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BBS 5069: Brain & Behavior II > Attentional Processes > Flashcards

Flashcards in Attentional Processes Deck (12)
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1
Q

phenomena associated with selective attention

A
  • Change Blindness
    • Ex. Continuity errors in movie
  • Inattentional Blindness
    • Simons and Chabris (1999) Gorilla Experiment
2
Q

behavioral consequences of attention

A
  • Visual attention and Foveation
    • But attention can also be directed without foveation
    • Timing of eye movements (200 ms) vs. attentional shifts (50 ms)
  • Shifting attention paradigm (Posner et al. 1980)
    • Cues enhanced visual processing
    • Detection (valid > invalid)
    • Faster reaction times to valid cues
3
Q

spatial attention summary

A
  • Attention can occur independent of gaze
  • Spotlight model of attention
  • Location of attention is mapped retinotopically in the same way that actual visual space is mapped according to spatial location
4
Q

three neural networks subserving attentional processes

A
  1. The Orienting Network
  2. The Arousal Network
  3. The Executive Network
5
Q

the orienting network overview

A
  • Frontal Eye Fields (FEF)
  • Superior colliculus
  • Posterior Parietal Cortex
    • Integration of visual and somatosensory information
    • Damage: impairs ability to disengage attention from present focus, difficulty shifting to a target contralateral to a location
6
Q

Frontal Eye Field (FEF)

A
  • Attention and Eye Movements
    • Frontal Eye Fields (FEF) are instrumental in directing attention to areas of interest for eye movements
  • Stimulation of neurons in FEF leads to sharpening of attention within motor field, and inhibition of surrounding areas
  • Works much like lateral inhibition in the visual system
7
Q

Superior Colliculus

A

Superficial layers project to V1 and PPC

8
Q

Posterior Parietal Cortex (PPC)

A
  • PPC (posterior parietal cortex) neurons fire when attending to novel objects in receptive field
  • Greater firing when attention precedes saccade to location of object
  • No increase in firing when saccade is away from target
  • Greater firing also when attending to object followed by passive response (release of lever to fading stimulus)
9
Q

the arousal network

A
  1. Ascending reticular activating system (ARAS) of brain stem
    • Projection to cortex via thalamus, hypothalamus and other limbic structures
  2. Arousal processes
    • Tonic Arousal
      • Diurnal alterations e.g. sleep/wakefulness (raphe nuclei)
      • Also influenced by suprachiasmic nucleus, which receives input from optic nerve, and influences circadian rhythm
    • Phasic Arousal
      • Sensory input to Ascending Reticular Activating System (ARAS) can lead to change in arousal level
      • Can lead to activation of hypothalamus – pituitary secretions– fight or flight response
        • ​Catecholamines and acetycholine
10
Q

neurotransmitters in ascending reticular activating system

A
  • Catecholamines
    • Norepinephrine: Wide cortical projection from locus coeruleus, which receives input from cingulate cortex, activates attentional network associated with posterior parietal (& secondarily prefrontal)
    • Dopamine: Projection from ventral tegmental area of substantia nigra through medial forebrain bundle to striatal-frontal areas, posterior parietal and several limbic structures
  • Acetylcholine: Receptors
    • Nicotonic: from basal nuclei; influence alertness through wide cortical projection
    • Muscarinic: from Pontomesencephalic complex; influence memory processes through projection to hippocampus
11
Q

the executive network

A
  • Selection of information relevant to achievement of goals leading to coherence of behavior; inhibition of irrelevant inputs
  • Anterior cingulate cortex
  • Connections with:
    • DLPFC (dorso-lateral prefrontal cortex à working memory)
    • Posterior Parietal Lobe (attention)
  • ACC implicated in
    • executive functions and
    • resolving conflicting information (Stroop task)
12
Q

Unilateral Neglect: Neurological substrate and clinical signs

A
  • Hemispatial Neglect
    • Side Inattention
  • Left hemiplegia:
    • Usually associated with RH
    • inferior parietal damage (with or without hemianopia) leading to contralateral (left) attentional hemineglect (or spatial neglect)
  • Neglect has also been found following frontal damage (rare)
  • Neglect can be shown in motor behavior or any perceptual modality (visual, auditory, tactile) and commonly involves a combination of deficits
    • Self Portrait of Anton Raderscheidt
      • recovery from stroke over course of several months