Layers and Lobes

Layers of the Brain

• The brain develops sequentially from the brainstem up, with the cortex developing last and continuously throughout life

Brain Stem and Mid Brain: Survival

• The autonomic nervous system is regulated by the brain stem. It is the first part of the brain to develop and mature. – Babies are born with

autonomic nervous system neurons fully myelinated (e.g. heart beat, breathing, sucking)

Organization of Nervous System

Brain Stem & Mid Brain cont’d• Brain stem and mid-

brain monitor the outer world through sensory input and activates the body to respond in ways that ensure self-preservation.

• Brain stem processes information at a subconscious level; it is quick and reactive

Brain Stem & Mid Brain cont’d

• Functions:– Autonomic nervous system– Fight/freeze/flight response– Defense mechanisms– Territoriality– Reflexes (along with the spinal cord)– Rote responses– Routine – Habits

• This is the least plastic layer of the brain - highly resistant to change

Brain Stem & Mid Brain cont’d

• Nickname is Reptilian Brain

Cerebellum: Coordination

• Automatic movements and balance

• Coordination of movement and of thought (balance)

Cerebellum:Coordination cont’d

• Procedural memory– motor skills– Does not involve

conscious thought, except when first learning (riding a bike)

• Matures in early childhood

• Works with brain stem

Limbic System: Emotions

• Receives, interprets and responds to emotional signals sent from the body

• Processes information at the subconscious level and forms emotional patterns.

• Long term memory• Matures during puberty• The heart of the brain

Cortex: Higher Level Thinking

• All higher level thinking at the conscious level occurs in the cortex.

Cortex: Higher Level Thinking

• Making sense of the world, decision making,creativity, reason, logic, imagination, self awareness, self control– everything that makes us

uniquely human is the result of the interplay between the cortex working in harmony with the lower brain structures.

Cortex cont’d

• The cortex loves change, novelty, fresh input, variety

• It is the most plastic layer of the brain

• The cortex is divided into specialized areas called lobes that are determined by their function

• Matures over a long period of time, from the back to the front

Lobes of the CortexSensory Lobes

• Back lobes are sensory related

• Occipital Lobe - processes vision and matures very early

• Temporal Lobe - processes hearing, speech and language, memory

Lobes cont’d

• Parietal Lobe - processes incoming sensory information; touch, pressure, pain, cold, heat, taste, proprioception

• Frontal Lobe - Gross and fine motor movements

Lobes of the CortexPrefrontal Lobes

• Responsible for critical thinking, creative thinking and problem solving

• Allows us to imagine, plan and rehearse future actions

• Connects to limbic system to regulate emotions

Prefrontal Lobes cont’d

• Integrates emotions with thought (essential to the decision making process)

• Working memory – Remembering something

or a series of things for a short time

– Max number for adults is 7 (+ or - 2)

Prefrontal Lobes cont’d

• Touch fingers lightly on forehead to engage the frontal lobes

• Prefrontal lobes start to develop around 8 months and continue to develop into late adolescence (around 18-20 or longer)

Phineas Gage Case study

• 1848 was a 25 year old railroad worker

• Tamping iron through left cheek out top of skull

Phineas Gage cont’d

• Frontal lobe damage• Memory and mental

abilities intact• Personality was not!

Review• Watching the Power

Point and looking at the diagram

• Movement you are doing• Sensing your hands on

your head• Listening to me and

remembering where the lobes are

• Makes it possible for you to think about your responses to these questions