Abstract
Following a multi-talker conversation relies on the ability to rapidly and efficiently shift the focus of spatial attention from one talker to another. The current study investigated the listening costs associated with shifts in spatial attention during conversational turn-taking in 16 normally-hearing listeners using a novel sentence recall task. Three pairs of syntactically fixed but semantically unpredictable matrix sentences, recorded from a single male talker, were presented concurrently through an array of three loudspeakers (directly ahead and +/−30° azimuth). Subjects attended to one spatial location, cued by a tone, and followed the target conversation from one sentence to the next using the call-sign at the beginning of each sentence. Subjects were required to report the last three words of each sentence (speech recall task) or answer multiple choice questions related to the target material (speech comprehension task). The reading span test, attention network test, and trail making test were also administered to assess working memory, attentional control, and executive function. There was a 10.7 ± 1.3% decrease in word recall, a pronounced primacy effect, and a rise in masker confusion errors and word omissions when the target switched location between sentences. Switching costs were independent of the location, direction, and angular size of the spatial shift but did appear to be load dependent and only significant for complex questions requiring multiple cognitive operations. Reading span scores were positively correlated with total words recalled, and negatively correlated with switching costs and word omissions. Task switching speed (Trail-B time) was also significantly correlated with recall accuracy. Overall, this study highlights (i) the listening costs associated with shifts in spatial attention and (ii) the important role of working memory in maintaining goal relevant information and extracting meaning from dynamic multi-talker conversations.
Highlights
In a cocktail party environment, listeners are faced with the challenging task of separating multiple simultaneous talkers overlapping in time, frequency, and space
Non-spatial cues are important in initial auditory grouping, differences in spatial location drive temporal streaming in complex multi-talker settings (Shinn-Cunningham, 2005; Allen et al, 2008; Ihlefeld and ShinnCunningham, 2008)
Planned pairwise comparisons indicated a significant recall advantage in no switch trials compared to respective switch trials (LL > LC, LR; central no switch condition (CC) > CL, CR; RR > RL, RC)
Summary
In a cocktail party environment, listeners are faced with the challenging task of separating multiple simultaneous talkers overlapping in time, frequency, and space. The auditory system is able to parse this complex mixture into meaningful perceptual objects (Griffiths and Warren, 2004) using perceived differences in spatial location (e.g., Freyman et al, 1999; Kidd et al, 2005) as well as non-spatial cues such as voice characteristics and prosody (e.g., Darwin and Hukin, 2000; Brungart et al, 2001; Darwin, 2008). These features drive selective attention and allow listeners. Little is known about the perceptual consequences of switching spatial attention especially in dynamic conversations which involves integration of information across space and time (Sacks et al, 1974; Hutchby and Wooffitt, 2008)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
