Subcortical structures are clusters of neurons, located deep within the brain. They lie beneath the wrinkled outer layer called the cerebral cortex, which is responsible for higher-level functions like conscious thought and perception.
1.Thalamus: Often referred to as the “gateway to the cortex,” it acts as a relay center for sensory information. Relaying sensory information: They act as communication hubs, receiving and sending signals between different parts of the brain, including the cortex and other subcortical structures
2.Basal ganglia: Involved in motor control, learning, and habit formation, they also influence which stimuli we attend to.
3.Hypothalamus: This structure is like the body’s control center, regulating hormones, temperature, hunger, and thirst.
4.Amygdala: Plays a key role in processing emotions, especially fear and aggression.
5.Hippocampus: Critical for memory formation and consolidation.
Attention
The process through which certain stimuli are selected from a group of others is generally referred to as attention. Besides selection, attention also refers to several other properties like alertness, concentration, and search.
1.Alertness refers to an individual’s readiness to deal with stimuli that appear before her/him. For Example, Alertness at starting point of race.
2.Concentration refers to focusing of awareness on certain specific objects while excluding others for the moment. For example- Teachers voice rather than other noises.
3.In Search, an observer looks for some specified subset of objects among a set of objects. For example we search for a friend.
Attention in this sense refers to “effort allocation”.
Attention has a focusas well as a fringe.Focus or Focal point of attention is when the field of awareness is centered on a particular object or event. On the contrary, Fringe is when the objects or events are away from the center of awareness and one is only vaguely aware of them.
Subcortical Structure & Attention
- Filtering and Prioritization:
- Thalamus: As the sensory information hub, the thalamus acts as a filter.
- It evaluates incoming signals based on various factors like intensity, novelty, and relevance to current goals.
- It amplifies important information and dampens down irrelevant noise, allowing the cortex to focus on crucial details.
- Basal Ganglia: These structures help prioritize stimuli by inhibiting responses to distractions.
- They work with the cortex to identify what’s important and suppress irrelevant information, allowing us to sustain attention on the task at hand.
2. Alertness and Arousal:
- Thalamus:The thalamus also plays a role in regulating alertness and arousal.
- By controlling the flow of information and influencing brain chemicals like dopamine, it keeps us engaged and focused.
- When properly stimulated, the thalamus allows for sustained attention.
3. Orienting Attention:
- Superior Colliculus:This structure acts like a spotlight operator.
- It coordinates eye movements and spatial attention,
- helping us shift focus to specific locations in our visual field.
- By directing our gaze, it guides where we allocate our attention.
Example – You’re studying at a cafe.
The thalamus filters out background noise like chatter and clinking cups, but keeps the sound of your friend’s explanation highlighted. The superior colliculus directs your gaze towards your friend’s face. The basal ganglia suppress the urge to check your phone or glance around at other patrons. Through this coordinated effort by subcortical structures, you can maintain focused attention on the conversation despite the surrounding distractions.
Summary
Integration and Processing: All these subcortical structures work together in a network. They don’t operate in isolation. The thalamus relays filtered information, the superior colliculus directs our gaze, and the basal ganglia suppress distractions. This integrated processing allows for focused attention on relevant stimuli within the broader environment.