Attention

What is attention

What is attention

attention controls what you consciously experience out of all the available information in the world

Endogenous attention

Voluntary, top down. Example: Posner spatial cueing paradigm- patients must detect and report a visual target as quickly as possible. Reaction time for expected locations are significantly faster than for unexpected or neutral locations

Exogenous attention

Reflexive, Bottom up. Stimulus-driven process for orienting oneself to salient stimuli

Spatial attention

Like a spotlight- can be moved voluntarily or drawn automatically to salient stimuli. Enhances visual processing of the area

ERP and attention

Event related potential measures the brain activity in response to stimulus or event. Attention increases ERP amplitudes to visual stimuli. It also increases ERP amplitudes to auditory

In example, there was an increase in ERP amplitude even when attending to a visual stimuli on left then when attending to nothing on the right.

Feature-based attention

Things like color, shape, letter

Conjunction search v Feature search

Conjunction search is much slower than feature search because you are paying attention to two features

Feature attention v spatial attention

Feature is slower and weaker than spatial attention. ERP for spatial attention are much greater in attended stream than unattended. For color, neural signal is a lot less different. Spatial attention may enhance color effect

Object based attention: specialization

Fusiform area- faces, parahippocampal place area - locations/places, word form area for reading

fMRI study of object-based attention

In face area, BOLD is high when attending to face whether moving or still. The same is for house area. There was less response when attending to the static face and moving face

Attention networks derived from rsfMRI and how were they created

Dorsal and Ventral- Areas that work together have correlated BOLD signals which is how they are mapped out

Dorsal attention network

Topographic- Has a map of space; important in top down processing. The frontal hub contains frontal eye field, superior parietal lobe, area above visual cortex

What does the frontal eye fields do in the dorsal network

plays a key role in directing where you are looking

What does the superior parietal lobe do in the dorsal network

The superior parietal lobe has a very fine grain map of space which plays a role in sending projections to V1 is amplify neural location in intended area.

What does the dorsal network area near the visual cortex

Processing things in space

What does damage to the dorsal network lead to

reduced modulation of visual activation by attention, so attention influences visual processing less. This is also seen in aging

Ventral attention network

Debatably right lateralized, not topographic. Bottom up-stimulus driven, detection of salient things, also very active in error-detection.

The result of damage to inferior parietal

Neglect syndrome

What is spatial neglect syndrome?

Ignore one side of space- people, objects, sound and are drawn to the other side. Patients are unaware of their deficits. They use strategies to try and overcome the problem w/o really recognizing it

How are patients with neglect affected by it?

Visual stream is fine but are unaware of items. Patients can orient to a cue on the neglected side if cued to attend but they have problems shifting attention from unneglected side to neglected side. They do not look at the left side the world and cannot do tasks in the left field of view. They forget info on the left (extinction)