chapter 22 Flashcards
Attention is
narrowing of awareness to a particular part of the sensory environment
Consciousness can be synonymous with awareness, but also has a
more complicated meaning that is more like awareness of awareness
Some researchers argue that consciousness and attention are different
Attention tends to be top-down and takes time to focus on a part of the sensory world
Consciousness provides a summary of all information that is relevant to the situation
Automatic processes can be
performed with little focused attention and occur unconsciously
Automatic processes can be
innate or the result of training
Automatic processes are
bottom-up, driven by sensory input
Conscious operations require
focused attention
Conscious operations are
op-down, requiring cognitive input and control
Given the different types of processing and input, it is likely that automatic and conscious processes rely on
different brain circuitry, possibly including the circuits related to consciousness
Certain types of visual search are automatic, such as
the addition of a vertical line or the use of bold type
Searches that require a combination of multiple features are
slower and require a serial search
Feature search is a strategy for
scanning the environment for an object with a specific combination of features
Object visually perceived in V1 is
broken down into features, to be processed serially by higher visual areas
Features of the object within the mental spotlight are somehow
recombined, possibly through reentry processes
Areas outside V1 or V2 should respond
differently to a stimulus, depending on whether attention is focused on that object
Experiments to test the effects of focus of attention must use
the same stimulus in all conditions
An experiment varied the location of a stimulus and identified different responses in higher visual areas (V4, TE) depending on
where the stimulus was presented and what the monkey was trained to attend to
There seem to be multiple visual attention systems, with one
selecting stimuli and another selecting and directing movements
Priority maps
encode stimulus location in terms of the behavioral significance
Priority maps are found in
in frontal eye fields, lateral intraparietal area, and superior colliculcus
Mental capacity is limited, so dividing attention to
multiple tasks can divide that limited resource and cause all tasks to be performed with lower efficiency
Routine tasks can be
performed with ease while performing another task
More complex tasks require more
attention
Cells in V4
can be selective about what they respond to
V4 Cells are normally responsive to a
combination of orientation and color, but will respond to lines of somewhat different orientation
When animals discriminate between lines of similar orientation, performance accuracy
decreases, indicating the task is harder, and activity of cells in V4 increases and the cells become more selective in what they respond to
Cells in the pulvinar project
throughout the cortex and may help direct the attentional spotlight
If there is only one object in the attentional spotlight, the visual system can
bind all the properties together
If multiple objects occupy the spotlight, cells in area
TE seem to process different objects in parallel to differentiate between them
Attention needs to be divided across
sensory modalities for multisensory stimuli
When attention is directed to one of the sensory modalities
activity increases in the relevant cortical areas
When attention is divided between two modalities
there are no changes in the individual sensory areas, but an increase in the left dorsolateral prefrontal cortex
A functional-brain-imaging study had two tasks, each of which used
the same stimuli but had different attentional demands
Attending to the moving light stimulus resulted in
in increased activity in the posterior parietal cortex
If the moving light was in the left visual field, only the
right parietal cortex was active
If the light was in the right visual field,
bilateral parietal cortex was active
Each visual field had a
different focus of activation in the right parietal lobe
A separate study had a selective-attention condition and a divided-attention condition
Different types of attention recruited different brain areas
Attentional tasks activate
anterior cingulate, prefrontal cortex, and specific sensory areas
Attentional system is distinct from the
sensory networks that process information
Attention is not a
single process, but a connection of areas distributed throughout the brain
Brain regions form three different networks supporting attention
Alerting network
Orienting network
Executive network
Alerting network structures
Locus Coeruleus, Frontal and parietal cortex
Alerting network modulator
Norepinephrine
Orienting structurers
Superior parietal, temporal parietal junction, frontal eye fields, superior colliculus, pulvinar
Orienting network modulator
Acetylcholine
Executive network strucutres
Anterior cingulate, anterior insula, Basal Ganglia
Executive network modulator
Dopamine
Alerting Network
Ascending reticular activating system from the midbrain maintains alertness
Noradrenergic neurons project from the
locus coeruleus to the forebrain
Noradrenergic neurons project from the locus coeruleus to the forebrain Alerts the prefrontal and posterior
parietal cortex to rapidly process and respond to stimuli
Noradrenergic neurons project from the locus coeruleus to the forebrain Alerts the prefrontal and posterior parietal cortex to rapidly process and respond to stimuli Activity in this network suppresses
processing in other cerebral networks
Orienting Network
Prioritizes one sensory modality over the others or a particular location in space
Orienting Network Modulated by which neurons
cholinergic neurons
Dorsal orienting network
Involves the frontal eye fields and intraparietal sulcus
Strongly right lateralized
Directs attention toward a specific object in a top-down process
Ventral orienting network
Involves the temporoparietal junction, ventral frontal cortex, and pulvinar
Synchronizes activity with bottom-up incoming sensory information
Two executive networks work via top-down influences
Dorsolateral-prefrontal cortex–parietal network, Anterior cingulate/medial frontal–anterior insula network
Dorsolateral-prefrontal cortex–parietal network
is active at the beginning of a task
Anterior cingulate/medial frontal–anterior insula network remains active
throughout the task
Activity in areas within a network is highly
correlated
Activity is not correlated between the two
networks
Controlling cognition and emotions is a form of
self-control
Controlling cognition and emotions is a form of self-control Such control is associated with activity in the
lateral prefrontal and cingulate regions
Stress changes the structure and gene expression patterns of the
prefrontal cortex, leading to deficits in cognitive control of emotion that are associated with neuropsychiatric conditions
Psychosocial stress impairs the performance of
medical students on attentional tasks by decreasing activity in the dorsolateral prefrontal cortex, anterior cingulate, premotor, and posterior parietal cortices
Disorders Associated with Attention Networks (Alerting)
Aging, ADHD
Disorders Associated with Attention Networks (orienting)
Autism, PTSD, Neglect
Disorders Associated with Attention Networks (executive)
Axiety disorders, Depression, OCD, Personality disorders, Schizophrenia, Substance abuse
Alerting \aAging symptoms
Sleep disorders
Alerting ADHD symptoms
Hyperactivity, Concentration
Orienting Autism symptoms
Disengage deficit
Orienting PTSD symptoms
Difficulty disengaging from fearful stimuli
Orienting Neglect symptoms
Orienting to contralesional space
Executive Anxiety disorder symptoms
Difficulty inhibiting fear
Executive Depression symptoms
Dwell on negative ideation
Executive OCD symptoms
Reoccurring thoughts, images or behaviors
Executive Personality disorders symptoms
Negative ideation, Lack of control
Executive Schizophrenia symptoms
hallucinations
Executive Substance abuse symptoms
Compelled behavior
It is unclear how the attention systems direct attention, but one hypothesis is that the attention system induces
synchrony between neurons that assess the sensory signal
The timing of action potentials is adjusted to have the input from two neurons arrive at the target at the
same time and be summed, increasing the chance of an action potential in the postsynaptic cell
During an attention-demanding task, there was increased activity in the
dorsal executive attention network and decreased activity in the default network
Attention increases
synchrony within the brain
Inattention
People fail to notice something while they are performing another task, a process known as inattention blindness
When distracted by a counting task, 70% of participants failed to
a researcher in a gorilla suit walk through the middle of a basketball game
Subjects routinely fail to notice changes in the environment if they
are not expecting them, which is known as change blindness
In the case of attentional blink, attending to one stimulus prevents the subject from being aware of a
second stimulus
Brain imaging shows these unattended items are detected by the sensory systems, but are
are filtered out before conscious awareness
Patients with damage to the right temporoparietal junction do not attend to the
left side of space around them
While objects in the right visual field can be attended to by the left or the right parietal lobe, objects in the left visual field are only attended to by the
right parietal lobe
Using a prism to shift objects from the left visual field to the right visual field for a few minutes a day resulted in significantly greater ability to
to attend to objects in the left visual field
Damage to the frontal lobes (BA 6) results in
contralateral neglect only for objects close enough to be grasped
Consciousness
Consciousness can be defined as the level of responsiveness of the mind to impressions made by the senses
Consciousness is not the same over time, with young children and individuals with dementia experiencing
experiencing a different level of consciousness
Similarly, levels of consciousness vary over the day, as we transition from
sleep to wakefulness
Reflexive responses to stimuli are not considered
indications of consciousness
Conscious awareness of a movement might occur only after the
movement is complete
Integrated information theory attempts to explain consciousness
Consciousness exists
Consciousness is structured and composed of multiple distinctions between the phenomena we observe
Consciousness is structured and composed of multiple
distinctions between the phenomena we observe
Consciousness is composed of specific information, and
each experience is distinct from other experiences
Consciousness is unified and cannot be
broken up into multiple subparts
Consciousness is made up of individual experiences that are
separated from other conscious experiences by cause-and-effect relationships
Conscious requires the interaction of
sensory areas, memory, and likely other systems such as emotion and executive function
Conscious includes
arousal, perception, attention, and working memory
Binding is likely important
to unify these four processes
Studies of perceiving and responding to faces show patterns of
synchronous activity, followed by asynchronous activity, and finally synchronous activity
researchers do not know the essential
neural regions for consciousness
Dorsolateral prefrontal cortex, medial frontal cortex, posterior parietal cortex, and posterior cingulate cortex are all
all inactive when the participant is unconscious
A network of frontoparietal areas is correlated during a
a quiet, resting, conscious state
Patients in a coma or vegetative state do produce
brain activity in response to verbal commands, such as imagining they are playing tennis or walking around their home
Studies of clinical patients and neuroimaging studies suggest that there is a
bilateral region of the parietal lobe that is necessary for consciousness, but no necessary area in the frontal lobe
Some researchers have proposed that the claustrum is the brain region that is critical in
binding together information, given that it receives connections from nearly the entire cortex
There is overlap in the brain regions associated with consciousness and those associated with
self-awareness
There is overlap in the brain regions associated with consciousness and those associated with self-awareness
Medial frontal cortex
Posterior cingulate cortex
consciousness may not be necessary to experience
Emotion
Nonconscious emotions can be demonstrated in experiments such as
fear conditioning
Blindsight, priming, dorsal-stream processing, and other experimental evidence suggests that
cognitive activity can occur on the nonconscious level
When asked to explain their behaviors, people often do not recognize and report the factors that
influenced their behaviors
Sensory systems take in large amounts of information, which is used to influence
decisions, but we are only consciously aware of a small amount of that information
Automatic processes use system
1 to generate rapid, nonconscious responses to stimuli
Conscious processes use system
2 to produce slower, controlled responses based on relevant knowledge and experience
Neuroeconomics
A fairly new interdisciplinary field that studies how the brain makes decisions
Current research is focused on neuroeconomics and health psychology to understand
how individuals make decisions about health and wellness behaviors
