psych 101 (6)

• Memory - an active system that receives information from the senses, puts that information into a usable form, organizes it as it stores it

  away, and then retrieves the information from storage
• Three Main Processes of Memory

  • encoding
  • storage
  • retrieval
• Information Processing Model

  • sensory memory
  • short-term memory
  • long-term memory
• Memory involves simultaneous processing across multiple networks.

  1. the representation of information is distributed (not local)
  2. memory and knowledge for specific things are not stored explicitly, but stored in the connections between units.
  3. learning can occur with gradual changes in connection strength by experience
• Memory depends on depth of processing
• sensory memory

  • iconic memory
  • echoic memory
• Iconic Memory

  • lasts for a few seconds
  • requires attention to perceive changes or identify objects
  • eidetic memory
  • holds info long enough for brain to decide whether it is important or not
• Echoic Memory

  • lasts for around 4 seconds
  • holds auditory information for high cortical processing
  • e.g. tuning instruments
• Broadbent’s filter Theory

  Selective Attention - The ability to focus on only one stimulus from among all sensory input
• Treisman’s Attenuation Theory - Sensory information that we haven’t attended only has “attenuated” signals in comparison to selectively attended information
• Short-term Memory Capacity

  • +-7 bits of information (5-9)
• working memory - “active system that processes the information present within short-term memory.”
• long term memory

  • declarative memory
  • semantic memory
  • episodic memory
• long term memory

  • non-declarative memory
  • emotional associations
  • reflexes
  • habits
• Semantic Network Model - Explains how memories are

  connected in long-term memory
• Nodes represent one declarative concept in the long-term memory
• Each nodes are connected if they are semantically similar
• elaborative rehearsal - “A way of increasing retrieval cues for information by connecting new with information with something that is already known”
• Retrieval cues - “More cues stored with a piece of information, the easier the retrieval”
• Encoding Specificity

  • context dependent
  • state dependent
• Recall - few or no external cues required
• Retrieval failure is where the information is in long-term memory, but cannot be accessed.
• The serial position effect is the tendency to remember the first and last items in a series better than those in the middle.
• Recognition - matching incoming sensory information to what is already in memory
• Misinformation Effect - creation of false memories due to information given after the event
• False Memory Syndrome - creation of false memories under suggestion particularly through hypnosis
• Reasons for Forgetting

  Encoding Failure

  • information has not been encoded
• Reasons for forgetting

  • memory trace decay theory
  • physical changes in the brain due to memory fades with disuse
• Reasons for forgetting

  • Proactive interference
  • older material interferes with recall of newer information
  • Retroactive interference
  • newer material interferes with recall of older information
• Changes in synaptic connection

  • long term potentiation
  • strengthening of synaptic connections;
  • neurons communication more often
• Changes in synaptic connection

  • memory consolidation
  • changes in synaptic sensitivity and structure of neurons
• hippocampus - consolidation of declarative memories
• Exercise training increased hippocampal volume by 2%, effectively reversing age-related loss in volume by 1 to 2 y. We also demonstrate that increased hippocampal volume is associated with greater serum levels of BDNF, a mediator of neurogenesis in the dentate gyrus. Hippocampal volume declined in the control group, but higher preintervention fitness partially attenuated the decline, suggesting that fitness protects against volume loss.