Attention Flashcards
Selective Attention
The ability to prioritize and attend to somethings while ignoring others
Not a global brain state (allocated among relevant inputs, thoughts and actions while simulatneously ignoring irrelevant or distracting ones)
How does selective attention affect us
It influences how we process sensory inputs, store that information in memory, process it sematically, and act on it.
What is an assumption we make about attention in cognitive psychology?
attention is a limited resource
Top-down or goal-driven attention
Driven by an individual’s behavioral goals and shaped by learned priorities
Dorsal Attentional Pathway (Fronto-parietal)
Bottom-up or reflexive
Driven by a stimulus and much less dependent on current behavioral goals
Attentional Control Mechanisms
determine where and on what our attention is focused on
Types of Attention
Voluntary
Reflexive
Overt Attention
Covert Attention
Voluntary Attention
Our ability to intentionally attend to something
top-down process
Reflexive Attention
A bottom-up stimulus driven process in which a sensory event–maybe a loud band, captures our attention
Overt Attention
Turn your head to orient towards a stimulus whether it is for your eyes to get a better look, your ears to pick up a whisper, or your nose to sniff food
Covert Attention
Attention without orientation. It appears that one’s attention is on something but actually it is on something else.
Unilateral Spatial Neglect
Damage to one hemisphere (mostly stroke) only
Most sever impact is when the right hemisphere is damaged
Neglect of space contralateral to damaged hemisphere (ipsilesional bias in attetion. Have normal vison)
Not due to a memory failure, but spatial neglect can affect memory
Neuropsychological Tests for Unilateral Spatial Neglect
Line Cancellation Test - asked to bisect horizontal lines precisely in the middle by drawing a vertical line
Copying a Simple line drawing - copying a drawing of a daisy
Imagination - visual memory is neglected; attention to parts of the recalled images were biased not due to lacking memories
Extinction
Presence of a stimutaneous stimulus in the ipsilateral hemifield prevents the detection of a contralesional stimulus
Balint’s Syndrome
Severe disturbances of visual attention and awareness (perception)
Caused by bilateral damage to posterior parietal and occipital cortices
Only one or a small subset of available objects are perceived at any one time
Three main deficits of Balint’s Syndrome
Simultanagnosia
Ocular Apraxia
Optic Ataxia
Simulatanagnosia
Difficulty perceiving the visual field as a whole scene
Ocular Apraxia
Deficit in making eye movements to scan the visual field
Optic Ataxia
Deficit in making visually guided hand movements
Hermann von Helmholtz
1879 - studied visual attention and observed tha thwile keeping his eye fizated in the center of a screen during a very brief illumination of the screen he could perceive the letters located within this region but had difficulty perceiving the latters at other locations.
He attributed this phenomenon to attention and speculated on the possible mechanisms underlying this ability
E.C. Cherry
Dichotic listening paradigm
Can accurately repeat info in one ear when attending to it but could not recall the unattended input)
Cocktail Party Effect
Perceptual processing has limited capacity (information processing bottlenecks)
Early Selection
Stimulus can be selected for further processing, or it can be tossed out as irrelevant before perceptual analysis of the stimulus is complete
“gating”
Late Selection
All inputs are processed equally by the perceptual system; selection takes place at higher stages of information processing
Cognitive Processing of information encoding
information is registered (early selection) –> perceptually analyzed (early then late) –> semantic encoding/analysis (late selection) –> executive functions –> decisions, memory, etc –> response
Problems for Early Selection Models
Attention can be captured by relevant/interesting information
What is the middle ground that supports both early and late selection?
Anne Treisman
Unattended information is not completely blocked from higher analysis, but rather is degraded or attenuated
We can look at reaction time information on experiemental tasks to furthur examine early vs late selection models
Cuing Task
Arrowhead tells the participant that they should attend to that part of the field with target apearing (valid, invalid, or neutral trial)
Valid, invalid and neutral cue differences
invalid - longest
neutral - middle
valid - fastest
Valid trials show the benefits of attention
Additional support for early selection
When in a cuing task: a cue tells you to attend left or right and the object either appears valid or appears on the other side (invalid); sensitivity to spatial attention supports early selection modles of attention since attention on stimulus occurs 100ms after stimulus apprears on screen ERP
shows benefit of attention (very fast and huge difference in neural processing)
Cuing Tasks and fMRI
attending to the left side of space produces contralateral activation in hemispheres (about visual)
Support for early attention models in the Subcortical Regions
Amplitude of activation in the thalamus is greater for attended information that for unattended information
Highly focused visuospatial attention can modulate activity in the thalamus
Additional support for early selection models
attention invole either activiating or inhibiting signal transmission from thalamus to visual cortex
highly focused spatial attention can modulate activity early in the visual system in the subcortical relay nuclei in the thalamus
Reflexive attention and Inhibition of Retun (IOR)
Exogeneous cues influence processing in and around their locations… but for only a short amount of time (~50ms)
IOR: after about 300ms, participants respond slower to stimuli that appear in the vicinity of an exogeneous cue
Feature Attention
Objects are defined by their collection of elementary features, such as color, shape, size, motion, etc
Pre-curing attention to a visual feature improves reaction time on a cuin task
fMRI evidence for selevtive attention in modality-specific cortical regions
Schoenfeld et al. (2007)
attending to motion activated V1
Attending to color activates region V4
Object Properties
The collection of elementary stimulus features that, when combined in a particular way, yield an identifiable object or person
Attention is facilitated within the confines of a single object rather than across multiple objects
Attentional control systems
involved in modulating throughts and actions, as well as sensory processes
Dorsal Attention Network
Goal based/ top-down attention
helps guide or orient our attention to spatial informaiton
includes parietal lobe and frontal eye fields (FEF)
both the dorsal and ventrla attention pathways were already activated before the target appeared
Frontal Eye Fields
in the dorsal attention network
coordinate eye movement and gaze shifts, which are important for orienting attention
Can influence visual cortex activity
Evidence for FEF
stimulation of FEFs in monkeys enhances performance on attention tasks
parietal cortex and attentonal control
attentional shifts correlated with signification changes in activity of parietal neurons
Ventral attention network
stimulus driven/bottom-up control
Strongly lateralized to the right hemisphere
Subcortical attentional control
superior colliculi
pulvinar nucleus
superior colliculi
recieves info from retina, sensory systems and cerebral cortex
sends projections to teh thalamus and the motor system that controls eye movements
overt aspects of attention
pulvinar nuclues
in thalamus
involved in voluntary and reflexive attention
covert spatial attention and filtering of stimuli
