Chapter 21: Brain Mechanisms of Emotion

What is attention?

The ability to focus on one part of all of the sensory input being recieved

What does attention involve?

Interactions between all sensory modalities

What does being attentive mean?

It means we preferentially process some information and ignore others

Attention has significant impacts on ———

Perception

What happens in our brain during attention?

The sensitivity of neurons in many parts of the brain change depending on where we focus our attention

What is filter theory?

Its when we open a gate for important info directed at something specific and filter out irrelevance. It has a very limited capacity

What is resting state activity?

More acitvity in certain regions of the brain when attention is not directed to one specific thing or engaged in a task

What do the DMN consist off?

1. Medial preforontal cortex

2. Posterior cingulate cortex

3. Posterior parietal cortex

4. Hippocampus

5. Lateral temporal cortex

In the DMN, what does the medial prefrontal cortex do?

decisions about the self (values, goals, autobiographical memories) and others

In the DMN, what does the Posterior cingulate cortex do?

Attention + memory, perception

In the DMN, what does the Posterior paretal cortex do?

Junction of auditory, visual, somatosensory information + attention

In the DMN, what does the hippocampus do?

remembering the past, imagining the future

In the DMN, what does the lateral temporal cortex do?

social knowledge

What activates the Default Mode Network?

• Passive rest

• Incessant Rumination

• Thinking about one’s self or others

• Remembering the past

• Imagining the future

What are two hypotheses for the function of the DMN?

1. The Sentinel Hypothesis

2. The Internal mentation Hypothesis

What is the The sentinel hypothesis?

The need to always monitor the environment even at rest

Whats the evidence behind the The sentinel hypothesis?

• Going from rest to fovea task is larger change in DMN activity than going from rest to peripheral vision task.

• DMN activates when participants needed to scan the periphery but not when they were told the specific location to watch.

• Simultangosia - patients with cingulate damage cannot integrate individual stimuli into a scene

What is the internal mentation hypothesis?

It is that the DMN supports thinking and remembering

What is the evidence behind the the internal mentation hypothesis?

Remembering the past and imagining the future both activate DMN compared to control tasks

According to the internal mentation hypothesis, the default mode network is most active when we are -

Daydreaming

What causes the shift from DMN to TPN?

Attention

What does it mean to be selectively attentive?

• direct specific attentiom at something

• Filter other irrelevant stimuli

• Very Limited in capacity

Name the two types of attention

1. Bottom up (exogenous)

2. Topdown (endogenous)

Other way to say top - down attention

Endogenous

Other way to bottom up attention

Exogenous

Exogenous attention =

Bottom up attention

Endogenous attention =

Top down

What is bottom up or exogenous means of attenion? What drives it and give an example

• When stimulus captures our attention without conscious control

• Driven by salient features in the environment, such as a loud noise or sudden movement.

• You hear something shatter and, without thinking, turn to look at what it is.

What is Top down or an endogenous means of attenion? What drives it and give an example

• The deliberate or voluntary focus directed by the brain

• Driven by goals and expectations, and influenced by prior knowledge.

• You are trying to read a book in a noisy café.

What is Attention - Deficit/Hyperactivity Disorder? Name its types

A disorder characterized by restlessness, inattentiveness, and impulsivity.

Three types of ADHD:

• Inattentive

• Hyperactive

• Combined

What percent of the population has ADHD? And why could that number be higher?

~10% Of the popuation has ADHD but the percentage is likely higher due to significant underdiagnosis in women

Average age of diagnosis for males

7

Average age of diagnosis for females

35

People with ADHD have an overactive ________

DMN

ADHD characteristics -

1. Restlessness

2. Inattentiveness

3. Impulsivity

What neurotransmitter is deficient in ADHD?

Dopamine