learning and memory in the auditory system the university of iowa department of psychology...

Learning and Memory in the Auditory System

The University of IowaDepartment of Psychology

Behavioral and Cognitive Neuroscience

Amy Poremba, Ph.D.

1

Introduction

Examples of learning about auditory cues will be used to infer some general learning

principles.

2

Training Rules for Discriminative Active Avoidance Conditioning

Danger/Fear

Safety

CS+Tone 1

CS-Tone 2

USFootshock

CRRun

X

3

UCRRun

4

Behavioral Learning Curve%

Cor

rect

Re

spo

nse

s

Training Sessions

100

75

50

25

0Pretraining First Exposure First Significant

DiscriminationContinuedTraining

Criterion Overtraining

CS+CS-

5

CR – conditioned responseCS – conditioned stimulusUS – unconditioned stimulusACC – anterior cingulate cortexPCC – posterior cingulate cortexMGN – medial geniculate n.MDN – medial dorsal n.AVN – anterior ventral n.MB – mammillary bodiesLDTN – lateral dorsal tegmental n.

USCS

Aud. Ctx

MGN

Amygdala

Neural Circuit for Avoidance Learning

tonefootshock

6

Two Types of Neuronal Plasticity

Excitation

Discrimination

ExcitationDiscrimination

7

8

CR – conditioned responseCS – conditioned stimulusUS – unconditioned stimulusACC – anterior cingulate cortexPCC – posterior cingulate cortexMGN – medial geniculate n.MDN – medial dorsal n.AVN – anterior ventral n.MB – mammillary bodiesLDTN – lateral dorsal tegmental n.

USCS

Aud. Ctx

MGN

Amygdala

Neural Circuit for Avoidance Learning

tonefootshock

9

X

X

X Talk et al., 2004

Poremba and Gabriel, 1999, 2001

Poremba and Gabriel, 1997

10

CR – conditioned responseCS – conditioned stimulusUS – unconditioned stimulusACC – anterior cingulate cortexPCC – posterior cingulate cortexMGN – medial geniculate n.MDN – medial dorsal n.AVN – anterior ventral n.MB – mammillary bodiesLDTN – lateral dorsal tegmental n.

ACC PCC

MDN AVN

MB

LDTN

MGN

Amygdala

Aud. CtxCR

USCS

Neural Circuit for Avoidance Learning

11

Cingulate Cortex

Limbic Thalamus

12

ACC PCC

MDN AVN

Cingulate Cortex

Limbic Thalamus

Acquisition Overtraining

% C

orr

ect

Re

spo

nse

sACC

MDN

13

ACC PCC

MDN AVN

Cingulate Cortex

Limbic Thalamus

Acquisition Overtraining

% C

orr

ect

Re

spo

nse

sPCC

AVN

14

ACC PCC

MDN AVN

Cingulate Cortex

Limbic Thalamus

Acquisition Overtraining

% C

orr

ect

Re

spo

nse

sACC PCC

MDN AVN

CR – conditioned responseCS – conditioned stimulusUS – unconditioned stimulusACC – anterior cingulate cortexPCC – posterior cingulate cortexMGN – medial geniculate n.MDN – medial dorsal n.AVN – anterior ventral n.MB – mammillary bodiesLDTN – lateral dorsal tegmental n.

ACC PCC

MDN AVN

MB

LDTN

MGN

Amygdala

Aud. CtxCR

USCS

Neural Circuit for Avoidance Learning

15

Cingulate Cortex

Limbic Thalamus

EARLY LATE

CR – conditioned responseCS – conditioned stimulusUS – unconditioned stimulusACC – anterior cingulate cortexPCC – posterior cingulate cortexMGN – medial geniculate n.MDN – medial dorsal n.AVN – anterior ventral n.MB – mammillary bodiesLDTN – lateral dorsal tegmental n.

ACC PCC

MDN AVN

MB

LDTN

MGN

Amygdala

Aud. CtxCR

USCS

Neural Circuit for Avoidance Learning

16

EARLY LATE

LAST?

17

CR – conditioned responseCS – conditioned stimulusUS – unconditioned stimulusACC – anterior cingulate cortexPCC – posterior cingulate cortexMGN – medial geniculate n.MDN – medial dorsal n.AVN – anterior ventral n.MB – mammillary bodiesLDTN – lateral dorsal tegmental n.

ACC PCC

MDN AVN

MB

LDTN

MGN

Amygdala

Aud. CtxCR

USCS

18

Neural Circuit for Avoidance Learning and ?

19

20

CR – conditioned responseCS – conditioned stimulusUS – unconditioned stimulusACC – anterior cingulate cortexPCC – posterior cingulate cortexMGN – medial geniculate n.MDN – medial dorsal n.AVN – anterior ventral n.MB – mammillary bodiesLDTN – lateral dorsal tegmental n.

Hippocampus

ACC PCC

MDN AVN

MB

LDTN

MGN

Amygdala

Aud. CtxCR

USCS

Neural Circuit for Avoidance and Approach Learning

21

EARLY LATE

X

CR – conditioned responseCS – conditioned stimulusUS – unconditioned stimulusACC – anterior cingulate cortexPCC – posterior cingulate cortexMGN – medial geniculate n.MDN – medial dorsal n.AVN – anterior ventral n.MB – mammillary bodiesLDTN – lateral dorsal tegmental n.

Hippocampus

ACC PCC

MDN AVN

MB

LDTN

MGN

Amygdala

Aud. CtxCR

USCS

Neural Circuit for Avoidance and Approach Learning

22

INPUT

EARLY LATE

CONTEXT

MemoryFilter

Summary for Simple Auditory Learning

2123

CONTEXT

Hippocampus

ACC PCC

MDN AVN

MB

LDTN

MGN

Amygdala

Aud. CtxCR

USCS

INPUT

EARLY LATE

MemoryFilter

This type of learning is better with trials spread across days rather than massed trials on one or two days. After a certain number of training trials, continued trials are no longer necessary for consolidation, i.e., moving the memory to long term storage.

There are multiple brain circuits for different stages of the learning.

Brain structures that are important for acquisition are not always necessary for long term memory storage.

The context surrounding the important signals to be learned helps attentional processing and the learning of more than one task.

There may be multiple brain circuits even for this simple type of task perhaps creating a filter for which memories will be remembered.

Types of learning may be layered, i.e., the input system in this case is similar to the fear conditioning system. Here the animals learn to avoid the footshock and other brain areas are then involved in the learning.