http://precedings.nature.com/tags/memory Recently posted documents tagged with 'memory' Nature Publishing Group en Nature Precedings http://precedings.nature.com/images/header_logo.gif http://precedings.nature.com http://precedings.nature.com/documents/3652/version/1 The cortical mechanisms underlying echoic memory and change detection were investigated using an auditory change-related component (N100c) of event-related brain potentials. N100c was elicited by paired sound stimuli, a standard followed by a deviant, while subjects watched a silent movie. The amplitude of N100c elicited by a fixed sound pressure deviance (70 dB vs. 75 dB) was negatively correlated with the logarithm of the interval between the standard sound and deviant sound (1 ~ 1000 ms), while positively correlated with the logarithm of the duration of the standard sound (25 ~ 1000 ms), indicating that the temporal representation of echoic memory is logarithmic. The amplitude of N100c elicited by a deviance in sound pressure, sound frequency and sound location was correlated with the logarithm of the magnitude of physical differences between the standard and deviant sounds, suggesting that Weber-Fechner's law holds for the automatic cortical response to sound changes. http://precedings.nature.com/documents/3652/version/1 Wed, 19 Aug 2009 09:13:12 UTC Logarithmic laws of echoic memory and auditory change detection in humans hdl:10101/npre.2009.3652.1 2009-08-19 Koji Inui Nature Precedings 2009-08-19T09:13:12Z Manuscript Neuroscience http://creativecommons.org/licenses/by/3.0/ http://dx.doi.org/10.1038/npre.2009.2926.1 Learning about the consequences of our actions (operant learning) is one of the major ways in which we learn to understand the world we live in. Despite our recent advances in the neurobiology of learning and memory, this “learning-by-doing” has largely withstood neurobiological scrutiny. This proposal aims to elucidate the molecular and neurobiological mechanisms of spontaneous behavioral choice and how decision-making is modulated by the consequences of such actions. This research will be done in a genetically amenable model system, the fruit fly Drosophila. We will use state-of-the-art genetic and behavioral techniques to identify the circuitry and molecular processes involved in generating spontaneous turning behavior and its modulation by operant learning. Operant learning is only one system among many which govern the organization of behavior. The long-term prospect of this research beyond this application is to understand how multiple memory systems interact to accomplish adaptive behavioral choice and decision-making. http://dx.doi.org/10.1038/npre.2009.2926.1 Fri, 06 Mar 2009 17:24:26 UTC The neurobiology of spontaneous actions and operant learning in Drosophila doi:10.1038/npre.2009.2926.1 2009-03-06 Björn Brembs Nature Precedings 2009-03-06T17:24:26Z Presentation Neuroscience http://creativecommons.org/licenses/by/3.0/ http://precedings.nature.com/documents/2540/version/1 We report evidence of a new phenomenon from three experiments: a leftward bias when people try to remember visually presented information. Experiments 1 and 2 showed lateral leftward biases in memory in a large (total N>60000) sample of participants, with data collected via the British Broadcasting Corporation (BBC) web site. Experiment 3 replicated the findings of a leftwards bias in short-term memory with a more intensive data collection. http://precedings.nature.com/documents/2540/version/1 Fri, 21 Nov 2008 16:21:54 UTC Items on the Left Are Better Remembered hdl:10101/npre.2008.2540.1 2008-11-21 Sergio Della Sala Nature Precedings 2008-11-21T16:21:54Z Manuscript Neuroscience http://creativecommons.org/licenses/by/3.0/ http://precedings.nature.com/documents/2272/version/1 The investigation of subjective experiences (SEs) of space and time is at the core of consciousness research. The term ‘space’ includes the subject and objects. The SE of subject, I-ness, is defined as ‘Self’. The SEs of objects, subject’s external body, and subject’s internal states such as feelings, thoughts, and so on can be investigated using the proto-experience (PE)-SE framework. The SE of time is defined as ‘phenomenal time’ (which includes past, present and future) and the SE of space as ‘phenomenal space’. The three non-experiential materialistic models are as follows: (I) The quantum-dissipation model [25] can connect the discrete neural signals to classical electromagnetic field to ‘quantum field theory and chaos theory’ for explaining memory. (II) The soliton-catalytic model [8] hypothesizes that all living processes including micro- and macro-processes can be explained by catalysis process. (III) The ‘sensation from evolution of action’ model [13] proposes that SEs are internalized during evolution. All these models can address to some extent the function of structures, such as perception. They cannot address explanatory gap. The complementary experiential PE-SE framework [37] addresses this psycho-physical gap and elucidates the SEs of space and time. http://precedings.nature.com/documents/2272/version/1 Wed, 10 Sep 2008 09:59:46 UTC Subjective Experiences of Space and Time: Self, Sensation, and Phenomenal Time hdl:10101/npre.2008.2272.1 2008-09-10 Ram Lakhan Pandey Vimal Nature Precedings 2008-09-10T09:59:46Z Manuscript Neuroscience http://creativecommons.org/licenses/by/3.0/ http://precedings.nature.com/documents/2119/version/1 Amyloid beta protein (Aβ) is well recognized as having a significant role in the pathogenesis of Alzheimer’s disease (AD). The reason for the presence of Aβ and its physiological role in non-disease states is not clear. In these studies, low doses of Aβ enhanced memory retention in two memory tasks and enhanced acetylcholine production in the hippocampus in vivo. We then tested whether endogenous Aβ has a role in learning and memory in young, cognitively intact mice by blocking endogenous Aβ in healthy 2-month-old CD-1 mice. Blocking Aβ with antibody to Aβ or DFFVG (which blocks Aβ binding) or decreasing Aβ expression with an antisense directed at the Aβ precursor APP all resulted in impaired learning in T-maze foot-shock avoidance. Finally, Aβ1-42 facilitated induction and maintenance of long term potentiation in hippocampal slices, whereas antibodies to Aβ inhibited hippocampal LTP. These results indicate that in normal healthy young animals the presence of Aβ is important for learning and memory. http://precedings.nature.com/documents/2119/version/1 Fri, 25 Jul 2008 10:57:12 UTC A Physiological Role for Amyloid Beta Protein: Enhancement of Learning and Memory hdl:10101/npre.2008.2119.1 2008-07-25 John Morley Nature Precedings 2008-07-25T10:57:12Z Manuscript Neuroscience http://creativecommons.org/licenses/by/3.0/ http://precedings.nature.com/documents/1354/version/1 At the heart of learning-by-doing lies a well-known psychological phenomenon: information will be remembered better if it is actively generated rather than passively read or heard. First described in humans, this generation effect can also be observed in various animal models. However, the neurobiological mechanisms underlying the generation effect are unknown. Here we show that two reciprocal interactions between its active and passive components contribute to the generation effect in flies. One interaction consists of the active (skill-learning) component facilitating the passive (fact-learning) component. Fact-learning, on the other hand, inhibits skill-learning. Experiments with adenylyl cyclase I deficient rutabaga mutant flies revealed that the fact- but not the skill-learning component requires this evolutionarily conserved learning gene. Using mushroom-body deficient transgenic flies we observed that the mushroom-bodies mediate the inhibition of skill-learning. This inhibition also enables generalization and prevents premature habit formation. Extended training in wildtype flies produced a phenocopy of mushroom-body impaired flies, such that generalization was abolished and goal-directed actions were transformed into habitual responses. Thus, our results identify various neural processes underlying learning-by-doing, delineate some of their synergisms and provide a framework for further dissecting them in a genetically tractable model system. http://precedings.nature.com/documents/1354/version/1 Tue, 20 Nov 2007 18:16:18 UTC Dissecting the mechanisms of learning-by-doing in Drosophila hdl:10101/npre.2007.1354.1 2007-11-20 Björn Brembs Nature Precedings 2007-11-20T18:16:18Z Manuscript Genetics & Genomics Neuroscience http://creativecommons.org/licenses/by/3.0/ http://precedings.nature.com/documents/905/version/1 Different brain circuits mediate the acquisition of skills and habits (via operant/instrumental learning) and the acquisition of facts (via classical/Pavlovian learning). Realistic learning situations always comprise interactions of skill- and fact-learning components (composite learning). So far, these interactions have escaped thorough scrutiny. Fixed flying Drosophila melanogaster at the torque meter provide one of the very few systems where the relationship of operant and classical predictors in composite learning can be studied with sufficient rigor. Experiments with wildtype, mutant and transgenic flies show that there is an interaction between predictive stimuli (classical component) and goal-directed actions (operant component) which makes composite conditioning more effective than the operant and classical components alone. Rutabaga (rut) mutants are impaired in learning about the (classical) stimuli, but show improved (operant) behavior learning. This is the first evidence that operant and classical conditioning differ not only at the circuit, but also at the molecular level. The interaction between operant and classical components is reciprocal and hierarchical, such that an impaired classical component (in rut flies) suppresses retrieval and an intact classical component suppresses acquisition of the operant component. Experiments with transgenic flies demonstrate that this suppression of operant acquisition is mediated by the mushroom-bodies and serves to ensure that the classical memories can be generalized for access by other behaviors. Extended training can overcome this suppression and transforms goal-directed actions into habitual responses. In conclusion, composite conditioning consists of two components with reciprocal, hierarchical interactions. Acquisition of the rut-dependent classical component suppresses acquisition of the rut-independent operant component via the mushroom-bodies. The operant component facilitates acquisition of the classical component via unknown, non-mushroom-body pathways. This interaction leads to efficient learning, enables generalization and prevents premature habit-formation. Habit formation after extended training reveals the gate-keeping role of the mushroom-bodies, allowing only well-rehearsed behaviors to consolidate into habits. http://precedings.nature.com/documents/905/version/1 Tue, 04 Sep 2007 12:04:55 UTC Mushroom-bodies mediate hierarchical interactions between fact- and skill-learning in Drosophila hdl:10101/npre.2007.905.1 2007-09-04 Björn Brembs Nature Precedings 2007-09-04T12:04:55Z Manuscript Genetics & Genomics Neuroscience http://creativecommons.org/licenses/by/2.5/