Lecture 18: Memory Mechanisms Flashcards
What is comparative cognition?
- Approach to the study of animal behaviour that focuses on ‘the mechanisms by which animals acquire, process, store, and act on the information from the environment’
- Includes perception and attention, learning, memory, etc.
- Tells us about the uniqueness of human behaviour
What is cognitive ethology?
- Advocates that animals are capable of conscious thought and intentionality
- Used to explain complex examples of animal behaviour
- Conscious intent cannot explain all complex human behaviours, so this is not a useful explanation of complex non-human behaviour
What kind of behaviour explanations does comparative cognition favour?
- Favours explanations of behaviour which are open to refutation by observation and experiment
- Cognitive mechanisms can be tied to unambiguous behavioural predictions and can then be supported/refuted by experimental evidence
- Constructs/models behaviours that cannot be characterized by simple S-R mechanism
- Uses simplest possible explanation for observations
What is anthropomorphism?
- Interpretation of complex behaviour in nonhuman animals based on the assumption that these animals might have the same thoughts, emotions, and intentions as people might have
- Hamper our understanding of cognitive mechanisms since they overemphasize conscious human experience and are often accepted without experimental proof
What do cognitive mechanisms involve?
- Internal representation of something and rules for manipulating that internal representation
- Must be inferred by behaviour
What is memory?
- The ability to respond based on information that was acquired earlier
- Humans can make explicit responses to memory tasks
- Animals are unable, so existence of memory in animals can be determined if their current behaviour is based on some aspect of earlier experience
How are studies of learning different from memory studies?
- Learning = manipulate conditions of acquisition
- Memory = focus on conditions of retention and retrieval
What are the 5 types of human learning/memory?
- Procedural memory
- Perceptual memory
- Semantic memory
- Primary/working memory
- Episodic/declarative memory
What is procedural memory?
- Memory for learned behaviour of cognitive skills that are performed automatically without need for conscious control (implicit)
- What to do/how to do it
- Ex. playing chess/riding bike
- Classical and instrumental conditioning
What is episodic memory?
- Explicit
- Memory for a specific event or episode
- What, where, when
- Ex. guest lecturer
What is working memory?
- Temporary storage and manipulation of information needed to complete the task at hand
- Ex. following multi-step instructions
What is reference memory?
- Long-term retention of information necessary for the successful use of incoming and recently acquired information
- General knowledge
- Required for use of working memory
- Need to know about how to fix car (reference), and which steps have been done (working)
What is the Delayed Matching to Sample test? What was found when patients with schizophrenia performed this test?
- Show sample, retention period, identify correct response
- Patients with schizophrenia showed a delay dependent deficit in task performance
- Schizophrenia includes WM deficit
What does the Delayed Matching to Sample test require?
- Working memory (retaining info from sample to choice)
- Reference memory (remembering structure of task)
- Most common procedure to study non-human WM
- Can determine how animals remember different types of stimuli
What are the procedural detriments of DMTS?
- Type of stimulus
- Duration of exposure to sample stimulus
- Retention interval after sample before choice (more likely to make mistakes with increased delay)
Does memory fade as a function of time?
- No
- Numerous factors contribute to memory failure
What is the effect of a delayed retention interval on DMTS? Who examined this?
- Sargisson and White
- Introduced different delay intervals from beginning of training to determine if introducing longer delay intervals during training would result in better performance
- Longer retention delays during training increased performance
- Best performance when tested on delay they were trained with
What effect might reward signal have on DMST performance?
- White and Brown
- Pigeons show better memory performance if they receive a signal prior to choice that the correct response will be rewarded with large rather than small reward
- Switching reward from large to small impairs memory
- Switching from small to large reward improves performance
- Memory is not a passive process, but matches the demands of the environment
How can we test whether participants are learning specific S-R relations or general same-as rule?
- Test how matching performance transfers to new stimuli
What is the type of learning related to?
- Size of stimulus set
- Small = S-R learning
- Large = General same-as learning
What are trials-unique procedures?
- Different stimulus serves as the sample on each trial
- Accurate performance only possible if participant learns general same-as rule
What is the Morris Water Maze?
- Spatial memory in mazes
- Platform hidden underwater
- Rats are motivated to find it
- Must learn where platform is in relation to spatial cues
- Measure latency and distance
- Escape latency and distance moved decreases over each day of training
What is the Radial Arm Maze?
- More ecologically valid lab technique
- 8 arms with food at end
- Food is not replaced
- Rats will attempt to complete in most efficient way
- With little training, rats rarely enter arm previously chosen
How are rats successful with the radial arm maze?
- Rats use distinctive features in the environment as landmarks and locate maze arms relative to those landmarks
- If landmarks are moved, rats will treat arm as new location
- Spatial location is determined by distal cues in room, not local cues in maze
What can the radial arm maze be used to assess?
Working memory capacity - Vary # of arms in maze (16-24) Duration of spatial memory - Insert retention interval - Allows rat to collect food from 4/8 arms, then removed for retention interval, then placed to retrieve remaining pellets
How does the intertrial interval affect the radial arm maze?
- Rats trained with the longer inter-trial interval performed better over each retention interval (better long-term memory)
- All groups performed better when retention interval was lower
