Thus, the spatial shifts probe the extent that occasionally changing stimulus location affects performance, presumably because a spatial shift captures attention.
The analyses will focus on perceptual-level effects of attention by infrequently shifting a target’s location, where the target response is determined by a non-spatial feature. Here we will test the impact of verbal and spatial short-term memory loads on attentional bias over space. Parametric studies within a domain are often done to understand how attention affects processing in domains such as space ( Cave and Bichot, 1999), frequency ( Scharf et al., 1987), faces ( Gratton et al., 2013), and lexical associations ( McEvoy and Nelson, 1982). This approach is useful for comparisons between conditions but does not provide insight into how memory load may affect processing within a domain. The above studies have all used a point estimate to gauge the influence of memory load on attentional processing, such as the difference in reaction time for compatible vs. This study will address some limitations of previous behavioral measures by parametrically assessing the influence of short-term memory load on auditory spatial attention. Thus, under some conditions short-term memory load induces a more general impairment in attention control, while in others memory load is more selective. Taken together, the specifics of the task, behavioral measures, and potentially stimulus modality are important considerations when drawing conclusions about short term memory influences on attention ( Wickens, 2008). (2009) showed that concurrent short-term memory load during a stimulus-response compatibility task increased attention capture. Berti and Schröger (2003) used an n-back task variant and found that adding a short-term memory load reduced attention capture ( Berti and Schröger, 2003). There have only been a few studies of short-term memory load on auditory attention capture, and the results are mixed. Short-term memory load may even facilitate performance if the type of information in memory overlaps with distracting information ( Kim et al., 2005 Park et al., 2007) cf. However, effects of short-term memory load on attention can also be selective, with attention capture only when information in short-term memory overlaps with task-relevant information (cf. Loading short-term memory with several items, such as numbers, before trials in a visual attention task increases the likelihood of attention capture by irrelevant singletons ( De Fockert, 2013), and has a general effect when the remembered information is not task-relevant ( Lavie and De Fockert, 2005). Nonetheless, even though the onset of a sound is a potent way to induce attention capture, most studies on relations between attention and short-term memory are done using the visual modality. Interruptions to attend to potentially important information are often beneficial, but extract a cost to ongoing cognitive activities such as maintaining goal-related attentional biases ( Cowan, 1995 Braver, 2012) and short-term memory processes ( Hughes and Jones, 2001). Orienting responses show that this acoustic “early warning system” can interrupt ongoing cognitive activities that utilize short-term memory. The auditory system has a special role in attention control because spatial hearing affords panoramic sensitivity that can detect threats, opportunities, and conspecifics at a distance or out of view ( Schafer, 1977 Scharf, 1998). The findings show that short-term memory influences the distribution of auditory attention over space and that the specific pattern depends on the type of information in short-term memory.
Spatial and verbal load increased switch costs between memory encoding and attention tasks relative to the no load condition. Verbal memory load had no (Experiment 1), or a minimal (Experiment 2) influence on reaction times. Spatial load further slowed responses at lateral locations, particularly in the left hemispace, but had little effect at midline. Reaction times progressively increased for lateral stimuli, indicating an attention gradient. Stimuli were presented from five virtual locations in the frontal azimuth plane, and subjects focused on the midline. Verbal or spatial information was maintained during an auditory spatial attention task and compared to no-load. Here we used auditory attention gradients as an analog measure to map-out the impact of short-term memory load over space. One factor for the mixed results may be reliance on point estimates of memory load effects on attention.
Short-term memory load can impair attentional control, but prior work shows that the extent of the effect ranges from being very general to very specific.