Tuesday, February 28, 2012

Nature Neuro Paper

This is a pretty interesting paper in NN this month. It combines MEG and modelling to look at changes in neural responses across the brain.

Mechanisms underlying cortical activity during value guided choice

Hunt et al.

there is also a News and Views piece on it

Sunday, February 26, 2012

Psyc Colloquium Thursday: Josh McDermott

Thursday, March 1, 4:00 p.m.

The Crick Conference Room
Mandler Hall, Room 3545

Josh McDermott

Center for Neural Science
New York University

Understanding Audition via Sound Analysis and Synthesis

Humans infer many important things about the world from the sound pressure waveforms that enter the ears. In doing so we solve a number of difficult and intriguing computational problems. We recognize sound sources despite large variability in the waveforms they produce, extract behaviorally relevant attributes that are not explicit in the input to the ear, and do so even when sound sources are embedded in dense mixtures with other sounds. This talk will describe my recent work investigating how we accomplish these feats. The work stems from two premises: first, that understanding perception requires understanding real-world sensory stimuli and their representation in the brain, and second, that a theory of the perception of some property should enable the synthesis of signals that appear to have that property. Sound synthesis can thus be used to probe phenomena inaccessible to conventional experimental methods. I will discuss two related strands of research along these lines. The first strand uses sound textures (as produced by rain, swarms of insects, or galloping horses) as a window into the auditory system, synthesizing textures from statistics of biological sound representations as tests of the perceptual relevance of different acoustic measurements. The second strand uses naturalistic synthetic sounds to reveal new aspects of sound segregation. Together they indicate that simple statistical properties of auditory representations capture a surprising number of important perceptual phenomena.


Friday, February 24, 2012

Open access?

There is an interesting thread running on CVNet about the benefits/costs of moving to open access publishing models. Also check out a relevant Guardian article here.

Thursday, February 23, 2012

Thursday, February 16, 2012

CNS Seminar: Stephanie White

February 21st

Stephanie White
Dept of Integrative Biology & Physiology

Molecular Microcircuits for Learned Vocalization

Abstract. Auditory-guided vocal communication is a complex behavior that emerges through sensorimotor experience. The neural mechanisms underlying this evolutionarily rare trait are not fully known, with human speech and birdsong being the two best characterized systems. While only humans possess language, similarities between the vocal learning subcomponent of language, speech, and birdsong, suggest parallel mechanisms. These include critical periods for learning, reliance on cortico-basal ganglia circuits, and involvement of the FoxP2 transcription factor. By pairing classical ethological experiments on zebra finches with systems analytic techniques, we tested the hypothesis that different behaviors are accompanied by different patterns of gene activation. In line with this idea, we found that distinct ensembles of genes are coactivated in area X, the subregion of the songbird basal ganglia dedicated to song. These ensembles were not similarly coactivated for other behaviors (such as hopping or perching), even in adjacent basal ganglia tissue. Thus, ‘molecular microcircuitry’ exists alongside anatomic and synaptic microcircuitry that, together, functionally specify the brain. This conceptual advance relied on the novel application of weighted gene coexpression network analysis (WGCNA) to birdsong, a procedurally learned natural behavior. Our findings reveal the importance ofgene co-regulation over gene expression levels in effecting behavior.


This seminar is supported by the Kavli Institute for Mind and Brain, and the UCSD Dept of Psychology


Friday, February 10, 2012

CNS Seminar: Paula Tallal

February 14th

Paula Tallal
Rutgers University

Temporal processing in the literate brain

Abstract. Developmental deficits affecting speech perception increases the risk for language and literacy problems with lowered academic and occupational attainment. Both normal development and disorders of speech perception have been linked to temporospectral auditory processing speed. Understanding the role of dynamic auditory processing in speech perception has led to the development of neuroplasticity-based intervention strategies aimed at ameliorating speech perceptual deficits and their sequalae. The fundamental building blocks of all languages are the phonemes (speech sounds) out of which words are built. These are unique to each language and are learned by young infants from environmental exposure to the native language(s). How phonemes come to be represented in the brain, and specifically the important role that spectrotemporal acoustic processing and neuroplasticity play in early phonological, and subsequent language and literacy development, will be the focus of this talk. Data derived from behavioral, physiological and neuroimaging studies of normal as well as language learning impaired children will be presented that demonstrate that individual differences in the speed and precision of spectrotemporal processing of complex acoustic signals (including speech) have a significant effect on language and literacy development. In addition, physiological cellular mapping studies of auditory cortex in animals will be presented to demonstrate the effect acoustic environment plays in mapping complex acoustic stimuli . Finally, translational research studies using behavioral and neuroimaging approaches will be presented to demonstrate how basic research on language development and disorders has been coupled with basic research on neuroplasticity to improve academic outcomes in struggling learners.

Sunday, February 5, 2012

CNS Seminar: Rich Ivry

February 7th @ noon

Rich Ivry
Department of Psychology
UC Berkeley

Competitive and Inhibitory Processes During Action Selection

Abstract. A central feature of human performance is our ability to interact with a highly variable environment such that an appropriate behaviour is selected from a vast set of possibilities. Even when the goal of an action has been specified, we must still specify a particular movement to achieve that goal. For example, we may reach for our glass of wine at the dinner table with either the left or right hand. I will review a set of experiments in which we use transcranial magnetic stimulation to examine the dynamics of this selection process, using TMS either as a tool to influence hand choice or as a probe on cortical excitability during the preparation and execution of movement. Previous work has suggested that the resolution of a competition between the two hands involves the inhibition of the nonselected hand. The current results suggest an additional inhibitory mechanism ensures that movements associated with potential actions are not initiated prematurely.

Rich Ivry Chalk Talk

9am to 10am on Wednesday February 8th in the Crick Conference room.

Dr Ivry will also be giving a chalk talk on "Strategic and implicit adaptive processes in motor learning".