Textbook Notes (369,067)
Canada (162,366)
Neuroscience (289)
NROC64H3 (81)
Chapter 21

Chapter 21

3 Pages
116 Views

Department
Neuroscience
Course Code
NROC64H3
Professor
Matthias Niemeier

This preview shows page 1. Sign up to view the full 3 pages of the document.
Description
Chapter 21: Attention Introduction o Attention: state of selectively processing simultaneous sources of information  There is interactions between modalities  Has to do with preferential processing of sensory information  ADHD: inattention, hyperactivity and impulsiveness  5-10% of all school aged children worldwide  Some continue to show symptoms as adults  Cause: unknown  Smaller prefrontal cortex and basal ganglia  Hereditary  Non genetic factors: brain damage, pre mature birth.  D4 and D2 dopamine receptor gene and dopamine transporter gene  Ritalin: mild central nervous system stimulant, increases dopamine effect  Cortical activity affected by attention Behavioural Consequences of Attention o We place object on fovea o Can pay attention to something on retina outside fovea Enhanced Detection o Experiment: cue stimulus at fixation point, half trials small target flashed left or right after delay period  Cue: plus sign (equally likely target left or right), arrow (4x more likely it would appear on side arrow points to)  Had valid and invalid cues with arrows (valid 4x more likely than unlikely) There was a covert switch in attention without moving the eyes that made valid cues more  detected than neutral and invalid cues less detected than neutral  Less sensitive to side opposite of attention Faster Reaction Times o Experiment 2: told to push button when they perceive a stimulus at either location  Same arrows or plus  Invalid greater reaction time than neutral and valid had a smaller reaction time than neutral  20-30 msec difference o Attention can alter speed of visual processing Neglect Syndrome as an Attentional Disorder o Neglect syndrome: ignore objects, people and sometimes themselves to one side of center gaze o Less common after left hemisphere damage o Best studied after damage to the right side (neglect left side); right has to do with spatial sense o Often also show denial o Draw wrong, point wrong, o Lesions in posterior parietal cortex in right hemisphere  also after prefrontal cortex, cingulate cortex and others  Posterior parietal: involved in attending to objects at different positions in extrapersonal space  Neglect: hard to capture attention on neglected side or disengage attention from neglected side Physiological Effects of Attention o Changes in activity that have to do with attention Functional MRI Imaging of Attention to Location o Enhancement in detection and reaction time are selective for spatial location o Attention like a spotlight o Use fMRI to study o Experiment:  Focus on center and press button based on colour and orientation of lines  Pattern of brain activity shifts retinotopically  Most activity in segment that was being attended to PET Imaging of Attention to Features o Features: ex. Speed, shape, colour o PET  Experiment:  Had to determine whether two successive images where the same or different  Recorded brain activity when attending to different features  Selective attention: attended to one feature  Divided attention: attended to all features  Subtracted divided attention from selective attention to get image of changes in brain activity associated with attention to one feature  Findings:  Ventromedial occipital cortex and V4 and IT and other visual areas in temporal lobe for shape and colour
More Less
Unlock Document

Only page 1 are available for preview. Some parts have been intentionally blurred.

Unlock Document
You're Reading a Preview

Unlock to view full version

Unlock Document

Log In


OR

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


OR

By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.


Submit