Biological Psychology

Biological Psychology

Branch of psychology concerned with the links between biology and behavior

Areas of study include neuroscience, the endocrine system and the relative contribution of genetics and evolution

The Brain

The Most Basic Structure: A Neuron

The Behaving Brain - Discovering PsychInner Workings NIMH

Diagram a neuron

Concepts in Neural Communication

Action Potential A neural impulse; a brief electrical charge that travels down an axon

Threshold The level of stimulation required to trigger a neural impulse

All or Nothing (None) response Like it sounds. Neurons fire on the basis of “all or nothing”

Refractory period The period of rest following a neural impulse

Describe the electrical transmission of an action potential along a neuron*

Synapse The junction between the axon tip of the sending neuron and the dendrite of a receiving neuron. Also called the synaptic gap or cleft. Synaptic vesicles

Neural Communication

Neurotransmitters Chemical messengers that traverse the synaptic gaps between neurons (held and released by synaptic vesicles). NTs bind to specific receptor sites on the receiving neuron, and cause a neural impulse.

Excess neurotransmitters are enzymatically broken down or reabsorbed by receptors in a reuptake process

Excitatory and inhibitory neurotransmitters

Explain the function of neurotransmitters. Describe the neurotransmission process from the sending to receiving neuron.

Know Specific Neurotransmitters, Their Functions and Effects on Health

Acetylcholine Learning, memory and muscle control. Deficit present in Alzheimer’s disease. Curare-, botulism -and black widows +

Endorphins Opiate-like action linked to pain control and to pleasure. Mimicked by opiates (agonist). Kosterlitz’s discovery The Mind: Endorphins

Norepinephrine/Noradrenaline Related to arousal and state of alert (fight or flight). Undersupply can affect motivation and mood (anti-depressants)

More Specific Neurotransmitters

Serotonin Mood, sleep, arousal, pain sensitivity and hunger regulation. Implicated in depression. Antidepressants raise levels. SSRIs

Dopamine Movement, learning and attention A deficit seen in Parkinson’s disease

Parkinson's...Use of l-dopa (passes BBB) Sacks and Awakenings.

Encephalitis lethargica Use of l-dopa An excess of Dopamine = schizophrenia

(use of dopa blockers)

Know specific neurotransmitters, their functions and effects on health

More Specific Neurotransmitters

Glutamate Used at the great majority of fast excitatory synapses in the brain. Involved in memory. Can overstimulate brain. Headaches and seizures. Epilepsy

GABA Inhibitory neurotransmitter. Low amounts present in seizures and insomnia. Many sedative/tranquilizing drugs act by enhancing the effects of GABA. Alcohol and increases GABA. Anti-anxiety meds Epilepsy and GABA

Substance P Responsible for transmission of pain from certain sensory neurons to the central nervous system

Know specific neurotransmitters, their functions and effects on health

Agonists

• Using an example explain the difference between an agonist and an antagonist

Antagonists

• Using an example explain the difference between an agonist and an antagonist

Neurotransmitters and Addiction

• Some drugs, like cocaine, increase dopamine by preventing reuptake, leaving more dopamine in the synapse. Cocaine addiction

• Amphetamines (stimulants) help to release more dopamine

• Opiates act as agonists, mimicking endorphins

• Adaptations to drug use = tolerance• The withdrawal hypothesis

• Using an example explain the difference between an agonist and an antagonist

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Additional Concepts Related to Neural Transmission

• The Secret Life of the Brain– Neural networks– Developmental Plasticity– Synaptic pruning

• Neurogenesis Adult Neurogenesis

• Brain damage Hemispherectomy and Plasticity

• Mirror neurons ScienceNow• Neurons and Ramachandran

The Nervous System

Central(brain and

spinal cord)

Nervoussystem

Autonomic (controlsself-regulated action of

internal organs and glands)

Skeletal (controlsvoluntary movements of

skeletal muscles)

Sympathetic (arousing)

Parasympathetic (calming)

Peripheral

The Nervous System

Somatic Nervous System controls the body’s skeletal muscles

Autonomic Nervous System controls the glands and the muscles of the internal organs Sympathetic Nervous System division of the ANS that

arouses the body, and mobilizes in stressful situations; fight or flight response

Parasympathetic Nervous System division of the ANS that calms the body, and conserves its energy

• Distinguish between the somatic and autonomic nervous systems and describe the difference between a sympathetic and a parasympathetic response

The Nervous System

The Nervous System

The Nervous System

Nerves “cables” connect the CNS with muscles, glands, and sense organs (SAME) Sensory Neurons (Afferent) Carry

information from the sense receptors to the CNS

Motor Neurons (Efferent) Carry outgoing information from the CNS to muscles and glands

Interneurons communicate quickly between sensory inputs and motor outputs

• Distinguish between sensory and motor neurons

Homunculus

The Cerebral Cortex

Measuring Brain Structures/Functions

Lesioning Experimentally caused

destruction of brain tissue EEG (Electroencephalograph)

Amplified recording of the waves of electrical activity

• Describe the various types of brain measuring and imaging techniques

Measuring Brain Structures/Functions

CT (computed tomography) Scan Series of x-ray photographs from

different angles. Shows structures

MRI (magnetic imaging) resonance Uses magnetic fields to produce

computer-generated images that distinguish among different types of soft tissue; allows us to see structures within the brain

• Describe the various types of brain measuring and imaging techniques

Measuring Brain Structures/Functions

PET (positron emission tomography) Scan Visual display of brain activity

that detects a radioactive form of glucose goes while the brain performs a given task

fMRI (Functional MRI) Series of MR images used to

see structures within the brain as they function

BBC Brain Story

The Hind Brain

Brainstem responsible for (autonomic) survival functions

Medulla Oblongata controls heartbeat and breathing

Reticular formation source of alertness and arousal. The Pons regulates sleep-wake cycle

Cerebellum regulates movement and coordination

Thalamus the brain’s sensory switchboard, located on top of the brainstem directs messages to the sensory receiving areas in the cortex

The Limbic System

The Limbic System

Limbic System doughnut-shaped system of neural structures at the border of the brainstem and cerebral hemispheres. Associated with emotions drives such as those for food and sex. Includes the hypothalamus amygdala, and hippocampus

Amygdala two almond-shaped neural linked to emotion; anger and aggression

The Brain: Aggression

Septum seat of fear

The Brain

Hypothalamus structure lying below (hypo) the thalamus; directs several maintenance activities (eating, drinking, body temperature) helps govern the endocrine

system via the pituitary gland linked to emotion as well sexual arousal, satiation,

pleasure (or rewards) centers

The Limbic System - Hypothalamus

Electrode implanted in reward center (Olds)

Pleasure and Addiction

The Cerebral Cortex

Cerebral Cortex The intricate fabric of interconnected neural

cells that covers the cerebral hemispheres The body’s ultimate control and information

processing center Comprised of two hemispheres and four lobes Folds or convolutions increase surface and

number of neural connections Association areas uncommitted areas

throughout cortex for higher thought processes Contralaterality

The Cerebral Cortex - FPOT

The Cerebral Cortex - Four Lobes

Frontal Lobes Involved in making plans and judgments, language (Broca), motor cortex located along rear The Mind: Frontal Lobe 9

Parietal Lobes Includes the sensory cortex.

Occipital Lobes Include the visual areas, which receive visual

information from the opposite visual field (angular gyrus)

Temporal Lobes Auditory processing (Wernicke)

Visual and Auditory Cortices

The Cerebral Cortex - Language

Broca’s Area an area of the left frontal lobe that directs the muscle movements involved in speech

Wernicke’s Area an area of the left temporal lobe involved in language comprehension and expression

Angular Gyrus an area in the left hemisphere that transforms visual images into auditory code

Aphasia impairment of language, usually caused by left hemisphere damage either to Broca’s area (impairing speaking) or to Wernicke’s area (impaired understanding), also angular gyrus

The Brain: Broca and Wernicke

Specialization and Integration

Our Divided Brain

Corpus Callosum Band of neural fibers

connecting the two brain hemispheres and carrying messages between the hemispheres

Issue of contralaterality

Jill Bolte Taylor

Corpus callosum

Our Divided Brain

The information highway from the eye to the brain

Role of the optic chiasm

Split Brain Research

A condition in which the two hemispheres of the brain are isolated by cutting the connecting fibers (mainly the corpus callosum) between them

Sperry and Gazzaniga The Brain: Split Brain Scientific American Split Brain NP.Org

The Endocrine System

Endocrine System The body’s “slow”

chemical communication system

A set of glands that secrete hormones into the bloodstream

Controlled by the hypothalamus and the pituitary gland