Attention Flashcards
What is attention?
The process by which the mind chooses what to focus on out of the various stimuli that strike the senses at any moment.
Capacity
Not enough neural resource to process all of the information in the environment.
Selectivity
Allows some information to be better processed and enter the consciousness.
Cocktail party effect
Phenomenon to explain how we can focus our auditory attention while filtering out irrelevant stimuli.
- Similarly to a partygoer focusing on a conversation in a crowded room.
Ways of selecting
Top down= voluntary; goal directed- pay attention to info relevant to goals.
Bottom-up= reflexive; stimulus driven- certain info attracts your attention because of ecological importance.
Behaviour
Most attention studies measured covert attention except for eye-tracking studies.
Covert attention- directing attention without moving eye gaze.
Overt attention- eyes gazed upon attended items with movement involved.
Attentional modulation: Spatial cueing paradigm (Posner, 1980)
Neuropsychological test used to assess attention and individuals ability to perform attentional shift.
- Measure eye movement reaction times to target stimuli to investigate covert orienting of attention in response to different cue conditions.
- Reaction times for expected locations are significantly faster than those for unexpected and neutral locations.
- Cued attention is also affected by age (older observers show longer engagement and delated disengagement).
- Injury to areas of the midbrain and PD affect orienting ability.
Attentional modulation: Spatial cueing paradigm (Posner, 1980)
Neuropsychological test used to assess attention and individuals ability to perform attentional shift.
- Measure eye movement reaction times to target stimuli to investigate covert orienting of attention in response to different cue conditions.
- Reaction times for expected locations are significantly
Spatial attention
O.Connor et al: fMRI study of spatial attention effects in the LGN.
- increased activations when stimulus attended is in the contralateral hemifield to brain region being measured.
- effect both observed in LGN and in multiple visual cortices.
Feature-based attention
Schoenfeld et al: stronger activation in feature-specific visual cortex when feature is attended.
Object-based attention
O’Craven et al: stronger activation in the object-specific brain area when that object is attended.
- fusiform face area & parahippocampal place area.
Attentional modulation: comparison
- Space-based attention: enhanced activities in visual cortices.
Vs. - Feature-based attention: enhanced activities in feature-specific cortices.
- Object- based attention: enhanced activities in object-specific cortices.
Preparatory bias
Before the onset of targets: visual cues lead to enhanced activity in contralateral visual cortex before the target appears.
Attentional control: preparatory biasing activity (Grent-t-jong & Woldorff)
3 versions of a visual-spatial cueing paradigm; used to investigate the functional relationships between posterior oscillatory-alpha changes and our slow-wave biasing-related negativity (SWBRN).
- Results suggest SWBRN reflects spatially specific, pretarget preparatory activity sensitive to the expected perceptual difficulty of the target detection task.
Attention disorders: Balint’s syndrome
- Bilateral damage to portions of posterior parietal and occipital cortices.
- Simultanagnosia: inability to perceive simultaneous objects in the visual field.
