NEUR305 - selective attention and anatomy of attention

burst mode

captures moment-to-moment flunctuations in this state of internal readiness

tonic alertness

captures the sustained vigilance of an aroused state

conflict monitoring

reliant on the frontoparietal and cingulo-opercular networks

involves detecting and resolving competition between dominant and nondominant responses

stroop task

say the names of the colors of the word and not the word itself

ie. the word is black, but it’s yellow. you want to say black since that’s the word but you have to go slower and say yellow

orienting (selective attention)

concerned with prioritizing the sensory representations that capture our attention

can be top-down, goal driving stimuli or through bottom up, salient stumuli

usually measured with spatial attention tasks

arousal

global physiological and psychological state of an organism

selective attention

ability to prioritize some things and not others (at any level of arousal)

selective attention involves

focusing on certain things while ignoring others

top down processing

a form of information processing in which an overall hypothesis about or general conceptualization of a stimulus is applied to and influences the analysis of incoming stimulus data

bottom up processing

a form of information processing in which incoming stimulus data initiate and determine the “higher level” processes involved in their recognition, interpretation, and categorization

what is the most important different between top down and bottom up processing of stimuli?

inference (being able to make a prediction via prior data, taking info you already have)

ADHD

• attention deficit hyperactivity disorder

• heterogeneous genetic and environmental factors

• may result from reduced white matter through the brain, especially the prefrontal cortex

• don’t know what mechanisms are affected by the disorder

symptoms of balint’s syndrome

1. difficulty perceiving visual field as a whole scene

2. inability to guide eye movements voluntarily

3. difficulty reaching to grab an object

causes of balint’s syndrome

caused by bilateral damage to regions of the posterior parietal and occipital cortex

could be caused by stroke, dementias

visuospatial neglect

patients have normal vision, but exhibit deficits in attending to and acting in the direction opposite to the side of unilateral brain damage

patients with left side neglect have damage to the

right side of the brain

visuospatial neglect also affects imagination…

not a problem with memory or recall itself, but attention to parts of recalled images was biased

extinction

occurs when patient presented with two stimuli simultaneously - the presence of the competing stimulus in the ipsalateral hemifield prevents the patient from detecting contra-leisonal stimulus

neglect patients can detect items in their neglected field when presented in isolation

dorsal system of attention

primarily involved with voluntary attention based on spatial location, features, and object properties

ventral system of attention

stimulus novely and salience

dorsal attention network

• regions only active when participants are cued to attend

• when targets appear after cue, different pattern of neural activity observed

• when participants passively view cues, the frontoparietal regions active when cued aren’t active

• areas: IPS, SPL, PC, FEF, SEF

parietal cortex and top-down control of attention

believed to be involved in attentional shifts

ventral attention network

novelty and attentional reorienting

areas: TPJ, MTG, and VFC

right hemisphere dominant

superior collilculus

projects multiple outputs to the thalamus and motor system, controls eye movements involving in changing focus of overt attention

pulvinar of thalamus

receives input from the SC

important role in attention and visual sensory processing (predictive coding), promotes synchronized activity of the cortex

FEF

coordinates eye movements and gaze shifts

brain mechanism for planning eye movements and directing visuospatial attention overlap

studies of microstimulation of FEF in monkeys (generate saccades) and with TMS in humans