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Cognitive Development4

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Cognitive Development4 Powered By Docstoc
					Course outline Cognitive development
Przemek Tomalski Centre for Brain and Cognitive Development Birkbeck College, University of London, UK
Office: Room 103 email: tomalski@mac.com

1. 2. 3. 4. 5. 6. 7.

Introduction. Key concepts and theories of cognitive development. Interactions with the physical world. Perception and object cognition. Conceptual development. Memory. Reasoning and problem solving. Executive functions. Language. Summary. Looking at cognitive development from different perspectives.

Early memory development

Memory

• Types of memory: explicit vs. implicit.
Autobiographical memory

• Explicit and pre-explicit memory in infancy • Procedural memory in infancy

Nelson & Webb (2002)
• explicit memory - ease of recall, single
trial learning, representations available semantically, highly associated with self

• non-explicit memory - various

systems (habits, motor plans, priming, conditioning), diverse methods of retrieval, less likely association with self

Early memory dev. (2)
• •
Bauer & Shore (1987) - 17-23 month olds remember temporally sequenced events (giving a bath to a teddy bear) even 6 weeks later Causal relations can organise events in early episodic memories (16-20 month olds, Bauer & Mandler, 1989) - the difference between arbitrary and causal sequences

Early episodic memory
• there is a gradual increase in memory for
temporally sequenced events between the ages of 1 and 3 years can retain the sequence for 1 month, while the same information is retained for 12 months in 36% 1 y-o and 67% 20 month olds

• 80% 1 year olds and 100% 20 month olds

Infantile amnesia
• Why children do not usually remember
events from the first 12 months of life?

Infantile amnesia (2)
• •
Freud suggested this lack of memory is due to the mechanism of repression, associated with emotionally traumatic events in early childhood others suggested that early memory is based on simple perceptual and motor qualities, thus irretrievable, since they are stored in a different format, not available to linguistically based encoding and retrieval mechanisms

• Moreover, autobiographical information is
not remembered well before the age of 3 years

• why?

Infantile amnesia (3)
• another hypothesis is related to the idea
that memory is a constructive process

Symbolic representations aid memory

• DeLoache was studying, how symbolic • 3 year olds but not 2.5 year olds can

• Fivush & Hammond proposed that the

representations can aid memory for places and events in 2.5 and 3 year olds effectively use symbolic (small-scale) representation to aid their memory for location of objects

absence of abstract structures for temporal and causal sequencing prevents infants from organising autobiographical memories in the first years in a retrievable form

Recognition memory
• recognition memory is the ability to
DeLoache 1989 recognise something is familiar and has been experience before recognition for previously presented pictures in 3-5 year olds (98%)

• Brown & Scott (1971) demonstrated high • the number of element repetitions (1 or 2)
mattered for the level of recognition

Implicit memory
• implicit memory can be defined as
•
memory without awareness; in tasks testing such memory children demonstrate they retain certain information but not necessarily being consciously aware of that recognition

Implicit memory (2)
perceptual learning task (Byrne & Kirsner 1985) - 5, 7 and 10 year olds observed a set of pictures of objects with either an easy or difficult second task, later participants’ memory was tested either with an implicit test or an explicit test second task difficulty did not matter for level of implicit recognition, but explicit recognition was better with the more difficult task, which allowed better (‘deeper’) processing of picture stimuli

• the essential difference: recall vs.

•

Implicit memory (3)
• word fragment completion task in 5, 8 and
11 year olds

Implicit memory (4)
• • •
‘old’ and previously presented word items had letters completed significantly more often than ‘new’ items the depth of processing did not affect the performance similar picture completion task with 4 and 6 year olds and adults showed comparable level of implicit recognition for 4 year olds and adults alike

• prior to fragment completion task, children

were presented with words from this task (67 % of all target words) and had a task on them either requiring deep (category judgement) or shallow (letter detection) processing

Implicit memory (5)
• • •
also memory for faces has been studied in a priming task the amount of implicit recognition in 5 and 8 year olds was equally high and slightly lower for 11 year olds (Ellis & Hosie, 1993) the levels of implicit and explicit recognition for the same familiar faces seems to differ in 10 year old children (Newcombe & Fox 1994)

Episodic memory
• scripts (schemas) - generic knowledge
structures that represent the temporal and causal sequences of events in a specific context (e.g. sequences of actions) awareness, the term usually refers to memory for episodes of life, involving explicit recall of these episodes or events

• episodic memory involves conscious

Episodic memory (2)
• • •
Nelson studied episodic memory 3-5 year old children, by asking them about various life events (birthday party, grocery shopping, etc.) he demonstrated good episodic memory even at the age of 3 years more so, he showed memories were organised by scripts, with different events represented in an ordered and conventionalized manner

Episodic memory (3)
• what is the function of scripts in memory
of life episodes?

• probably, as suggested by Nelson, scripts

provide structure for organising also novel episodes, allowing them to better remember, possibly through highlighting certain aspects (emotional context, unique events)

Working memory
• components of working memory:
- central executive - visuospatial sketchpad - phonological loop

Visuospatial sketchpad
• Conrad (1971) - information about objects • older children (aged 6-11 years) showed
stored in the visuospatial sketchpad not affected by phonological similarity of object names in preschool children (3-5 year olds) better memory for objects with names that were not similar phonologically

• characteristics of WM: limited capacity and
retain time, modality and code-dependent, limited resources

V-S sketchpad (2)
•
it seems that short-term storage is based more on visual information in preschool children, while older children tend to rely more on phonological loop more on visual working memory rather than verbal w.m. representations

Phonological loop
• • •
capacity - effects of word length and speech rate Hulme et al. found that capacity of phonological loop is related throughout development to speech rate (subjects recall as much as they can rehearse in 1.5 s) Henry & Millar - rehearsal (working memory) develops out of naming behaviour, thus development of WM is intimately related to development of semantic long-term memory

• also, deaf children were shown to rely

Summary
• early memory development for event
sequences faces

• implicit memory for pictures, words and • the role of scripts in episodic memory • working memory - visuospatial sketchpad
vs. phonological loop