dissecting fear

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Dissecting the fear for snake SNAKE!

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Page 1: Dissecting Fear

Dissecting the fear for snake SNAKE!

Page 2: Dissecting Fear

• “After hunting in the jungle for several hours, Sam was tried, thirsty, and hungry. He sat down beside a coca tree for a short rest. Before he even finished the first sip of the water, a moving thing slipped through the corner of his eye. With just this glimpse, he felt that the movement is from some long, soft stuff. ‘Snake!’ He shouted immediately and leaped into the air but only found a dark green ribbon on a tree branch and blowing in the wind”

THE “SNAKE” SCENARIO

Page 3: Dissecting Fear

• Mental process 1. Cognitive input: Seeing something long, soft and moving

2. Neurological Change: Signals from retina is processed and the amygdala is alerted

3. Neuronal state detection: Detect the alerted amygdala and looking for a explanation

4. Conscious interpretation: Find the interpretation based on the cognitive input and the neuronal state – “Snake”

5. Decision making: Decide to escape from the “snake”

6. Behavioral expression: Leap into the air

MENTAL PROCESS

Page 4: Dissecting Fear

• Input from the visual system• Corner of the eye: • more RODS, less CONES

• Cones have:• Lower resolution

• Better motion detection

• Weak color detection

• Hence:• More information collected for motion

• Less collected for color and shape

• “Not enough information” for V1, V2 and V3 (Recognition failed)• Detection of Motion by V5 (Middle Temporal)

COGNITIVE INPUT

Page 5: Dissecting Fear

• Amygdala activation• Prefrontal cortex: predictions• What is expected? (Trees, grass, fallen leaves)

• What shall it look? (Normal look of the trees,…)

• The predictions sent to thalamus:• See expected to see? – No! Activate amygdala

• Looks familiar? – No! ! Activate Hippocampus• Hippocampus activation• Store the input for future analysis

NEUROLOGICAL CHANGE

Page 6: Dissecting Fear

• High arousal of Amygdala = More calculation needed• This will activate more neo-cortex

NEURONAL STATE DETECTION

Page 7: Dissecting Fear

• Orbitofrontal Cortex Activation

• Input from amygdala: surprised• Input from anterior cingulate

cortex: The anticipation of the moving object

• Insular Cortex Activation• Input from amygdala:

Conscious of the situation

CONSCIOUS INTERPRETATION

surprise

Page 8: Dissecting Fear

• Prefrontal Cortex • Activate fusiform gyrus to move the eyes to focus on the moving

things• for “leap”

DECISION MAKING

Page 9: Dissecting Fear

• Motor Cortext:• The idea for “leap” • Cerebellum:• Modulate and • Brain is doing predictions

BEHAVIORAL EXPRESSION