Brain Mechanisms of Emotion and Memory Flashcards
1
Q
types of emotion
A
- Basic Regulatory Emotions: Induce Motivational States
- Hunger, Pain (sharp, dull), Cold, Hot
- Directed Emotions: Involving external source
- Fear, Panic, Anger, Rage, Disgust, Lust, Joy, Calmness
- Cognitive Emotions: Involving Semantic Content
- Jealousy, Love, Hatred, Boredom
2
Q
the relationship between the
Autonomic Nervous System and Fear
A
The James-Lange Theory of Emotion (1884)
vs.
The Cannon-Bard Theory (1927)
3
Q
Problems with Cannon-Bard Theory
A
- Emotional states can be manipulated by changing superficial postures (“putting on a happy face”)
- Sometimes physiological effects of emotional impact can occur without conscious awareness of stimuli (Unconscious Emotions)
4
Q
Origins of the Limbic System Concept
A
- Broca’s (1878) Limbic Lobe (in blue)
- Group of cortical areas Forms a ring around brain stem (primitive cortex) (limbus = “border”)
- Not originally linked with emotion by Broca
5
Q
The Papez Circuit (1930s)
A
- James Papez: Emotional system on the medial wall of the brain
- Links cortex with hypothalamus in circuit
6
Q
McLean - Limbic System (1952)
A
- Popularized designation of “Limbic system”
- Expanded Papez’s circuit to include functionally and anatomically associated structures, including:
- Amygdala (inputs from hippocampus)
- Septal nuclei
- Orbitofrontal cortex
- Nucleus accumbens
7
Q
limbic system - “old nose brain”
A
- direct olfactory projections to amygdala
- secondary projections go to hypothalamus, septal area and hippocampus
8
Q
current beliefs about the limbic system
A
- Hippocampus no longer implicated strongly in emotion
- Difficulties with the Single Emotion System Concept
- Diverse emotions experienced unlikely to be governed by a single system in the brain
- Diverse Structures involved in emotion
- No one-to-one relationship between structure and function
9
Q
brain structures - fear and aggression
A
- The Temporal Lobe
- Specifically, the Amygdala (Medial Temporal Lobe)
10
Q
The Klüver-Bucy Syndrome
A
- Temporal lobectomy in rhesus monkeys
- Decreased fear and aggression
- Allowed approach of dangerous animals and did not learn from being attacked
- Decreased vocalizations and facial expressions
- Inability to recognize objects visually
- Increased interest in sex
- Temporal lobectomy in humans
- Exhibit at least 3 of these symptoms for diagnosis for Kluver Bucy: Amnesia, Docility, Dietary changes and/or Hyperphagia, Hypersexuality
11
Q
amygdala
A
- Groups of nuclei located in temporal pole just below cortex on medial side
- Three major groups: basolateral, corticomedial and central nucleus
- Anatomical relationships
- Inputs: sensory information secondary and tertiary areas
- Output to hypothalamus (with connections to pituitary) and periacqueductal gray matter of brain stem, provides for influence on endocrine, autonomic and motor responses
12
Q
the amygdala and fear
A
- Bilateral amygdalectomy in animals reduces fear and aggression
- Range of effects of amygdala lesions in humans:
- Loss of fear, anger, sadness, and disgust
- Inability to recognize fear in facial expressions
- Can feel pain, but do not care
- Cannot be conditioned to fear painful stimulus
- Electrical stimulation of amygdala
- Increased vigilance or attention
13
Q
the amygdala and aggression
A
2 Kinds of Aggression:
- Predatory Aggression—Attacks
- Against different species for food
- Few vocalizations; Attack head or neck
- No activity in sympathetic ANS
- Affective aggression— Warning/Dominance
- Used for show, not to kill for food
- High levels of sympathetic ANS activity
- Vocalizations; Threatening posture
14
Q
Sham rage
A
Evidence suggests that:
- Posterior portion of hypothalamus is responsible for rage reaction (removal leads to amelioration)
- Anterior hypothalamus and cortex act to suppress and modulate rage reactions to appropriate situations
15
Q
acquisition of new information
A
learning
20
Q
memory pathways
A
- LTM may or may not first go through STM
- Working memory: Temporary information storage (like RAM)
21
Q
types of amnesia
A
- Dissociated amnesia: Pure form of amnesia with no other cognitive deficit (rare)
- Retrograde amnesia: Forget things you already knew
- Anterograde amnesia: Inability to form new memories
- Transient global amnesia: Shorter period; Disoriented, ask same questions repeatedly; Subsides in a couple of hours; Permanent memory gap
22
Q
search for the engram
A
- Lashley’s (1920) Studies of Maze Learning in Rats
- Lashley’s lesions were unfocused and might have destroyed multiple areas
- Other lesion studies show more specific memory deficits
- Lesion made in infero-temporal cortex (IT) in macaques suggest loss of specific memroy for objects
- Cannot discriminate objects
- Do not remember stimulus
23
Q
Hebb (1949) and the Cell Assembly
A
- External events are represented by cortical cells
- Cells reciprocally interconnected – “reverberation”
- Active neurons – cell assembly
- Consolidation by “growth process”
- “Fire together – get wired together”
24
Q
temporal lobe and declarative memory
A
- The Effects of Temporal Lobectomy (HM)
- Extensive anterograde amnesia
26
Q
hippocampus and declarative memory
A
- Rats w/ hippocampal lesions show no improvement on radial arm maze for locations where food has been eaten
- However, they can learn over time to avoid arms in the maze that are ALWAYS empty upon entering
- WHY? This is like learning a procedure or a rule
- What they cannot do is update their knowledge online using Working Memory
28
Q
the neocortex and working memory
A
- Numerous areas in prefrontal cortex are involved in working memory
- Especially Dorsolateral Prefrontal Cortex (DLPFC)
- Connections to Basal Ganglia and Cerebellum
