Childhood amnesia, language and thought?

Reflections on Simcock & Hayne (2002)

Why should we be interested in childhood amnesia in a language

class?• Review types and processes of memory• examine the idea of “representation”• Representation may be in modalities

– Propositions/mentalese– Language (English, Pirahan…)– Visual, auditory, tactile, olfactory images

• Memory “stores” representations• Examine role of language in memory

– Encoding, retrieval, filing system, ???– Translation among modalities– Making thought conscious-- (when possible?)

Relate to the sign language cases?

• Cases of later sign acquisition– Ballard (James)

– Ildephonso (Pinker)

– NSL teacher in Kegl video

• Have a common themes of– Ability to translate prior memories into sign

– Extolling the newly acquired system

– In some cases attributing greater powers of thought to it

Encoding into memory

Amnesia

The loss of memory or memory abilities

Childhoodamnesia

Review of memory

• Classification of memory types including an indication of significant brain structures involved. (This is not meant to be complete.)

Causes of memory loss

• Injury or damage to brain

• Changes in normal aging

• Disease

• Psychogenic memory loss

• Childhood amnesia

• And of course, inadequate encoding can lead to memory failure.

Injury or damage to specific area

• Head trauma• Stroke• Surgery• Chemical (including drugs, alcohol , e.g.

Korsakoff’s syndrome)• Electric shock

– (ECT may induce retro- and antergrade amnesia)

Possible effects of brain injury on memory

H.M’s case

• Surgery on medial temporal lobes including the hippocampus to eliminate epileptic seizures at age 27 (“bilateral surgery”)

• Immediate STM seemed normal

• Preserved semantic memory but lost previous 11 years events

• No new long-term memories apparently formed -- hence “anterograde amnesia”

• Later research showed certain implicit LTM memories were formed.

H.M.’s anterograde amnesia

Hippocampus views 1

Hippocampus views 2

HM’s lesions

• Kensinger EA, Ullman MT, and Corkin S (2001). Bilateral medial temporal lobe damage does not affect lexical or grammatical processing: Evidence from amnesic patient H.M. Hippocampus, 11, 347-360.

Comments on HM’s surgery

• Clearly not all medial temporal lobe structures have been removed; nor is are the lesions totally symmetrical.

• It is likely the right and left lobes normally function differently.

• Moderate loss in some individuals, especially on names

• Causes include general health issues, e.g. CV issues, and cell loss

• Extreme cases may be described as “senile dementia”

Normal aging

Aging dendrites

Alzheimer’s disease and memory loss

• AD is typically a progressive disease of older people moving from barely notable forgetting to major loss of factual and even procedural memory --

• How to brush teeth

• How to comb hair

Alzheimer’s example

QuickTime™ and aVideo decompressorare needed to see this picture.

Psychological causes of memory loss

• Hypnotic

• Hysteria/fugue

• Stress induced cases

• Repression?

• And of course normal causes -- interference, decay…..

Childhood amnesia

• Few have episodic (i. e. event or autobiographical) memories before three years

• Not likely to be due to Freudian “repression”

• Just a fact of brain development?

• No language related structures yet?

Review of memory

• Classification of memory types including an indication of significant brain structures involved. (This is not meant to be complete.)

“working memory”- what is it?

• A scratchpad- phonological loop, visual, episodic??

• Holds representations for processing

• Focus of attention?

• LTM memory “nodes” that are “activated”?

Working memory- one sketch

Freud on childhood amnesia• "We conclude therefor that we do not deal

with a real forgetting of infantile impressions but rather with an amnesia similar to that observed in neurotics for later experiences, the nature of which consists in their being kept away from consciousness (repression). But what forces bring about this repression of the infantile expressions? He who can solve this riddle will also explain hysterical amnesia.

. We may say that without infantile amnesia there would be no hysterical amnesia

• I therefore believe that the infantile amnesia which causes the individual to look upon his childhood as if it were a prehistoric time and conceals from him the beginning of his own sexual life -- that this amnesia, is responsible for the fact that one does not usually attribute any value to the infantile period in the development of the sexual life. P.582

• Freud, S. (Ed.). (1938). Three contributions to the theory of sex: II Infantile sexuality. New York: The Modern Library.

Freud (continued)

Neither Freud nor modern versions of “repressed memory” notions have much

empirical support

Is language development responsible for the end of childhood amnesia?

• There's an obvious correlation between childhood memories and language skill.

• Conversations about the past enhance memory for autobiographical facts

• Children's ability to use another person's (or self?) language to cue retrieval of their own memory increases the probability that retrieval will occur

• Encoding specificity suggests verbally directed recall will miss memories in non-verbal codes -- unless those memories are "translated" into words.

What’s encoding specificity?

• Its why you might remember something better in the place or other circumstances where you first encountered that something.

• Professor Tulving (1982-3) said– The probability of successful retrieval of the target item

is a montonically increasing function of informational overlap between the information present at retrieval and the information stored in memory.

• Simcock, G., & Hayne, H. (2002). Breaking the barrier? Children fail to translate their preverbal memories into language. Psychological Science, 13, 225-231.

• "The primary goal of the present experiment was to determine whether or not children could translate preverbal aspects of their memory into language once they had acquired the vocabulary necessary to do so.”

Preverbal memory established

Acquire relevant language

Report preverbal memory?

Language evaluation

Seven shrinking toy trials

1.verbal test

2.photo

3.action

6 months

12 months

Language evaluation

Memory evaluation procedure

Results of memory assessment

• Proportion of information retained by age, mode, and interval shows clear evidence young (preverbal?) children can have memories of the “toy” event.

Memory data

Results relating words to memory

• "As shown in Table 3, there was not a single instance in which a child used a word or words to describe the event that had not been part of his or her productive vocabulary at the time of encoding……they could not translate the information into words even though they had acquired the vocabulary to do so.”

Items remembered

Results overall

• "In short, children's verbal reports of the event were frozen in time, reflecting their verbal skill at the time of encoding, rather than at time of the test….at the time of the test the children recognized photographs and performed actions for which they did not have the relevant vocabulary at the time of original encoding.

Words in target vocabulary

Conclusions

• "across the entire age range tested, children's verbal memory performance lagged substantially behind their nonverbal memory performance.”

• "language development did not render these perceptually based memories accessible to verbal recall…

• (in no instance did children report an aspect of the event that had not been part of their productive vocabulary at the time of original encoding (Table 3).

• "We hypothesize that the inability to translate early, preverbal experiences into language prevents these experiences from becoming part of autobiographical memory."230

The end (?)

Follow up: exceptions?

• Morris, G., & Baker-Ward, L. (2007). Fragile but real: Children's capacity to use newly acquired words to convey preverbal memories. Child Development, 78(2), 448-458.

• "the apparent limitations in the contexts in which words can be used to report preverbal experiences indicate that this capacity is fragile..."457

• This study suggests “translation” into new words is very limited but possible for some children under some circumstances.

More new references• Peterson, C., Grant, V. V., & Boland, L. D. (2005). Childhood amnesia in children and adolescents: Their

earliest memories. Memory, 13, 622-637.

Rats, too

Richardson, Rick & Hayne, HarleneYou Can't Take It With You: The Translation of Memory Across Development.Current Directions in Psychological Science 16 (4), 223-227.

Rats, too (caption)

• Fig. 1. Test of memory development in rats. Rats given pairings between a conditioned stimulus (CS; in this case, an odor) and an unconditioned stimulus (US; a shock) at 16 days of age (P16) express their learned fear of the odor CS when they are tested 24 hours later through some behaviors (e.g., avoidance, freezing) but not others (FPS; fear-potentiated startle).

• Rats trained at 22 days of age (P22) and tested 24 hours later express their learned fear of the odor through all three behaviors.

• The critical finding is that rats trained at 16 days of age and then tested at 23 days of age (P23) retain the odor–shock association across the 7-day interval, but they only express their learned fear through response systems (i.e., avoidance and freezing) that were mature at the time of training.

Narrative quantity-accuracy tradeoff in amnesia too?

• Do better stories make better memories? Narrative quality and memory accuracy in preschool children

• Sarah Kulkofsky *, Qi Wang, Stephen J. Ceci

• The present study examines how the quality of children's narratives relates to the accuracy of those narratives.

Quantity_accuracy tradeoff?

• Children's narratives were coded for volume, complexity and cohesion as well as for accuracy. Correlational results showed that overall, narrative skills enable the reporting of more information, while decreasing the proportion of information that was accurate. These results appeared to be driven by a quantity-accuracy trade-off; in an ensuing regression analysis with all narrative variables entered into the model, volume was associated with decreases in accuracy while narrative cohesion was associated with increases in accuracy.

Encoding into memory

Encoding into memory

Verbal overshadowing - can language interfere with encoding

or retrieval of non-verbal memories?

• Fiore, S. M., & Schooler, J. W. (2002). How did you get here from there? Verbal overshadowing of spatial mental models. Applied Cognitive Psychology, 16, 897-910.

HM meets childhood amnesia???

• Both are failures to report previous experiences• To some extent in either case, this is not indicative of memory

failure itself?• Crucially, however, kids learn new words, HM doesn’t!

But many issues left hanging

• HM has some declarative memories of the past.• What is the extent of confabulation in each case?• Is HM’s confabulator partially damaged?

(cingulate gyrus??)• To what extent are lexical processes dissociated?

-- acquisition and use

it has become clear that one small area of this region, called the dentate gyrus, does not fully mature until age 4 or 5. This area acts as a kind of bridge that allows signals from the surrounding structures to reach the rest of the hippocampus, so until the dentate gyrus is up to speed, early experiences may never get locked into long-term storage, Bauer says. "If the route isn't sufficiently mature to allow the information to get in, it's not going to effectively consolidate."

Hayne agrees that the brain continues to mature over a long period of development, and that this is an important step in establishing long-term memories. Yet children can still remember some events before this region is fully developed, so it can't be the be-all and end-all of childhood amnesia.

cannot be explained by brain maturation alone," she says. Clearly, there must be more pieces to the puzzle.

What's more, there are puzzling cross-cultural differences in the age of earliest memories. In one cross-cultural study, for example, researchers found the average age of first memories in people of European descent hovered around 3.5 years, compared with 4.8 years for east Asians and 2.7 years for Maori people in New Zealand (Memory, vol 8, p 365).

Cognition- the big picture

• Thinking is the manipulation of representations• Several modes of concept representation• A ‘logical’ system to relate/compute/manipulate

relations among concepts• Language -- if not one of the modes -- is an

important factor– Priming– Autocoding of thoughts into L in fluent users– Perhaps a means of communication both between

individuals but also within? (hemispheric specialization)

Overview of kids memory

• As a body, the research on the later verbal accessibility of early memories supports some general conclusions as to when we might expect to see verbal children successfully engage in conversations about events from early in life. First, if the children were younger than 20 months at the time of experience, with high levels of contextual support, they may be able to report on the event after some months have passed (i.e. as in Bauer et al., 1998, in which children 16 months of age at the time of experience of laboratory events spontane- ously talked about those that they had been permitted to imitate). However, even with high levels of contextual support, they are unlikely to be able to report on the event after a lengthy delay (Bauer et al. 1998, 2002, and Experiment 1 of the present research). Second, for children 20 to 25 months of age at the time of experience of events, verbal accessibility can be maintained over the long term. Contextual reinstatement is not necessary to elicit verbal reports even after long delays (Experiment 2 of the present research), yet photo- graphs alone may not be effective retrieval aids (Experiment 1 of the present research). In addition, long-term verbal accessibility may be dependent upon an effective reinstating experience at some point in the retention interval.

• Bauer et al (• Children who were younger than 20 months of age at the time of experience of events did not evidence verbally accessible memories at the age of 3 years, even when they were tested with the highest level of contextual support. In none of the groups

did evidence of later verbal recall extend to events experienced only once, at Delayed-recall Test 1. Thus, later verbal accessibility of early memories seems to depend on children’s ages at the time of the events, whether the events were experienced once or multiple times, and whether at the time of retrieval, children are supported by effective cues such as the props associated with to-be-remembered events.