Attention Flashcards
Posner cuing test
On a screen with a fixation point, a cue appears directing which way the participant should shift their attention. A target then appears on screen afterwards
Invalid Posner cuing test trial
Cue points to the opposite side of the screen where the target will appear
Valid Posner cuing test trial
Cue points to the same side of the screen where the target will appear
Neutral Posner cuing test trial
Cue points to either side of the screen
How do reaction times change for valid and invalid trails
Invalid trials have a much longer response time than valid trials, while neutral trials are in the middle
Reflexive capture of attention
On a screen with a fixation point, an unexpected stimulus pops up. After a delay, a target appears.
How do short delays affect reaction time in reflexive capture of attention
Short delays enhance reaction time in valid trials
How do long delays affect reaction time in reflexive capture of attention
Long delays cause slower reaction time in valid trials
- Have a faster reaction time for invalid trials than valid trials
Endogenous/top-down attention
Cuing yourself to redirect your attention (looking for somebody you know is coming from the other side of the street)
Exogenous/bottom-up attention
An external unexpected stimulus causes you to redirect your attention
Timeline and intensity of endogenous attention
Endogenous attention happens slowly, but can be maintained for longer periods of time
Timeline and intensity of exogenous attention
Exogenous attention happens rapidly, but fades very quickly unless the stimulus is important
Feature search
Looking for a single attribute (looking for a yellow object or looking for a square object)
Conjunction search
Looking for two or more attributes at the same time (looking for a yellow circle or a green square)
Reaction time differences for feature and conjunction search
- Feature search has the fastest reaction time
- Conjunction search with a present target is slower than feature search
- Conjunction search with the target absent takes the longest time
Event related potentials
EEGs of multiple trials are averaged
- Earlier waveforms in the ERP are exogenous attention cues
- Later waveforms in the ERP are endogenous attention cues
N1 effect
Large negativity in the ERP occurring about 100 ms after presentation of a stimulus, which is enhanced for input we consciously direct our attention to
P3 effect
Large positivity in the ERP occuring 300-500 ms after presentation of a stimulus, which is associated with higher order processing and late selection effect of auditory stimuli
P1 effect
Large positivity in the ERP that occurs 70-100 ms after presentation of a stimulus, which is enhanced for VISUAL input we consciously direct our attention to
How does covert orientation of attention affect neural processing and detection
Valid cues that covertly direct attention toward a stimulus significantly enhance neural processing and detection shown by enhancements in P1 and N1 components in the ERP
N2pc effect
Second negativity after stimulus presentation that is triggered at occipitotemporal sites contralateral to visual target; reflects selective processing of targets
Pd effect
Large positivity associated with ignoring distractors
What ERP changes are observed when a participant is asked to attend to one stimulus and ignore another
N2pc is seen and associated with covert attention when instructed to focus on the red line, while Pd was a different ERP component associated with ignoring distractors
Information from which hemiretina crosses over
Nasal hemiretina
Information from which hemiretina stays ipsilateral
Temporal hemiretina
What do PET and fMRI scans show us about attention
Brain regions that process key aspects of the visual stimuli show an enhancement of activity
How does brain activity differ when covert attention is directed to one stimulus versus dividing it between two stimuli
Covert attention to one stimuli resulted in enhanced activity in one region of visual cortex; attention to two stimuli resulted in enhanced activity in two corresponding regions of the visual cortex
What are some ways attention can change the activity of individual neurons?
- Enhanced or suppressed response: neurons fire either more or less in response to possible stimuli
- Tuning to more specific stimuli: neurons only fire for a smaller range of stimuli
- Tuning to favor different stimulus: neurons fire for different stimuli
Effect of preferred vs. ineffective visual stimuli within a receptive field on neuron activity
When attention was directed toward an ineffective stimulus within a receptive field without shifting gaze, rates of firing for a neuron were significantly diminished compared to a preferred stimulus
How can attention affect receptive fields
Covertly shifting attention within a receptive field without shifting gaze can shift peak sensitivity within a receptive field (as well as shrink receptive field to reduce distractors)
Superior colliculus and attention
Directs visual gaze and visual attention to intended stimuli (compared to covert stimuli)
Pulvinar and attention
Important for orienting and shifting attention; directs and synchronizes relevant information in response to attentional demands
Frontal eye field
Area in the frontal lobe that establishes gaze based on cognitive goals
Dorsal frontoparietal system
Intraparietal sulcus and frontal eye field; cognitive control of voluntary attention
Right temporoparietal system
Temporoparietal junction, ventral frontal cortex; reflexive capture of attention
ER-fMRI
Event related fMRI; links rapid behavioral events to changes in activity of selected brain regions
What brain patterns were seen in ER-fMRIs when directing voluntary attention
Enhanced activity in the frontal eye field and intraparietal sulcus
What brain activity is seen when unexpected stimuli appear
Regardless of the location of the stimulus (right of left), brain activity is enhanced in the right temporoparietal junction when shifting attention to a new location
Connection between IPS and TPJ systems
Allow for shift of attention between intended objects of attention as well as novel stimuli
What is hemispatial neglect
Failure to pay attention to objects presented to one side of the body
How does hemispatial neglect prove a lateralization of attention
People with hemispatial neglect ignore things on the left, reinforcing the idea of specialized attentional mechanisms in the right hemisphere
- Only drawing the right side of objects
- Failure to eat food on the left side of their plate
- Won’t dress the left side of their body
What similarity in brain areas can be seen between people with hemispatial neglect and the cortical attention network
The areas lesioned in hemispatial neglect greatly overlap with the frontoparietal attention network
Name 2-3 aspects of consciousness
- Theory of mind
- Mirror recognition
- Imitation
- Empathy and emotion
- Tool use
- Language
- Metacognition (considering the content of our own thoughts and cognitions)
Default mode
State of the brain when it’s awake, at rest. Most activated when we are introspective and reflective as opposed to focusing on external sitmuli (daydream network)
What parts of the brain have reduced activity when unconscious
A frontoparietal network including:
- Dorsolateral prefrontal cortex
- Medial frontal cortex
- Posterior parietal cortex
- Posterior cingulate
Claustrum
Grey matter in between the external and extreme capsule
What role does the claustrum play in consciousness
Its reciprocal connections with almost every area of the cortex lead to stimulation of the claustrum causing a switching off of conscious awareness
Evidence that unconscious people can communicate
Two different mental images were used to create distinct yes or no patterns of brain activity; patients in a deep vegetative state showed similar brain activity when answering questions when compared to control subjects
Easy problem of consciousness
Understanding how particular patterns of neural activity can create specific conscious experiences
Hard problem of consciousness
How to read people’s subjective experience of consciousness
Brain activity reflecting the easy problem of consciousness
Being able to interpret patterns of brain activity as responses to certain images or being asked to reconstruct a simple shape
Brain activity reflecting the hard problem of consciousness
Being able to tell what color a person was looking at based off brain activity, but not knowing what it feels like in another person’s mind
- Can both identify a color as red but the color red might look different to two different people
Evidence for a lack of free will
Participants are shown a screen flashing a random sequence of letters, and are asked to recall what letter was on the screen when they pressed a button on either the right or left
- Based on brain activity in decision making regions, scientists are able to predict which button participants will press up to 10 seconds before they press the button
What major brain region separates humans from other animals
The prominence of our prefrontal cortex (PFC) compared to the rest of our cerebral cortex
Phineas Gage
A man who underwent drastic behavioral changes after extreme damage to his frontal lobe
Wisconsin card sorting test
Sort a card into a category based on rules that change every 10 seconds
How does PFC damage affect performance on the Wisconsin card sorting task
PFC damage makes it hard to adapt to the changing rules; they keep sorting cards according to previous rules
Dysexecutive syndrome
Diminished judgement and planning, diminished self care, motor programming deficits
Disinhibited syndrome
Stimulus driven behavior, diminished social insight, distractibility
Apathetic syndrome
Diminished spontaneity, diminished verbal output, increased response latency
Prefrontal brain region affected in dysexecutive syndrome
Dorsolateral prefrontal
Prefrontal brain region affected in disinhibited syndrome
Orbitofrontal prefrontal
Prefrontal brain region affected in apathetic syndrome
Mediofrontal
Stroop task
Read aloud color names printed in the same color (the word blue printed in blue) or incongruent color (the word blue printed in white)
Controlled oral word association test
Saying as many words as possible that start with a specific letter
Effect of cooling brain regions on delay tasks
Cooling the dorsolateral prefrontal cortex leads to a decrease in correct answers of a delay task compared to cooling the posterior parietal cortex
