets and distractors had the same objective luminance (measured by the colorimeter) and subjective lightness (measured by flicker photometry), preventing a match between the top-down set for target and cue contrast. Even though a match between the cues and topdown settings was prevented, in both experiments, the cues captured attention, with faster response times in valid than invalid cue conditions (Experiments 1 and 2) and faster response times in valid than the neutral conditions (Experiment 2). The results support the conclusion that subliminal cues capture attention in a stimulus-driven way.

A disaccharide degradation product of chondrotin sulfate proteoglycan-disaccharide (CSPG-DS) has been implicated previously in the inhibition of neurodegeneration by influencing microglia activation. In this study, genome-wide microarray analysis was used to identify specific gene expression profiles of CSPG-DS-stimulated BV-2 microglia-like cells. Gene products involved in phagocytosis, detoxification, migration, immune regulation, and antigen presentation were found to be altered significantly. These findings were replicated and compared with IFN-gamma-stimulated primary microglia using real-time quantitative RT-PCR validation. Importantly, a unique transcriptional phenotype with anti-inflammatory and IFN-gamma counter-regulatory properties partially related to alternatively activated macrophages was identified. Using functional cell assays, we found that CSPG-DS-stimulated microglia possess increased phagocytic capacity but lack direct cytotoxic effects such as secretion of NO. Furthermore, conditioned media from CSPG-DS-treated microglia did not diminish the viability or cause apoptosis of cultured photoreceptor cells and partially rescued these cells from IFN-gamma-induced apoptosis. Taken together, our data provide a unique transcript dataset and important in vitro findings about the functional properties of CSPG-DS-activated microglia. These might be starting points to explore the in vivo role of CSPG-DS as a bioactive microglia regulator and its potential, therapeutic application in immune-related, neurodegenerative disorders.