1
Q
attention
A
the narrowing down or focusing of awareness selectively to a part of the sensory environment or to a class of stimuli
2
Q
automatic processing
A
- unconscious (direct behavior occurs without intention)
- bottom up
- data driven
- relies almost exclusively on stimulus info presented by environment
- when stimuli comes to notice unexpectedly
- ex: stopping at a red light
3
Q
conscious processing
A
- not automatic, controlled, effortful, and attentive, requires focused attention
- top down
- conceptually driven
- relies on info already in memory
- when you are actively looking for something
- ex: actively searching for a street sign to make a turn
4
Q
whatever unique cortical circuits are recruited in attentive processing must include processes of consciousness
A
- response times differed dramatically depending on the nature of the stimulus
- when task requires identifying a target with an extra line - search time is indep of number of distractors
- when task requires participant to find target, distinguished by the lack of a feature, the time taken to find target varies directly with the number of distractors
- certain aspects of visual processing are automatic (left), but all other aspects of visual processing depend on focused attention to locate the conjunction (combination of features)
- concluded: although practice can speed up feature processing, it remains dependent on specific automatic neural associations between features, as wells as on serial processing pathways
5
Q
conjunction search
A
- serial process
- as if a mental spotlight were scanning from one location to another
- looking for particular combinations of sensory info
6
Q
perceptual feature search
A
cognitive strategy for scanning for specific features of stimuli
- a stimulus registered in area v1 is broken down into separate feature maps → info is serially processed in parallel pathways
- bits of visual world must be processed serially with some reentry process
- attention is directed to each location and feature present in same fixation of attention are combined to form a single object
- when features are assembled, the object can be perceived and held in memory as a unit
7
Q
what is a feature?
A
- properties the visual system codes cells to detect
- biologically significant stimuli
8
Q
A
- participants faster at detecting sad faces upside down or right side up
- biologically something is more important about detecting sad, negative than happy positive stimuli
- maybe certain cells in amygdala are especially tuned to fear related stimuli
- negative stimuli appear to be attended to very efficiently and to demand attention more than do targets for more positive features
9
Q
evidence of attentionn
A
the same stimulus must activate a neuron at one time and not at another → rules out possibility that the changes in neural activity are somehow related to the actual features of the target stimuli
10
Q
evidence of attention
A
- the same visual stimulus could be presented to different regions of the neuron’s receptive fields, but the importance of the info varied with its location
- cells in V4: sensitive to color and form
- different neurons responded to different conjunctions of features
- the cell was highly active only when the effective stimulus was in the correct location
- conclusion: when attention is focused on place in the visual world, neurons appear to respond only to the stimuli appropriate to that place
11
Q
perceptual systems do not always work at peak efficiency → divided attention
A
- the capacity to perform mental activity is limited and must be allocated among different concurrent activities
- we can process only so much info at once, and if we are overloaded a bottleneck in processing occurs
- one aspect of attention is therefore the amount of effort directed toward a particular task
- if a task is routine (driving on a road without much traffic), little attention or focus is used and the driver can carry on a conversation
- at a busy intersection however, attention must be focused on the task and the conversation briefly interrupted
- some process must be active to shift and focus attention in reponse to changing task demands
12
Q
selective attention: how do cells vary their firing characteristics in accord with the amount of the effort needed to solve a problem?
A
a given V4 cell responds optimally to a given orientation and color, but this tuning is not precise, and the cell will respond to orientation and colors that approximate the preferred range
13
Q
parallel processing of sensory input
A
- binding problem of processing multiple objects in the attentional spotlight
- different objects must be retained as separate items
14
Q
solutions to binding problem of processing multiple objects
A
- cells sensitive to complex configurations
- a neuron could respond to a square above a circle, but not to a circle above a square
- serial selection of items (parallel processing)
- a scene will be processed in very brief cycles that allow us to process items in parallel
- cross modal: locate our attention both within and between modalities as we process audovisual info
15
Q
cross modal
A
locate our attention both within and between modalities as we process audovisual info
16
Q
experiment: participants asked to perform a task requiring that they attend to the stimuli
A
- greater brain activation in areas corresponding to the modality of attentional force
- selective attention led to an increased activation in relevant sensory cortices and a decreased activation in irrelevant ones
- no change in sensory cortical activation relatively to a passive baseline resting conditionn
- sensory activation less than the sum of the activity seen in unimodal conditions
- major change in activation shown in left DLPFC
- distinct neural processes control the two forms of attention
- talking while driving - must recruit additional PFC
- if the PFC is already engaged because ex we are planning a driving route, attention to one or more of the concurrent tasks will be likely lost
17
Q
task: row of boxes viewed by participants who fixated on another box located just above the row
testing?
A
- fixed attention (maintain fixation on central box and ignore movement of light)
- shifting attention (as light moved from box to box)
18
Q
task: row of boxes viewed by participants who fixated on another box located just above the row
results
A
- increase of activation in the posterior parietal cortex attending to the moving light
- the right parietal cortex active when the stimulus is in either visual field
- the left parietal cortex active only when the stimulus is in contralateral right visual field
- findings may explain why patients with right posterior parietal lesions show more pronounces contralateral neglect than do patients with left hemisphere lesions
- in absence of left parietal cortex - representation of right visual field remains in the right parietal cortex
- in absence of right parietal cortex - there is no representation of the left visual field and the region is therefore neglected
19
Q
Petersen & Posner
comprehensive integrative theory outlining several discrete networks of attention
(#)
A
- the attention system is anatomically separate from the sensory systems
- attention includes networks of distributed anatomical areas
- these areas form distinct networks, alerting, orientating, and executive control
20
Q
network?
A
alerting network
21
Q
alerting network
A
- ascending reticular activating system (RAS): maintain alertness, neuromodulating noradrenergic projection from LC
- drugs acting on noradrenergic release affect the alerting system
- locus coeruleus (LC)
- ex: warning cue provides no info about what is to follow, but when it appears an experimental participant’s orientation and response to target automatically speed up
- locus coeruleus (LC)
22
Q
locus coeruleus (LC)
A
prepare regions, esp in prefrontal and posterior parietal cortices, to detect stimuli rapidly
alerting network
23
Q
orienting network
A
prioritizes sensory inputs by selecting a sensory modality or a location in space or a feature of the stimulus
includes: dorsal and ventral orientating network
24
Q
dorsal orienting network
A
- right lateralized
- top down process to synchronize visuospatial orienting system activity
- lesions in the region are central to the neglect syndrome
25
26
ventral orienting network
1. synchronizing orienting system activity with bottom up sensory input (coming in the primary and secondary regions)
* reduce the influence of other competing sensory inputs
2. influenced by the pulvinar nucleus in the thalamus
* pulvinar neurons respond to the same stimuli more vigorously as targets of behavior, then when these stimuli are not targets of behavior the cells have a low firing rate
* and when the same stimulus signifies every word, the cell become more active
* may play some role in attentional spotlight
27
28
29
executive control of attention system
top down role
includes frontoparietal network and cingulo-opercular network
30
dorsolateral-pFC-parietal network (frontoparietal network)
executive control of attention system
relate task instructions that are transient at the beginning of a new task
31
anterior cingulate/medial frontal anterior insular network (cingulo-opercular network)
executive control of attention system
sustained activity across a task
32
dorsolateral-pFC-parietal network (frontoparietal network)
33
anterior cingulate/medial frontal anterior insular network (cingulo-opercular network)
34
attentionn
self regulation
* self-control correlates with activity in the lateral prefrontal and cingulate regions of the attentional networks
* children's self regulation is largely based on orientation to sensory events, and it is not until the executive attentional systems begin to mature about three to four years of age
35
attention
stress
* stress may interfere with the frontoparietal executive attentional networks
* decreased DLP FC anterior cingulate cortex and premotor and posterior parietal cortices
36
mechanisms of attention - how does the attentional spotlight select what's important?
the attentional system includes synchrony across a population of neurons that assess some sensory signal
37
synchronous outputs
synchronous outputs are summed to initiate larger excitatory post synaptic potentials (EPSPs) leading to action potentials in postsynaptic neurons
38
inattention
each shows failure to detect detectable stimuli
39
inattention blindness
* fail to notice an event that occurs as they are performing another task
* task: failure to notice a dot flashed on a computer monitor during a performance of a simple visual task
* 70% of participants did not see the gorilla
40
change blindness
* participant fails to detect change in the presence, identity, or location of objects in a scene
* most likely to occur when people do not expect changes
41
attentional blink
* fail to detect a second visual target presented within 500 milliseconds of the first one
* attention to first target prevents to be aware of the second one, even if the change is extremely conspicuous
42
sensory neglect
* person does not respond to sensory stimulation → parietal cortex lesion
* left side of surrounding space ceased to exist
43
sensory neglect experiment
* right parietal region is engaged when attended stimuli are in the right or left visual fields
* the left parietal region is engaged only for stimuli in the right visual field
* when the right parietal region is damaged, no backup system exists for the left side of space and it is excluded from conscious awareness
* frontal lobe involvement in directing attention leads us to wonder whether frontal lesions will also produce a neglect sundrome
44
prism adaptation experiment: test if possible to modify attentional system to attend to left side info
* improvement long lived and lasted for at least two hours after prism removal
* activity in either the healthy left or remaining right parietal region recruited to deal with distorted visual inputs
45
consciousness
def and criteria
level of responsiveness of the mind to impressions made by the senses
1. it is likely a collection of many processes
2. it is not always the same and varies across the development and even across the span of the day
3. more than simply being responsive to sensory stimulation or being able to produce movement
* bc the isolated spinal cord is not conscious
4. language fundamentally changes the nature of human consciousness
* but ppl who are aphasic have not lost consciousness awareness
5. provides adaptive advantage in processing complex information
46
neural correlates of consciousness
arousal, perception, attention, working memory
47
arousal
waking the brain up via nonspecific neural modulatory systems
48
perception
detection unbinding of sensory features
49
attention
| (neural correlate)
selection of a restricted sample of all available info for faster processing
50
working memory
short term storage of ongoing events
51
phase synchrony
* all processes either require or modify the operation of an overall binding process, implemented by the synchronization of neural discharges
* neuronal groups exhibit synchronous oscillations (6-80 Hz) and can shift from a desynchronized state to a rhythmic state in milliseconds
* phase synchrony acts not only to bind the sensory attributes but also to bind all dimension of the cognitive act, including associative memory, emotional tone, and motor planning
52
mooney faces
* when viewing mooney faces, synchronous activity in the gamma range (40 hz) can be recorded from participants' brain
* when viewing them upright, the faces can be clearly found
* when viewing inverted, finding the face is impossible
53
As the human brain evolved an increased sensory capacity, it also required a mechanism for selective awareness and stimulus response. This mechanism is called...
attention
54
Searching for a street sign in order to make a turn is an example of a(n) _____ process.
top down
55
Stimuli that “pop out” in a visual array illustrate the concept of ...
bottom-up processing
56
Moran and Desimone showed that monkey neurons responded selectively to specific stimuli in their visual fields ...
a. after reward training
b. when the stimulus was green
c. when the stimulus was presented to the right hemifield
d, when the stimulus was presented to the left hemifield
a. after reward training
57
Summarizing several studies, Corbetta and colleagues found that the parietal cortex is particularly active during tasks that require attention to \_\_\_\_\_.
location
58
When subjects fail to detect a second visual target if it is presented within half a second of the first one, this is called ...
attentional blindness
59
Sensory neglect is a disorder that involves lesions to which brain region?
the right parietal cortex
60
All of the following are processes believed to be prerequisites for consciousness EXCEPT...
a. attention
b. arousal
c. language
d. working memory
c. language
61
the narrowing down or focusing of awareness selectively to a part of the sensory environment or to a class of stimuli
attention
62
* unconscious (direct behavior occurs without intention)
* bottom up
* data driven
* relies almost exclusively on stimulus info presented by environment
* when stimuli comes to notice unexpectedly
* ex: stopping at a red light
automatic processing
63
* not automatic, controlled, effortful, and attentive, requires focused attention
* top down
* conceptually driven
* relies on info already in memory
* when you are actively looking for something
* ex: actively searching for a street sign to make a turn
conscious processing
64
* serial process
* as if a mental spotlight were scanning from one location to another
* looking for particular combinations of sensory info
conjunction search
65
cognitive strategy for scanning for specific features of stimuli
* a stimulus registered in area v1 is broken down into separate feature maps → info is serially processed in parallel pathways
* bits of visual world must be processed serially with some reentry process
* attention is directed to each location and feature present in same fixation of attention are combined to form a single object
* when features are assembled, the object can be perceived and held in memory as a unit
perceptual feature search
66
* properties the visual system codes cells to detect
* biologically significant stimuli
what is a feature?
67
* participants faster at detecting sad faces upside down or right side up
* biologically something is more important about detecting sad, negative than happy positive stimuli
* maybe certain cells in amygdala are especially tuned to fear related stimuli
* negative stimuli appear to be attended to very efficiently and to demand attention more than do targets for more positive features
68
the same stimulus must activate a neuron at one time and not at another → rules out possibility that the changes in neural activity are somehow related to the actual features of the target stimuli
evidence of attentionn
69
* the same visual stimulus could be presented to different regions of the neuron's receptive fields, but the importance of the info varied with its location
* cells in V4: sensitive to color and form
* different neurons responded to different conjunctions of features
* the cell was highly active only when the effective stimulus was in the correct location
* conclusion: when attention is focused on place in the visual world, neurons appear to respond only to the stimuli appropriate to that place
evidence of attention
70
* the capacity to perform mental activity is limited and must be allocated among different concurrent activities
* we can process only so much info at once, and if we are overloaded a bottleneck in processing occurs
* one aspect of attention is therefore the amount of effort directed toward a particular task
* if a task is routine (driving on a road without much traffic), little attention or focus is used and the driver can carry on a conversation
* at a busy intersection however, attention must be focused on the task and the conversation briefly interrupted
* some process must be active to shift and focus attention in reponse to changing task demands
perceptual systems do not always work at peak efficiency → divided attention
71
a given V4 cell responds optimally to a given orientation and color, but this tuning is not precise, and the cell will respond to orientation and colors that approximate the preferred range
selective attention: how do cells vary their firing characteristics in accord with the amount of the effort needed to solve a problem?
72
* binding problem of processing multiple objects in the attentional spotlight
* different objects must be retained as separate items
parallel processing of sensory input
73
1. cells sensitive to complex configurations
* a neuron could respond to a square above a circle, but not to a circle above a square
2. serial selection of items (parallel processing)
* a scene will be processed in very brief cycles that allow us to process items in parallel
* cross modal: locate our attention both within and between modalities as we process audovisual info
solutions to binding problem of processing multiple objects
74
locate our attention both within and between modalities as we process audovisual info
cross modal
75
* greater brain activation in areas corresponding to the modality of attentional force
* selective attention led to an increased activation in relevant sensory cortices and a decreased activation in irrelevant ones
* no change in sensory cortical activation relatively to a passive baseline resting conditionn
* sensory activation less than the sum of the activity seen in unimodal conditions
* major change in activation shown in left DLPFC
* distinct neural processes control the two forms of attention
* talking while driving - must recruit additional PFC
* if the PFC is already engaged because ex we are planning a driving route, attention to one or more of the concurrent tasks will be likely lost
experiment: participants asked to perform a task requiring that they attend to the stimuli
76
1. fixed attention (maintain fixation on central box and ignore movement of light)
2. shifting attention (as light moved from box to box)
task: row of boxes viewed by participants who fixated on another box located just above the row
testing?
77
* increase of activation in the posterior parietal cortex attending to the moving light
* the right parietal cortex active when the stimulus is in either visual field
* the left parietal cortex active only when the stimulus is in contralateral right visual field
* findings may explain why patients with right posterior parietal lesions show more pronounces contralateral neglect than do patients with left hemisphere lesions
* in absence of left parietal cortex - representation of right visual field remains in the right parietal cortex
* in absence of right parietal cortex - there is no representation of the left visual field and the region is therefore neglected
task: row of boxes viewed by participants who fixated on another box located just above the row
results
78
1. the attention system is anatomically separate from the sensory systems
2. attention includes networks of distributed anatomical areas
3. these areas form distinct networks, alerting, orientating, and executive control
Petersen & Posner
comprehensive integrative theory outlining several discrete networks of attention
(#)
79
* ascending reticular activating system (RAS): maintain alertness, neuromodulating noradrenergic projection from LC
* drugs acting on noradrenergic release affect the alerting system
* locus coeruleus (LC)
* ex: warning cue provides no info about what is to follow, but when it appears an experimental participant's orientation and response to target automatically speed up
alerting network
80
prepare regions, esp in prefrontal and posterior parietal cortices, to detect stimuli rapidly
alerting network
locus coeruleus (LC)
81
prioritizes sensory inputs by selecting a sensory modality or a location in space or a feature of the stimulus
includes:
orienting network
dorsal and ventral orientating network
82
1. right lateralized
2. top down process to synchronize visuospatial orienting system activity
* lesions in the region are central to the neglect syndrome
dorsal orienting network
83
1. synchronizing orienting system activity with bottom up sensory input (coming in the primary and secondary regions)
* reduce the influence of other competing sensory inputs
2. influenced by the pulvinar nucleus in the thalamus
* pulvinar neurons respond to the same stimuli more vigorously as targets of behavior, then when these stimuli are not targets of behavior the cells have a low firing rate
* and when the same stimulus signifies every word, the cell become more active
* may play some role in attentional spotlight
ventral orienting network
84
top down role
includes frontoparietal network and cingulo-opercular network
executive control of attention system
85
executive control of attention system
relate task instructions that are transient at the beginning of a new task
dorsolateral-pFC-parietal network (frontoparietal network)
86
executive control of attention system
sustained activity across a task
anterior cingulate/medial frontal anterior insular network (cingulo-opercular network)
87
* correlates with activity in the lateral prefrontal and cingulate regions of the attentional networks
attention
self regulation
88
* interferes with the frontoparietal executive attentional networks
* decreased DLP FC anterior cingulate cortex and premotor and posterior parietal cortices
attention
stress
89
the attentional system includes synchrony across a population of neurons that assess some sensory signal
mechanisms of attention - how does the attentional spotlight select what's important?
90
synchronous outputs are summed to initiate larger excitatory post synaptic potentials (EPSPs) leading to action potentials in postsynaptic neurons
synchronous outputs
91
each shows failure to detect detectable stimuli
inattention
92
* fail to notice an event that occurs as they are performing another task
* task: failure to notice a dot flashed on a computer monitor during a performance of a simple visual task
* 70% of participants did not see the gorilla
inattention blindness
93
* participant fails to detect change in the presence, identity, or location of objects in a scene
* most likely to occur when people do not expect changes
change blindness
94
* fail to detect a second visual target presented within 500 milliseconds of the first one
* attention to first target prevents to be aware of the second one, even if the change is extremely conspicuous
attentional blink
95
* person does not respond to sensory stimulation → parietal cortex lesion
* left side of surrounding space ceased to exist
sensory neglect
96
level of responsiveness of the mind to impressions made by the senses
1. it is likely a collection of many processes
2. it is not always the same and varies across the development and even across the span of the day
3. more than simply being responsive to sensory stimulation or being able to produce movement
* bc the isolated spinal cord is not conscious
4. language fundamentally changes the nature of human consciousness
* but ppl who are aphasic have not lost consciousness awareness
5. provides adaptive advantage in processing complex information
consciousness
def and criteria
97
arousal, perception, attention, working memory
neural correlates of consciousness
98
waking the brain up via nonspecific neural modulatory systems
arousal
99
detection unbinding of sensory features
perception
100
selection of a restricted sample of all available info for faster processing
attention
| (neural correlate)
101
short term storage of ongoing events
working memory
102
* all processes either require or modify the operation of an overall binding process, implemented by the synchronization of neural discharges
* neuronal groups exhibit synchronous oscillations (6-80 Hz) and can shift from a desynchronized state to a rhythmic state in milliseconds
* phase synchrony acts not only to bind the sensory attributes but also to bind all dimension of the cognitive act, including associative memory, emotional tone, and motor planning
phase synchrony
103
* when viewing mooney faces, synchronous activity in the gamma range (40 hz) can be recorded from participants' brain
* when viewing them upright, the faces can be clearly found
* when viewing inverted, finding the face is impossible
mooney faces
