Attention: Neural Mechanisms and Attentional Control Networks Attention 2

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Reynold Jackson
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1 Attention: Neural Mechanisms and Attentional Control Networks Attention 2 Hillyard(1973) Dichotic Listening Task N1 component enhanced for attended stimuli Supports early selection Effects of Voluntary (Endogenous) Spatial Attention Attend to left or to right ERPs recorded to attended and ignored stimuli P1, N1 enhanced with attention 1

Moran & Desimone(1985) Does attention influence individual

Trained macaque monkeys to covertly shift attention

Non-preferred stimulus Moran & Desimone(1985) Attending to

non-preferred stimulus decreased V4 firing McAdams and Reid

2 Moran & Desimone(1985) Does attention influence individual neurons? Trained macaque monkeys to covertly shift attention Measured firing of single V4 neurons Preferred stimulus Non-preferred stimulus Moran & Desimone(1985) Attending to preferred stimulus enhanced V4 firing Attending to non-preferred stimulus decreased V4 firing McAdams and Reid (2005) Examined whether attention enhanced V1 activity Macaque monkeys made saccades to colored target Simple cells Complex cells 2

McAdams and Reid (2005) Enhanced V1 activity 25-70 ms

25-70 ms after onset when ignored (blue) What About

Hopfinger(2001) Modified spatial cuing task Central

using fmri Hopfinger(2001) Enhanced processing mainly

3 McAdams and Reid (2005) Enhanced V1 activity ms after onset when attended (red) Inhibited V1 activity ms after onset when ignored (blue) What About Attention and Human Cortical Activity? Hopfinger(2001) Modified spatial cuing task Central arrow cue Bilateral target display V1 activation in V1 using fmri Hopfinger(2001) Enhanced processing mainly in area VP Ventral posterior area( Ventral V3 ) Connections to may other brain regions 3

Biased Competition Model for Selective Attention Desimone& Duncan (1995) Stimuli

given to neuron s preferred stimulus Neuron s Receptive Field Kastner(1998)

simultaneously, with or without attention Kastner(1998) In absence of attention,

4 Biased Competition Model for Selective Attention Desimone& Duncan (1995) Stimuli within a receptive field compete Attention helps resolve the competition Favor given to neuron s preferred stimulus Neuron s Receptive Field Kastner(1998) Examination of biased competition Presented stimuli sequentially or simultaneously, with or without attention Kastner(1998) In absence of attention, nearby stimuli compete Attention reduces competition Occurs more in extrastriate areas (V4) Reduction 4

Attention Effects Operate at All Levels of Visual

visual patterns Small (local) level Large (global) level

large patters had differential effects on cortical

5 Attention Effects Operate at All Levels of Visual Processing Hopf(2006) Receptive field differences Process visual patterns Small (local) level Large (global) level Hopf(2006) Attending to small vs. large patters had differential effects on cortical processing Attending to Features Spatial Attention Feature Attention Liu et al. (2007) Posner cuing task Cued location of target (spatial attention) Or, cued feature of target (feature attention) Cuing enhanced accuracy 5

Attending to Features Hillyard and Münte (1984) Isolated responses attending to features from responses attending to locations ERPs recorded while attending to different locations and colors Push

6 Attending to Features Hillyard and Münte (1984) Isolated responses attending to features from responses attending to locations ERPs recorded while attending to different locations and colors Push button to shorter red bars on the left only. Push button to shorter blue bars on the right only. Uncoupled spatial attention from feature attention + Attending to Features Hillyard and Münte (1984) Different pattern for spatial attention effects vs. feature attention effects Spatial attention enhanced P1, N1, N2 Color (feature) attention No enhancement in P1 N1 and N2 enhancement No enhancement at unattended location Attending to Features Where Do Feature Attention Effects take Place? Corbetta et al. (1991) Divided attention vs. selective attention Shape, color, motion stimuli Change-detection task PET scans Reference Stimulus Test Stimulus 6

Interplay Between Features and Location Are Features Selected Before a Location is Attended?

covert selection Occurs before object recognition Interplay Between Features and Location Hopf et al.

7 Attending to Features Corbetta et al. (1991) Change detection better under selective attention Selective attention activated distinct cortical regions Interplay Between Features and Location Are Features Selected Before a Location is Attended? Important ERPs P1 component N2pc N2 wave Posterior electrode site Contralateral to attended stimulus Sign of covert selection Occurs before object recognition Interplay Between Features and Location Hopf et al. (2004) Examined feature selection ERPs and N2pc Visual search task with popout target Feature ERPs ~140 ms after display onset in ventral occipitotemporal cortex N2pc followed by ~30 ms in anterior occipitotemporal cortex 7

Interplay Between Features and Location Does Competition Affect Feature Processing in Unattended Locations?

Irrelevant probe at unattended location Interplay Between Features and Location Zhang & Luck (2009) ERPs showed

location Attention is Both Goal-Directed and Stimulus-Driven Selective attention may mediate neuronal

8 Interplay Between Features and Location Does Competition Affect Feature Processing in Unattended Locations? Zhang & Luck (2009) Continuous displays of red and/or green Attend to one color Other color may also appear Irrelevant probe at unattended location Interplay Between Features and Location Zhang & Luck (2009) ERPs showed selective enhancement No competition = no enhancement Competition = enhancement for attended color at unattended location Attention is Both Goal-Directed and Stimulus-Driven Selective attention may mediate neuronal excitability via Posterior parietal cortex Dorsolateral prefrontal cortex Superior prefrontal cortex Pulvinar nucleus in thalamus 8

Two Separate Frontoparietal Networks Corbetta &

attention Ventral attentional system Non-spatial

(DFAN) Dorsal regions show increased activity to

Supplementary eye fields(sef) Intraparietal sulcus

(PC) SEF Hopfinger(2000) Central cue enhanced

9 Two Separate Frontoparietal Networks Corbetta & Shulman (2011) Dorsal attentional system Spatial attention Ventral attentional system Non-spatial attention Dorsal Frontoparietal Attentional Network (DFAN) Dorsal regions show increased activity to goal-directed behavior Frontal eye fields(fef) Supplementary eye fields(sef) Intraparietal sulcus (IPS) Superior parietal lobule (SPL) PC Precuneus (PC) SEF Hopfinger(2000) Central cue enhanced activity in areas of DFAN Activity was prior to stimulus presentation 9

Frontal Cortex and Attentional Control Morishima et al.

to stimulate FEF Measured ERPs V5/MT (MT+) FFA Morishima et al.

discrimination Increased FFA activity during face

Frontoparietal Attention Network (VFAN) Stimulus-driven

10 Frontal Cortex and Attentional Control Morishima et al. (2009) Motion discrimination or face discrimination Used TMS to stimulate FEF Measured ERPs V5/MT (MT+) FFA Morishima et al. (2009) Stimulation to FEF Increased MT+ activity during motion discrimination Increased FFA activity during face discrimination FEF has an influence on visual cortex Ventral Frontoparietal Attention Network (VFAN) Stimulus-driven control Right-lateralized Temporoparietal junction (TPJ) Ventral frontal cortex(vfc) 10

Corbetta(2002) Unexpected stimuli activate TPJ Stimuli in

Leber(2010) Examined neural predictors of attentional control

Leber(2010) Focused on pretrial activity in MFG Less capture with

11 Corbetta(2002) Unexpected stimuli activate TPJ Stimuli in unexpected locations activate TPJ Target detection activates TPJ Leber(2010) Examined neural predictors of attentional control Attentional capture task Focused on middle frontal gyrus (MFG) Leber(2010) Focused on pretrial activity in MFG Less capture with increased MFG activity Left MFG contributes to internal states of attentional control. 11

Control of visuo-spatial attention. Emiliano Macaluso

Control of visuo-spatial attention Emiliano Macaluso CB demo Attention Limited processing resources Overwhelming sensory input cannot be fully processed => SELECTIVE PROCESSING Selection via spatial orienting