Psychology 352 – Motivation

Chapter 3 – The Motivated & Emotional Brain

Why is the brain important?

Name structures in the brain related to motivated behaviors?

• The brain is the center of motivation and emotion, as well as thinking.

Three principles that organize how motivational researchers study the brain:

    A.  Specific brain structures generate specific motivational states

• Hypothalamus, limbic system

     B.  Biochemical agents stimulate these brain structures

• Neurotransmitters and hormones

     C.  Daily events stir biochemical agents into action

• A positive life event stimulates dopamine release that causes the brain to react and leads to a positive mood state

How can we look inside the brain?

Limbic system – comprised of the hypothalamus, amygdala, hippocampus, septal area, and ventral tegmental area. (Figure 3.5, Table 3.1)

• Hypothalamus
• Medial Forebrain Bundle
• Amygdala
• Septo-Hippocampal Circuit
• Reticular Formation
• Prefrontal Cortex

A.  Hypothalamus – regulates important biological functions, including eating, drinking and sexual behavior.

• The hypothalamus regulates the body’s internal environment to adapt to the external environment
• The hypothalamus controls the pituitary gland – the endocrine system’s “master gland”.
• The hypothalamus controls the autonomic nervous system. It is sub-divided into the sympathetic and parasympathetic nervous system.

B. Medial Forebrain Bundle

• Large fibers that connects the hypothalamus to the septal area and ventral tegmental area.
• Stimulating the area produces generally positive feelings

C. Amygdala

• Interconnected nuclei that detects and responds to threatening events
• Stimulation can generate emotional anger, fear, defensive behavior.
• Helps us to perceive other people’s emotions, facial expressions, and our own mood.
• Helps us to learn new emotional associations.

D.  Septo-Hippocampal Circuit

• Several structures – septal area, hippocampus, cingulated gyrus, fornix, thalamus, hypothalamus, mammillary bodies. (Figure 3.5)
• Anti-anxiety meds produce their effects quickly in this area

E.  Reticular Formation

• Arousal and awakening the brain’s motivational and emotional issues. Found within the brain stem.

F. Prefrontal Cortex

• Stimulation can indirectly generate emotional states
• Thoughts that stimulate the right prefrontal cortex generate negative feelings. People with sensitive right prefrontal lobes show a greater sensitivity to punishment, negative emotion, and avoidance-oriented behaviors.
• Thoughts that stimulate the left prefrontal cortex generate positive feelings. People with sensitive left prefrontal lobes show a greater sensitivity to reward, positive emotion, and approach-oriented behaviors.

Neurotransmitter Pathways in the Brain

• Neurotransmitters act as chemical messengers within the brain’s central nervous system.
• Neurons communicate with one another through neurotransmitters.
• 4 motivationally relevant neurotransmitter pathways:
  • Dopamine
  • Serotonin
  • Norepinephrine
  • Endorphin

4 motivationally relevant neurotransmitter pathways:

     A.  Dopamine – generates good feelings associated with reward

• The anticipation of pleasure triggers neurons to release dopamine, and the resulting positive affect produces enhanced functioning, such as creativity and insight.
• The Ventral Tegmental area releases dopamine in a predictable proportion to when a person expects and actually receives rewards.
• Dopamine release also occurs with the anticipation of rewards. Therefore, we often experience more pleasure in thinking about something than we do when actually engaging in something.
• Dopamine release also teaches us which events in the environment are rewarding. Release is greatest when the rewards are unpredicted or underpredicted.
• Dopamine release activates voluntary goal-directed approach responses.

    B. Serotonin – influences mood and emotion

    C.  Norepinephrine – regulates arousal and alertness

     D. Endorphin – inhibits pain, anxiety and fear by generating good feelings to counter these negative feelings

How can I motivate myself and/or others?

• You can begin to use your knowledge of the brain to create social environments that function as natural stimulates to the motivated and emotional brain.
• Remember that the individual’s motivational state cannot be separated from the social context