2011
, 2011
A sensorimotor account of phenomenal consciousness
Lecture
Wednesday, February 16, 2011
Hour: 11:00
Location:
Gerhard M.J. Schmidt Lecture Hall
A sensorimotor account of phenomenal consciousness
Prof. J Kevin O'Regan
Laboratoire Psychologie de la Perception
CNRS - Université Paris Descartes
The problem of consciousness is sometimes divided into two parts: An "easy" part, which involves explaining how one can become aware of of something in the sense of being able to make use of it in one's rational behavior. This is called access consciousness. And a "hard" part, which involves explaining why sensations feel like something, or have a kind of sensory presence, rather than having no feel at all. This is called phenomenal consciousness. Phenomenal consciousness is considered hard because there seems logically no way physical mechanisms in the brain could explain such facts. For example why does red look red, rather than looking green, or rather than sounding like a bell. Indeed why does red have a feel at all? Why do pains hurt instead of just provoking avoidance reactions?
The sensorimotor approach provides a way of answering these questions by appealing to the idea that feels like red and pain should not be considered as things that happen to us, but rather as modes of ineraction with the environment. I shall show how the idea can be applied to color, touch, pain, and sensory substitution. In addition to helping understand human consciousness, the approach has applications in virtual reality and in robotics.
New Insights on Structural Neuroplasticity from MRI
Lecture
Tuesday, February 15, 2011
Hour: 12:30
Location:
Arthur and Rochelle Belfer Building for Biomedical Research
New Insights on Structural Neuroplasticity from MRI
Prof. Yaniv Assaf
Dept. of Neurobiology
Tel Aviv University
Neuro-plasticity is one of the key processes in our brain's physiology. This process allows our brain to change itself, functionally and structurally, following the acquisition of a new skill or experience. While functional aspects of neuro-plasticity can be studied using non-invasive techniques such as fMRI, EEF and MEG, investigation of the structural tissue characteristics of neuro-plasticity requires invasive histological approaches.
Long-term experience necessitates structural plasticity which, in the adult brain, is characterized by changes in the shape and number of the synapses (synaptogenesis) as well as other process (neurogenesis, gliogenesis and white matter plasticity).
Structural MRI studies of brain plasticity reveal significant volumetric changes via voxel-based morphometry of T1 weighted scans. Yet, the micro-structure correlates of these changes are not well understood.
Diffusion tensor imaging (DTI) became one of the most popular imaging techniques in neuroimaging and is regarded as a micro-structural probe. Recently, tract-based spatial statistics (TBSS) analysis of DTI scans before and after long-term motor coordination training (juggling) revealed regional fractional anisotropy (FA) increase in parietal pathways. In that study, FA changes were reported following few weeks of training.
An open question is what happens at shorter term learning and memory processes?
In a short term spatial navigation study performed both in humans and rodents, we found that diffusion MRI can detect structural changes in cell morphology induced by plasticity within mere hours. Both in humans and rodents, the micro-structural changes, as observed by MRI, were localized to the anticipated brain regions: hippocampus, para-hippocampus, visual cortex, cingulate cortex and insular cortex.
Our results indicate that significant structural occur in the tissue within mere hours - an interesting result by itself from the neurophysiological point of view. However, by investigating the induced structural changes both by histology and MRI it is possible to elucidate the relations between tissue micro-structure and the diffusion MRI signal. Preliminary results of such comparison indicate that in gray matter tissue one of cellular correlates of diffusion MRI indices is the density and shape of astrocyte. Indeed more studies should be directed
A new, "sensorimotor", view of seeing
Lecture
Monday, February 14, 2011
Hour: 14:00
Location:
Gerhard M.J. Schmidt Lecture Hall
A new, "sensorimotor", view of seeing
Prof. J Kevin O'Regan
Laboratoire Psychologie de la Perception
CNRS - Université Paris Descartes
There seem to be numerous defects of the eye that would be expected to interfere with vision. Examples are the upside down retinal image, the blind spot in each eye's visual field, non-uniform spatial and chromatic resolution, and blur and image shifts caused by eye saccades. In order to overcome such defects scientists have proposed a variety of compensation mechanisms. I will argue that such compensation mechanism not only face empirical difficulties, but they also suffer from a philosophical objection. They seem to require the existence of a "homunculus" in the brain that contemplates the picture-like output of the compensation mechanism. A new view of what "seeing" consists in is required.
The new view of seeing considers seeing as a particular way of actively exploring the environment. This "sensorimotor" approach is subtly different from the idea of "active vision" known today in cognitive or computer science. The sensorimotor approach explains how, despite the eye's imperfections and despite interruptions in the flow of sensory input, we can have the impression of seeing everything in the visual field in detail and continuously.
I shall show how the phenomenon of "inattentional blindness" (or "Looked but Failed to See") is expected from the new approach, and I shall examine the phenomenon of "change blindness" which arose as a prediction from the theory. Finally I examine the question of the photographic quality of vision: why we have the impression of seeing things all over the visual field, why everything seems simultaneously and continuously present, and why things seem to visually impose themselves upon us in a way quite different from how memory and imagining do. To explain these facts I shall invoke four objectively measurable aspects of visual interactions: richness, bodiliness, partial insubordinateness and grabbiness.
Reconfiguring Memory
Lecture
Sunday, February 13, 2011
Hour: 12:30
Location:
Gerhard M.J. Schmidt Lecture Hall
Reconfiguring Memory
Shuli Sade
Artist, NYC
: Sadé will talk about the relevance in collaboration between artists and scientists, and will introduce her recent art project: “Reconfiguring Memory”. Sadé collaborates with Professor Andre Fenton at NYU Neuroscience labs to develop art for the renovated Neuroscience labs at NYU. Her work with memory, time and light led to this collaboration and will result in art relating to the questions: How does the brain store experience as memories and how the expression of knowledge activates information that is relevant without activating what is irrelevant, and what visual methods can be used for recording the activity of memory, gain or loss.
Olfaction: from receptors to behavior
Conference
Thursday, February 10, 2011
Hour: 08:00 - 16:30
Location:
Dolfi and Lola Ebner Auditorium
Face to Face, Brain to Brain: Exploring the Mechanisms of Dyadic Social Interactions
Lecture
Thursday, February 3, 2011
Hour: 12:00
Location:
Arthur and Rochelle Belfer Building for Biomedical Research
Face to Face, Brain to Brain: Exploring the Mechanisms of Dyadic Social Interactions
Prof. Uri Hasson
Dept of Psychology
Princeton University
Cognitive neuroscience experiments typically isolate human or animal subjects from their natural environment by placing them in a sealed quiet room where interactions occur solely with a computer screen. In everyday life, however, we spend most of our time interacting with other individuals. Using fMRI, we recently recorded the brain activity of a speaker telling an unrehearsed real-life story and the brain activity of a listener listening to a recording of the story. To make the study as ecological as possible, we instructed the speaker to speak as if telling the story to a friend. Next, we measured the brain activity of a listener hearing the recorded audio of the spoken story, thereby capturing the time-locked neural dynamics from both sides of the communication. Finally, we asked the listeners to complete a detailed questionnaire that assessed their level of comprehension. Our results indicate that during successful communication the speaker’s and listener’s brains exhibit joint, temporally coupled, response patterns. Such neural coupling substantially diminishes in the absence of communication, for instance, when listening to an unintelligible foreign language. In addition, more extensive speaker–listener neural couplings result in more successful communication. The speaker-listener neural coupling exposes a shared neural substrate that exhibits temporally aligned response patterns across communicators. The recording of the neural responses from both the speaker brain and the listener brain opens a new window into the neural basis of interpersonal communication, and may be used to assess verbal and non-verbal forms of interaction in both human and other model systems.
Ode To Memory A mini-series devoted to memory in cenema
Lecture
Tuesday, February 1, 2011
Hour: 14:00
Location:
Dolfi and Lola Ebner Auditorium
Ode To Memory A mini-series devoted to memory in cenema
Prof. Yadin Dudai
Dept of Neurobiology, WIS
Response fluctuations in neurons and networks
Lecture
Tuesday, February 1, 2011
Hour: 12:30
Location:
Jacob Ziskind Building
Response fluctuations in neurons and networks
Prof. Shimon Marom
Dept of Physiology
Technion Haifa
Experimental analyses of fluctuations in responses to long series of stimuli will be presented. The experiments are performed at the single neuron, population of synapses and network levels. Sources and impacts of these fluctuations will be discussed.
Ode To Memory A mini-series devoted to memory in cinema
Lecture
Tuesday, January 25, 2011
Hour: 14:00
Location:
Dolfi and Lola Ebner Auditorium
Ode To Memory A mini-series devoted to memory in cinema
Prof. Yadin Dudai
Dept of Neurobiology, WIS
The evolution of behavioral mechanisms: theory and experiments on learning rules and their adaptive (or maladaptive) consequences
Lecture
Tuesday, January 25, 2011
Hour: 12:30
Location:
Jacob Ziskind Building
The evolution of behavioral mechanisms: theory and experiments on learning rules and their adaptive (or maladaptive) consequences
Prof. Arnon Lotem
Dept of Zoology
Tel-Aviv University
My talk will be based on our recent attempts to explain apparently maladaptive behaviors in humans and other animals as the consequences of generally adaptive learning mechanisms. I will first describe several cases where seemingly paradoxical behavior can be explained as the result of using relatively simple learning rules. I will then discuss the evolution of such learning rules in the context of individual decision making under variable conditions, as well as in the context of social foraging games of searchers and followers.
Pages
2011
, 2011
Face to Face, Brain to Brain: Exploring the Mechanisms of Dyadic Social Interactions
Lecture
Thursday, February 3, 2011
Hour: 12:00
Location:
Arthur and Rochelle Belfer Building for Biomedical Research
Face to Face, Brain to Brain: Exploring the Mechanisms of Dyadic Social Interactions
Prof. Uri Hasson
Dept of Psychology
Princeton University
Cognitive neuroscience experiments typically isolate human or animal subjects from their natural environment by placing them in a sealed quiet room where interactions occur solely with a computer screen. In everyday life, however, we spend most of our time interacting with other individuals. Using fMRI, we recently recorded the brain activity of a speaker telling an unrehearsed real-life story and the brain activity of a listener listening to a recording of the story. To make the study as ecological as possible, we instructed the speaker to speak as if telling the story to a friend. Next, we measured the brain activity of a listener hearing the recorded audio of the spoken story, thereby capturing the time-locked neural dynamics from both sides of the communication. Finally, we asked the listeners to complete a detailed questionnaire that assessed their level of comprehension. Our results indicate that during successful communication the speaker’s and listener’s brains exhibit joint, temporally coupled, response patterns. Such neural coupling substantially diminishes in the absence of communication, for instance, when listening to an unintelligible foreign language. In addition, more extensive speaker–listener neural couplings result in more successful communication. The speaker-listener neural coupling exposes a shared neural substrate that exhibits temporally aligned response patterns across communicators. The recording of the neural responses from both the speaker brain and the listener brain opens a new window into the neural basis of interpersonal communication, and may be used to assess verbal and non-verbal forms of interaction in both human and other model systems.
Ode To Memory A mini-series devoted to memory in cenema
Lecture
Tuesday, February 1, 2011
Hour: 14:00
Location:
Dolfi and Lola Ebner Auditorium
Ode To Memory A mini-series devoted to memory in cenema
Prof. Yadin Dudai
Dept of Neurobiology, WIS
Response fluctuations in neurons and networks
Lecture
Tuesday, February 1, 2011
Hour: 12:30
Location:
Jacob Ziskind Building
Response fluctuations in neurons and networks
Prof. Shimon Marom
Dept of Physiology
Technion Haifa
Experimental analyses of fluctuations in responses to long series of stimuli will be presented. The experiments are performed at the single neuron, population of synapses and network levels. Sources and impacts of these fluctuations will be discussed.
Ode To Memory A mini-series devoted to memory in cinema
Lecture
Tuesday, January 25, 2011
Hour: 14:00
Location:
Dolfi and Lola Ebner Auditorium
Ode To Memory A mini-series devoted to memory in cinema
Prof. Yadin Dudai
Dept of Neurobiology, WIS
The evolution of behavioral mechanisms: theory and experiments on learning rules and their adaptive (or maladaptive) consequences
Lecture
Tuesday, January 25, 2011
Hour: 12:30
Location:
Jacob Ziskind Building
The evolution of behavioral mechanisms: theory and experiments on learning rules and their adaptive (or maladaptive) consequences
Prof. Arnon Lotem
Dept of Zoology
Tel-Aviv University
My talk will be based on our recent attempts to explain apparently maladaptive behaviors in humans and other animals as the consequences of generally adaptive learning mechanisms. I will first describe several cases where seemingly paradoxical behavior can be explained as the result of using relatively simple learning rules. I will then discuss the evolution of such learning rules in the context of individual decision making under variable conditions, as well as in the context of social foraging games of searchers and followers.
Synaptic mechanisms of sensory perception
Lecture
Wednesday, January 19, 2011
Hour: 10:00
Location:
Gerhard M.J. Schmidt Lecture Hall
Synaptic mechanisms of sensory perception
Prof. Carl Petersen
Brain Mind Institute,
EPFL Lausanne, Switzerland
Ode To Memory A mini-series devoted to memory in cinema
Lecture
Tuesday, January 18, 2011
Hour: 14:00
Location:
Dolfi and Lola Ebner Auditorium
Ode To Memory A mini-series devoted to memory in cinema
Prof. Yadin Dudai
Dept of Neurobiology, WIS
A cellular mechanism for general enhancement of learning capability
Lecture
Tuesday, January 18, 2011
Hour: 12:30
Location:
Jacob Ziskind Building
A cellular mechanism for general enhancement of learning capability
Dr. Edi Barkai
University of Haifa
Learning-related cellular modifications occur not only at synapses but also in the intrinsic properties of the neurons. Learning-induced enhancement in neuronal excitability is evident in hippocampal and piriform cortex pyramidal neurons following a complex olfactory-discrimination operant conditioning task. Such enhanced excitability is manifested in reduced spike frequency adaptation that results from reduction in the slow afterhyperpolarization (AHP), which develops after a burst of action potentials. AHP reduction is apparent throughout the pyramidal cells neuronal population. The AHP amplitude tends to return back to its initial value within days when training is suspended. This recovery is accompanied by reduced learning capability, but not by loss of memories for learned odors.
The post-burst AHP reduction is mediated by decreased conductance for a specific calcium-dependent potassium current, the slow IAHP. This long-lasting reduction is dependent on persistent activation of the PKC and ERK second messenger systems. Similar long-lasting AHP reduction can be induced in-vitro by repetitive synaptic stimulation or by kainate application. Such activity-dependent AHP reduction is occluded by prior learning.
Olfactory-learning induced enhanced neuronal excitability in CA1 pyramidal neurons is also accompanied by enhanced learning capability in a novel hippocampus-dependent task, the Morris water maze.
We suggested that AHP reduction is the cellular mechanism that enables neuronal ensembles to enter into a state which may be best termed "learning mode". This state lasts for up to several days and its behavioral manifestation is enhanced learning capability in tasks that depend on these particular neuronal ensembles. Specifically, enhanced neuronal excitability sets a time window in which most neurons in the relevant neuronal network are more excitable, and thus activity-dependent synaptic modifications are more likely to occur.
What the brain knows about what’s in the nose: Neural processing of pheromone signals
Lecture
Monday, January 17, 2011
Hour: 12:30
Location:
Arthur and Rochelle Belfer Building for Biomedical Research
What the brain knows about what’s in the nose: Neural processing of pheromone signals
Dr. Yoram Ben-Shaul
Harvard University
Understanding the neuronal events linking sensory inputs with behavioral outputs in complex organisms is a central goal of neuroscience. First steps in this enormous endeavor can be made by focusing on the relatively simple and stereotyped class of chemosensory triggered innately encoded physiological processes. Until recently, analysis of the circuits that underlie these processes was hampered by the lack of a reliable method for stimulus delivery to the vomeronasal system, which in mice, like many other mammals, plays a key role in processing pheromonal information. To address this issue, I developed an experimental preparation that allows in-vivo stimulus delivery to the mouse vomeronasal system and combined it with multisite neuronal recordings to measure stimulus evoked neuronal activity. Recordings from the early processing stage of the accessory olfactory bulb reveal the broad range and high acuity of ethologically relevant sensory representations, and furthermore suggest that these involve integrative processing. Recording from subsequent processing relays in the vomeronasal amygdala reveal several similarities to the olfactory bulb representations but also some intriguing differences raising new hypotheses about the role of the amygdala in these processes. Finally, I will describe how I am extending this approach by employing optogenetic techniques to record neuronal activity from scarce and genetically defined neurons in subsequent processing regions. Taken together, these experiments are beginning to illuminate the function of entire neuronal circuits involved in mediating ethologically and clinically relevant endocrine processes.
Topographic mapping of a hierarchy of temporal receptive windows using natural stimuli
Lecture
Thursday, January 13, 2011
Hour: 12:00
Location:
Arthur and Rochelle Belfer Building for Biomedical Research
Topographic mapping of a hierarchy of temporal receptive windows using natural stimuli
Prof. Uri Hasson
Dept of Psychology,
Princeton University
Space and time are two fundamental properties of our physical and psychological realms. While much is known about the integration of information across space within the visual system, little is known about the integration of information over time. Using two complementary methods of functional magnetic resonance imaging (fMRI) and intracranial electroencephalography (iEEG), I will present evidences that the brain uses similar strategies for integrating information over space and over time. It is well established that neurons along visual cortical pathways have increasingly large spatial receptive fields. This is a basic organizing principle of the visual system: neurons in higher-level visual areas receive input from low level neurons with smaller receptive fields and thereby accumulate information over space. Drawing an analogy with the spatial receptive field (SRF), we defined the temporal receptive window (TRW) of a neuron as the length of time prior to a response during which sensory information may affect that response. As with SRFs, the topographical organization of the TRWs is distributed and hierarchical. The accumulation of information over time is distributed in the sense that each brain area has the capacity to accumulate information over time. The processing is hierarchical because the capacity of each TRW increases from early sensory areas to higher order perceptual and cognitive areas. Early sensory cortices such as the primary auditory or visual cortex have relatively short TRWs (up to hundreds of milliseconds), while the TRWs in higher order areas can accumulate information over many minutes.
Pages
2011
, 2011
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