lecture 16 Flashcards
what is Classical Conditioning (Pavlovian Learning)
Unconditioned responses are reflexive, hardwired, fairly inflexible behavioural responses to unconditioned stimuli. For example, salivating in response to the taste of food or blinking in response to puffs of air to the eye. When these behaviours come under control of conditioned stimuli, it is called Classical Conditioning or Pavlovian Learning. Importantly, in these types of learning experiments the animal has no control over its environment. The animal will react to things, but they cannot really change what will happen
what is Instrumental Conditioning (Operant Conditioning)
• Animals are always exploring their environments and sometimes their actions have consequences. Learning from the consequences of your
actions is called Instrumental Conditioning, Operant Conditioning, or Reinforcement Learning. Instrumental behaviours start off as flexible, volitional exploratory behaviours (e.g., pressing a lever or flipping on a light switch) and the likelihood these actions will be repeated depends on whether or not they were reinforced or punished.
what is another term for Instrumental conditioning
Operant conditioning
Reinforcement learning
simplify Instrumental conditioning
Learning that occurs in response to reinforcement, in response to consequences. The likelihood of you repeating an action depends on whether it was previously punished or reinforced.
In contrast to Classical (Pavlovian) learning, operant conditioning requires what
that the animal can move and make decisions that have consequences
what is Reinforcing stimulus
Appetitive stimulus. When it follows a particular behavior, it increases the likelihood the animal will repeat the behaviour. Reinforcement makes the behavior more likely to occur.
what is Punishing stimulus
Aversive stimulus. When it follows a particular behavior, it decreases the likelihood the animal will repeat the behaviour. Punishment makes the behavior less likely to occur.
whats Reinforcement
Learning provides a means for people to profit from experience—to make responses that provide favorable outcomes
• When good things happen (that is, when reinforcing stimuli occur), reinforcement mechanisms in brain become active, and the establishment of synaptic changes is facilitated
The process of reinforcement strengthens what
a connection between neural circuits involved in perception (sight of the lever) and those involved and those involved in movement (the act of lever pressing).
The are two major pathways between sensory association cortex and motor association cortex, what are they
Direct transcortical connections
Connections via basal ganglia and thalamus
explain Direct transcortical connections
(connections from one area of the cerebral cortex to another)
explain Connections via basal ganglia and thalamus.
- The synaptic strength of cortical and thalamic inputs to the basal ganglia is heavily dependent on dopamine signaling, which comes from the midbrain.
- The input nuclei of the basal ganglia (caudate + putamen + accumbens = striatum) are the primary locations for instrumental conditioning.
what are the NEURAL CIRCUITS INVOLVED IN REINFORCEMENT
Ventral tegmental area (VTA)
Nucleus accumbens
what is Ventral tegmental area (VTA)
Group of dopaminergic neurons in the midbrain whose axons primarily project to the ventral striatum (nucleus accumbens.)
• Dopamine release is a reinforcement signal
what is Nucleus accumbens
Nucleus of ventral striatum (basal forebrain) near PFC
• Receives dopaminergic inputs from the ventral tegmental area and is thought to be involved in goal selection
Studies with laboratory animals found that lesions of basal ganglia do what
disrupt instrumental conditioning but do not affect other forms of learning
Lesions of the striatum (caudate nucleus and putamen) that receive visual information from ventral stream do what
do not disrupt visual perceptual learning, but they do impair monkeys’ ability to make learned visually guided operant responses
As action sequences (movement and goal decisions) get repeated again and again what happens
they become more and more habitual, more ingrained and automatic.
As action sequences (movement and goal decisions) get repeated again and again, they become more and more habitual, more ingrained and automatic.
Across this transition, different circuits within the basal ganglia become involved what
the action selection and action execution processes.
Areas involved in the initial learning of movement sequences are different from what
those involved in automated actions
what are THE DECLARATIVE MEMORIES
Episodic memory
Semantic memory
what is Episodic memory
Personal experiences associated with a time and place. Autobiographical memory
what is Semantic memory
Memory of facts and general information. This knowledge need not be associated with the time or place in which we learned the information
explain the case of Henry Gustav Molaison (HM) and the hippocampus
first described by Brenda Milner in 1957
• Doctors cut out his hippocampus bilaterally to cure his epilepsy.
• It worked, but he lost the ability to form new explicit memories (severe anterograde amnesia).
• He also suffered from a graded retrograde amnesia (events that occurred within 1 or 2 years were lost as well as some that happened even longer ago than that.
• He still had a brief working memory and a high IQ, but he could not learn new words or names or learn to navigate a new space.
Researchers have been recording neural activity in the hippocampus now for over 50 years and trying to make sense of the firing patterns.
what is Anterograde amnesia
refers to the inability to learn new information or retain new information ‘after’ brain injury. Memory for events that occurred before the injury remain largely intact
what is Retrograde amnesia
refers to the inability to remember events that occurred ‘before‘ the brain injury
is Complete amnesia in either direction common
no, it is rare
what is Korsakoff’s syndrome
Permanent anterograde amnesia caused by brain damage, usually resulting from chronic
alcoholism. Korsakoff’s patients are unable to
form new memories but can still remember old ones before the brain damage occurred
what is Confabulation
Reporting of memories of events that did not take place without intention to deceive
Seen in people with Korsakoff’s syndrome
Damage to the hippocampus or to regions of the brain that supply its inputs and receive its outputs causes what
anterograde amnesia
When amnesic patients are trained and tested, we find that they are capable of how many types of learning
three of the four major types of learning: perceptual learning, stimulus–response learning, and motor learning
Although amnesic patients show many forms of implicit learning, they do not explicitly remember what
anything about what they have learned.
what is Declarative (explicit) memory
Memory that can be verbally expressed, such as facts and personal events. Memory that can be consciously accessed
what is Nondeclarative (implicit) memory
Unconscious memory whose formation does not depend on the hippocampal formation; a
collective term for perceptual, motor, and unconscious stimulus–response memory.
Most psychologists believe that learning consists of at least two stages, what are they
short-term memory and long-term memory
what is the Simplest model of the memory process
Says that sensory information enters short-term memory, rehearsal keeps it there, and eventually, the information makes its way into long-term memory, where it is permanently stored
what is the Role of the Hippocampal Formation in Consolidation of Declarative Memories
The hippocampus is not the location of either short-term or long-term memories
• Patients with damage to the hippocampal formation can remember events that happened before their brain became damaged, and their short-term memory is relatively normal
• But hippocampal formation clearly plays role in process through which declarative memories are formed
what is Memory Consolidation
Memory consolidation is the process by which short-term memories are crystallised into long-term memory
Activity of the hippocampus is elevated when
after learning a memory task which correlates positively with performance
In rodents, the hippocampus is required for what
newly learned spatial information, not information learned 30 days ago.
During 30 days, other regions
of the cerebral cortex consolidate and store the information.
what is the Reconsolidation of Memories
Established memories can be altered or connected to newer memories
• In recent years, researchers have been investigating a phenomenon known as reconsolidation, which appears to involve modification of long-term memories
During memory reactivation (memory recall) memories do what
enter a labile, unstable state and can be modified before being reconsolidated
During memory reactivation (memory recall) memories enter a labile, unstable state and can be modified before being reconsolidated.
▪ Events that interfere with consolidation interfere with reconsolidation as well and can do what to memories
erase or make the memory inaccessible
People with anterograde amnesia are unable to remember information about what kinds of things
the location of rooms, corridors, buildings, roads and other important items in their environment
Subjects played a virtual reality game in which they had to navigate around a town until they became familiar with it.
▪ Subjects then played the game while their heads were in a PET scanner.
▪ During navigation, what became active
the right hippocampal formation became active and the amount of activity there was associated with subjects accuracy in navigation
Hippocampal lesions disrupt ability to keep track of and remember what
spatial locations
what is the The Morris water maze
The Morris water maze requires relational learning to navigate around the maze
•Animals get their bearings from relative locations of stimuli located outside maze—furniture, windows, doors, and so on
Mazes can also be used for nonrelational, stimulus– response learning
•If animals are always released at same place, they learn to head in particular direction—for example, toward a particular landmark they can see above the wall of maze
