slide1 l.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
Discrete working memory PowerPoint Presentation
Download Presentation
Discrete working memory

Loading in 2 Seconds...

play fullscreen
1 / 31

Discrete working memory - PowerPoint PPT Presentation


  • 281 Views
  • Uploaded on

Discrete working memory. Discrete working memory. Delay. Discrete working memory. Discrete working memory. Discrete working memory. Green cue. Delay. Red cue. Delay. 27. 27. Spike rate (Hz). Spike rate (Hz). 0. 0. 15. 30. -15. 0. -15. 0. 15. 30. Time (sec). Time (sec).

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Discrete working memory' - Jims


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
slide5

Discrete working memory

Green cue

Delay

Red cue

Delay

27

27

Spike rate (Hz)

Spike rate (Hz)

0

0

15

30

-15

0

-15

0

15

30

Time (sec)

Time (sec)

Data from inferotemporal cortex

Fuster and Jervey, Science (1981)

slide7

Spatial working memory

Direction of monkey's gaze

slide12

Data from

Funahashi et al. (1989)

J. Neurophysiol. 61:331

slide13

Parametric Working Memory and Sequential Discrimination

Experiments by group of R. Romo et al., UNAM

Nature 399:470 (1999), Cereb. Cort. 13:1196 (2003)

slide16

base

delay

f1(Hz)

10

14

18

22

26

30

34

Rastergram:

30

Trial-averaged

firing rate

Firing rate (Hz)

0

0.5

Time (sec)

3.5

18

Romo et al.

Nature 1999

Tuning curve of

memory activity

Firing rate (Hz)

(from Miller et al.

Cerebral Cortex 2003)

5

10

Stimulus, f1 (Hz)

34

slide17

Delay activity in PFC ties the task together

Number of tuned neurons

Firing rates

Primary somatosensory

cortex:

Secondary somatosensory

cortex:

Premotor cortex:

Prefrontal cortex:

Romo et al. Philos Trans Roy Soc: Biol, 2002

slide19

Rate=f(I)

I

Rate

I=f(Rate)

Network model: firing rates with weak feedback

Firing rate curve

Feedback current

Rate

slide20

I(app)

Rate=f(I)

I

Rate

I=f(Rate)

Network model: firing rates with weak feedback

Firing rate curve

Feedback current

Rate

slide21

Network model: firing rates with strong feedback

Firing rate curve

Feedback current

slide23

I(app)

Rate=f(I)

I

Rate

I=f(Rate)

Network model: firing rates with strong feedback

Firing rate curve

Total current

slide25

Network model: recurrent excitation

= pool of tens to hundreds of self-exciting neurons

slide27

Miller and Wang,

Chaos 2006

cf Miller et al,

PLOS Biol. 2005

Stability increases exponentially

with number of neurons in pool

slide28

Rate=f(I)

I

Rate

I=f(Rate)

Network model: Continuous attractor with moderate feedback

Firing rate curve

Feedback current

W

Rate

slide29

I(app)

Rate=f(I)

I

Rate

I=f(Rate)

Network model: Continuous attractor with moderate feedback

Firing rate curve

Feedback current

slide30

I(app)

Rate=f(I)

I

Rate

I=f(Rate)

Network model: Continuous attractor with moderate feedback

Firing rate curve

Feedback current