Week 1 flashcards

The Brain and Behavior

Section 1: The Brain's Architecture

• The brain is a vast network of billions of interconnected brain cells (neurons).

• It operates through a triad (three connected) of architectural, electrical, and chemical components.

• The brain is divided into several key regions:

• Hindbrain: Controls basic life functions.

• Midbrain: Involved in orienting and movement.

• Cerebellum: Coordinates voluntary movements and balance.

• Forebrain: Involves higher functions like emotion and cognition.

Section 2: The Hindbrain

• Medulla: Connects to the spinal cord; regulates breathing, heart rate, blood circulation, and balance.

• Pons: Above the medulla; controls attentiveness, sleep, and dreaming.

• Damage can lead to a semi-permanent sleep state.

• Reticular Formation: A network of nerves involved in autonomic functions, pain modulation, sleep, and consciousness.

Section 3: The Midbrain

• Helps orient organisms in their environment and guides movement toward stimuli.

• Regulates pain experience, mood, and motivation.

Section 4: The Cerebellum

• Coordinates voluntary movements, posture, and balance.

• Recent studies suggest roles in time judgment, emotion modulation, and sensory integration.

Section 5: The Forebrain

• Composed of structures such as:

• Thalamus: Involved in sleep, wakefulness, and sensory signal relay.

• Hypothalamus: Controls motivated behaviors (eating, drinking, sexual activity) and involuntary rhythms (sleep/wake cycle).

• Amygdala: Plays a role in emotional responses, particularly fear and anger.

• Hippocampus: Critical for learning, memory, and spatial orientation.

• Cerebral Cortex: Involved in thought, perception, language, and emotion; constitutes about 80% of the brain.

Section 6: The Neuron

• Neurons are the primary communication cells in the brain and spinal cord.

• There are approximately 85 billion neurons, each capable of processing and transmitting messages to thousands of others.

Neurons consist of:

• Dendrites: Receive signals from other neurons.

• Cell Body: Contains the nucleus and metabolic components.

• Axon: Sends neural impulses to other neurons.

Section 7: Glial Cells

• Glial cells support neurons by providing nourishment, controlling nutrient supply, and increasing blood flow during heightened activity.

• They play a role in brain development and the stabilization of neural connections.

Section 8: Neurotransmitters

• Neurotransmitters are chemical messengers that transmit signals between neurons.

They can be categorized into:

• Excitatory Neurotransmitters: Increase the likelihood of neuron firing (e.g., epinephrine, norepinephrine).

Inhibitory Neurotransmitters: Decrease the likelihood of neuron firing (e.g., serotonin, GABA).

• Dual-Function Neurotransmitters: Can have both effects depending on receptor types (e.g., acetylcholine, dopamine).

Section 9: Mechanisms of Action

Neurotransmitters interact with receptors on neurons, influencing neural activity.

• Reuptake: The process by which neurotransmitters are reabsorbed into the presynaptic neuron after exerting their effects.

• Agonists: Chemicals that enhance neurotransmitter activity (e.g., antidepressants).

Antagonists: Chemicals that diminish neurotransmitter activity (e.g., some antipsychotics).

Section 10: Complexity and Degeneracy

• The brain exhibits degeneracy, meaning multiple combinations of neurons can produce similar outcomes.

• Different brain areas can serve multiple functions, highlighting the brain's complexity.

Section 11: Limitations of Neuroscience

• Caution against oversimplification of brain functions and the acceptance of dubious claims in neuroscience.

• Reference to studies showing that people are more likely to accept flawed research when presented with brain scan data.

Emotion

Theories of Emotion

• James-Lange Theory: Emotions result from bodily reactions to external stimuli (e.g., feeling sad because one is crying).

• Cannon-Bard Theory: Emotions and physiological responses occur simultaneously and are not easily distinguishable.

Classical View of Emotions

• Emotions are seen as built-in from birth, universally recognized across cultures.

• Cross-cultural studies have shown variability in emotion recognition, challenging the universality claim.

Limitations of Emotion Recognition Methods 

• Basic Emotion Method: Relies on human judgment and has been shown to be unreliable.

• Facial Electromyography (fEMG):

Attempts to objectively measure facial muscle movements associated with emotions but fails to produce consistent patterns.

Theory of Constructed Emotion

• Emotions are not universal but are constructed by the brain based on bodily sensations and environmental cues.

• Emotions emerge from a combination of physical properties, brain function, and cultural influences.

Evidence from Studies

• Bridge Study: Demonstrated how context can influence emotional interpretation (fear as attraction).

• Cultural Variability: Studies with the Himba tribe showed that emotion recognition is not uniform across cultures.

Emotion Regulation

• Cognitive Reappraisal: Changing the meaning of a situation to decrease emotional response (more effective).

• Suppression: Trying to hide emotional reactions (less effective, can lead to increased physiological arousal).

Right and Left Brain

The Origins of the Myth

• Sperry's Research: Conducted on patients with severe epilepsy who underwent commissurotomy (severing the corpus callosum).

• Findings: Different brain hemispheres control different processes (e.g., language in the left hemisphere, spatial reasoning in the right).

• Caution Against Generalization: Sperry warned against oversimplifying his findings, noting individual variations and the complexity of brain functions.

The Popularization of the Myth

• Media Influence: Articles in the New York Times Magazine and Time magazine in the 1970s popularized the left-brain/right-brain dichotomy.

• Self-Help Culture: Emergence of personality tests and self-help books claiming to identify individuals as left-brained or right-brained, based on oversimplified interpretations of Sperry's research.

Debunking the Myth

• 2013 Research: A study analyzing over a thousand fMRI scans found no evidence supporting the idea of left-brained or right-brained individuals.

• Findings: While certain brain areas are more active during specific tasks, there is no consistent pattern of one hemisphere being more active than the other.

The Importance of Brain Lateralization

• Concept Validity: Brain lateralization is a real phenomenon that allows for efficient processing and multitasking.

• Complexity: The interaction between hemispheres is crucial; both sides communicate constantly to perform tasks, indicating that individuals can possess a range of intellectual talents.