A Computational Model of Emotional Influences on Visual Working Memory Related Neural ActivityNienke Korsten Nikos Fragopanagos John Taylor

OF

CD

LPF

C

detection task memory task

Simulated BOLD responses

OF

CD

LPF

C

detection memory

fMRI results

Handout

Working Memory

Separable brain structure for maintenance or emergent property of recurrent interactions between neural areas?

Implicated brain sites:• PFC• Inferior temporal cortex• VAC• Parietal cortex

These areas are also often associated with attentional processing.

AbbreviationsBOLD

CODAM bla

DLPFC

IMC

OFC

PFC

VAC

WM

Blood Oxygen Level Dependent

Corollary Discharge of Attention Movement

Dorsolateral prefrontal cortex

Inverse Model Controller

Orbitofrontal cortex

Prefrontal cortex

Visual Association Cortex

Working Memory

Emotional Influences on WM

Dolcos & McCarthy find that emotional distracters during delay period in visual WM task

• deactivate DLPFC and parietal cortex

• activate amygdala and ventrolateral PFC

Similarly, in the Perlstein paradigm there is an inverse relationship between DLPFC and OFC activation, indicating a mutual inhibition between these two structures

ModelBased on CODAM model in which attention is created by ‘attention movement control signal’ generated by IMC.

3 dedicated nodes per module, representing pleasant, neutral and unpleasant stimuli.

Lateral inhibition between nodes in object map, exogenous goals, corollary discharge and IMC modules.

Input module: node has activation of 1 when corresponding stimulus is presented in paradigm, 0 otherwise.

Other single nodes consist of graded neurons with a sigmoid response function and no internal structure.

X in schematic outline represents multiplicative modulation, causing attentional amplification in object map by IMC.

Outstanding QuestionsNo agreement with some aspects of behavioral data.

Is DLPFC accurate site of stimulus – probe matching?

Attentional model applied to WM: is distraction caused by attentional mechanism?

Perlstein, Elbert & Stenger (2002)

0 - 2.5 s Presentation of unpleasant, neutral or pleasant stimulus

Memory task: Subject is required to remember stimulus

Memory task: Assessment if probe is equal to remembered cue

Detection task: Comparison of two pictures within probe

2.5 - 14 s

14 s

ReferencesDolcos, F. and McCarthy, G. (2006) "Brain systems mediating cognitive interference by emotional distraction," Journal of Neuroscience 26(7) 2072-2079

Fragopanagos, N., Kockelkoren, S., and Taylor, J. G. (2005) "A neurodynamic model of the attentional blink," Cognitive Brain Research 24(3) 568-586

Korsten, N., Fragopanagos, N., Hartley, M., Taylor, N. and Taylor, J.G. (2006) “Attention as a Controller” Neural Networks In Press

Perlstein, W. M., Elbert, T., and Stenger, V. A. (2002) "Dissociation in human prefrontal cortex of affective influences on working memory-related activity," PNAS 99(3) 1736-1741

Taylor, J. G. (2000) "Attentional Movement: the Control Basis for Consciousness," Abstracts of the Society of Neuroscience 26 2231 (#839.3)

Taylor, J. G. (2005) "Mind and consciousness: Towards a final answer?," Physics of Life Reviews 2(1) 1-45

Schematic outline of the model

Table of weights

Omitted connections are either 1 or nonexistent.

Order of differential weights is U-N-P.

ABSTRACT - We analyze the interaction between

emotion and cognition in terms of a simulation of

the inhibitory interaction observed between the

orbito-frontal cortex and the dorso-lateral

prefrontal cortex while subjects are processing

pictures of various levels of emotional valence. The

CODAM attention framework is used to simulate

the cognitive character, and in addition amygdala

activation is used as a further bias of attention.

Good agreement with observations is obtained.

Paradigm

GOALS

IMC / Corollary Discharge

Obj Map / Sensory WM

Analogous neural sites

MFC

Parietal areas

VAC

CNS Group

Dept. of Mathematics

This research was supported by

UK (NF)

EC cognitive robot project (JT)

EC Network of Excellence (NK)

ConclusionsWith the current model, we have suggested an account of WM as an emergent property of recurrent interactions between the DLPFC and sensory areas, influenced by emotional stimuli via the amygdala and OFC. This account agrees with fMRI data as presented by Perlstein et al (2002).