David Brang

University of Michigan | U-M · Department of Psychology

Specialized neocortical circuits selectively organize neuronal signals and encode features of cognitive processing via local and long-range connections. Since glioma-infiltrated cortex is excitable and can participate in cognitive processing, the underlying laminar structure and functionality may still be preserved despite infiltration. Moreover, s...

BACKGROUND AND OBJECTIVES Although diffuse gliomas in the primary somatosensory cortex (S1) are often considered resectable, gliomas in the primary motor cortex require motor mapping to preserve motor function. Recent evidence indicates that some somatosensory cortex neurons may trigger motor responses, necessitating refined somatosensory mapping t...

Congruent visual speech improves speech perception accuracy, particularly in noisy environments. Conversely, mismatched visual speech can alter what is heard, leading to an illusory percept that differs from the auditory and visual components, known as the McGurk effect. While prior transcranial magnetic stimulation (TMS) and neuroimaging studies h...

Congruent visual speech improves speech perception accuracy, particularly in noisy environments. Conversely, mismatched visual speech can alter what is heard, leading to an illusory percept known as the McGurk effect. This illusion has been widely used to study audiovisual speech integration, illustrating that auditory and visual cues are combined...

BACKGROUND We recently demonstrated that glioma-infiltrated cortex engages in task-specific computations but may encode less information while doing so. The mechanistic underpinnings of glioma burden and its behavioral impact remains unknown OBJECTIVE To investigate the relationship between glioma burden and degree of cognitive impairments. METHO...

Gliomas synaptically integrate into neural circuits1,2. Previous research has demonstrated bidirectional interactions between neurons and glioma cells, with neuronal activity driving glioma growth1–4 and gliomas increasing neuronal excitability2,5–8. Here we sought to determine how glioma-induced neuronal changes influence neural circuits underlyin...

INTRODUCTION It has been shown recently that infiltration of gliomas into healthy neural tissue alters local neuronal spiking patterns, leading to circuit dysfunction. It is unknown, however, if glioma infiltration also impacts the coordination of local neuronal computations with other networks during behavioral tasks. Cross-frequency coupling of h...

INTRODUCTION Recent evidence indicates that diffuse gliomas engage with neurons at the single-unit and circuit level through differing mechanisms. Certain malignant gliomas form glioma-neuron excitatory glutamatergic synapses and modulate neuron-neuron synapses through activity-dependent paracrine signaling, while others establish glioma-glioma con...

Prior work demonstrated synaptic integration of malignant gliomas into neural circuits induces local hyperexcitability and tumor proliferation. However, prognostication and therapeutic vulnerabilities are lacking from preclinical models. Here, we integrate in vivo and in vitro neurophysiology spatially matched with gene expression programs and prot...

Recent evidence indicates that diffuse gliomas engage with neurons at the single-unit and circuit level through differing mechanisms. Certain malignant gliomas form glioma-neuron excitatory glutamatergic synapses and modulate neuron-neuron synapses through activity-dependent paracrine signaling, while others establish glioma-glioma connections via...

Watching a speaker’s face improves speech perception accuracy. These benefits are owed, in part, to implicit lipreading abilities present in the general population. While it is established that lipreading can alter the perception of a heard word, it is unknown how information that is extracted from lipread words is transformed into a neural code th...

Sounds enhance our ability to detect, localize, and respond to co-occurring visual targets. Research suggests that sounds improve visual processing by resetting the phase of ongoing oscillations in visual cortex. However, it remains unclear what information is relayed from the auditory system to visual areas and if sounds modulate visual activity e...

INTRODUCTION Although awake brain mapping is the gold-standard for the preservation of neurological function in patients with tumors in eloquent regions, it is resource-intensive, costly, and exposes patients to additional perioperative risks. Therefore, the tasks used to map out the brain should be carefully selected and limited to cognitive proce...

Language, cognition, and behavioral testing have become a fundamental component of standard clinical care for brain cancer patients. Many existing publications have identified and addressed potential ethical issues that are present in the biomedical setting mostly centering around the enrollment of vulnerable populations for therapeutic clinical tr...

Multisensory stimuli speed behavioral responses, but the mechanisms subserving these effects remain disputed. Historically, the observation that multisensory reaction times (RTs) outpace models assuming independent sensory channels has been taken as evidence for multisensory integration (the “redundant target effect”; RTE). However, this interpreta...

Significance As gliomas proliferate, they infiltrate healthy brain tissue. Often, patients with such tumors in the language areas of the brain develop aphasia. Understanding how gliomas interact with normal neural circuits is critical for developing neuroprostheses that restore speech. Recent evidence demonstrates that glioma cells interact synapti...

INTRODUCTION Recent developments in the biology of malignant gliomas have demonstrated that glioma cells interact with neurons through both paracrine signaling and electrochemical synapses. Glioma-neuron interactions consequently modulate the excitability of local neuronal circuits, and it is unclear the extent to which glioma-infiltrated cortex ca...

Speech perception is a central component of social communication. Although principally an auditory process, accurate speech perception in everyday settings is supported by meaningful information extracted from visual cues. Visual speech modulates activity in cortical areas subserving auditory speech perception including the superior temporal gyrus...

Movies, audio stories, and virtual reality are increasingly used as stimuli for functional brain imaging. Such naturalistic paradigms are in sharp contrast to the tradition of experimental reductionism in neuroscience research. Being complex, dynamic, and diverse, naturalistic stimuli set up a more ecologically relevant condition and induce highly...

Recent developments in the biology of malignant gliomas have demonstrated that glioma cells interact with neurons through both paracrine signaling and electrochemical synapses. Glioma-neuron interactions consequently modulate the excitability of local neuronal circuits, and it is unclear the extent to which glioma-infiltrated cortex can meaningfull...

OBJECTIVE Intraoperative tasks for awake language mapping are typically selected based on the language tracts that will likely be encountered during tumor resection. However, diminished attention and arousal secondary to perioperative sedatives may reduce a task’s usefulness for identifying eloquent cortex. For instance, accuracy in performing sele...

Multisensory stimuli speed behavioral responses, but the mechanisms subserving these effects remain disputed. Historically, the observation that multisensory reaction times (RTs) outpace models assuming independent sensory channels has been taken as evidence for multisensory integration (the “redundant target effect”; RTE). However, this interpreta...

Lexical retrieval requires selecting and retrieving the most appropriate word from the lexicon to express a desired concept. Few studies have probed lexical retrieval with tasks other than picture naming, and when non-picture naming lexical retrieval tasks have been applied, both convergent and divergent results emerged. The presence of a single co...

Objectives Focal cortical dysplasia type II (FCDII) is one of the most common underlying pathologies in patients with drug‐resistant epilepsy. However, mechanistic understanding of FCDII fails to keep pace with genetic discoveries, primarily due to the significant challenge in developing a clinically relevant animal model. Conceptually and clinical...

Gliomas synaptically integrate into neural circuits. Prior work has demonstrated bidirectional interactions between neurons and glioma cells, with neuronal activity driving glioma growth and gliomas increasing neuronal excitability. In this study we wanted to know how glioma induced neuronal changes influence neural circuits underlying cognition an...

Gliomas exist within the framework of complex neuronal circuitry in which network dynamics influence both tumor biology and cognition. The generalized impairment of cognition or loss of language function is a common occurrence for glioma patients. The interface between intrinsic brain tumors such as gliomas and functional cognitive networks are poo...

Cognitive decline is common among patients with low- and high-grade glioma and can significantly impact quality of life. Although cognitive outcomes have been studied after therapeutic interventions such as surgery and radiation, it is important to understand the impact of the disease process itself prior to any interventions. Neurocognitive domain...

Lexical retrieval requires selecting and retrieving the most appropriate word from the lexicon to express a desired concept. Few studies have probed lexical retrieval with tasks other than picture naming, and when non-picture naming lexical retrieval tasks have been applied, both convergent and divergent results emerged. The presence of a single co...

Lexical retrieval requires selecting and retrieving the most appropriate word from the lexicon to express a desired concept. Prior studies investigating the neuroanatomic underpinnings of lexical retrieval used lesion models that rely on stereotyped vascular distributions, functional neuroimaging methods that lack causal certainty, or awake brain m...

BACKGROUND Unlike cancers affecting many solid organs, gliomas exist within the context of complex neural circuitry. It remains unknown whether glioma-neuron interactions play a role in maintaining functional circuits underlying cognition. We test the hypothesis that malignant gliomas remodel functional circuits through glioma-neuron interactions....

Objective To describe the spatio-temporal dynamics and interactions during linguistic and memory tasks. Methods Event-related electrocorticographic (ECoG) spectral patterns obtained during cognitive tasks from 26 epilepsy patients (aged: 9-60 y) were analyzed in order to examine the spatio-temporal patterns of activation of cortical language areas...

The ability to understand spoken language is essential for social, vocational, and emotional health, but can be disrupted by environmental noise, injury, or hearing loss. These auditory deficits can be ameliorated by visual speech signals that convey redundant or supplemental speech information, but the brain regions critically responsible for thes...

Speech perception is a central component of social communication. While principally an auditory process, accurate speech perception in everyday settings is supported by meaningful information extracted from visual cues (e.g., speech content, timing, and speaker identity). Previous research has shown that visual speech modulates activity in cortical...

Significance Multisensory signals can facilitate perception by clarifying unreliable unisensory signals. These multisensory interactions are particularly apparent in audiovisual speech perception, in which visual speech substantially enhances auditory speech processes, remediating perceptual deficits produced by noisy environments, hearing disorder...

Signals encoded in one sensory modality can enhance cortical sensitivity for co-occurring signals in another modality. Previous research has demonstrated that this facilitation occurs through crossmodal modulations of cortical oscillatory activity. However, the source and content of the information conveyed by this mechanism remain poorly understoo...

INTRODUCTION Little is known about the mechanisms by which gliomas integrate into functional neural networks and influence complex cognitive processes such as language. Glioma-neuron interactions are bidirectional, with increased neuronal activity promoting tumor growth and the latter in turn influencing neuronal excitability and synaptic connectio...

High-grade gliomas are a lethal group of cancers whose progression is robustly regulated by neuronal activity. Activity-regulated release of growth factors into the tumor microenvironment represents part of the mechanism by which neuronal activity influences glioma growth, but this alone is insufficient to explain the magnitude of the effect that a...

In synaesthesia, stimulation of one sensory modality evokes additional experiences in another modality (e.g. sounds evoking colours). Along with these cross-sensory experiences, there are several cognitive and perceptual differences between synaesthetes and non-synaesthetes. For example, synaesthetes demonstrate enhanced imagery, increased cortical...

Visual cues facilitate speech perception during face-to-face communication, particularly in noisy environments. These visual-driven enhancements arise from both automatic lip-reading behaviors and attentional tuning to auditory-visual signals. However, in crowded settings, such as a cocktail party, how do we accurately bind the correct voice to the...

Visual speech facilitates auditory speech perception, but the visual cues responsible for these effects and the crossmodal information they provide remain unclear. Because visible articulators shape the spectral content of auditory speech, we hypothesized that listeners may be able to extract spectrotemporal information from visual speech to facili...

OBJECTIVE Maximal safe tumor resection in language areas of the brain relies on a patient’s ability to perform intraoperative language tasks. Assessing the performance of these tasks during awake craniotomies allows the neurosurgeon to identify and preserve brain regions that are critical for language processing. However, receiving sedation and ana...

Objective: High Frequency Oscillations (HFOs) are a promising biomarker of epilepsy. HFOs are typically acquired on intracranial electrodes, but contamination from muscle artifacts is still problematic in HFO analysis. This paper evaluates the effect of myogenic artifacts on intracranial HFO detection and how to remove them. Methods: Intracrania...

Antisocial behavior (AB), including violence, criminality, and substance abuse, is often linked to deficits in emotion processing, reward-related learning, and inhibitory control, as well as their associated neural networks. To better understand these deficits, the structural connections between brain regions implicated in AB can be examined using...

Co-occurring sounds can facilitate perception of spatially and temporally correspondent visual events. Separate lines of research have identified two putatively distinct neural mechanisms underlying two types of crossmodal facilitations: Whereas crossmodal phase resetting is thought to underlie enhancements based on temporal correspondences, latera...

While most people take identification with their body for granted, conditions such as phantom limb pain, alien hand syndrome, and xenomelia suggest that the feeling of bodily congruence is constructed and susceptible to alteration. Individuals with xenomelia typically experience one of their limbs as over-present and aversive, leading to a desire t...

Auditory speech is typically accompanied by related visual cues that enhance speech perception and compensate for degraded auditory processing due to environmental noise or auditory deficits. This crossmodal enhancement is partly due to lip articulations crossmodally providing redundant contextual information to facilitate phoneme identification. H...

Background: The accurate localization of implanted ECoG electrodes over the brain is of critical importance to invasive diagnostic work-up for the surgical treatment of intractable epileptic seizures. The implantation of subdural electrodes is an invasive procedure which typically introduces non-uniform deformations of a subject's brain, increasin...

Plasticity is essential in body perception so that physical changes in the body can be accommodated and assimilated. Multisensory integration of visual, auditory, tactile, and proprioceptive signals contributes both to conscious perception of the body’s current state and to associated learning. However, much is unknown about how novel information i...

Neurophysiological studies with animals suggest that sounds modulate activity in primary visual cortex in the presence of concurrent visual stimulation. Non-invasive neuroimaging studies in humans have similarly shown that sounds modulate activity in visual areas even in the absence of visual stimuli or visual task demands. However, the spatial and...

When two people are engaged in a conversation and feel they understand each other's perspectives, they often describe their experience as "on the same wavelength." During these interactions, people tend to automatically mirror one another's gestures and facial expressions. It has recently been shown that this overt behavioral mimicry is correlated...

Perception of multisensory events, such as a person speaking, relies on binding information from distinct sensory modalities into a unitary percept. A temporal window of integration for multisensory events allows flexibility to account for latency differences arising from both variable physical transmission rates through the environment and neural...

Body representation processes underlie individuals' coherent sense of body ownership and knowledge of the spatial boundaries of the body. These experiences are highly dynamic, changing throughout development or due to damage and disease. Indeed, large individual differences exist in the ability to dynamically update one's body representation, typic...

The brain's primary motor and primary somatosensory cortices are generally viewed as functionally distinct entities. Here we show by means of magnetoencephalography with a phantom-limb patient, that movement of the phantom hand leads to a change in the response of the primary somatosensory cortex to tactile stimulation. This change correlates with...

Grapheme-color synesthesia is a neurological phenomenon in which letters and numbers (graphemes) consistently evoke particular colors (e.g., A may be experienced as red). These sensations are thought to arise through the cross-activation of grapheme processing regions in the fusiform gyrus and color area V4, supported by anatomical and functional i...

The redundant-target effect is a basic and well-replicated finding that participants respond faster to a multisensory target (a combined sound and light) than to a unisensory target (an isolated sound or light). This response speeding is generally attributed to superadditive effects at the level of individual neurons, such that the neural response...

Misophonia is a relatively unexplored chronic condition in which a person experiences autonomic arousal (analogous to an involuntary “fight-or-flight” response) to certain innocuous or repetitive sounds such as chewing, pen clicking, and lip smacking. Misophonics report anxiety, panic, and rage when exposed to trigger sounds, compromising their abi...

Time-space synesthesia is a variant of sequence-space synesthesia and involves the involuntary association of months of the year with 2D and 3D spatial forms, such as arcs, circles, and ellipses. Previous studies have revealed conflicting results regarding the association between time-space synesthesia and enhanced spatial processing ability. Here,...

Our senses interact in daily life through multisensory integration, facilitating perceptual processes and behavioral responses. Numerous multisensory regions have been identified in humans and animals, raising the question of whether a single mechanism can support the dynamic range of experiences and behaviors multisensory processing engenders. The...

The claim that some individuals see colored halos or auras around faces has long been part of popular folklore. Here we report on a 23-year-old man (subject TK) diagnosed with Asperger's disorder, who began to consistently experience colors around individuals at the age of 10. TK's colors are based on the individual's identity and emotional connota...

Synesthesia is a perceptual experience in which stimuli presented through one modality will spontaneously evoke sensations in an unrelated modality. The condition occurs from increased communication between sensory regions and is involuntary, automatic, and stable over time. While synesthesia can occur in response to drugs, sensory deprivation, or...

In 2001, Ramachandran and Hubbard introduced the cross-activation model of grapheme-colour synaesthesia. On the occasion of its 10-year anniversary, we review the evidence from experiments that have been conducted to test the model to assess how it has fared. We examine data from behavioural, functional magnetic resonance imaging (fMRI), anatomical...

In one common variant of time-space synaesthesia, individuals report the consistent experience of months bound to a spatial arrangement, commonly described as a circle extending outside of the body. Whereas the layout of these calendars has previously been thought to be relatively random and to differ greatly between synaesthetes, Study 1 provides...

Damage to the right parietal lobe has long been associated with various disorders of body image. The authors have recently suggested that an unusual behavioural condition in which otherwise rational individuals desire the amputation of a healthy limb might also arise from right parietal dysfunction. Four subjects who desired the amputation of healt...

Grapheme-color synesthesia is a neurological phenomenon in which letters and numbers (graphemes) consistently evoke particular colors (e.g. A may be experienced as red). The cross-activation theory proposes that synesthesia arises as a result of cross-activation between posterior temporal grapheme areas (PTGA) and color processing area V4, while th...

Some people report that they consistently and involuntarily associate time events, such as months of the year, with specific spatial locations; a condition referred to as time-space synesthesia. The present study investigated the manner in which such synesthetic time-space associations affect visuo-spatial attention via an endogenous cuing paradigm...

Background: It has been proposed that individuals with grapheme-color synesthesia have increased levels of connectivity, particularly between V4 and Visual Word Form Area (Hubbard and Ramachandran, 2005 ). To investigate whether increased connectivity may be a widespread phenomenon, we asked whether color and motion interactions are stronger in syn...

After amputation of an arm the sensory map of the body changes radically, causing the sensory input from face to 'invade' the original hand area in the brain. As a result, touching the face of the amputee evokes tactile sensations on the phantom. These sensory referrals from the face to phantom hand occur in a stable, topographically organized mann...

Time-space synesthetes report that they experience the months of the year as having a spatial layout. In Study 1, we characterize the phenomenology of calendar sequences produced by synesthetes and non-synesthetes, and show a conservative estimate of time-space synesthesia at 2.2% of the population. We demonstrate that synesthetes most commonly exp...

Historically, language researchers have assumed that lexical, or word-level processing is fast and automatic, while slower, more controlled post-lexical processes are sensitive to contextual information from higher levels of linguistic analysis. Here we demonstrate the impact of sentence context on the processing of words not available for consciou...

Grapheme–color synesthesia is a heritable trait where graphemes (“2”) elicit the concurrent perception of specific colors (red). Researchers have questioned whether synesthetic experiences are meaningful or simply arbitrary associations and whether these associations are perceptual or conceptual. To address these fundamental questions, ERPs were re...

Autism is a disorder characterized by social withdrawal, impoverished language and empathy, and a profound inability to adopt another's viewpoint - a failure to construct a "theory of mind" for interpreting another person's thoughts and intentions. We previously showed that these symptoms might be explained, in part, by a paucity of mirror neurons....

Synesthesia is a perceptual experience in which a stimulus presented through one modality (e.g., hearing) will spontaneously evoke a sensation experienced in an unrelated modality (e.g., vision). For example, an individual may experience a specific color for every given note (e.g., C sharp is red) or every number may be tinged with a specific hue (...

JS was a grapheme-color synesthete in whom numerals and letters of the alphabet consistently evoked colors. In the first set of experiments we showed that the color - in a consistent and reliable manner - was most pronounced in the left visual field and in central vision. In the second experiment we devised a novel test for eidetic imagery and show...

After amputation of a limb, the majority of patients experience phantom sensations, such as phantom pain. Such patients provide an opportunity for the exploration of the perceptual correlates of recently discovered "mirror neurons," which fire not only when individuals move their own limb but when they watch the movements of the corresponding limb...

Following limb amputation patients continue to feel the vivid presence of a phantom limb. A majority of patients also experience pain in the phantom and sometimes (as in our case DS) the pain is severe. Remarkably we find that optically 'resurrecting' the phantom with a mirror and using a lens to make the phantom appear to shrink caused the pain to...