Hans Scherberger

• German Primate Center

Advances in computer vision and increasingly widespread video-based behavioral monitoring are currently transforming how we study animal behavior. However, there is still a gap between the prospects and practical application, especially in videos from the wild. In this Perspective, we aim to present the capabilities of current methods for behaviora...

Neural decoding involves correlating signals acquired from the brain to variables in the physical world like limb movement or robot control in Brain Machine Interfaces. In this context, this work starts from a specific pre-existing dataset of neural recordings from monkey motor cortex and presents a Deep Learning-based approach to the decoding of n...

Cerebrospinal fluid contacting neurons (CSF-cNs) are a specific type of neurons located around the ventricles in the brain and the central canal in the spinal cord and have been demonstrated to be intrinsic sensory neurons in the central nervous system. One of the important channels responsible for the sensory function is the polycystic kidney dise...

Hand movements are an essential way that primates interact with the environment and they comprise some of our most complex behaviors. Despite remarkable recent progress in intracortical brain-computer interfaces, current neuroprostheses still lack the fine control required to interact with objects of daily living. We present a BCI training approach...

Protest in response to unequal reward distribution is thought to have played a central role in the evolution of human cooperation. Some animals refuse food and become demotivated when rewarded more poorly than a conspecific, and this has been taken as evidence that non-human animals, like humans, protest in the face of inequity. An alternative expl...

Science is changing: the volume and complexity of data are increasing, the number of studies is growing and the goal of achieving reproducible results requires new solutions for scientific data management. In the field of neuroscience, the German National Research Data Infrastructure (NFDI-Neuro) initiative aims to develop sustainable solutions for...

p>Fat intra-body communication (Fat-IBC) is a novel concept of communication through the low-loss fat tissue layer of the body. This new data transmission approach is promising for the implementation of wireless, in-body, bidirectional Brain-Machine-Body connectivity, which will profoundly impact different fields, such as brain implants with read/w...

One of the essential functions of biological neural networks is the processing of information. This includes everything from processing sensory information to perceive the environment, up to processing motor information to interact with the environment. Due to methodological limitations, it has been historically unclear how information processing c...

p>Fat intra-body communication (Fat-IBC) is a novel concept of communication through the low-loss fat tissue layer of the body. This new data transmission approach is promising for the implementation of wireless, in-body, bidirectional Brain-Machine-Body connectivity, which will profoundly impact different fields, such as brain implants with read/w...

p>Fat intra-body communication (Fat-IBC) is a novel concept of communication through the low-loss fat tissue layer of the body. This new data transmission approach is promising for the implementation of wireless, in-body, bidirectional Brain-Machine-Body connectivity, which will profoundly impact different fields, such as brain implants with read/w...

The lack of reproducibility of research results is a serious problem – known as “the reproducibility crisis”. The German National Research Data Infrastructure (NFDI) initiative implemented by the German Research Foundation (DFG) aims to help overcoming this crisis by developing sustainable solutions for research data management (RDM). NFDI comprise...

In this issue of Neuron, Natraj et al. (2021) demonstrate that finger and hand grasping movements are represented in the human fronto-parietal grasp network in a compartmentalized fashion. The movements are encoded in a distributed network that is preserved across various hand actions. The neural dynamics are specific to particular hand movements,...

Inequity aversion plays a central role in human cooperation. Some animals similarly show frustration and become demotivated when rewarded more poorly than a conspecific, which has been taken as evidence of inequity aversion. An alternative explanation - social disappointment - shifts the cause of frustration from the unequal reward to the human exp...

Inter-areal coherence between field potentials is a widespread phenomenon in cortex. Coherence has been hypothesized to reflect phase-synchronization between oscillators and flexibly gate communication according to behavioral and cognitive demands. We reveal an alternative mechanism where coherence is not the cause but the consequence of communicat...

One of the essential functions biological neural networks is the processing of information. This comprises processing sensory information to perceive the environment, up to processing motor information to interact with the environment. Due to methodological concerns, it has been historically unclear how information processing changes during differe...

Movements are defining characteristics of all behaviors. Animals walk around, move their eyes to explore the world or touch structures to learn more about them. So far we only have some basic understanding of how the brain generates movements, especially when we want to understand how different areas of the brain interact with each other. In this s...

Grasping movements are some of the most common movements primates do every day. They are important for social interactions as well as picking up objects or food. Usually, these grasping movements are guided by vision but proprioceptive and haptic inputs contribute greatly. Since grasping behaviors are common and easy to motivate, they represent an...

Motor actions in fMRI settings require specialized hardware to monitor, record, and control the subjects behavior. Commercially available options for such behavior tracking or control are very restricted and costly. We present a novel grasp manipulandum in a modular design, consisting of MRI-compatible, 3D printable buttons and a chassis for mounti...

Preparing a neurophysiological data set with the aim of sharing and publishing is hard. Many of the available tools and services to provide a smooth workflow for data publication are still in their maturing stages and not well integrated. Also, best practices and concrete examples of how to create a rigorous and complete package of an electrophysio...

Increasing complexity and volume of research data pose increasing challenges for scientists to manage their data efficiently. At the same time, availability and reuse of research data are becoming more and more important in modern science. The German government has established an initiative to develop research data management (RDM) and to increase...

Significance Grasping objects is something primates do effortlessly, but how does our brain coordinate such a complex task? Multiple brain areas across the parietal and frontal cortices of macaque monkeys are essential for shaping the hand during grasping, but we lack a comprehensive model of grasping from vision to action. In this work, we show th...

Manipulation of an object requires us to transport our hand towards the object (reach) and close our digits around that object (grasp). In current models, reach-related information is propagated in the dorso-medial stream from posterior parietal area V6A to medial intraparietal area, dorsal premotor cortex, and primary motor cortex. Grasp-related i...

Optogenetics offers unprecedented possibilities to investigate cortical networks. Yet, the number of successful optogenetic applications in non-human primates is still low, and the consequences of opsin expression in the primate brain are not well documented. We assessed histologically if we can target cerebrocortical networks with three common opt...

What does neuronal coherence tell us about neuronal communication? Does coherence between field potentials (e.g. LFP, EEG, MEG) reflect spiking entrainment or coupling between oscillators? Is it a mechanism for communication between brain areas, or a byproduct of interareal connectivity? We hypothesized that interareal coherence is explained by the...

Collar-mounted monitoring devices for collecting behavioural or positional data (e.g. sound recorders, accelerometers, GPS, VHF) are increasingly used in wildlife research. Although these tools represent an improvement in terms of data quality, they require capturing animals. Using remotely releasable collars allows for reducing the number of captu...

One of the main ways we interact with the world is using our hands. In macaques, the circuit formed by the anterior intraparietal area, the hand area of the ventral premotor cortex, and the primary motor cortex is necessary for transforming visual information into grasping movements. We hypothesized that a recurrent neural network mimicking the mul...

Abstract Considerable progress has been made over the last decades in characterizing the neural coding of hand shape, but grasp force has been largely ignored. We trained two macaque monkeys (Macaca mulatta) on a delayed grasping task where grip type and grip force were instructed. Neural population activity was recorded from areas relevant for gra...

Abstract Optogenetics in non-human primates is challenged by limited set of genetic tools, large tissue volumes, and not well understood long-term effects of opsin over-expression. To investigate the impact of frontal lobe on parietal and temporal areas with optogenetics in rhesus monkeys (Macaca mulatta), we evaluated the protocol for viral vector...

Our voluntary grasping actions lie on a continuum between immediate action and waiting for the right moment, depending on the context. Therefore, studyinggraspingrequiresaninvestigationintohowpreparationtimeaffectsthisprocess. Twomacaquemonkeys(Macacamulatta; one male, one female) performed a grasping task with a short instruction followed by an im...

Preparing and executing grasping movements demands the coordination of sensory information across multiple scales. The position of an object, required hand shape, and which of our hands to extend must all be coordinated in parallel. The network formed by the macaque anterior intraparietal area (AIP) and hand area (F5) of the ventral premotor cortex...

Expansion of the dorsal pulvinar in humans and its anatomical connectivity suggests its involvement in higher-order cognitive and visuomotor functions. We investigated visuomotor performance in a 31 year old patient with a lesion centered on the medial portion of the dorsal pulvinar (left > right) due to an atypical Sarcoidosis manifestation. Unlik...

Preparing and executing grasping movements demands the coordination of sensory information across multiple scales. The position of an object, required hand shape, and which of our hands to extend must all be coordinated in parallel. The network formed by the macaque anterior intraparietal area (AIP) and hand area (F5) of the ventral premotor cortex...

Our voluntary grasping actions lie on a continuum between immediate action and waiting for the right moment, depending on the context. Therefore, studying grasping requires investigating how preparation time affects this process. Two macaque monkeys (Macaca mulatta) performed a grasping task with a short instruction followed by an immediate or dela...

In this issue of Neuron, Zhang et al. (2017) demonstrate that neurons in human parietal cortex represent effector responses functionally segregated, while other movement variables are associated in a subordinated fashion. Such partially mixed selectivity facilitates efficient motor control in various behavioral contexts.

To probe fronto-parietal cortical networks with optogenetics in rhesus monkeys (Macaca mulatta), we first histologically evaluated the effectiveness of viral transduction, expression spread, neuronal specificity, and long-range axonal projections to target areas of two opsins proteins: Channelrhodopsin [hChR2(H134R)] and Halorhodopsin [eNpHR3.0]

Recent models of movement generation in motor cortex have sought to explain neural activity not as a function of movement parameters, known as representational models, but as a dynamical system acting at the level of the population. Despite evidence supporting this framework, the evaluation of representational models and their integration with dyna...

Simulation of a complex-kinematic tuning based model with variable neuron-kinematic latencies. (a) Four example neurons with differing latencies. (b-d) Comparison of rotational dynamics for (b) observed, (c) permuted without covariance matching, and (d) covariance-matched data in the first jPCA plane. p-value in b are from the CMPT for the rotation...

Latency offsets produce derivative-like principal components. (a) Firing rates of six simulated neurons (normal distributions with identical SD) over time with random time offsets (drawn from normal distribution). (b) The first three principal components of the simulated units. (c) The plane formed by the first two principal components, showing a ‘...

Tuning curves of RNN neurons during movement. Mean firing rate during the movement epoch of all movement directions for 16 randomly selected RNN neurons. (EPS)

How does our brain learn to produce the large, impressive, and flexible array of motor behaviors we possess? In recent years, there has been renewed interest in modeling complex human behaviors such as memory and motor skills using neural networks (Sussillo et al. 2015; Rajan, Harvey, and Tank 2016; Hennequin, Vogels, and Gerstner 2014; Carnevale e...

ELife digest In order to grasp and manipulate objects, our brains have to transform information about an object (such as its size, shape and position) into commands about movement that are sent to our hands. Previous work suggests that in primates (including humans and monkeys), this transformation is coordinated in three key brain areas: the parie...

Neurons in premotor and parietal cortex are known to represent a broad variety of different cognitive processes including visual, decision, intention, and movement signals. Recent experiments revealed that several cognitive features are mixed-coded within and between individual neurons, and can be studied by analyzing the neuronal population dynami...

The execution of reach-to-grasp movements in order to interact with our environment is an important subset of the human movement repertoire. To coordinate such goal-directed movements, information about the relative spatial position of target and effector (in this case the hand) has to be continuously integrated and processed. Recently, we reported...

The hand is a powerful tool and its loss causes severe physical and often mental debilitation. Surveys on artificial hands reveal that 30 to 50% amputees do not use their prosthetic hand regularly, due to its low functionality. The fundamental issue is therefore to improve the voluntarily-controlled dexterity to allow amputee to perform tasks that...

Objective. In the last decade, multiple brain areas have been investigated with respect to their decoding capability of continuous arm or hand movements. So far, these studies have mainly focused on motor or premotor areas like M1 and F5. However, there is accumulating evidence that anterior intraparietal area (AIP) in the parietal cortex also cont...

Unlabelled: Neural networks of the brain involved in the planning and execution of grasping movements are not fully understood. The network formed by macaque anterior intraparietal area (AIP) and hand area (F5) of the ventral premotor cortex is implicated strongly in the generation of grasping movements. However, the differential role of each area...

Humans and other primates possess a unique capacity to grasp and manipulate objects skillfully, a facility pervasive in everyday life that has undoubtedly contributed to the success of our species. When we reach and grasp an object, various cortical areas in the parietal and frontal lobes work together effortlessly to analyze object shape and posit...

Despite recent advances in decoding cortical activity for motor control, the development of hand prosthetics remains a major challenge. To reduce the complexity of such applications, higher cortical areas that also represent motor plans rather than just the individual movements might be advantageous. We investigated the decoding of many grip types...

Reach-to-grasp tasks have become popular paradigms for exploring the neural origin of hand and arm movement. This is typically investigated by correlating limb kinematic with electrophysiological signals from intracortical recordings. However, it has never been investigated whether reach and grasp movements could be well expressed in the muscle dom...

Voluntary movements are frequently composed of several actions that are combined to achieve a specific behavior. For example, prehension involves reaching and grasping actions to transport the hand to a target to grasp or manipulate it. For controlling these actions, separate parietofrontal networks have been described for generating reaching and g...

The investigation of grasping movements in cortical motor areas depends heavily on the measurement of hand kinematics. Currently used methods for small primates need either a large number of sensors or provide insufficient accuracy. Here, we present both a novel glove based on electromagnetic tracking sensors that can operate at a rate of 100 Hz an...

This chapter reviews the roles of the parietal and premotor cortices in motor planning and discusses brain-computer interface (BCI) studies that have focused on these brain areas. BCIs based on recordings from both parietal cortex and premotor cortex have the potential to benefit people with paralysis by providing high-level, goal-related informati...

Despite recent advances in harnessing cortical motor-related activity to control computer cursors and robotic devices, the ability to decode and execute different grasping patterns remains a major obstacle. Here we demonstrate a simple Bayesian decoder for real-time classification of grip type and wrist orientation in macaque monkeys that uses high...

Hand grasping requires the transformation of sensory signals to hand movements. Neurons in area F5 (ventral premotor cortex) represent specific grasp movements (e.g., precision grip) as well as object features like orientation, and are involved in movement preparation and execution. Here, we examined how F5 neurons represent context-dependent grasp...

In the past decade the field of neural interface systems has enjoyed an increase in attention from the scientific community and the general public, in part due to the enormous potential that such systems have to increase the quality of life for paralyzed patients. While significant progress has been made, serious challenges remain to be addressed f...

Advancements in the understanding of the primate motor system and improvements in recording technology have revitalized the idea of a neural prosthesis for restoring motor deficits in paralyzed patients. Several research groups have demonstrated the feasibility of such a brain–computer interface (BCI) by decoding reach movements online in monkeys a...

Neural interfaces (NIs) for motor control have recently become increasingly advanced. This has been possible owing to substantial progress in our understanding of the cortical motor system as well as the development of appropriate decoding methods in both non-human primates and paralyzed patients. So far, neural interfaces have controlled mainly co...

To perform grasping movements, the hand is shaped according to the form of the target object and the intended manipulation, which in turn depends on the context of the action. The anterior intraparietal cortex (AIP) is strongly involved in the sensorimotor transformation of grasping movements, but the extent to which it encodes context-specific inf...

A brain machine interface (BMI) for visually guided grasping would provide significant benefits for paralyzed patients, given the crucial role these movements play in our everyday life. We have developed a BMI to decode grasp shape in real-time in macaque monkeys. Neural activity was evaluated using chronically implanted elec-trodes in the anterior...

The selection of visual stimuli as a target for a motor action may depend on external as well as internal variables. The parietal reach region (PRR) in the posterior parietal cortex plays an important role in the transformation of visual information into reach movement plans. We asked how neurons in PRR of macaque monkeys reflect the decision proce...

The primate's large brain-to-body weight ratio and high complexity are unusual in the animal kingdom. There is compelling evidence that it is an evolutionary adaptation that allows its owner to live a long life because of its competence in solving a wide range of problems. How primates use their brain to achieve such competence is of course of cent...

The cortical local field potential (LFP) is a summation signal of excitatory and inhibitory dendritic potentials that has recently become of increasing interest. We report that LFP signals in the parietal reach region (PRR) of the posterior parietal cortex of macaque monkeys have temporal structure that varies with the type of planned or executed m...

An important challenge for neural prosthetics research is to record from populations of neurons over long periods of time, ideally for the lifetime of the patient. Two new advances toward this goal are described, the use of local field potentials (LFPs) and autonomously positioned recording electrodes. LFPs are the composite extracellular potential...

Recent development of neural prosthetics for assisting paralyzed patients has focused on decoding intended hand trajectories from motor cortical neurons and using this signal to control external devices. In this study, higher level signals related to the goals of movements were decoded from three monkeys and used to position cursors on a computer s...

The posterior parietal cortex (PPC) sits at the interface between sensory and motor areas and performs sensorimotor transformations. Current research is beginning to unravel the details of this transformation process. The first part of this chapter focuses on planning signals found in the PPC. Experiments show that the thought to reach can be read...

The implantation of chronic recording electrodes in the brain has been shown to be a valuable method for simultaneously recording from many neurons. However, precise placement of these electrodes, crucial for successful recording, is challenging if the target area is not on the brain surface. Here we present a stereotaxic implantation procedure to...

An essential reference book for visual science. Visual science is the model system for neuroscience, its findings relevant to all other areas. This massive collection of papers by leading researchers in the field will become an essential reference for researchers and students in visual neuroscience, and will be of importance to researchers and prof...

The selection of one of two visual stimuli as a target for a motor action may depend on external as well as internal variables. We examined whether the preference to select a leftward or rightward target depends on the action that is performed (eye or arm movement) and to what extent the choice is influenced by the target location. Two targets were...

Eye muscle fibers can be divided into two categories: nontwitch, multiply innervated muscle fibers (MIFs), and twitch, singly innervated muscle fibers (SIFs). We investigated the location of motoneurons supplying SIFs and MIFs in the six extraocular muscles of monkeys. Injections of retrograde tracers into eye muscles were placed either centrally,...

Saccade-related burst neurons in the paramedian pontine reticular formation (PPRF) of the head-restrained monkey provide a phasic velocity signal to extraocular motoneurons for the generation of rapid eye movements. In the superior colliculus (SC), which directly projects to the PPRF, the motor command for conjugate saccades with the head restraine...

We examined three-dimensional eye positions in alertness and light sleep when monkeys were placed in different roll and pitch body orientations. In alertness, eye positions were confined to a fronto-parallel (Listing's) plane, torsional variability was small and static roll or pitch induced a torsional shift or vertical rotation of these planes. In...

This paper investigates the influence of static head tilt on the relation between activity in the motor layers of the superior colliculus (mSC) and saccadic oculomotor output. Based on single-unit recordings and electrical microstimulation in awake rhesus monkeys, we report that head roll changes the direction of the saccade vector generated by the...