1. Melanie Boysen & Gwendolyn Walton
Attention
Melanie Boysen & Gwendolyn Walton

2. Watanabe, Forssman, Green & Bohlin (2012)
Aim: Development of cognitive control and its effect on the attention process
Participants: month olds and month olds
Babies sat on parent’s lap during the experiment

3. Method Babies separated into distractor or no distractor condition
Looked at a screen with Mickey Mouse
Image disappeared, delay, reappeared
Four A trials, long B trial (9 secs), short B trial (5.5 secs)
A and B trials
A: Image disappeared, 3.5 sec, sound, reappeared
B: image disappeared, delay,
Distractor
Bouncing ball presented for 2 s, after Mickey disappeared for .5 secs

4. Demonstration Test given to each 10 and 12 month old babies.
Used in both A and B trials

5. Results Eye tracker recorded eye movements during anticipation
12 month olds spent less time looking at A during B trials
No difference in age for increased attentional demand
10-month babies showed more (correct) perservative looking than 12-month babies
Development of inhibitory process needed for executive attention
Ability to shift attention and use working memory are needed to master goal-directed behavior

7. Wu, Libertus, Meyerhoff, & Woldorff (2011)
Feature Integration Theory by Treisman & Gelade
Studies from this time pointed to focal attention’s importance
Other research results showed less slope so focal attention might not be as important
Availability of focal attention greatly reduced, still perform perceptual tasks well

8. Study’s Aims
Investigate perceptual categorization of objects on visual pathway under distributed vs focal spatial attention
Explore temporal dynamics of neural activity reflecting object categorization processing during the transition from distributed attention state to focused attention (focal attention is shifted to specific object)
Our ability to categorize things we are seeing in distributed versus focal spatial attention
Look at ERPs to determine when attention is being shifted and when participants could successfully complete the tasks

9. Participants Only 16 Other participants were excluded
With Normal or corrected-to-normal vision
Other participants were excluded
Eye blinks
High frequency noise with some malfunctioning equipment

10. Method Participants instructed to focus on “X”
Shift attention to the image that changed to a color scheme different than the rest and press button if the image was slightly blurred (whether a house or a face)
Recorded brain activity with EEG against two markers: N2pc and N170
Wu and colleagues used a color popout visual search task. Participants were told to look at the x in the center of six images (3 houses and 3 faces). After a specified amount of time that varied depending on the trial, the images shifted from gray-scale to either yellow or cyan. One of the six images was one color and the other five were the other color. When the images changed color, participants were to shift their attention to the image of the odd color. If that image was blurry, participants were to push a button. EEG was used to monitor brain activity during the task

11. N2pc and N170 (FH_Ndiff) ERP markers
N2pc is a second negative potential
Peaks msec after stimulus array with goal-relevant popout item
Amplitude usually largest over posterior parieto-occipital scalp contralateral to goal-relevant popout item
N170 is a negative ERP component largest for face stimuli compared to other object stimuli
Used to compare the responses to houses and faces
Peaks 170msec after stimulus onset of color change
Renamed because it was after onset of color change not beginning of recording. Name of it isn’t that important.

12. Behavioral Results Participants accurately detected presence of blur
Delay of attentional allocation reflected in relative delays of mean RT
No delay = 468msec
50ms delay = 507msec
100ms delay = 565msec
Highly significant
Difficulty level of identifying blurred face was very similar to identifying blurred house

13. Electrophysiological Results
As predicted, participants shifted spatial attention according to three delays of color-popout attentional shifting cues
Shown by corresponding delays of N2pc effects
Object-specific categorization processes were taking place without focal spatial attention at least enough that face-specific neurophysiological activity occurred

14. Discussion
Some degree of object specific representation can be performed in parallel when spatial attention is distributed
Once spatial attention is shifted to a specific location, enhancement and extension of neural activity occurs
Initial parallel processing of input seems to speed up attentional enhancement of neural processing once focused attention is directed to that item, because of presence of stimulus information in visual pathways before attentional shift

15. References
Watanabe, H., Forssman, L., Green, D., Bohlin, G., & von Hofsten, C. (2012). Attention Demands Influence 10- and 12-Month-Old Infants' Perseverative Behavior. Developmental Psychology, 48(1), doi: /a
Wu, C. T., Libertus, M. E., Meyerhoff, K. L., & Woldorff, M. G. (2011). The Temporal Dynamics of Object Processing in Visual Cortex during the Transition from Distributed to Focused Spatial Attention. Journal Of Cognitive Neuroscience, 23(12),