Search bioRxiv⌕ Search

Biology subjects

Noyce, A. L.

Publications and source records attributed to Noyce, A. L..

6 recordsLinked to original sources

Distinct talkers combat catastrophic failures of spatial attention due to interruption

Task-irrelevant features can impact formation of auditory objects and influence the effectiveness of selective attention, including the buildup of attention over time. Using a previously established paradigm exploring the effects of random interruptions on spatial selective attention, this study explores how the task-irrelevant feature of talker identity impacts the buildup of spatial attention and whether it alters the impact of interruptions. Participants performed a sequence recall task in which participants were presented with two competing syllable sequences coming from different spatial directions and were asked to report the syllable sequence coming from the target direction. On half of the trials, an unpredictable, novel interrupting sound occurred, disrupting attentional focus. Two experiments explored how talker influenced performance, specifically, whether 1) making the two streams come from different talkers facilitates task performance and reduces the impact of interruption compared to when the streams are spoken by the same talker, and 2) talker discontinuity interferes with attention buildup and harms syllable recall performance compared to when the talker is the same from one syllable to the next. Our results showed that distinct talker features, though task-irrelevant in this spatial task, significantly improved syllable recall performance and reduced the impact of interrupters. Further, irrelevant talker discontinuities damaged attention buildup and reduced syllable recall performance.

neuroscience↗

Combined Auditory, Tactile, and Visual fMRI Reveals Sensory-Biased and Supramodal Working Memory Regions in Human Frontal Cortex

Selectivity for sensory modality characterizes distinct subregions of the human brain, well beyond the primary sensory cortices. We previously identified frontal and posterior cortical regions that are preferentially recruited for visual vs. auditory attention and working memory (WM). Here, we extend our approach to include tactile cognition and to characterize cortical regions recruited by WM in each of three sensory modalities. The joint organization of visual-selective, auditory-selective, tactile-selective, and supramodal WM recruitment within individual subjects has not been fully investigated previously. Male and female human subjects participated in a blocked fMRI task requiring them to perform N-back WM judgements in auditory, visual, or tactile (haptic) modalities. We confirmed our prior reports of multiple visual-biased and auditory-biased frontal lobe regions. We also observed several bilateral tactile-selective regions abutting previously described visual- and auditory-selective regions, including dorsal and ventral precentral sulcus, the postcentral sulcus, and the anterior intraparietal sulcus. Several cortical regions were recruited by WM in all three sensory modalities in individual subjects, including precentral sulcus, inferior frontal sulcus, intraparietal sulcus, anterior insula and pre-supplementary motor area. Supramodal regions exhibited substantial overlap with visual-biased regions in frontal and parietal cortex and comparatively little overlap with tactile- or auditory-biased regions. Lastly, resting-state analyses revealed that auditory-, visual- and tactile-selective WM regions segregate into modality-specific networks that span frontal and posterior cortex. Together, these results shed light on the functional organization of sensory-selective and supramodal regions supporting higher-order cognition. SIGNIFICANCE STATEMENTUsing within-subject fMRI analyses of three different sensory modalities, we identify the fine-scale architecture of sensory-biased and supramodal working memory structures within human frontal cortex. Sixteen bilateral frontal lobe regions are identified: five auditory-biased, four visual-biased, two tactile-biased, and five multiple-demand / supramodal regions. These parcels are largely distinct with the notable exception that the visual-biased regions each partially overlap with supramodal regions, suggesting a tight link between visual and supramodal working memory representations. Sensory-biased frontal lobe regions form modality-specific networks with traditionally-identified posterior sensory cortical regions. The findings demonstrate a pervasive role for sensory modality in the functional organization of frontal cortex and offer a fine-scale parcellation of the human frontal lobe regions supporting working memory.

neuroscience↗

Neural representation of spatial and non-spatial auditory attention in EEG signals

Neural representation, capturing the content and format of encoded information, provides insight into the internal states of neural units. Studies of neural representation contrast with studies of neural processes, which focus on how one neural unit influences another. Representational similarity analysis (RSA), a multivariate analysis approach, has been used in previous studies to explore the neural representation of object categories in various neuroimaging modalities. In this study, we employed RSA to examine the neural representation of executive function. We designed an experiment involving a rich set of conditions where participants engaged in an auditory task requiring either spatial or non-spatial attention. We extracted representational features from their electroencephalography (EEG) scalp voltage and alpha power and compared these features with ideal conceptual models representing perfect categorization of different attentional states. The results demonstrate the feasibility of investigating internal cognitive states using RSA. Specifically, we identified time intervals during which attentional state contrasts, such as differences between attention types or locations, manifested in the measured neural responses from scalp voltage and alpha power distributions.

neuroscience↗

Similarity in sensory modality and information domain impair processing in a dual-task context: Evidence from behavior, pupillometry, and EEG

Project AbstractMaking sense of our environment requires us to extract simultaneous temporal and spatial information from multiple sensory modalities, particularly audition and vision. This sensory information can be stored in working memory (WM) to guide future actions, at which point it must be safeguarded against interference from ongoing sensory processing. Recent fMRI research has uncovered regions in human frontal cortex well-suited to coordinate this interplay between attention and WM for multisensory and multidimensional information. Which of these brain regions are engaged depends on both the sensory modality of the input and the information domain of the task, forming the basis of two complementary networks specialized for auditory/temporal and visual/spatial processing. Motivated by the functional specializations of these networks, we examined whether similarity in sensory modality and information domain modulates neural and perceptual interference between two concurrent tasks. Participants stored temporal or spatial information about auditory or visual stimuli in WM, and on some trials, performed an intervening temporal or spatial auditory task during WM retention. WM recall and auditory perceptual judgments were impaired when the two tasks relied on the same sensory modality and/or information domain. Pupil dilations were also larger in these conditions, indicating increased cognitive effort. Event-related potentials (ERPs) revealed a neural signature of domain-based interference that was masked by behavioral ceiling effects. These results demonstrate that modality and information domain jointly affect how task information is represented in WM, and concomitantly, how tasks engage the complementary auditory-temporal and visual/spatial cognitive control networks.

neuroscience↗

Extended frontal networks for visual and auditory working memory

Working memory (WM) supports the persistent representation of transient sensory information. Visual and auditory stimuli place different demands on WM and recruit different brain networks. Separate auditory- and visual-biased WM networks extend into the frontal lobes, but several challenges confront attempts to parcellate human frontal cortex, including fine-grained organization and between-subject variability. Here, we use differential intrinsic functional connectivity from two visual-biased and two auditory-biased frontal structures to identify additional candidate sensory-biased regions in frontal cortex. We then examine direct contrasts of task fMRI during visual vs. auditory 2-back WM to validate those candidate regions. Three visual-biased and five auditory-biased regions are robustly activated bilaterally in the frontal lobes of individual subjects (N=14, 7 women). These regions exhibit a sensory preference during passive exposure to task stimuli, and that preference is stronger during WM. Hierarchical clustering analysis of intrinsic connectivity among novel and previously identified bilateral sensory-biased regions confirms that they functionally segregate into visual and auditory networks, even though the networks are anatomically interdigitated. We also observe that the fronto-temporal auditory WM network is highly selective and exhibits strong functional connectivity to structures serving non-WM functions, while the fronto-parietal visual WM network hierarchically merges into the multiple-demand cognitive system.

neuroscience↗

Top-down attention modulates auditory-evoked neural responses in neurotypical, but not ADHD, young adults

Individuals differ in their ability to selectively attend to goal-relevant auditory stimuli. People with Attention-Deficit/Hyperactivity Disorder (ADHD) in particular tend to show cognitive deficits associated with distractibility and inefficiencies in inhibition and attention. We hypothesized that people with ADHD would exhibit poorer performance and weaker neural signatures of attentional control when undertaking a challenging auditory task that required strong top-down attention. Neurotypical (N = 20) and ADHD (N = 25) young adults with normal hearing listened to one of three concurrent, spatially separated speech streams and reported the order of the syllables presented while we recorded electroencephalography (EEG). We tested both the ability to sustain attentional focus on a single "target" stream and the ability to monitor the target but flexibly switch attention to an unpredictable "interrupter" stream from another direction if and when it appeared. Although both stimulus structure and task demands affected behavioral performance, ADHD status did not. In both groups, the interrupter evoked larger neural responses when it was to be attended compared to when it was irrelevant, including for the P3a "reorienting" response previously described as involuntary. This attentional modulation was weaker in ADHD listeners, even though their behavioral performance was no lower. Across the entire cohort, individual performance correlated with the degree of top-down modulation of neural responses. These results demonstrate that listeners differ in their ability to modulate neural representations of sound based on task goals. Adults with ADHD have weaker volitional control of attentional processes than their neurotypical counterparts. Significance StatementADHD and neurotypical listeners attended to one speech stream among distractors while neural responses were measured with electroencephalography. Behavioral performance varied with stimulus structure and task demands, but not with ADHD status. In both groups, top-down attention modulated stimulus-evoked neural responses: interrupting sounds elicited weaker responses when the sounds were ignored compared to when they were attended. This modulation affected a late "orienting" response (P3a) that has been previously described as automatic and not dependent on internal state. Importantly, ADHD subjects showed weaker attentional filtering than did neurotypical controls. At the individual level, performance correlated with neural metrics. Our results demonstrate that people vary widely in how flexibly they can use attention to modulate sensory responses based on task goals.

neuroscience↗