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NEUR305: Attention

Learning Outcomes

  • Differentiate between arousal and selective attention

  • Understand top-down vs. bottom-up attentional control with examples

  • Identify and localize 6 major brain regions linked to attention

  • Distinguish symptoms of Bálint's syndrome vs. Neglect

  • Understand overt vs. covert attention

  • Explain the cocktail party effect and its assessment

Alerting

  • Maintenance of an aroused state

Relay neurons have two modes (difference in depolarization levels of neuron):

  • Burst Mode: moment-to-moment fluctuations

  • Tonic Alertness: sustained vigilance

2. Conflict Monitoring

  • Relies on frontoparietal and cingulo-opercular networks

  • Involves detecting/resolving competition between dominant and non-dominant responses

  • Example: Stroop Task (red the word or the color of the word)

3. Orienting (Selective Attention)

  • Prioritizing certain stimuli over others!

  • Can be top-down (goal-driven) or bottom-up (salient stimuli)

  • Measured with spatial attention tasks

Anatomy of Attention

  • Involves cortical and subcortical areas

    • Posterior Parietal: Information about “where in space” shifts our eyes

    • Superior Frontal Cortex: Frontal eye fields

    • Superior colliculus: Head and eye movements

  • Key region: Anterior cingulate cortex

Selective Attention vs. Arousal

  • Arousal: global physiological/psychological state

  • Selective Attention: prioritizing certain stimuli, not multitasking

  • Attention is limited; multitasking involves rapid switching

Processing Types

Top-down Processing

  • Hypothesis-driven; influences stimulus analysis

Bottom-up Processing

  • Data-driven; relies on incoming stimulus data

  • Example: Learning to read

Differences between Top-down and Bottom-up Processing

  • Key aspects: Automaticity, Inference, Encoding, Sensitivity

Neural Systems of Attention

  • Brain imaging, damage studies, physiology

  • Focus on areas affected in ADHD

Symptoms of Bálint’s Syndrome

  • Can see only one object at a time

  • Difficulty perceiving whole visual field

  • Inability to guide eye movements

Causes of Bálint’s Syndrome

  • Bilateral damage to posterior parietal and occipital cortex

Visuospatial Neglect

  • Patients exhibit left side neglect post-unilateral damage

  • Symptoms include ignoring half of visual field

Extinction in Neglect

  • Patients can detect isolated items but fail when two stimuli are present

Cortical Systems of Attention

Dorsal Attentional Network

  • Involves voluntary attention based on spatial location

Ventral Attentional Network

  • Focus on stimulus novelty and salience

  • Right hemisphere dominant

Summary

  • Goal-directed systems influence perception

  • Attentional control involves distributed brain regions

  • Interaction between goal-directed attention and stimulus saliency determines awareness.