studying intelligence in animals 2

• assessing memory - radial arm mazes (RAM)

  • working memory
  • food = positive reinforcement
  • explores each arm to find food

  RAM test for errors: should remember what one they've been in

  long term memory - not all will have food in it - will remember what arms have food

  
• assessing memory - the water maze

  spatial memory

  need to learn where hidden platform is

  • water submersion = negative reinforcement
  • water is opaque
  • swim to find hidden escae platforms
  • use extra-maze cues to navigate
• assessing memory - operant boxes

  working memory

  DELAYED MATCHING TO POSITION (DMTP)

  • operant box
  • put animal in box
  • shown one of two levers
  • they press lever
  • food arrives
  • they eat
  • lever then REMOMOVED

  CHOICE PHASE:

  • light off and both levers presented
  • pressing correct lever = light on and food
• capacity

  amount of information that can be stores
• durability

  length of time information is retained
• Episodic memory

  what, when and where memory

  • Episodic memory loss prevalent in ageing and neurodegenerative diseases
• episodic memory - scrub jays

  • nuts in location A
  • worms in location B
  • interval of either 4 or 124 hours, birds given choice between A or B
  • 4 HOURS - B was chosen - worms fav.
  • 124 HOURS - A - worms would have gone off
• methods of navigation

  • way marking
  • sun position
  • magnetoreception
  • pheromone trails
  • polarised light
• navigation: geometric relations

  nutcracker birds

  • trained to find food midway between red and blue landmark
  • Landmarks separated by distances 40 to 100cm
  •  ​Test: landmarks separated by more than 100cm, birds still searched at the midpoint
  • suggests they are integrating information from both landmarks to find the food at the midpoint
• navigation: shape of area

  RATS

  • trained to find food in one corner of rectangle area with landmarks in other 3

  TEST:

  • remove landmark in corner opposite to food = rats searched both corners for food

  suggests they used shape of the area (long edge on right and short edge on left) not the landmarks to locate the food ​
• navigation: cognitive maps

  RATS

  • trained to find hidden platform in rectangular area

  TEST

  • kite shaped area
  • spent most time in two different corners only one corner was long and short edge, the other was 2 long edges

  suggests they used local landmarks, not shape of area to make sequence of rules = cognitive maps

  • Head for long wall then turn right

  
• Hippocampus

  long term and spatial memories

  -          Has neurones that respond to a specific location on the environment
• hippocampal place cells

  rats

  • Trained to find food in a cross shaped maze using room cues
  • Electrodes recorded the activity of cells in the hippocampus
  • Found specific cells, normally inactive, fired when a rat entered a specific part of the maze