Monday 28 July 2014
SYMPOSIUM 01: Frontal-Striatal
Interaction In Reward-Guided Decision Making
We know that the frontal lobes are important for reward-guided decision-making but the mechanisms that underlie this role are currently a topic of investigation. The aim of this symposium is to bring together a group of researchers using disparate approaches (single neuron recording, experimental lesions, neuroimaging, computational neuroscience, and learning theory) but with a common focus on determining how several areas in the frontal cortex, including the medial frontal cortex and anterior cingulate cortex, come to have a critical role in reward-guided decision-making. As well as attempting to understand the neural mechanisms in these areas another common interest shared by the speakers is the understanding of the interactions between these brain regions and the striatum during decision-making. Using a variety of rodent models Bernard Balleine will explain the key circuits on which goal-based decision-making depends. Using a combination of single neuron and fMRI data Tim Behrens will propose a mechanism for mediating value-guided decision making. Matthew Rushworth will summarize recent fMRI and lesion experiments showing how these mechanisms operate when multiple choices are available simultaneously. Rob Hester will examine the role of these areas in error-based learning and cognitive control processes.
Matthew Rushworth, University of Oxford, UK
Bernard Balleine, University of Sydney, Australia
Rob Hester, University of Melbourne, Australia
Rei Akaishi, Tokyo Metropolitan Institute of Medical Science, Japan
SYMPOSIUM 02: Multi-Frequency Brain Network Dynamics In Human Memory
A central challenge to understanding human memory is elucidating how the brain efficiently consolidates and retrieves the details of prior experience across distributed functional networks. While the medial temporal lobe (MTL) plays a well-established role in memory function, contemporary neuroscience has highlighted the importance of interactions between the MTL and distributed neocortical regions, both sensory and associative in function. Mechanisms for coordinating such distributed functional networks have progressively focused on long-range rhythmic synchrony between regions. While theta band oscillations have become synonymous with memory systems, a wide diversity of oscillatory motifs exists across the cerebral cortex. This symposium will present recent findings chiefly from human intracranial recordings that highlight the role of multi-frequency brain dynamics in facilitating memory network function. Specific topics covered include hippocampal oscillatory dynamics and memory behavior (Staresina); frequency specific hippocampal-neocortical oscillatory interactions and episodic memory content (Ekstrom) and parietal cortico-cortical oscillatory dynamics during autobiographical retrieval and resting-state (Foster). Collectively, these data suggest that multi-frequency brain dynamics provide important mechanisms for temporal coordination of distributed memory networks, and provide a wide repertoire of dynamical states that may accommodate the rich informational content of human memory.
Arne Ekstrom, University of California Davis, USA
Brett Foster, Stanford University, USA
Bernhard Staresina, Cambridge University, UK
Implications Of Age-Related Cerebrovascular
Changes On Brain Structure And Function
It is well established that aging is associated with structural brain changes and cognitive decline. However, the extent to which these age-related changes can be explained by cerebrovascular changes is yet to be determined. Monica Fabiani and Todd Jolly co-chair this symposium on cerebrovascular health in ageing, its association with brain structure and function and implications for age-related cognitive decline. Leeanne Carey will present findings on the changes to limbic-cortical networks and associated grey matter regions at 3 and 12 months post-stroke and how these changes provide insights into post-stroke depression. Kaarin Anstey will cover work that provides evidence of the importance of postural hypotension as a cardiovascular risk factor and its implications on cognitive aging. Monica Fabiani will show how lifestyle factors affect the cerebrovascular system and how this relationship impacts on age-related changes in brain structure and function. Todd Jolly will provide evidence for a link between intracranial arterial pulsatility and white matter microstructure and how they affect age-related deficits in cognitive control.
Monica Fabiani, University of Illinois at Urbana-Champaign, USA
Leeanne Carey, Florey Institute of Neuroscience and Mental Health, Australia
Kaarin Anstey, Australian National University, Australia
Todd Jolly, University of Newcastle, Australia
Role of Brain Oscillations in Perception, Attention, and Memory
There has been considerable interest in the past few years on the role played by neural oscillations throughout the cognitive processing spectrum, ranging across perception, attention, as well as short- and long- term memory. Experiments have examined the role of frequency, phase, and amplitude but also whether such oscillations arise naturally or from external entrainment, e.g., flicker, transcranial stimulation (magnetic and electrical). Our symposium will review a range of findings from a diverse set of approaches, suggesting that oscillations have a profound effect on human cognition. We will present evidence that entrainment at 10-16Hz (alpha, beta) has important implications for not only the complex attentional blink phenomenon but even on perception of a single target. Experiments using long-term memory paradigms will present convergent results from multi-modal imaging and rTMS studies demonstrating that decreases in beta oscillations causally mediate memory encoding. We will also show that the pre-stimulus oscillatory state of the brain including spontaneous fluctuations in the power and phase of alpha band oscillations affect not only working memory but even the conscious experience of stimuli.
Simon Hanslmayr, University of Birmingham, UK
Denes Szucs, University of Cambridge, UK
Nicholas Myers, University of Oxford, UK
Indices Of Primitive Intelligence: From The Midbrain To Cortex
The ability of the auditory system to detect change in background sounds even in the absence of active attention is remarkable. Recent research indicates that this extraordinary sensitivity relies on a capacity to model regularities in background sounds, and that these perceptual achievements are based on properties that are encoded at the earliest stages of the auditory pathway. The term ‘primitive intelligence’ has been used to capture the ability of the auditory system to not only model simple and complex acoustic regularities but also to predict future events and detect violations of these predictions. In human electrophysiology, ‘primitive intelligence’ was first identified via the mismatch negativity or MMN — an event-related potential (ERP) evoked by the occurrence of a deviant sound. In this symposium, the four speakers will demonstrate 1) that embryonic aspects of the principles underpinning this remarkable capacity of the auditory system are evident already at the midbrain in both rodents (Malmierca) and humans (Grimm) and 2) that higher order aspects reflecting detection of events deviating from modelled regularities are only evident at a cortical level in both rodents (Harms) and humans (Näätänen). The latter properties also provide tools for investigating clinical conditions, such as schizophrenia.
Manuel S. Malmierca, University of Salamanca, Spain
Sabine Grimm, University of Barcelona, Spain
Lauren Harms, University of Newcastle, Australia
Risto Näätänen, University of Arhus, Denmark
Cross-Modal Integration And Plasticity Of
Sensory Systems In The Normal And Peripherally Deprived Brain
The brain is well wired at birth in order to treat the unisensory and multisensory information to which it is exposed. However, it undergoes substantial transformations to adapt to its specific environment and capabilities. In the first presentation we show, using functional Magnetic Resonance Imaging (fMRI), how haptic stimuli recruit in a functionally specific manner brain structures related to visual objects and spatially related imagery. In the second, we compare deaf and hearing cats on a battery of visual cognitive tasks and show not only normal performance but, even more importantly, cross-modal compensation and superior performance for discriminating visually complex images of conspecific and human faces. The third presentation illustrates how super-performance for discriminating haptic and auditory stimuli in blind humans can be attributed to the recruitment of visually related areas as well as how auditory cortex is activated by visual stimuli, including faces in the deaf. The fourth presentation examines both how the blind treat sound and touch and how the technological development of Sensory Substitution Devices (SSD) using sound and touch can allow the rehabilitation of these sensory deprived individuals so that they can be more independent and ‘see’ in a manner similar to bats and dolphins.
Franco Lepore, University of Montréal, Canada
Krish Sathian, Emory University, USA
Stephen G. Lomber, University of Western Ontario, Canada
Amir Amedi, Hebrew University Jerusalem
PANEL DISCUSSION 01:
Cognitive Neuroscience: Understanding Attention And Multitasking On The Roadway
Driver distraction caused by multitasking is a significant source of injuries and fatalities on the roadway. This panel will discuss what basic cognitive and neuroscience research in the laboratory, driving simulator, and instrumented vehicle can tell us about the mechanisms underlying multitasking behavior. Our approach will sample from a wide variety of methods and techniques including sophisticated behavioral analysis using driving simulation and instrumented vehicles, measures of eye movement behavior, spectral EEG and ERP measures, as well as fMRI, and DTI from individuals with extraordinary multitasking ability. We will examine the factors that lead a person to multitask in the first place (and why they keep doing it) despite that fact that they readily acknowledge that it is dangerous (at least for others). We will also examine how multitasking impairs the sampling of information from the driving environment, suppressing visual scanning, impairing awareness of safety-critical objects in the drivers field of view, degrading the anticipation of potential hazards, and worsening situation awareness of the driving environment. We consider driving to be a complex skill that is supported by a hierarchical network of control that is differentially affected by different multitasking activities. Finally, we show individual differences in the efficiency of a frontal-mediated attentional network that supports multitasking in this real-world context.
David Strayer, University of Utah, USA
Paul Atchley, University of Kansas, USA
Jason McCarley, Flinders University, Australia