Thursday, June 23, 2011

Thursday, June 16, 2011

in this week's Nature

Control of visual cortical signals by prefrontal dopamine

Noudoost & Moore

ABSTRACT The prefrontal cortex is thought to modulate sensory signals in posterior cortices during top-down attention, but little is known about the underlying neural circuitry. Experimental and clinical evidence indicate that prefrontal dopamine has an important role in cognitive functions, acting predominantly through D1 receptors. Here we show that dopamine D1 receptors mediate prefrontal control of signals in the visual cortex of macaques (Macaca mulatta). We pharmacologically altered D1-receptor-mediated activity in the frontal eye field of the prefrontal cortex and measured the effect on the responses of neurons in area V4 of the visual cortex. This manipulation was sufficient to enhance the magnitude, the orientation selectivity and the reliability of V4 visual responses to an extent comparable with the known effects of top-down attention. The enhancement of V4 signals was restricted to neurons with response fields overlapping the part of visual space affected by the D1 receptor manipulation. Altering either D1- or D2-receptor-mediated frontal eye field activity increased saccadic target selection but the D2 receptor manipulation did not enhance V4 signals. Our results identify a role for D1 receptors in mediating the control of visual cortical signals by the prefrontal cortex and suggest how processing in sensory areas could be altered in mental disorders involving prefrontal dopamine.

Wednesday, June 15, 2011

Codes and representations

A friend sent me this paper yesterday, and although its 10 years old, its a very nicely written piece on the relationship between neural codes and representations.

Saturday, June 11, 2011

Women in Science

Here is an interesting piece in NYT on women in science. 4 top women scientists discuss the challenges they faced in rising through the ranks and in their respective fields.

Monday, June 6, 2011

New Serences Lab paper in TICS

Reciprocal relations between cognitive neuroscience and formal cognitive models: opposites attract?

Forstmann, Wagenmakers, Eichle, Brown and Serences

SFN comments on the new Lab Animal Guide

The new lab animal guide being proposed would have a significant, and potentially negative, effect on laboratory research. In this statement by SFN, they correctly point out that many of the proposed new guidelines are not founded on any data.

Read their full statement here

Thursday, June 2, 2011

UCSD Symposium on Neural Computation

Joint Symposium on Neural Computation

Date: Saturday, June 4, 9:00 am - 5:30 pm
Location: Institute for Neural Computation, UCSD, La Jolla, CA

Conference Program and Posters:

Sponsored by Qualcomm and Brain Corporation

Keynote Talks:
Kwabena Boahen, Stanford
Toby Berger, University of Virginia


SESSION 1: Vision
Chair: Charles Chubb, UCI

9:00 am - Nuno Vasconcelos, UCSD
"Discriminant saliency networks"

9:30 am - Alyssa Brewer, UCI
"Functional Plasticity in Human Parietal Cortex:
Adapting to Reversed Visual Input"

10:00 am - break

SESSION 2: Sensorimotor Control
Chair: Bosco Tjan, USC

10:15 am - Stefan Schaal, USC
"Path Integral Reinforcement Learning for Motor Skills"

10:45 am - Tansu Celikel, USC
"Closed loop sensorimotor computation for haptic object localization"

11:15 am - break

11:30 am - Keynote Talk
Chair: Gert Cauwenberghs, UCSD

Kwabena Boahen, Stanford
"Emulating a million neurons in the cortex"

12:30 pm Poster Spotlights

1:00 pm Lunch

SESSION 3: Neural Dynamics
Chair: Mayank Mehta, UCLA

2:00 pm - Dean Buonomano, UCLA
"Telling Time with Neural Dynamics"

2:30 pm - Khaleel Razak, UCR
"Neural mechanisms underlying FM sweep selectivity in the auditory cortex"

3:00 pm - break

SESSION 4: Neural Systems
Chair: Thanos Siapas, Caltech

3:15 pm - Tanya Sharpee, Salk
"Minimal models of multidimensional neural computations"

3:45 pm - Pietro Perona, Caltech
"The multidimensional wisdom of crowds"

4:15 pm - break

4:30 pm - Keynote Talk
Chair: Terry Sejnowski

Toby Berger, University of Virginia
"Neurons as Finite-State Channels with Feedback"

5:30 pm - Closing Remarks - Terry Sejnowski

46 Posters:


Registration fee: $35. Payable at the door by cash or by check made out
to UC Regents. Registration fee includes lunch and refreshments.

Wednesday, June 1, 2011