Attention Flashcards
alertness and arousal
the most basic levels of attention
vigilance
the ability to maintain alertness continuously over time
selective attention
the selection of information essential to a task
mental effort required
focusing and concentrating
cocktail party effect
divided attention
spit attention across tasks
multitasking
no concensus
prefrontal regions? - increased activity, greater demands on brain. ie/ talking on phone while driving
main regions in the brain involved with attention
superior colliculus
thalamus (LGN and Pulvinar)
Anterior cingulate cortex
Parietal cortex
Frontal cortex
Reticular activating system (RAS)
reticular activating system
responsible for overall arousal and sleep-wake cycles
ventral and dorsal substream
damage can result in coma
ventral subsystem of RAS
projects to the cortex via the basal forebrain
a branch from the raphe nucleus relies on serotonin
a branch from the locus coeruleus relies on noepinephrine
dorsal subsystem of RAS
projects to the cortex via the thalamus
relies of ACh
vigilance and sustained attention
needs both the cholinergic and noradrenergic systems
more effort needed to sustain attention requires more ach
the noradrenergic system prepares the brain to receive info - focus on certain area that receive info first
thalamus interfaces between arousal and sustained attention
cortical regions (especially right hemisphere) involved
- activation of right hemisphere seen in vigilance tasks
cocktail party effect
choosing what we are wanting to listen to and then ignoring the rest
bottom-up attention selection
some intrinsic aspect of the stimulus itself causes it to be attended
something in the enviroment
developed first as it is important for survival
ie/ a loud sound, plate dropping and breaking
top-down attentional selection
the person determines how to direct his or her attention
ie/ you might direct your attention to a particular person
stimulus-driven/involuntary attention
mediated by subcortical areas (particularly the superior colliculus)
goal driven/ voluntary attention
mediated by cortical areas (parietal and frontal corticies)
early selection viewpoint
selection occurs at an early stage of processing, before items are identified
late selection viewpoint
selection occurs only after sensory processing is complete and items have been identified and categorized
automatic orienting in the superior colliculus
plays a role in the localization of visual stimuli, the control of saccades, and stimulus driven attention shifts to stimuli in visual space
good for attentional processing and liking eye movements
- has a set of neurons that respond quickly to visual stimuli
- has a retinotopic map of the contralateral side of space
- has a different set of neurons sensitive to both sensory characteristics and to orienting movement
superior colliculus lesions
disrupts attentional shift - general slowing of responses, possibly because of an impaired ability to localize stimuli
inferior colliculus
role in auditory info
Lateral geniculate nucleus
plays gate keeper to the cortex
depending of the focus of attention is act to
- enhance relevant info
- surpress irrelevant info
pulvinar
aids in regulating info transmission between cortical regions that are processing info relevant to attention
aids in synchronizing activity between those brain regions
filtering: greater activation of the pulvinar when identifying small targets surrounded by distractors as opposed to large targets with no distractors
selective attention and the parietal lobe
involved in overall allocation of attentional resources to a particular stimulus or task
plays a role in selecting info in a more precise manner after the early gating of sensory information by the thalamus
types of attentional selection (top-down/bottom-up)
intraparietal sulcus
where these two streams of info are thought to be integrated
superior parietal lobe
involved in top-down influences on attention directed by the person’s goals or desires rather than stimuli in the environment
inferior parietal lobe of right hemisphere
more involved in more bottom-up aspects of attentional control
(preattentive/parallel search)
targets defined by only one feature will “pop out”
type of feature integration theory
attentive/ serial search
targets defined by feature combinations requires attention to “glue” features together
feature integration theory
attention allows features of an item to be bound together
basic features are detected and automatically processed and proceed in parallel across all locations
damage to parietal regions
disrupts the ability to bind features together
can not detect the conjunction of features, can detect a single feature
salience maps
some info is processed relatively automatically (bottom-up) helps to influence where attention is directed
top-down like your current goal also influences where your attention is directed
salience map is constructed from this to help prioritize where attention should be directed
feature maps
signal for presence of each features
attention to a master map location provides access to information at that location in each of the feature maps
this integrates the features possessed by the item at that location
illusory conjunctions
attention is required to combine features of an object
attention is also required to precisely determine the locations of object features
when attention is limited, may not properly put features together in the right location
inattentional and change blindness
when attention is focused at a location or on an object, it is necessarily withdrawn from other locations and object
unattended objects are processed less efficiently than the object that is attended to
something has to be important to you for you to pay attention; we do not remember what we do not pay attention to
automaticity
skills and tasked can become automatic, requiring minimal attention to perform, freeing up attentional capacity to focus on other things
multi-tasking can be possible
anterior cingulate
intracranial recordings show alterations in activity just prior to and after a response
neuroimaging findings suggest that these regions specifically increase their activity when response mappings are hard
lateral prefrontal cortex
serve as sources for top-down attentional control, providing the abstract category or goal that should guide attention
send signals to posterior brain regions that act as the sites of attentional control that are actively involved in the selection process
bias processing towards particular info
what are the three systems attention can be divided into
alerting
orienting
executive attention
alerting
allows brain to maintain a tonic level of arousal and to respond to signals warning of upcoming events
involves the locus coeruleus, thalamic regions, frontal and parietal regions of the cortex; linked to noepinephrine
orienting
aligns attention with sensory signals and selects among multiple sensory inputs
involves the superior colliculus, parietal areas and frontal eye fields; linked to Ach
executive attentions
controls how attention is directed according to goals and desires
involves the basal gangli, lateral prefrontal cortex and the anterior cingulate; linked to dopamine
dorsal attention system
system prepares and applies goal oriented (top-down) selection of stimuli and responses
composed of portions of the intraparietal cortex, superior frontal cortex and frontal eye fields
ventral attention system
system detect and reorients attention to behaviourally relevant stimuli, especially when salient or unexpected
composed of temproparietal cortex, inferior frontal cortex and anterior insula
mainly lateralized to the right hemisphere
executive attention deficits
symptoms: difficulty concentrating, increased distractability, poorer ability to divide of sustain focused attention, impaired response inhibition
primarily associated with frontal cortex dysfunction
typically caused by brain diseases, also injuries (such as concussions)
spatial attention deficits
deficits associated with difficulty processing info at specific locations
syptoms: can include neglect, impaired search, impaired attentional disengagement
primarily associated with parietal cortex dysfunction
typically caused by damage due to strokes, also injuries
symptoms of ADHD
excessive distractibility
impulsivity
restlessness
lack of inhibition
uneven attentional span
underfocusing and hyperfocusing
hypotheses of ADHD
surpressed frontal lobe activity
dysregulation of default mode network
disruption of attentional filtering by thalams
disruption of right hemisphere function
underproduction of dopamine
differences between ADHD brain and non-ADHD brain
slight reduction in size of the frontal lobes and basal ganglia
differences are not consistant enough to provide a diagnostic test but do correlate with the symptoms
frontal lobe: helps with organization, time management and decision-making
basal ganglia” help to regulate moods and to control impulsive outbursts
hemineglect
patients with this do not pay attention to one side of space
mainly considered a spatial phenomenon
the neglect of info occurs with reference to a spatial frame
all types of info, regardless of modality are ignored on the neglected side of space
manifestation of hemineglect
individuals do not pay attention to the side of space contralateral to their lesion
symptoms: vary depending on time since brain damage
- neglect- usually severe at first
- over time (or if damage is mild) may only be observed under conditions of double simultaneous stimulation; referred to as extinction
patients with right hemisphere lesionn
may fail to:
notice items on the left side of the world - spatial neglect
draw the left side of object - allocentric neglect
use the left side of the body - personal neglect
more prominent then left hemisphere damage
- possibly that the right hemisphere has a greater role in attention
extinction
awareness of object in the left visual field provided there are no objects in the right visual fields
when objects are in the right visual field, other visual field becomes neglected again
object-based neglect
neglect the left half of the object, regardless of the position of the stimulus in space
when are neglected stimuli processed
at early stages of the visual system, so they do influence performance in subtle ways
because they do not gain access to higher-order visual processing areas, they are not perceived consciously
hemineglect theories
internal mental representation of the left space is lost
other theories arise from competition between hemispheres
- sensory stimuli on the non-neglected side of space prevents these patients from attending to the info on the neglected side. right parietal, biasing attention towards its preference
the greater the imbalance ( the weaker the damaged side is) - the more attention is drawn to the preference of the intact side
evidence of competition theory
patients with parietal lobe lesions have difficulty disengaging attention from the non-neglected side
patients show less neglect when they “cancel items by erasing them, thereby reducing competing info on the non-neglected side
treating hemineglect
using TMS or tDCS have attempted to:
- down-regulate activity in the left hemisphere, up-regulate activity in the damaged right hemisphere or both
other approaces use methods that orient attention and action to the left side of space
top- down approaches teach patients to guide their attention with aid from a therapist of using training in a virtual reality environment
many patients can recover
traumatic brain injuries (TBIs)
the effects on TBI on attention depends on the location of the injury. (frontal or parietal lobe, specific area within), but can include
poor concentration and lack of “mental energy”
increased interference by distractors
slower detection of targets during search
impaired capacity of divided attention
increased stroop interference
reduced activation of executive attention areas
attentional neglect
mental slowing
