![]() ![]() Extending these findings, studies in primate AC and VC have reported entrainment local field potential (LFP) oscillations by modality-selective attention, which serves to modulate excitability and sharpen feature tuning within sensory cortex corresponding to the attended modality ( Hocherman et al., 1976 Lakatos et al., 2009 Lakatos et al., 2008 O’Connell et al., 2014). ![]() Human fMRI studies have reported differential activation patterns in auditory and visual cortex (AC, VC) reflecting the attended modality ( Johnson and Zatorre, 2005 Petkov et al., 2004 Shomstein and Yantis, 2004 Woodruff et al., 1996). This mode of attention highlights behaviorally relevant sensory streams while filtering less relevant ones. On the other hand, fewer studies have examined how modality-selective attention affects encoding in sensory cortex. These studies, largely from the visual domain, have shown that attention to a stimulus feature or space will often increase stimulus-evoked spiking responses and reduce thresholds for eliciting a response likewise, responses to unattended stimuli are often decreased ( Reynolds and Chelazzi, 2004). A major focus of this work has been characterizing transformations of stimulus representations in sensory cortical areas, due to their pivotal position between ascending sensory pathways and behavioral networks implementing top-down control ( Lamme et al., 1998 Sutter and Shamma, 2011). Most effort has been devoted to understanding the neural mechanisms of feature-selective attention within a single modality ( Desimone and Duncan, 1995 Fritz et al., 2007). How might sensory cortex differentially encode stimuli from an attended versus filtered modality?Īttentional selection operates cooperatively at many levels of sensory processing. In these cases, contextual cues support allocating attention to either the auditory domain or the visual domain, and the perceptual experience of the music is qualitatively different. ![]() On the other hand, a similar shift away from the music is unlikely while listening at home. For example, hearing a siren while listening to music in the car might prompt an attentional shift away from the auditory stream, toward a visual search for emergency vehicles. The brain must therefore continuously assign limited attentional resources to processing simultaneous information streams from each sensory modality. Information from one or another sensory pathway may become differentially relevant due to environmental changes. Together, these findings suggest auditory attention facilitates sound discrimination by filtering sound-irrelevant background activity in AC, and that the deepest cortical layers serve as a hub for integrating extramodal contextual information. ![]() Importantly, spiking reductions predicted trial-to-trial behavioral accuracy during auditory attention, but not visual attention. Similarly, task-irrelevant mapping stimuli during inter-trial intervals evoked fewer spikes without impairing stimulus encoding, indicating that attentional modulation generalized beyond training stimuli. Despite reduced spiking, stimulus decoder accuracy was preserved, suggesting improved sound encoding efficiency. Attending to sound elements in an AV stream reduced both pre-stimulus and stimulus-evoked spiking activity, primarily in deep-layer neurons and neurons without spectrotemporal tuning. We conducted translaminar recordings in mouse auditory cortex (AC) during an audiovisual (AV) attention shifting task. In everyday behavior, sensory systems are in constant competition for attentional resources, but the cellular and circuit-level mechanisms of modality-selective attention remain largely uninvestigated. ![]()
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