Talk postponed until fall

Mary Farbood of NYU will present a talk in room 272 of the Fine Arts Center’s music wing at 2:30 of Friday March 31. A title and abstract follow.

Title: The temporal dynamics of music versus speech processing

Abstract: Two studies comparing the temporal dynamics of music and speech are presented. The first focuses on tempo and how it affects key-finding; these results are then compared to various timescales associated with speech processing. The second study examines decoding time of musical structure using a key-finding task and discusses those results in the context of analogous speech research. These experiments highlight both differences and similarities in how music and speech are processed in time.

Charles Randy Gallistel, Distinguished Professor Emeritus of Psychology at Rutgers University, will be the 5 Colleges Cognitive Science Speaker this year, in a talk co-sponsored by the Initiative in Cognitive Science. He will present “It’s the neuron! How the brain really works” in Integrative Learning Center room N400 from noon to 1 pm on Wednesday April 19. An abstract and a poster follow.

Abstract. It is generally assumed that the brain’s computational capacities derive mostly from the structure of neural circuits—how it is wired—and from process(es) that rewire circuits in response to experience. The computationally relevant properties ascribed to the neuron itself have not changed in more than a century: It is a leaky integrator with a threshold on its output (Sherrington, 1906). The concepts at the core of molecular biology were undreamed of in Sherrington’s philosophy. They have transformed biological thinking in the last half century. But they play little role in theorizing about how nervous tissue computes. The possibility that the neuron is a full-blown computing machine in its own right, able to store acquired information and to perform complex computations on it, has barely been bruited. I urge us to consider it.

My reasons are: 1) The hypothesis that acquired information is stored in altered synapses is a conceptual dead end. In more than a century, no one has explained even in principle how altered synapses can carry information forward in time in a computationally accessible form. 2) It is easy to suggest several different models for how molecules known to exist inside cells can carry acquired information in a computationally accessible form. 3) The logic gates out of which all computation may be built are known to be implemented at the molecular level inside cells. Implementing memory and computation at the molecular level increases the speed (operations/s), energy efficiency (operations/J) and spatial efficiency (bits/m³) of computation and memory by many orders of magnitude. 5) Recent experimental findings strongly suggest that (at least some) memory resides inside the neuron.

Junha Chang (UMass) will present in the Cognitive Bag Lunch Wednesday, March 29 at 12pm in Tobin 521B. All are welcome! Title and abstract follow.

Title: Search guidance can be adjusted by experience with search discriminability

Abstract: Several recent studies show that previous experience can influence search strategy in a way that improves search performance. The purpose of the present study is to investigate how the experience of difficult color discriminability affects search strategies. Two participants groups either experienced difficult color discriminability in a half of the trials (i.e., hard-discrimination group) or experienced easy search in all trials (i.e., easy-discrimination group) in a dual-target search task. Participants were required to respond to the presence of a target (colored T) among distractors (colored pseudo-L). Eye movements were recorded to understand which feature information is used to guide attention, and response times and error rates were measured to compare search efficiency between the two participant groups. The hard-discrimination group fixated more distractors with target-dissimilar colors than the easy-discrimination group, suggesting the hard-discrimination group used shape information to guide search more than the easy-discrimination group. However, the error rates and response times were not significantly different between groups. The results demonstrate that the experience of difficult color discriminability discourages participants from guiding attention by color, and encourages them to use shape information.

From Gaja Jarosz:

The next meeting of CLC will take place at Psycholinguistics Workshop this Friday, March 24 (10am, ILC N400), and the theme for our discussion will be “Computational Arguments for Abstract Linguistic Structure”.

Andrew McKenzie (2012 UMass PhD) will give the Department Colloquium on March 24 at 3:30 in ILC N400. The title of Andrew’s talk is:

Sources of intensionality in Kiowa noun incorporation and English synthetic compounds.

Here is the abstract for the talk.

Andrew McKenzie is an Assistant Professor of Linguistics and an Affiliate Professor in Indigenous Studies at the University of Kansas. He specializes in Formal Semantics and Linguistic Fieldwork, with a focus on Native American languages, in particular Kiowa.

who: David Moorman, UMass Amherst
when: noon, Thursday, March 23
where: Computer Science Building Rm 150
food: Antonio’s pizza
generous sponsor: ORACLE LABS

Making Sense Of Neuron Ensembles: Advances And Issues In Neural Coding

Abstract: The brain contains approximately 80 billion neurons, and any perception, behavior, or thought requires the integration across thousands to millions of these neurons. Advances in neural technology now allows us to monitor the activity of hundreds to thousands of neurons simultaneously, in real time. Although we are able to collect rich data sets, our ability to interpret them, and to use this information to explain behavior, is still limited.

In this talk I will give an overview of issues surrounding neural encoding with a focus on what remains to be done to make sense of this complex information. I will also discuss some of our own research, but my main goal will be to identify problems in neuroscience that could be better addressed with advanced computation and analysis, potentially even by interested members of the UMass community.

Bio: David Moorman is an Assistant Professor in Psychological and Brain Sciences at UMass Amherst. His lab studies neural systems involved in motivation and cognition, and how these systems are disrupted in psychiatric disorders. More information can be found at: moormanlab.org

On March 8, Will Hopper (UMass) will give the next Cognitive Bag Lunch presentation at 12pm in Tobin 521B. All are welcome!

Title: Convergent Retrieval Learning: An Account of the Testing Effect

Abstract: Studies contrasting the effect of restudy and retrieval practice on memory retention reveal that restudying produces better memory in the short term, while a practice test produces better retention over time. There is not a clear, process based explanation of this “testing effect”, and it is difficult to reconcile with extant memory models. I propose a novel account that extends the foundation of two-stage memory models and assumes successful recall benefits memory due to a selective enhancement for the second stage of recall (dubbed Convergent Retrieval). Data from three new experiments confirm predictions of the Convergent Retrieval account about the effect of retrieval practice on the transfer of learning between retrieval cues and for recall latencies.