1. 11 Attention
Psychology 355

2. Introduction
Attention: State of selectively processing simultaneous sources of information
Benefits: Performance of behavioral tasks
Brain Imaging – changes in cortical activity
Behavioral manifestations
Visual attention; Auditory attention
Psychology 355

3. Introduction Functions of attention
Concentrate on one object in visual field
Selectively attend to information (while ignoring other information)
Preferential processing of sensory information
Attention-deficit hyperactivity disorder
Demonstrates critical nature of intact attentional mechanisms
Brain imaging studies
Show that cortical activity is altered by attention
Psychology 355

4. Behavioral Attention Visual attention
Move eyes until object imaged on fovea
Shifting attention
Enhanced visual processing
1) Enhanced detection
2) Faster reaction times
Psychology 355

5. Behavioral Attention +
->
<-
Psychology 355

6. Behavioral Attention Faster Reaction Times Enhanced Detection
Psychology 355

7. Behavioral Attention Neglect Syndrome as an Attentional Disorder
Person ignores objects, people, and their own body to one side of the center of the gaze
Psychology 355

8. Physiological Attention
Shifting attention
What happens to neural activity?
What brain areas are involved?
Observed in high-level cognitive and numerous sensory areas e.g., Area V1 to visual cortical areas in the parietal and temporal lobes
Psychology 355

9. Physiological Attention
Functional MRI Imaging of Attention to Location
Subjects view stimulus
Change location of attended sector
Brain activity shifts retinotopically
Psychology 355

10. Physiological Attention
PET Imaging of Attention to Features
Same-different discrimination task
Features: Color, shape, speed
(A) Selective attention: one feature
(B) Divided attention: all features
Subtract B from A shows brain activity associated with attention to one feature
Psychology 355

11. Physiological Attention
PET Imaging
Attention to
Features
Speed
Color
Shape
Psychology 355

12. Physiological Attention
Enhanced Neuronal Responses in Parietal Cortex
Attention: Experimental vs. Normal conditions
What happens to attention under normal conditions?
Test the Hypothesis: Attention changes location prior to eye movement
Wurtz, Goldberg, and Robinson: Record neural activity from Posterior Parietal
Psychology 355

13. Physiological Attention
Enhanced Neuronal
Responses in Parietal
Cortex
A Posterior parietal cortex neurons
B Directing eye movements
C Response significantly enhanced neuronal response when eyes went to target
Its either an attention shift or a premotor signal
Psychology 355

14. Physiological Attention
Receptive Field Changes in Area V4
Psychology 355

15. How is Attention Directed?
Cortical, subcortical areas
Modulate the activity of neurons in sensory cortex areas
The Pulvinar Nucleus
In humans: Damage to the PN results in slow responses to stimuli on the contralateral side
Muscimol (GABA agonist; suppresses activity) in monkey PN results in impairment of attention shifting
Psychology 355

16. How is Attention Directed?
Attention and Eye Movements
Eye moves to attended object
Eye movements & attention closely related
Recent experiments
Brain circuitry: Directing eyes to objects of interest
Frontal Eye Fields (FEF)
Cortical area
FEF neurons
Psychology 355

17. How is Attention Directed?
Attention and Eye Movements (Cont’d)
Experiment
Train monkeys to look at display of small light spots
Place electrode in FEF and determine motor field of neurons at the tip
Small electrical stimulation enhancement?
Psychology 355

18. How is Attention Directed?
Attention and Eye Movements (Cont’d)
Results
FEF involved in directing attention; Enhancing visual performance
Conclusion
Guidance of attention Integrated with system to move eyes
Psychology 355

19. Concluding Remarks Studies of attention
Point to flexibility of the human brain
More mental energy to one location
Enhanced sensitivity & reaction time
Ignoring competing stimuli
Need for attention
e.g.,- Cannot process ALL information in area V1
Selects what information should access the limited processing resources
Psychology 355

20. End of Presentation
Psychology 355