Neurobiological and neuroethological findings on insects can be used to design and construct small robots controling their navigation on the basis of biologically inspired visual strategies and circuits. Animals’ visual guidance is partly... more
Neurobiological and neuroethological findings on insects can be used to design and construct small robots controling their navigation on the basis of biologically inspired visual strategies and circuits. Animals’ visual guidance is partly mediated by motion sensitive neurons, which are responsible for gauging the optic flow. Although neurons of this kind were discovered in vertebrates’ and invertebrates’ visual systems more than 50 years ago, the principles and neural mechanisms involved have not yet been completely elucidated. Here I propose first of all to outline some of the findings we made during the last few decades by performing electrophysiological recordings on identified neurons in the housefly’s eye while applying optical stimulation to identified photoreceptors. Whereas these findings shed light on the inner processing structure of an elementary motion detector (EMD), recent studies in which the latest genetic and neuroanatomical methods were applied to the fruitfly’s visual system have identified some of the neurons in the visual chain which are possibly involved in the neural circuitry underlying a given EMD. I will then describe some of the proof-of-concept robots that we have developed on the basis of our biological findings. The 100-gram robot OCTAVE, for example, is able to avoid the ground, react to wind and land autonomously on a flat terrain without ever having to measure any state variables such as distances or speeds. The 100-gram robots OSCAR 1 and OSCAR 2 inspired by the microscanner we discovered in the housefly’s eye are able to stabilize their body using mainly visual means and track a moving edge with hyperacuity. These robots react to the optic flow, which is sensed by miniature optic flow sensors inspired by the housefly’s EMDs. Constructing a “biorobot” gives us a unique opportunity of checking the soundness and robustness of a principle that is initially thought to be understood by bringing it face to face with the real physical world. Bio-inspired robotics not only help neurobiologists and neuroethologists to identify and investigate worthwhile problems in animals’ sensory-motor systems. They also provide engineers with ideas for developing novel devices and machines with promising future applications, in the field of smart autonomous vehicles and microvehicles, for example.
The evolution of the field of neuroscience has been propelled by the advent of novel technological capabilities, and the pace at which these capabilities are being developed has accelerated dramatically in the past decade. Capitalizing on... more
The evolution of the field of neuroscience has been propelled by the advent of novel technological capabilities, and the pace at which these capabilities are being developed has accelerated dramatically in the past decade. Capitalizing on this momentum, the United States launched the Brain Research through Advancing Innovative Neurotechnologies (BRAIN) Initiative to develop and apply new tools and technologies for revolutionizing our understanding of the brain. In this article, we review the scientific vision for this initiative set forth by the National Institutes of Health and discuss its implications for the future of neuroscience research. Particular emphasis is given to its potential impact on the mapping and study of neural circuits, and how this knowledge will transform our understanding of the complexity of the human brain and its diverse array of behaviours, perceptions, thoughts and emotions.
Neural reuse theories should interest developmental psychologists because these theories can potentially illuminate the developmental relations among psychological characteristics observed across the lifespan. Characteristics that develop... more
Neural reuse theories should interest developmental psychologists because these theories can potentially illuminate the developmental relations among psychological characteristics observed across the lifespan. Characteristics that develop by exploiting pre-existing neural circuits can be thought of as developmental homologues. And, understood in this way, the homology concept that has proven valuable for evolutionary biologists can be used productively to study psychological/behavioral development.
The cerebral cortex receives multiple afferents from the thalamus that segregate by stimulus modality forming cortical maps for each sense. In vision, the primary visual cortex also maps the multiple dimensions of the stimulus in patterns... more
The cerebral cortex receives multiple afferents from the thalamus that segregate by stimulus modality forming cortical maps for each sense. In vision, the primary visual cortex also maps the multiple dimensions of the stimulus in patterns that vary across species for reasons unknown. Here we introduce a general theory of cortical map formation, which proposes that map diversity emerges from variations in sampling density of sensory space across species. In the theory, increasing afferent sampling density enlarges the cortical domains representing the same visual point allowing the segregation of afferents and cortical targets by additional stimulus dimensions. We illustrate the theory with a computational model that accurately replicates the maps of different species through afferent segregation followed by thalamocortical convergence pruned by visual experience. Because thalamocortical pathways use similar mechanisms for axon sorting and pruning, the theory may extend to other sensory areas of the mammalian brain.
The evolution of the field of neuroscience has been propelled by the advent of novel technological capabilities, and the pace at which these capabilities are being developed has accelerated dramatically in the past decade. Capitalizing on... more
The evolution of the field of neuroscience has been propelled by the advent of novel technological capabilities, and the pace at which these capabilities are being developed has accelerated dramatically in the past decade. Capitalizing on this momentum, the United States launched the Brain Research through Advancing Innovative Neurotechnologies (BRAIN) Initiative to develop and apply new tools and technologies for revolutionizing our understanding of the brain. In this article, we review the scientific vision for this initiative set forth by the National Institutes of Health and discuss its implications for the future of neuroscience research. Particular emphasis is given to its potential impact on the mapping and study of neural circuits, and how this knowledge will transform our understanding of the complexity of the human brain and its diverse array of behaviours, perceptions, thoughts and emotions.
Body motion is a rich source of information for social interaction, and visual biological motion processing may be considered as a hall-mark of social cognition. It is unclear, however, whether the social brain is sex specific. Here we... more
Body motion is a rich source of information for social interaction, and visual biological motion processing may be considered as a hall-mark of social cognition. It is unclear, however, whether the social brain is sex specific. Here we assess sex impact on the magnetoen-cephalographic (MEG) cortical response to point-light human loco-motion. Sex differences in the cortical MEG response to biological motion occur mostly over the right brain hemisphere. At early laten-cies, females exhibit a greater activation than males over the right parietal, left temporal, and right temporal cortex, a core of the social brain. At later latencies, the boosts of activation are greater in males over the right frontal and occipital cortices. The findings deliver the first evidence for gender-dependent modes in the time course and topography of the neural circuitry underpinning visual processing of biological motion. The outcome represents a framework for studying sex differences in the social brain in...
Sensory information is processed and transmitted through the synaptic structure of local cortical circuits, but it is unclear how modulation of this architecture influences the cortical representation of sensory stimuli. Acetylcholine... more
Sensory information is processed and transmitted through the synaptic structure of local cortical circuits, but it is unclear how modulation of this architecture influences the cortical representation of sensory stimuli. Acetylcholine (ACh) promotes attention and arousal and is thought to increase the signal-to-noise ratio of sensory input in primary sensory cortices. Using high-speed two-photon calcium imaging in a thalamocortical somatosensory slice preparation, we recorded action potential activity of up to 900 neurons simultaneously and compared local cortical circuit activations with and without bath presence of ACh. We found that ACh reduced weak pairwise relationships and excluded neurons that were already unreliable during circuit activity. Using action potential activity from the imaged population, we generated functional wiring diagrams based on the statistical dependencies of activity between neurons. ACh pruned weak functional connections from spontaneous circuit activations and yielded a more modular and hierarchical circuit structure, which biased activity to flow in a more feedforward fashion. Neurons that were active in response to thalamic input had reduced pairwise dependencies overall, but strong correlations were conserved. This coincided with a prolonged period during which neurons showed temporally precise responses to thalamic input. Our results demonstrate that ACh reorganizes functional circuit structure in a manner that may enhance the integration and discriminability of thalamic afferent input within local neocortical circuitry.
