© Cengage Learning 2016 Learning and Memory Chapter 12

© Cengage Learning 2016 Three categories of learning –Reflexes –Fixed action patterns (instincts) –Learning Types of learning –Associative learning Classical and operant conditioning –Nonassociative learning Habituation and sensitization Learning

© Cengage Learning 2016 Reflexes Provide Fast, Reliable Responses

© Cengage Learning 2016 Contagious Yawning Might Be a Fixed Action Pattern

© Cengage Learning 2016 Habituation occurs when an organism reduces its response to unchanging, harmless stimuli Sensitization occurs when repeated exposure to a strong stimulus increases response to other environmental stimuli Habituation and Sensitization

© Cengage Learning 2016 Organisms learn that stimuli act as signals that predict the occurrence of other important events First articulated by Pavlov in 1927 –Conditioned responses (CR) are those behaviors that must be learned –Unconditioned responses (UCR) appear without prior experience to a stimulus Classical Conditioning

© Cengage Learning 2016 The Process of Classical Conditioning

© Cengage Learning 2016 Studied by B.F. Skinner Organisms form connections between a behavior and its consequences that impact the subsequent frequency of that behavior Reinforcing and punishing consequences increase and decrease likelihood of repeating the behavior Operant Conditioning

© Cengage Learning 2016 Studying invertebrates gives a rich opportunity to understand changes taking place at the level of the synapse Frequently studied organisms –Fruit flies –Sea slug (Aplysia californica) Learning at the Synapse

© Cengage Learning 2016 Aplysia californica

© Cengage Learning 2016 The Neuroanatomy of Aplysia

© Cengage Learning 2016 Habituation in Aplysia –Gill-withdrawal reflex –Reduced activity at synapse between sensory and motor neurons –Direct result of decreased neurotransmitter release Short-Term Habituation at the Synapse

© Cengage Learning 2016 Sensitization in Aplysia –A stimulus gains the ability to influence more than one neural pathway –Increased neurotransmitter release by sensory neuron Short-Term Sensitization at the Synapse

© Cengage Learning 2016 Habituation and Sensitization in Aplysia

© Cengage Learning 2016 Long-term habituation training decreases the number of presynaptic terminals of sensory neurons Long-term sensitization training increases the number of presynaptic terminals of sensory neurons Both are likely the result of gene expression processes controlled by transcription factors Long-Term Habituation and Sensitization at the Synapse

© Cengage Learning 2016 Structural Changes in Synapses Result from Learning

© Cengage Learning 2016 Biochemical Correlates of Sensitization in Aplysia

© Cengage Learning 2016 The cAMP-PKA-MAPK-CREB Pathway Leads to Long-Term Changes in Behavior

© Cengage Learning 2016 Classical conditioning in Aplysia –Sequential activation of sensory neurons by CS and UCS leads to greater neurotransmitter release –Classical conditioning in Lymnaea can occur to both rewarding unconditioned stimuli (food) and aversive conditioning stimuli (electric shock) Classical Conditioning at the Synapse

© Cengage Learning 2016 Classical Conditioning in Aplysia

© Cengage Learning 2016 Results when an organism’s naturally occurring behavior becomes more or less frequent in response to its consequences “Fix” what had been a fairly random pattern of behavior into a more reliable, stereotyped pattern Operant Conditioning at the Synapse

© Cengage Learning 2016 Operant Conditioning in Aplysia

© Cengage Learning 2016 Classical conditioning of threat –“Fear” is a conscious feeling of being afraid –“Threat” is the unconscious mobilization of defensive behaviors Amygdala plays an important role in the classical conditioning of emotional responses Brain Structures and Circuits Involved in Learning

© Cengage Learning 2016 The Amygdala Participates in Threat Conditioning

© Cengage Learning 2016 Rabbit studies –Nictitating membrane –Interpositus nucleus of the cerebellum is necessary for learning to occur Human studies –The cerebellum is involved in classical conditioning Classical Conditioning of the Eyeblink

© Cengage Learning 2016 The Role of Interpositus Nucleus in Classical Conditioning

© Cengage Learning 2016 The Purkinje cells are perfectly situated to influence the output of the cerebellum Learning will occur if the climbing-fiber and parallel-fiber synapsing onto a Purkinje cell are activated at the same time Reduced activity in the Purkinje cells is known as long-term depression Cerebellar Circuits and Classical Conditioning

© Cengage Learning 2016 Connections within the Cerebellum

© Cengage Learning 2016 Delay conditioning –The CS overlaps the UCS –No stimulus-free interval Trace conditioning –The CS and the UCS do not overlap –A stimulus-free interval occurs –Requires the participation of forebrain areas –Requires conscious, declarative processes Trace Conditioning

© Cengage Learning 2016 Delay Versus Trace Conditioning

© Cengage Learning 2016 Pavlov described how conditioned responding would gradually decrease, or undergo extinction, when the conditioned stimulus was presented repeatedly without the unconditioned stimulus Extinction

© Cengage Learning 2016 Steps in the memory pathway –Encoding –Consolidation –Retrieval –Reconsolidation Types of Memory

© Cengage Learning 2016 Information flows through a series of stages on its way to permanent storage in memory –Sensory memory –Short-term memory –Long-term memory Declarative memories (semantic and episodic) Nondeclarative memories (procedural) Anterograde amnesia Engrams Information Processing Model

© Cengage Learning 2016 Atkinson-Shiffrin Model of Memory

© Cengage Learning 2016 Types of Long-Term Memory

© Cengage Learning 2016 Early efforts to locate memory functions –Lashley: engram –Penfield: recordings during surgery for epilepsy Temporal lobe and memory –H.M.’s anterograde amnesia –The delayed nonmatching to sample (DNMS) test (monkeys) Brain Structures and Circuits Involved in Memory

© Cengage Learning 2016 Karl Lashley Observed the Results of Brain Lesions on Maze-Learning Performance

© Cengage Learning 2016 Evidence of the temporal lobe’s involvement in memory –Case studies of patients with anterograde amnesia Amygdala appears to play a role in processing emotional memories The hippocampus involved in the formation of long-term memories The Temporal Lobe and Memory

© Cengage Learning 2016 Surgical Removal of Henry Molaison’s Temporal Lobe Tissue

© Cengage Learning 2016 The Mirror-Drawing Task

© Cengage Learning 2016 The Delayed Nonmatching to Sample (DNMS) Task

© Cengage Learning 2016 Provide a basis for learning and memory –The application of a rapid series of electrical shocks to input pathways increases the postsynaptic potentials in their target neurons LTP as a memory mechanism –Associativity, cooperativity, and synaptic tags LTP and behavioral memory –Spatial memory; avoidance situations Long-Term Potentiation (LTP)

© Cengage Learning 2016 The Hippocampus and Its Associated Structures

© Cengage Learning 2016 Long-Term Potentiation (LTP)

© Cengage Learning 2016 LTP and the NMDA Receptor

© Cengage Learning 2016 The Morris Water Maze Requires Spatial Memory

© Cengage Learning 2016 Disruption of the hippocampus and other areas of the temporal lobe results in amnesia Case studies of patients with diencephalic lesions support the role of this area in memory Alcoholics and amnestic confabulatory (Korsakoff’s) neurocognitive disorder The Diencephalon and Memory

© Cengage Learning 2016 Damage to the Diencephalon in Patient N.A.

© Cengage Learning 2016 Semantic knowledge is widely distributed in the cortex Retrieving these distributed memories requires a coordinated effort and the use of “convergence zones” –Left lateral inferior frontal gyrus Semantic Memory and the Cerebral Cortex

© Cengage Learning 2016 Semantic Memories Are Widely Distributed

© Cengage Learning 2016 Concept of an independent episodic memory store for our personal experiences Patients with source amnesia can create new semantic memories but forget how the knowledge was gained originally Prefrontal areas are involved with long- term management of episodic memories Use episodic memories to distinguish between fantasy and reality Episodic Memory and the Cerebral Cortex

© Cengage Learning 2016 Four components of working memory –A central executive –The phonological loop –The visuo-spatial scratchpad –An episodic buffer The dorsolateral prefrontal cortex (DLPFC) and the anterior cingulate cortex (ACC) play roles in attentional aspects of short- term memory Short-Term Memory and the Brain

© Cengage Learning 2016 Object Permanence

© Cengage Learning 2016 The striatum –Role in forming procedural memories –Basal ganglia Memories of motor patterns –Nucleus accumbens Emotional and rewarding correlates of a procedure The Striatum and Procedural Memory

© Cengage Learning 2016 The Radial Arm Maze

© Cengage Learning 2016 Acetylcholine (ACh) is essential to memory functions Cholinergic activity has different effects in different phases of memory –Increases in the hippocampus are associated with better encoding of new information but consolidation and retrieval of memory appear to be impaired by high cholinergic activity Glutamate is involved in encoding and consolidation of memories The Biochemistry of Memory

© Cengage Learning 2016 Stress and healthy aging produce relatively mild but noticeable changes in the way memories are processed The Effects of Stress and Healthy Aging on Learning and Memory

© Cengage Learning 2016 The critical variable determining the effects of stress on memory appears to be timing –In the Atkinson-Shiffrin model, memories pass through a series of stages during which they are relatively fragile and open to modification – At each stage, stress and biochemical correlates can have unique effects on how information is encoded, stored, and retrieved Effects of Stress on Memory

© Cengage Learning 2016 Flashbulb Memories Seem More Vivid and Complete

© Cengage Learning 2016 Stress Has Different Effects at Different Times in the Memory Process

© Cengage Learning 2016 The lateral nucleus of the amygdala is the target for both norepinephrine and glucocorticoids released by the adrenal glands as a result of stress The stress-induced actions of norepinephrine and glucocorticoids in the amygdala initiate a “memory formation” state in the prefrontal cortex, the hippocampus, and the caudate nucleus Effects of Norepinephrine and Glucocorticoids on Memory

© Cengage Learning 2016 Effects of Glucocorticoids and Norepinephrine on Memories for Stressors

© Cengage Learning 2016 Cognitive ability of healthy older adults is stable –Comparison of young adults, healthy older adults, those at high risk for Alzheimer’s, and those with Alzheimer’s disease –People compensate for age-related declines in brain function The Effects of Healthy Aging on Memory

© Cengage Learning 2016 Electronic Games and Healthy Aging