Neuropsychological Perspectives on Long-Term Memory Problems in Children and Adolescents

1. Neuropsychological Perspectives on Long-Term Memory Problems in Children and Adolescents Milton J. Dehn, Ed.D., NCSP Schoolhouse Ed. Services mdehn2@msn.com

2. Long-Term Memory (LTM) Topics • Systems and processes • Brain structure • Development • At-risk populations • Assessment • Instruction • Intervention

3. Why Is This Important? • A frequent underlying impairment • Advances in neuroscience • Under-identified in children & adolescents • A growing problem, e.g, juvenile diabetes • Evidence-based interventions available • Needs to be included in more evaluations

4. LTM Memory Systems • Explicit/declarative • Episodic • Semantic • Implicit/nondeclarative • Priming • Procedural Learning • Classical conditioning

5. Explicit vs Implicit • ExplicitImplicit • Conscious Unconscious • Knowledge Skills • Flexible expression Rigid expression • Hippocampus-dependent Non-hippocampus • Recollection expressed Performance expresses • Cognitive only Non-cognitive also • Effortful retrieval also Automatic retrieval only • Develops until adulthood Developed by age three • Vulnerable to injury Resistant to injury

6. Episodic vs Semantic • EpisodicSemantic • Memory for events Memory for facts • Remembering Knowing • Context dependent Context free • Subjective focus Objective focus • Vulnerable to pathology Resistant to pathology • Develops later Develops first • Known source Unknown source • Mostly visuospatial Mostly verbal • Unintentional encoding More intentional • Chronological Categorical • Organized spatiotemporally Organized by meaning • Subject to rapid forgetting Less rapid forgetting

7. Episodic-Semantic Interactions • School learning is initially episodic but eventually semantic • Episodic helps build the semantic • Semantic provides the schemas and scripts for the episodic • Memory tests are episodic • Must use IQ subtests for semantic

8. Flow of Information • Environment • Sensory Memory • STM • WM • LTM • Expression • Flow Link • Systems interaction link

9. STM vs LTM • STMLTM • Very limited capacity Extensive capacity • Retention for seconds Retention for minutes to years • Conscious access to all content Limited conscious access • Only two types Multiple types • Depends on attention Less dependent on attention • Immediate retrieval only Retrieval can be extended • Forgetting is immediate Forgetting is gradual • Amenable to simple strategies Amenable to elaborate strats. • Easy to assess Difficult to assess • Less susceptible to brain injury Very susceptible to brain injury The chimpanzee?

10. LTM Processes • Encoding • Consolidation • Storage • Retrieval • Forgetting

11. Encoding • Requires attention • Associated with learning • All other memory depends on • Enhanced by strategies • Hippocampus dependent

12. Learning • Mainly refers to initial learning, encoding, and short-term recall • Learning curve---improves rapidly then plateaus • What is difficult to learn is difficult to remember and vice versa • Can be separated from memory---same degree of learning but different retention

13. Forgetting • Fast at first, then slows down • 50% forgotten within 24 hours • Some retain well within 30 minutes or 1st day but then have very poor retention afterwards • Is it lost, or not retrievable at moment • Interference: proactive and retroactive

14. Consolidation • Often ignored • Evidence from TBI and amnesia • Takes time • Unconscious mostly • Movement from medial temporal lobe/hippocampus to cortical areas • Episodic to semantic • Much of it occurs during sleep

15. Storage • Memory traces---changes in strength of synapses • In networks of interconnected neurons • Depends on the pathways between neuronal networks • Memories end up being stored in same areas that sensed, perceived, and processed incoming information

16. Retrieval • Mostly automatic • WM involved in effortful retrieval • Hippocampus “pulls together” information • Reasoning involved in reconstruction • If can recognize but can’t recall problem is with retrieval, not storage

17. Neuroanatomy

18. LTM and the Brain Lobes • Temporal lobes---most memory functions • Frontal lobes---memory strategies • Parietal---storage; auditory and spatial • Occipital---storage; visuospatial

19. The Hippocampus • Horseshoe shape in temporal lobe • Sensitive to injury, glucose, cortisol • Necessary for STM-LTM transfer • Consolidates and re-integrates • May hold some episodic long-term • Explicit memory only

20. Other Brain Structures • Amygdala---emotional content; more implicit than explicit memory • Thalamus---memory relay station

21. Memory Development • Memory structures fully developed by age 6 except those related to exec. functions • Consistent improvements in retention • Due to expanded background knowledge • Due to growth of effective strategies • Retained episodic memories by age 3 • Semantic before episodic (infantile amnesia) • Implicit before explicit

22. Metamemory • More than self-awareness • Knowing what you know • Judgments of learning • Understanding memory functions • Monitoring and regulating • Strategy knowledge and monitoring • Conditional knowledge • Absolutely essential intervention piece

23. Judgments of Learning • More accurate with age • Overly optimistic • Influences what is studied and for how long but average student still does not study difficult material long enough • Fooled by STM retrieval and not taking forgetting into account

24. Memory Strategies • Simple strategy use by age 3 • After age 6, account for LTM improvement • Strategy use and recall (r = .81) • From simple to complex to integrated • Use depends on metamemory (r = .41) and knowledge of efficacy • Development spurred by academic requirements

25. Disorders and Impairments • Amnesia: Retrograde and anterograde • Impairments: • Verbal Visuospatial • Episodic Semantic • Encoding Consolidation • Storage Retrieval • Metamemory Strategic

26. At-Risk Conditions, Disorders • Risk created by damage to hippocampus • Sometimes, damage to prefrontal cortex • Some present at birth or early infancy; others acquire later • Some temporary with recovery, some stable, some progressively worse • Limitation: More adult than child research for most conditions

27. TBI • .25% of youth acquire a TBI each year • Severe TBI: 36 – 53% have ongoing impairments in LTM • Implicit more resistant to injury • More verbal problems than visuospatial • Most mild cases recover within a month • But some can have persistent problems • Most moderate cases within 1-2 years • Metamemory when frontal lobes involved

28. TBI Example • Fractured skull (parietal area) as infant • Surgery; surgeon predicted no LTM deficit • Normal development at age 3 • Expressive language delays in kindergart. • Spec. Ed. by grade 3 • Memory problems at home evident • Deficits in STM, WM, and LTM • Problems: Encoding, storing, retrieving • Delayed strategy development

29. Post-Concussion Syndrome • 19% chance school athlete per year • Likely memory problems: few days/weeks • Loss of consciousness increases risk • Possibility of persistent LTM problems should be considered • Athletes will deny so they can play again • Pre-season baseline testing important • Example: Soccer player

30. Type I Diabetes • Hippocampus sensitive to glucose levels • Growing numbers of diabetic children • Greater risk with earlier onset • Greater risk with poorly controlled insulin • Hypoglycemia damages hippocampus • Memory functions decline over time • Children of diabetic mothers also at risk • Even nondiabetics with poor insulin control

31. Epilepsy • 10% have significant memory impairment • Depends on type, severity, frequency, and location of seizures • Temporal lobe type most devastating • Especially known for “accelerated forgetting” • Seizures disrupt consolidation

32. PTSD • Due to abuse, trauma or witnessing violence • More PTSD symptoms, more LTM deficits • Vietnam PTSD; 26% hippocamp reduction • Cortisol damages hippocampus • Temporary elevated cortisol reduces encoding • Chronic stress causes LTM problems

33. FAS and Alcohol Consumption • FAS children have a smaller hippocampus • Even mild alcohol consumption increases risk for LTM problems, which usually go undetected • Effects are dose-dependent • Difficulty inhibiting interference

34. Language-Impaired • Adequate phonological STM is essential • Problems with encoding, retrieval, semantic memory • Difficulty with rehearsal strategies • Retention is okay once they have learned material

35. LD • Also, STM and WM problems • LTM problems usually unidentified • Verbal with reading and writ. lang. • Visuospatial with math • Encoding is primary dysfunction • Slow retrieval frequently a concern

36. Developmental Amnesia • Recent research on these cases • Often from prenatal, perinatal, neonatal risk-factors • May learn okay despite severe problems with episodic retention and everyday memory problems • Structure and parental monitoring masks their real memory functioning

37. Other Conditions/Disorders • See handout chart for others along with most likely specific memory impairments • Handout

38. Assessment Challenges • Time consuming • Cognitive abilities versus strategy usage • Everyday vs formal test activities • Episodic vs semantic • Difficult to isolate memory processes • Tests don’t check long-term forgetting • Poor labeling on standardized measures • Influence of STM, WM, other processes

39. Assessment Strategies • Generate memory hypotheses based on concerns, observations, existing data • All informal methods important • Select memory types and processes • Select batteries and subtests • Include verbal and visuospatial • Include STM and LTM • Consider everyday memory

40. History • Development and health are essential • Consider risk factors • Academic markers • Progress worse as memory demands increase • Studies but performs poorly on exams

41. Observations • Attention • Opportunities to encode • Mnemonic classroom environment • Evidence of strategy use • Retrieval speed and difficulty • Recognition vs retrieval

42. Interviews • Examinee, parents, teachers • Unrealistic child implicates metamemory • Poor memory for non-academics • Is the info. being encoded adequately • Strategy use • Rate of learning and rate of forgetting

43. Metamemory Assessment • A standardized measure is lacking • Knowledge of memory functions • Knowledge of LTM strengths/weaknesses • Accuracy of JOL’s • Knowledge of strategies See handout of interview item examples

44. LTM Test Chart • See handout of instruments and types of memory assessed • Sign up to receive copy via email

45. Semantic Memory Assessment • Need to use verbal subtests from IQ and other tests • Information, Vocabulary, Similarities, Academic Knowledge • Classroom exam performance • Vocabulary development

46. WMS-IV • 2009, Pearson; ages 16-90 • Co-normed with WAIS-IV • Fewer subtests/factors than WMS-III • Primarily a measure of declarative episodic memory (novel & contextually bound)

47. WMS-IV Structure • Immediate and Delayed: 4 subtests each • Auditory and Visual: 4 subtests each • Visual Working Memory • 2 subtests (not part of above factors) • Brief Cognitive Status • 11 subtests (counting delayed versions) • Must compute clinical factors for auditory delayed and visual delayed

48. Learning Disabled ReadingMath Immediate 98.1 89.1 Delayed 96.6 91.7 Auditory 99.5 92.4 Visual 95.0 91.1 VWM 100.1 89.0

49. Logical Memory I and II • Narrative memory under free recall • Consists of 2 short stories presented orally • New story for ages 65-90 that has less language demand and is more age approp • Story A is presented twice • Do II 20 – 30 minutes later • Video

50. Design Memory I and II • Examinee is presented with 4 to 8 designs on a grid, cards with designs and foils to place on grid; scored for correct location and correct design independently, with bonus for both • Scores: Immediate Spatial, Immediate Content, Immediate Total, Same 3 Delayed scores, Delayed Recognition • See DE I See DE IISee DE II Recognition