Attention Deficits and Disorders Flashcards
Categories of Attention Deficits
> Executive Attention Deficits
—- decreased executive function
Spatial Attention Deficits
—- difficulty processing information at specific locations
Executive Attention Deficits
Deficits associated with decreased executive function
— symptoms can include difficulty concentrating, increased distractibility, poorer ability to divide or sustain focused attention, impaired response inhibition
»> associated with frontal cortex dysfunction
»> mainly caused by brain diseases and injuries (like concussions)
Anything that affects frontal cortex has these types of deficits involved
Goal-directed
Spatial Attention Deficits
Deficits associated with difficulty processing information at specific locations
— Symptoms include neglect, impaired searched, impaired attentional disengagement
»> associated with parietal cortex dysfunction
»> Mainly caused by damage due to strokes and injuries
Stimulus-driven stuff impaired
Attention Deficit/ Hyperactivity Disorder
Symptoms:
– Excessive distractibility
– Impulsivity
– Restlessness
– Lack of inhibition
– Uneven attention span
– Underfocusing and hyperfocusing
Hypotheses:
– Suppressed frontal lobe activity
– Dysregulation of Default Mode Network
….. collection of brain networks that ___ (GOOGLE)
– Disruption of attention filtering by the thalamus
– Underproduction of dopamine
Some brain scans shows differences between ADHD and non-ADHD brains
— slight reduction in the size of the frontal lobes and basal ganglia
— differences are not consistent enough to provide a diagnostic test but do correlate with symptoms
»»> as the frontal loves help with organization, time management, and decision-making, the basal ganglia helps to regulate moods and control impulsive outbursts
Hemineglect
Individuals do not pay attention to one side of space
Mainly a spatial phenomenon
» neglect of spatial information occurs with reference to a spatial frame
» all types of information are ignored on the neglected side of space
Typical Manifestation:
»> Individuals do not pay attention to the side of the space contralateral to their lesion
— spatial (only notice items on one side), allocentric (draw one side of objects), and personal neglect (uses one side of the body)
– Attentional bias of each hemisphere for information on the contralateral side of space
—->Would suggest left-side deficits for right hemisphere damage and right-side deficits for left hemisphere damage
»> symptoms vary depending on time since brain damage
—– neglect is usually severe at first, over time, may only be observed under the conditions of double simultaneous stimulation; aka extinction
» Neglected stimuli can still influence performance, even if unrecognized
»»> Still processed, but only slightly compared higher level visual processing (which aids conscious perception)
! Hemineglect is more severe after right hemisphere damage, suggestion the right hemisphere may play a bigger role in attention
Clinical Aspects of Hemineglect
> > Different behavioural manifestations of neglect are associated with different types of damage to a diverse set of right-hemi regions
– Locations of lesions associated deficits on different tests of neglect
—– Line bisection, Cancellation, Combination, Allocentric, Personal, Extinction
Different ventral network damage = different symptoms
Is hemineglect associated with sensory deficits?
No. Evidence suggest otherwise. Neglect is observed for all modalities of information in the contralateral side of space
Extinction
Awareness of objects in the left visual field provided there are no objects in the right visual field.
Hemineglect Modulate by Attentional Factors
Salient information on the neglected side is not ignored
Neglect can be diminished by the manipulation of attention or attentional cues
If information from the neglected slide is needed to make sense of information, it is not ignored
Motivational factors can reduce the degree of neglect
Object-based neglect
The individual neglects the other half of a stimulus/ object
» happens regardless of the position of the object in space
