Auditory cortex

When we attend a demanding task, our performance is poor at low arousal (when drowsy) or high arousal (when anxious), but we achieve optimal performance at intermediate arousal. This celebrated Yerkes-Dodson inverted-U law relating performance and arousal is colloquially referred to as being "in the zone." In this talk, I will elucidate the behavioral and neural mechanisms linking arousal and performance under the Yerkes-Dodson law in a mouse model. During decision-making tasks, mice express an array of discrete strategies, whereby the optimal strategy occurs at intermediate arousal, measured

Hallucinations are percepts experienced in the absence of external sensory input. Patients with hallucinations show both behavioral and neural alterations in statistical learning in simple sensory tasks. Predictive processing accounts of hallucinations suggest that these alterations bias patients’ perception toward their sensory expectations. However, 1) whether this framework holds when considering real-world hallucinations with complex content and 2) which upstream neural mechanisms cause these alterations in learning are hotly debated. To address these questions, we used fMRI to record neur

Neural responses throughout the auditory pathway show tuning for modulations in a time-frequency representation of sound, but how these spectrotemporal modulations are encoded in the human auditory cortex remains poorly understood. Classical, linear spectrotemporal receptive field (STRF) models are simple to understand and fit but have limited predictive power, particularly for complex natural sounds in non-primary regions of the human auditory cortex. We measured responses to a diverse set of natural sounds using spatiotemporally precise intracranial recordings from human neurosurgical patien

The mammalian auditory system is remarkably adaptable, allowing animals to flexibly respond to sensory information in dynamic environments. Flexible behaviors, such as perceptual learning, involve the engagement of various neural circuits including top-down regions such as frontal areas. However, how multiple brain areas communicate to support learning is unclear. Here, we investigate how frontal and sensory cortical areas interact to enable flexible behavior. We used high-density silicon probes to record single-unit responses simultaneously from auditory cortex (AC), and a downstream region i

To discern speech or appreciate music, the human auditory system detects how pitch increases or decreases over time. However, the algorithms used to detect changes in pitch, or pitch motion, are incompletely understood. Here, using psychophysics, computational modeling, functional neuroimaging, and analysis of recorded speech, we ask if humans can detect pitch motion using computations analogous to those used by the visual system. We adapted visual stimuli to create novel auditory correlated noise stimuli that elicit robust pitch motion percepts. Crucially, these stimuli are inharmonic and pos

…can localize the source of remote auditory signal and rewards associated with its spatial position. Given previous evidence for auditory sensitivity in the hippocampus [1-2], we recorded extracellular electrophysiological activity from auditory cortex and intermediate-ventral hippocampus simultaneously, us

…temporal integration in feed-forward auditory circuits to facilitate this. We tested this using an ethological mouse behavior that depends on left auditory cortex. Mothers find and retrieve isolated pups into the nest when pups emit ultrasonic vocalizations (USVs). Virgin females don’t usually retrieve pups, but learn after sever

…cue representation in the sensory cortex. However, evidence is growing that animals learn more rapidly than classical performance measures suggest, challenging the prevailing model of sensory cortical plasticity. Here, we investigated the relationship between learning and sensory cortical representations. We traine

…this, we trained mice on an auditory detection task with hidden switches in stimulus probability across trials. Mice dynamically adjusted their decision thresholds, tracking these changing sound probabilities. We monitored dopamine in the tail of the striatum (TS), a region at the interface of sensory processing and action selection that receives direct auditory cortex inputs. Given mesolimbic dopamine's estab

…Auditory and cognitive models have often cast neural integration in terms of time and structure, respectively, but whether neural computations in the auditory cortex reflect time or structure remains unknown. To answer this question, we rescaled the duration of all speech structures using time stretching/compression and measured integ

Corticocollicular (CC) projections arise in deep layers of the auditory cortex and modulate upstream auditory information in the inferior colliculus (IC), forming feedback loops. They are crucially involved in auditory-related learning and frequency response modulations in auditory brainstem. Through widefield and 2-photon calcium imaging in awake mice we prior were able to show that layer 5 CC neurons display only a subtle topographic organization when compared to other layer 5 neuron types (Schmitt et al., 2023, Front Neural Circuit). However, these data were acquired under passive listening

…to amplitude modulations in the auditory cortex. EEG studies revealed, in addition, attentional modulation of subcortical neural responses at the fundamental frequency of speech (speech-FFR). Recent MEG studies have identified cortical contributions to the speech-FFR (Coffey et al. (2017), Kulasingham et al. (2020), Schüller et al. (2024)), but it remains unclear if these cortica

Vocal communication is described as transfer of intraspecific signals between a sender and a receiver across humans and many animal species. It demands constant self-monitoring of vocal feedback to ensure precise emission of voice. The most representative phenomenon facilitated by vocal-feedback mechanism is known as the Lombard effect. Lombard effect, along with other spectro-temporal vocal modifications, is termed as noise-induced vocal modifications (NIVMs). However, despite the functional importance of NIVMs, our current knowledge of the neural mechanisms underlying this vital vocal feedba

…The prefrontal cortex was long thought to be the specific site for working memory in mammals. However, there is growing evidence that parallel distributed circuits may be responsible for working memory stressing the importance of sensory cortices for the active maintenance of information in working memory. The specific functions of working memory representations in sensory versus associate areas remains unknown. One possibility is that associative areas co

The posterior most region of the striatum receives dense innervation from sensory brain regions and has been demonstrated to play a role in behaviors that require sensorimotor integration including discrimination, avoidance and defense​ responses. The output neurons of the striatum, the D1 and D2 striatal projection neurons (SPNs) that make up the direct and indirect pathways, respectively, are thought to play differential roles in these behavioral responses, although it remains unclear if or how these neurons display differential responsivity to sensory stimuli. Here, we use whole cell membra

…recordings in the prefrontal cortex revealed compromised neuronal activity to some extent. The present study tested whether hearing loss would lead to altered expression of the GABA and dopamine (DA) systems in key re

Cortex harbors a diverse range of inhibitory interneuron (IN) types, each of which shapes cortical activity in a unique way. Collectively, these INs control and orchestrate neuronal activity, thereby bestowing cortex with its computational power. Whereas genetic markers have greatly facilitated the study of various cortical IN types, a selective marker for INs in L1 has long been missing. Here, we use the recently identified neuron-derived neurotrophic factor (NDNF) to characterize the properties of mouse auditory cortex L1INs in vitro. First, using in vitro patch-clamp recordings in combinati

Previous research indicated that neural responses to acoustic signals can differ in musicians and non-musicians. For instance, subcortical responses to speech sounds are stronger in musicians (Anderson et al. 2012). These neural responses include the frequency-following response at the fundamental frequency of the speech signal (speech-FFR). However, the speech-FFR also includes a cortical contribution with potential dependence on musical experience which is not yet known.We measured the cortical contribution to the speech-FFR via MEG recordings in 42 participants with different levels of musi

Hormones regulate brain function to achieve adaptive cognitive and behavioural responses. Consequently, disruption of sex hormone signaling may underlie some aspects of sex and gender bias in psychiatric and developmental brain disorder frequency and presentation. Currently, the basis by which sex steroid hormones (e.g. estradiol) alter sensory processing and cortical function is largely unexplored, as most research focuses on impacts within the hypothalamus and limbic system. Therefore, mechanistic insight is needed to understand the fundamental organization of sex hormone action on cortical

The tonotopic organization of the auditory system plays a crucial role in facilitating efficient processing of diverse auditory information that appears to be conserved across mammalian species. Approaches to date have mostly used electrophysiological or static approaches to map the representation of sound frequencies within the rodent auditory system, meaning that a comprehensive mapping in real-time was not feasible. Here, we used 7-Tesla fMRI in awake male rats to simultaneously determine tonotopic frequency representations in cortical and subcortical structures. Presentation of four differ

…The mouse auditory cortex sends numerous projections to the primary visual cortex and surrounding higher visual areas. These inputs may be crucial to the integration and binding of auditory and visual signals. Yet the exact nature of the auditory infor

…for patients with damaged auditory nerves are scarce: the only alternative is the Auditory Brainstem Implant (ABI), which presents poor clinical outcomes and difficult surgical approach.Here, we propose to target the auditory cortex directly, using a soft auditory cortex implant, for hearing restoration. By leveraging microfabrication techniques, we developed soft Electrocorticography (ECoG) arrays that would conform the curvilinear surface of the cortex, suppor

Sounds are represented in the mouse auditory cortex in the form of a representational map, in which the similarity of global activity patterns elicited by a pair of sounds encodes their perceptual relationship. Interestingly, sensory processing in cortex is generally robust despite loss of neurons during aging, and even the accelerated loss during prodromal phases of neurodegeneration. Here, we probed the robustness of the representational map against the permanent removal of specific neurons and tested in how far its structure is stabilized by homeostatic network mechanisms. We combined longi

There is strong evidence that alterations in the structural and functional properties of synaptic connections during learning are underlying the formation of long-term memories. However, what specific changes in the architecture of the neuronal network are mediated by learning-induced plasticity is still poorly understood. A major limiting factor of current in vivo imaging studies of synaptic dynamics is that typically only at a small number of synapses are assessed in a given animal, typically tens to hundreds. Here, we started to apply longitudinal in vivo two-photon imaging of more than a m