1. A pioneer of the scientific study of memory: Hermann Ebbinghaus (1850 – 1909)
Worked as philosopher at university in Berlin
Was inspired by lawfulness of relation between physical properties of perceptual stimuli and psychological sensations in psychophysics
e.g. Fechner’s law; Weber’s law

2. Classic finding in psychophysics: Weber’s law

3. A pioneer of the scientific study of memory: Hermann Ebbinghaus (1850 – 1909)
performed experiments on himself published in classic volume entitled: ‘Über das Gedächtnis’ (1885)

4. Memory experiments by Ebbinghaus
Fame: pioneer of empirical approach; inventiveness as experimenter
New: systematic and controlled study of memory in laboratory
e.g. - created new stimulus material
- applied scientific accuracy (metronome), - established method to quantify memory performance and describe regularities

5. Memory experiments of Ebbinghaus: Focus on retention of newly learnt material
invented lists of 16 nonsense syllables to minimize influence of meaningful associations and
learner’s history
goal: study memory in ‘pure’ form
introduced criterion for successful learning
(2 errorless recitations)
introduced savings method to measure retention/forgetting of lists

6. Memory experiments of Ebbinghaus: Example of memory task
Memorize the following list:
falem
zeb
xalvo
monul
rull
namak

7. Memory experiments of Ebbinghaus: Examination of forgetting curve with savings method
most forgetting happens immediately after learning
-> not a linear relationship between forgetting and delay

8. Memory experiments of Ebbinghaus Other important findings
List-length effect: ease of learning and amount of information not related in linear one-to-one fashion; disproportionate increase in difficulty with more than 7 syllables
Beneficial effects of distributed practice for repetitions

9. Memory research of Ebbinghaus Why is it such a major contribution?
discovery of important regularities (basic findings)
memory can be studied empirically with experiments
mental phenomena can be studied even if they are not linked momentarily to physical world via perceptual organs

10. Memory research of Ebbinghaus What was missing?
research criticized as atheoretical
But: emphasis on observations rather than theories typical for early research in new field

11. The Ebbinghaus Legacy: Verbal-learning research 1950s – 1970s
systematic study of factors affecting verbal learning:
e.g. numbers of repetitions, word frequency
behaviourist tradition (S-R / S-S associations)
mind as black box
later replaced by information-processing approach: growing emphasis on mental representations

12. Richard Semon (1859 – 1918): An early memory theorist
work strongly influenced by evolutionary biology (Darwin)
emphasis on commonality between heredity and memory:
elasticity of biological tissue that allows effects of experience to be preserved over time
three stages of memory (new terms invented)
Engraphy – acquisition of new information
Engram – enduring change in nervous system that allows for retention
Ecphory – recovery of stored information

13. Richard Semon (1859 – 1918): An early memory theorist
concept of ‘engram’ motivated research on brain basis of memory in 20th century: What are the manifestations of memory traces in the brain?
concept of ‘ecphory’ strongly influenced cognitive psychology of memory starting in 1970s (Tulving):
How can a dormant memory trace be awaken?
-> emphasis on processes at time of retrieval (recovery) of info from memory
-> emphasis on presence of suitable retrieval cues

14. Information-processing approach to memory (starting 1960s)
motivated by emerging of computers and computer science as scientific discipline
human mind can be understood with computer metaphor:
e.g. storage of information in different memory buffers
RAM vs hard-disk <-> STM vs LTM
central importance of information and mental representations (mind not a black box)
focus on cognitive processes that deal with (e.g. create, access, compare) mental representations

15. Information-processing approach to memory: A practical example
correct

16. Information-processing approach to memory: Basic framework
3 stages of processing for manipulation of mental representations:
Encoding (acquisition of info)
Storage (retention of info)
Retrieval (recovery of info)
Encoding
Retrieval
time

17. Information-processing approach to memory: Typical research questions
do we store different types of memory representations? Are they retained equally well?
e.g.
‘bear’

18. Information-processing approach to memory: Typical research questions (cont’d)
do we need attentional resources to encode new information into memory?
e.g. can be studied through examination of influence of distraction
can we access information in memory unconsciously?
e.g. can be studied in patients under anesthesia

19. Information-processing approach to memory: Application to Ebbinghaus’ research
what were the syllables you memorized in the example I gave earlier?

20. Information-processing approach to memory: Application to Ebbinghaus’ research
which of the following syllables was on the list?
halek or xalvo
-> forgetting curves will vary depending on whether syllables need to be recalled or recognized
-> more detailed analysis of cognitive processes required to understand regularities in forgetting

21. Information-processing approach to memory: Application to Ebbinghaus’ research
e.g. ‘zeb’ may or may not make you think of ‘zebra’ at encoding
-> consequences for subsequent remembering
-> even learning of simple stimuli such as non-sense syllables is affected by variations in cognitive processing and pre-existing knowledge
-> memory can’t be investigated in pure form

22. Cognitive-neuroscience approach to memory
multidisciplinary approach (psychology, computer science, neurology, radiology)
emphasis on relationship between behavior, cognition, and the brain
Central question: How is memory organized in the mind and brain?
General idea: to understand the organization of memory (e.g. how many different types?) we should focus on neurological and cognitive aspects

23. Cognitive-neuroscience approach to memory: Different types of investigation
Lesion studies in neurological patients
examination of effects of different types of brain damage on memory processing
Functional neuroimaging
examination of brain activity in healthy individuals while they perform memory tasks
Computational modeling
testing of memory theories with computer models that incorporate a brain-like organization (neural networks; connectionist models)

24. Cognitive-neuroscience approach to memory: Example of functional neuroimaging study
do different parts of the brain become active when we try to remember pictures as compared to words?
pictures
words

25. Cognitive-neuroscience approach to memory: Example of early finding in patient with brain lesion
amnesic patient of Claparède (1911):
pin-prick episode
-> behavior can be influenced by past without conscious remembering
supports distinction between implicit (unconsious) and explicit (conscious) form of memory proposed 70 years later