Biological Influences

• Selective attention:

  • There's a limited capacity for how much we can focus at any given moment on one stimulus or event
  • Highest level of consciousness - total awareness and focus on what you have selected to focus on
  • Focused only on what we are doing and are oblivious to other things going on in the environment
  • Someone who is fully alert and produces brainwaves that show electrical activity in the brain (Beta brainwaves)
• Divided attention: The capacity to attend to and perform two or more activities at the same time.

  How successfully we divide our attention depends on how much conscious effort is required for each of the tasks:

  • Task difficulty: Complexity of the task
  • Task similarity: Stimuli that are presented in the same sense makes it harder to divide attention compared to when they are presented differently
  • Task familiarity: How used to doing a task an individual is
• Sleep: An altered state of consciousness where awareness of the external environment is extended and is accompanied by a number of physiological changes to the body.

  • We are not totally unconscious when we sleep
  • It is essential to our physical and mental wellbeing
• Frontal lobe:

  Location:

  • Very front of the brain

  Function:

  • Responsible for higher order functions such as the ability to reason, make decisions, problem solve, and think abstractly.
• Temporal lobe:

  Location:

  • Side of the brain, near your ear

  Function:

  • Responsible for receiving and processing auditory information that allows us to understand language.
  • Also connects sounds of words with semantic meaning (facts)
• Parietal lobe:

  Location:

  • Above the temporal lobe, near the middle/ back of the brain

  Function:

  • Vital for sensory perception and integration, including the management of the 5 senses
  • Responsible for integrating touch and vision to perceive depth in our surroundings
• Occipital lobe:

  Location:

  • Under the parietal lobe, very back of the brain

  Function:

  • Responsible for perceiving and processing visual information
• Karl Lashley:

  • Lashley searched for the Engram: The physical location of a memory
  • He trained rats and monkeys to complete a maze
  • He would then destroy progressively larger areas of the rat and monkey's brain tissue, then reintroduce them to the maze
  • The rats and monkeys retained the memory (of the maze), suggesting it was distributed to many parts of the brain
• Lashley findings:

  • Increasing the amount of tissue removed degraded memory, but where the tissue was removed from made no difference
• Lashley - Implications for brain studies:

  • Many types of memory are used in the processing of complex tasks (such as rats running mazes)
  • Memory involved in complex tasks are likely to be distributed among a variety of neural systems
• Henry Molaison - Effects of the procedure:

  • Lost parts of his memory + had anterograde amnesia
  • Even though HM was not actually conscious of it, he could still learn new motor skills through repeated practice
• Henry Molaison - Implications for brain studies:

  • Supports that motor learning is distinct from other parts of memory such as recording new facts, faces, and experiences
  • This means that these multiple different memory systems are located in different parts of the brain
• Phineas Gage - Incident:

  • A tamping iron was propelled through Gage's skull, entering through his left cheekbone and exiting through the top of his head
  • He was surprisingly conscious and able to move immediately after the accident
  • Later passed away from seizure's as an effect of the accident
• Phineas Gage -Effects of the incident:

  • Physically, Gage recovered very well
  • His mental condition was severely impacted after the accident
  • He lost all social inhibitions
  • Seemed to have a completely different personality to before the accident
• Phineas Gage - Implications for brain studies:

  • Some of the first evidence which proved the frontal cortex was related to personality and behaviour
  • Years later it was found that the accident damaged the connections between the frontal cortex and the limbic system
• Electroencephalography (EEG):

  • Measures the electrical activity of the brain, via electrodes attached to the scalp
  • Show changes in brain activity that may aid in diagnosing brain conditions

  Advantages:

  • Safe and painless
  • Can record in milliseconds

  Disadvantages:

  • Doesn't tell you where in the brain the waves are from
  • Does not produce an image
• Computerised Axial Tomography (CAT):

  • Gives detailed images of the inside of the body to identify disease/ injury

  Advantages:

  • Short study time (15-20 minutes)
  • High quality images

  Disadvantages:

  • Involves radiation
  • No information about brain function
• Functional Magnetic Resonance Imaging (fMRI):

  • Detects blood flow/ oxygen consumption of neurons in the brain to measure brain activity
  • Used to diagnose conditions that affect soft tissue such as tumours/ brain disorders

  Advantages:

  • Doesn't involve radiation
  • Produces very detailed pictures

  Disadvantages:

  • Can be an uncomfortable/ claustrophobic experience
  • Patient must stay very still or the quality of the images decreases
• Hippocampus: Important for learning and memory, for converting short term memory to more permanent memory, and for recalling spatial relationships in the world around us.