Psychology

• Dendrites


  • Constitute the major input region of the neuron
  • Receive impulses from other neurons
  • Extensions projecting outward from the cell body
  • Propagate signals towards this region
  • One neuron may contain hundreds or even thousands of dendrites
• Cell body (soma)


  • The cell's DNA is contained within the nucleus
  • Proteins are synthesised within this region and carried to other regions of the neuron
• Axon hillock


  • Forms the base of the axon
  • Known as the integration region of the neuron
  • Collects all the information that the neuron receives before a signal may be sent to the axon
• Axon


  • Constitutes the conducting region of the neuron
  • In most neurons, the axon is sheathed (myelinated) by certain types of non-neuronal cells (glia)
  • Axons covered in myelin conduct neural impulses quicker than unmyelinated axons
• Axon terminals


  • Located at specialised regions called synapses
  • Form the neuron's output regions
  • Where neural impulses are transmitted to other neurons
• Synaptic cleft


  The gap between vertebrate cells, about 20 nanometers in width
• Information transmission


  1. Neurotransmitters carry the information or commands

  2. Information is transmitted from the axon terminal of the presynaptic neuron to the dendrite of the postsynaptic neuron via neurotransmitters released in the synapse

  3. The presynaptic neuron outputs information that the postsynaptic neuron receives as input
• CNS


  Central Nervous System
• Cells in the brain and nervous system


  • Neurons are the main info processing unit
  • Specialised cells adapted to transport electrical signals and communicate
  • 100 billion neurons in the human brain
  • Neurons typically contain: cell body, dendrites, axon, synapses
• Dendrites


  Major input region of the neuron, receive impulses from other neurons
• Cell body (soma)


  Contains the cell's DNA, proteins are synthesised within this region and carried to other regions
• Axon hillock


  Forms the base, collects all info that the neurons receive
• Axon


  Conducting region of the neuron, sheathed by certain types of non-neural cells (glia)
• Synapse


  Where a neuron contacts another cell to relay info, separated by a gap (synaptic cleft), neuron uses chemical neurotransmitters to carry info
• Unipolar neuron


  Only has one process extending from soma
• Sensory neurons


  Carry info to the CNS
• Motor neurons


  Transmit signals from the brain to spine to periphery to activate muscles
• Consciousness


  Awareness of our own thoughts and feelings, created by complex patterns of brain activity
• Normal waking consciousness


  • Experience of being awake and aware, the standard for other states of consciousness
• Altered states of consciousness


  • Deviate from normal waking consciousness, characterised by different elements: awareness, perceptions, memories, and self-control
• Elements of altered states of consciousness


  • Perception (vivid and dull)
  • Emotional awareness (more intense or duller emotions)
  • Self-control (no self-control, can lead to danger)
  • Cognitive (disorganised and memory loss)
• Selective attention


  Focused, awareness limited to one specific stimulus or event
• Divided attention


  Ability to perform two or more activities at once
• Automatic (autopilot/zombie mode)


  Requires low level of attention
• Controlled process


  Requires high level of attention
• States of consciousness


  • Total awareness
  • Selective attention
  • Meditation
  • Ordinary wakefulness
  • Divided attention
  • Asleep
  • Unconsciousness
  • Hyperarousal
  • Waking consciousness
  • Daydreaming
  • Sleep
  • Anaesthetic
  • Coma
• REM


  Rapid Eye Movement
• Consciousness


  Depends on our level of awareness, not constant over time, emerges by activating particular brain regions
• Sleep


  Altered state of consciousness associated with reduced awareness, includes different phases (REM, NREM) associated with certain levels of brain activity
• Circadian rhythm


  24hr cycle that makes up awake and sleep time, also regulates other internal rhythms like metabolism and body temperature
• Ultradian rhythms


  Biological rhythms that occur within less than 24hr cycles
• Polysomnography


  Sleep studies completed while a patient is asleep
• EEG


  Electroencephalogram, measurement of electrical activity in the brain (brainwaves)
• EMG


  Electromonography, measurement of electrical activity of muscles
• EOG


  Electrooculography, measures electrical activity produced by eye movements
• Frontal lobe


  • Voluntary thought and movement, complex decision making
• Prefrontal lobe


  • Decision making, mood, foresight, personality, and self-restraint
• Motor cortex


  • Controlling voluntary movement
• Parietal lobe


  • Processing sensory perception, touch, muscle, and joints
• Inferior parietal lobe


  • Integrating sensory information