1. The Neuropsychology of Memory
Milton J. Dehn, Ed.D., NCSP
Schoolhouse Educational Services
April 2015

2. Notice of Copyright 2015
This PowerPoint presentation and accompanying materials are copyrighted by Milton J. Dehn and Schoolhouse Educational Services, LLC. The PowerPoint and materials are not to be reprinted, copied, presented, or electronically disseminated without written permission. To obtain permission,

3. Workshop Information Sources
Working Memory and Academic Learning
Long-Term Memory Problems in Children
Essentials of Working Memory Assessment
Working Memory in the Classroom
Essentials of Processing Assessment, 2nd Ed.
Presenter Contact:

4. Essentials of Working Memory

5. Working Memory Definition
ST retention + processing = WM
“WM: the limited capacity to retain information while simultaneously manipulating the same or other information for a short period of time”
Keeping information in mind from moment to moment
STM is part of WM; WM “manages” STM as needed

6. WM Capacity STM adult span of 7; Digit span of 80?
WM limit of 4 “chunks”
Can be as little as one chunk in children
Processing & storage use same WM resource
Duration affected by rehearsal & amount of interference
See ABC News Chimps vs Humans

7. Dehn’s Integrated Model of WM

8. The Big Three Executive WM Processes
Inhibiting: Suppressing distractors and interference
Shifting: Alternating between different processing tasks or between processing and storage (rehearsal)
Updating: Continual replacement of no longer relevant information with current information

9. Activated LTM Recently activated LTM representations
WM works with these, going back and forth
Up to 20 at a time
Effectively expands capacity of WM because these are not stored in STM/WM
Is part of verbal and visual-spatial WM
WM may draw from these more than STM
Problem: No way to easily assess this

10. Working Memory and Related Cognitive Processes
Should be considered when WM is deficient:
Attention
Executive functions
Fluid Reasoning
Language
Long-term memory
Processing speed
Phonological processing

11. What WM and Attention Have in Common
Both are in dorsolateral prefrontal cortex
Both part of general executive functions
Both involve controlled attention
Inhibition deficit underlies both ADHD and WM
Both respond to Ritalin
Problems manifest in similar ways
When a student has a WM deficit, the number one thing reported by teachers is that the student has an attention problem

12. WM and Attention The control of attention is part of WM
Paying attention is a necessary but insufficient condition for processing and retention in STM and WM
If child is paying attention and still can’t remember in the moment, it’s probably WM
Attention problems diminish WM performance in a normal WM

13. WM vs ADHD The majority with ADHD have a WM problem
ADHD behavior issues have little to do with WM, except for poor decision-making
Attention involves arousal & motor inhibition
WM deficit closely related to Inattentive ADHD, not Hyperactive/Impulsive type
ADHD involves mainly visuospatial WM
Divided attention closest to WM
As WM load increases, hyperactivity increases

14. Neuroanatomy

15. Occipital Lobe Dedicated to vision and visual-spatial processing
Receives sensory data from the thalamus
Visual and spatial processing are separate
Dorsal stream (upper) sends spatial information to parietal lobe
Ventral stream (lower) sends visual information to temporal lobe

16. Temporal Lobe Auditory processing
Long-term memory processing in the hippocampus
Some visual processing
Semantic memory storage

17. Parietal Lobe Integrates sensory information Language processing
Phonological processing

18. Frontal Lobe The “output” lobe; others are input
Executive functions---prefrontal cortex
Working memory---prefrontal cortex
Attentional control---prefrontal cortex
Fluid reasoning
Fine motor
Oral expression
No storage of long-term memories

19. Prefrontal Cortex Image

20. Brain Lobes and STM & WM
Frontal (Dorsolateral Prefrontal Cortex): Executive WM
Temporal: Episodic WM (especially during LTM encoding and retrieval)
Parietal Lobes: Phonological STM and Verbal WM in language processing areas
Occipital Lobes: Visuospatial STM and WM

21. Neuropsychology of WM
“working memory can be viewed as neither a unitary nor a dedicated system. Thus, working memory is not localized to a single brain region but probably is an emergent property of the functional interactions between the PFC and the rest of the brain” (D’Esposito, 2007)

22. WM Neurological Basis
Individual differences in WM capacity are correlated with the structural integrity of white matter pathways connecting domain general regions with the fronto-parietal network
Thus, WM is related to integrity (strength) and extent of myelinated axons
WM training increases the integrity of white matter (Takeuchi et al., 2010)

23. Phonological STM and Verbal WM
Left-hemisphere inferior parietal areas
Brodmann’s area 40 in parietal lobe is the storage area; Brodmann’s is involved in phonological processing; part of #3 below
Supramarginal gyrus in parietal lobe is also involved; supramarginal gyrus is involved in language processing
Broca’s area (language function) in inferior left frontal lobe is subvocal rehearsal area

24. Visuospatial STM and WM
Right hemisphere
Occipital lobe
Inferior frontal areas
Visual is occipital
Spatial is more parietal (dorsal stream)

25. Other Brain Involvement in General WM
Striatum: part of the forebrain and the basal ganglia system. Mainly involved with planning movement.
Anterior cingulate: a “collar” around the corpus callosum involved in decision making
Dopamine level is important for WM. A deficiency in dopamine can impair WM performance.

27. LTM Processes
Encoding
Consolidation
Storage
Retrieval

28. Consolidation
Memories become more stable and resistant to interference over time
Memories are forgotten because they are not consolidated
LT memories are initially and temporarily stored in the hippocampus and adjoining medial temporal lobe structures
Over time they are transferred to the cortex for more “permanent” storage

29. Consolidation Details
Neuroscience construct; not cognitive psych.
Evidence from TBI, amnesia, & sleep studies
Ribot’s gradient
Takes time: hours to several days
Unconscious mostly
Much of it occurs during sleep
Especially important for semantic memory
Reactivations improve consolidation

30. Sleep and Consolidation
During both types of sleep
Hippocampus “replays” experiences/learning
“Organizes” information; Strengthens connections
“Moves” information to cortical areas
Sleep also reduces interference
Sleep accounts for 69% of next day improvement in procedural tasks
Immediate sleep: 81% recall; delayed: 66%

31. LTM and the Brain Lobes
Temporal lobes---encoding, retrieval, consolidation, temporary storage of long-term episodic memories, semantic storage
Frontal lobes---memory strategies for encoding and retrieval (no actual storage of long-term memories)
Parietal---auditory and spatial storage
Occipital---visuospatial storage

32. The Hippocampus

33. Hippocampus Image

34. The Hippocampus Horseshoe shape in temporal lobe
Necessary for STM-LTM transfer
Encodes, consolidates, retrieves, reintegrates
May hold some episodic permanently
Explicit memory only
Sensitive to injury, glucose, oxygen, & cortisol levels

35. The Hippocampus
Responsible for transferring memories to cortex (consolidation); active during sleep
Has a spatial side and a verbal side
Spatial memory depends on it (more than verbal memory); London’s taxi drivers
Large EEG signals
High levels of glucocorticoid receptors
Size matters; bigger is better

36. The Hippocampus Clearly necessary for episodic memory
May not be as essential for semantic memory
More involved with automatic retrieval; conscious retrieval may depend more on the prefrontal cortex
The hippocampus primarily stores associations between memories rather than the memories themselves; holds the key to the connections

37. The Hippocampus Hippocampus contains stem cells
Hippocampus can grow (London taxi drivers)
New neurons can be created from stem cells; up to six weeks to mature
Rats given Prozac had a 70 percent increase in hippocampi cells after three weeks
Humans who recover from depression have more hippocampal volume than those who are chronically depressed

38. What the Hippocampus Needs
Oxygen
Glucose
Sleep (no permanent damage from lack of)
No cortisol
No impact
No electricity
See YouTube Video: “Hippocampus Damage”

39. Non-Hippocampal LTM Structures
Thalamus (sensory relay station)
Amygdala (emotions strengthen memories)
Ventral visual stream (RAN)
Parahippocampal cortex (surrounds hippocampus; memory encoding)
Entorhinal cortex (interface between hippocampus and neocortex)
Perirhinal cortex (visual recognition)

40. Thalamus Relay station for sensory information Near the hippocampus
Involved in procedural memory formation
Damage can cause amnesia

41. Amygdala Is next to the hippocampus
Recognizes stimuli with strong emotional content or survival value
Involved in classical conditioning
May be involved in processing cross-modal associations
Does not actually store memories

42. Implicit Memory Does not appear to depend on the hippocampus
Not consciously accessible
Demonstrated through performance, not recall
Precedes development of explicit memory
Example of implicit memory without explicit

43. Priming (Type of Implicit Memory)
Performance or recall is enhanced by recent, prior exposure
A form of very specific cueing; might be considered a memory process
Thought to be more perceptual processing than an actual memory function
“Milk” example
Conceptual priming, such as an advance organizer, is more explicit memory

44. Implicit Memory Structures
Generally not in medial temporal lobe but parietal and occipital
Cerebellum---conditioning
Striatum---procedural learning
Also, temporal cortices, amygdala, basal ganglia, and motor cortex
Range of structures may serve a protective function

45. HM: Classic Case of No Hippocampus
Hippocampus, parahippocampal gyrus, entorhinal cortex, and amygdala were surgically removed in 1957 at age 27 because of epilepsy
Anterograde amnesia but STM and WM fine; could modify some semantic knowledge, such as celebrities’ names, but no new episodic memory
Some retrograde amnesia: Most events 1-2 years prior to surgery forgotten but prior semantic memory was good

46. HM Performed normally on intellectual tests
Could learn new motor skills (implicit, procedural memory) but could not remember that he had learned them
He could draw a map of the house he was living in (that he moved to after the surgery), maybe from locomotion recall
His case had strong influence on memory theories and brain mapping of memory

47. Organization of LTM Memories from Cognitive Perspective
Schemas
Logical linking at the neurological level may result from thinking about two things at the same time (associations) (“fire together; wire together”)
Scripts
Memory traces
Associations

48. Organization and Storage of Memories
The connections more important and better understood than the cellular changes
Memory traces (pathways): synapses
New memories: new synapses or changes in strength
In networks of interconnected neurons, with associated items linked more closely
Memories end up being stored in same areas that sensed, perceived, and processed info
Different components of a memory stored separately; then reintegrated during retrieval

49. Summary: The Neurological Sequence of LT Memory
Encoding, automatic or effortful
Associations with related networks
Strengthening, building, altering synapses
Changing neurons and building neural networks
Temporary storage in hippocampus and medial temporal lobe
Consolidation and “permanent” storage in the cortex
Memories end up being stored in same areas that sensed, perceived, processed
Recall
Uncued or minimally cued retrieval
Cued retrieval or recognition