biopsych exam notes

• Three approaches to understand the relationship between brain and behavior:

  1. Somatic Intervention:

  • A manipulation is done on the function of the brain to observe changes in behavior

  2. Behavioral Intervention:

  • A manipulation is done in behavior to observe how it affects the brain

  3. Correlation:

  • Relates changes in the brain to changes in behavior, without implying causation
• Levels of behavioral neuroscience analysis:

  • Social level
  • Organ level
  • Neural system level
  • Brain region level
  • Circuit level
  • Cellular level
  • Synaptic level
  • Molecular level
• Herman von Helmholtz (1821-1894):

  • First person to effectively measure the speed of neuron signal transmission
  • Transmission speeds range from 24.6-38.4 m/s
• Psychophysiology:

  • Relates physical stimulus to physiological response, such as neural response
• Non-invasive Imaging Techniques:

  • Neuroanatomical imaging technologies provide detailed images of the brain's anatomical structure
  • Examples include MRI and CT scans
• MRI (Magnetic Resonance Imaging):

  • Function: Creates detailed images of internal body structures using magnets and radio waves
  • Advantage: Provides superb contrast between different soft tissues, non-invasive
  • Disadvantage: Some individuals may have contraindications due to metallic implants
• CT (Computed Tomography):

  • Function: Produces detailed images of the inside of the body
  • Advantage: Non-invasive, quick, and high-quality images
  • Disadvantage: Excessive radiation exposure risks
• Functional Imaging Technologies:

  • Measure brain activity by detecting changes in blood flow, metabolism, or electrical activity
  • Examples include fMRI, PET, MEG, ERP, NIRS, DTI, EEG, and TMS
• fMRI (Functional Magnetic Resonance Imaging):

  • Function: Measures changes in blood flow in the brain
  • Advantage: High spatial resolution, non-invasive
  • Disadvantage: Relatively low temporal resolution compared to other techniques
• PET (Positron Emission Tomography):

  • Function: Provides detailed 3D images of the body, detects metabolic processes
  • Advantage: Used in cancer detection, provides quantitative information
  • Disadvantage: Requires radioactive tracers, low spatial resolution
• MEG (Magnetoencephalography):

  • Function: Measures magnetic fields generated by brain electric currents
  • Advantage: High temporal resolution, direct measurement of neuronal activity
  • Disadvantage: Can't see deep into the brain, requires expertise to interpret results
• ERP (Event-Related Potentials):

  • Function: Records brain electrical activity in response to stimuli
  • Advantage: Used in cognitive psychology and neuroscience research
  • Disadvantage: Limited spatial resolution, task-specific focus
• NIRS (Near-Infrared Spectroscopy):

  • Function: Measures changes in blood oxygenation in the brain using near-infrared light
  • Advantage: Used in cognitive neuroscience research and neurorehabilitation
  • Disadvantage: Limited depth of brain visualization, requires careful setup
• DTI (Diffusion Tensor Imaging):

  • Function: Maps brain white matter tracts by measuring water diffusion
  • Advantage: Used to study brain connections, plan surgeries
  • Disadvantage: Can cause discomfort, limited depth of stimulation
• EEG (Electroencephalography):

  • Function: Records brain electrical activity using scalp electrodes
  • Advantage: Used in diagnosing seizures, studying brain function
  • Disadvantage: Limited spatial resolution, susceptible to noise
• TMS (Transcranial Magnetic Stimulation):

  • Function: Applies magnetic pulses to modulate neural activity
  • Advantage: Used in treating depression, studying brain function
  • Disadvantage: Can cause discomfort, limited depth of stimulation
• Taxi Drivers in London:

  • Their hippocampus, associated with memory and spatial navigation, was found to be larger than non-taxi drivers
  • Example of neuroplasticity, the brain's ability to restructure in response to experiences and environmental changes
• Purpose of the brain:

  • Optimize an organism's internal state by responding to and anticipating needs
• The Nervous System:

  • Made up of neurons and glial cells
  • Neurons process information and communicate through synapses
• Four Principal Divisions of Neurons:

  1. Input zone: Receives information through dendrites

  2. Integration zone: Combines received information to decide whether to send a signal

  3. Conduction zone: Axon carries electrical signals away from the cell body

  4. Output zone: Axon terminals transmit signals across synapses to other cells
• Neurons can be classified according to their function, shape, and size
• Three principal forms of neurons are multipolar neurons, bipolar neurons, and unipolar neurons
• Motor neurons trigger movements and have long axons reaching out to synapse on muscles
• Sensory neurons carry messages from peripheral tissue back to the spinal cord and brain
• Interneurons are majority in the brain, receive information from other neurons, process it, and pass the integrated information to other neurons
• Vertebrate nerve cell bodies vary in size, ranging from 10 micrometers to over 100 micrometers
• Larger neurons tend to have more complex inputs and outputs, convey information more rapidly, and cover greater distances
• The neurons connecting the brain and spinal cord to the body can have axons up to a meter in length
• Axons and dendrites have distinct properties such as number, diameter, and length
• At each synapse, information is transmitted from the axon terminal of the presynaptic neuron to the postsynaptic neuron
• The three principal components of a synapse are the presynaptic membrane, synaptic cleft, and postsynaptic membrane
• Presynaptic axon terminals contain synaptic vesicles with neurotransmitter molecules
• The postsynaptic membrane contains a high density of receptors for neurotransmitters
• Synapses on a neuron's dendrites and cell body are constantly changing in response to new patterns of synaptic activity
• Glial cells hold the nervous system together, communicate with neurons, and contribute to information processing
• Types of glial cells include astrocytes, microglial cells, oligodendrocytes, and Schwann cells
• Oligodendrocytes and Schwann cells are involved in myelination, which increases the speed of electrical signals down the axon
• Glial cells can divide throughout life and form tumors, respond to brain injury, and be associated with various diseases
• The peripheral nervous system consists of nerves outside the bony skull and spinal column
• The somatic nervous system consists of nerves that interconnect the brain and major muscles and sensory systems of the body