Early memory development

Question 1

Episodic memory

Answer 1

A form of long term memory. Involves mental re experience of events from the personal past. It is usually a representation that is sensory rich, involves details of objects, people, time and space all integrated together to form a coherent episode.

Question 2

Different types of long term memory across development, general views

Answer 2

It is traditionally thought of as late developing and early declining. This is in distinction to semantic memory which is thought to remain relatively stable after relatively early development and to be maintained well into old age.

Question 3

Neural basis of episodic memory: the hippocampus

Answer 3

The hippocampus consists of the dentate gyrus, the cornus ammonis and the subiculum. It can also be divided along the other axis into posterior and anterior. The functions are diverse but it is very important for episodic memory and spatial cognition.
Posterior - spatial
Anterior - episodic/associative memories

Question 4

Neural basis of episodic memory: beyond the hippocampus

Answer 4

Episodic memory involves a large network of areas. The default network is the network including the frontal, temporal and parietal episodic memory areas. Particularly important are areas within the prefrontal cortex which are involved in organising stored and retrieved memories and monitoring. As well as areas within the parietal lobe which are involved in integration of sensory information and subjective feeling of re-experiencing an event. We thought these were areas of the brain that were just always active but we now know that it is to do with episodic memory, we can never stop people from doing a bit of memory stuff. Areas in frontal lobe are good at deciding which memories are needed and which we want right now. Parietal is more integrative and making you feel immersed like you are reliving an event.

Question 5

Early brain development: the foetal hippocampus

Answer 5

Seress et al (2001) Studied using post mortem. Pyramidal neurons in the human hippocampus proper form a distinguished cell layer at the 15th gestational week. Most of these cells are generated in the first half of pregnancy. In contrast, granule cells of the dentate gyrus proliferate during the second half of pregnancy and after birth. At 1 year of age, the surface area of the dentate gyrus is 5 times what it was at 24 weeks gestation.

Question 6

Early brain development: the first two years longitudinal study

Answer 6

Gilmore et al (2011) longitudinal MRI of children at two weeks, 1 and 2 years of age. Much greater growth in the first than second year. The fastest growing areas in the first year were in the frontal, temporal and parietal cortices. The fastest growing areas in the second year were also in the frontal, temporal and parietal lobe cortices. the hippocampus slower although it was one of the fastest growing subcortical structures in the second year. The default network is doing its development in the early years and is the fastest growing in the 2nd year. Hippo is slower than the network but sub cortical areas are always slower growing than cortical areas. Hippo is the fastest or sub cortical areas growing. So all episodic memory areas are growing fast in early life.

Question 7

Early brain development: the first two years with preterm infants

Answer 7

Fransson et al (2007) Preterm infants (41 gestational weeks) show no evidence of a default network

Question 8

Early brain development: the first two weeks compared to two years

Answer 8

Gao et al (2009) Primitive and incomplete default network evident at 2 weeks. By 2 years default network resembles adults but we should note overconnectivity. First we form all the connections, work out which are important then prune the ones we don’t need to make it the most efficient.

Question 9

Developmental and infantile amnesia

Answer 9

Olson and Newcomb (2013) Ask human adults to remember childhood. Most people don’t have any memories from before they are about 2-3 years old. This is termed infantile amnesia. Proportionally fewer memories from ages 2-8. Linked to maturity of hippocampus but does that mean no memories form before 2?

Question 10

Measuring memory ability in very eraly childhood

Answer 10

We are limited by the behaviour available to measure:
- immature language before around 7 years
- no language at all before around 18 months - 3 years
- no locomotion before around 8 months
Assessments that are available:
- conditioned reinforcement
- eye tracking
- locomotion
- delayed imitation

Question 11

What can foetuses hear?

Answer 11

Querleu and Renard (1981) Foetuses in the third trimester are able to respond to sounds and maternal speech is audible in utero.

Question 12

Foetus remembering the mothers voice in the womb

Answer 12

DeCasper and Spence (1986) asked pregnant women to read a particular passage every day for the last 6 weeks of their pregnancy. New-borns given an operant learning task with recording of that and a novel passage as reinforcers. New-borns who hear something they like, suck faster. So they suck more when they hear their mothers voice. Babies were then read by their mum, the passage they had heard and one they had not heard. Infants preferred (sucked more) to hear the passage experienced prenatally regardless of the identity of the reader (mother or other person). Suggests they remembered something about the passage that was independent of their mothers voice. Control infants did not show this preference.

Question 13

Dishabituation and object permanence

Answer 13

Baillargeon (1987) Babies dishabituated more to the impossible event than the possible one. They remembered there was an object there and that the paddle could not pass through it. This shows they have some sort of memory of the event and the object is permanent.

Question 14

Two ways of studying looking time

Answer 14

Dishabituation - more looking at the thing that is most different
Familiarity - increased looking at familiar things, particularly early in presentation

Question 15

Dishabituation studies

Answer 15

Dishabituation studies involve habituation to a specific stimulus then showing a new stimulus. If infants regard the new stimulus as broadly the same, they do not look more, if they view it as a meaningful change then they dishabituate and start looking intently again. They involve changing something about the stimulus:
conceptual - the concept of the stimulus is different but it looks the same
perceptual - the concept of the stimulus is the same but looks different

Question 16

Eye tracking study: looking time

Answer 16

Fagan (1970) Looking time techniques have demonstrated that infants can distinguish between simultaneously presented novel and familiar items from 2 months.

Question 17

Eye tracking studies: gaze direction

Answer 17

Richmond et al (2009) They showed them all three faces on random backgrounds. Then showed all three faces on one of these backgrounds. The babies look more at the face that was associated with the context Gaze direction indicates infants can remember item context combinations from 6 months and item place from 9 months. In adults, this gaze preference is hippocampal.

Question 18

Maze tasks: locating hidden mother

Answer 18

Clearfield (2004) Adaption of the Morris water maze. They look at the parent and they wave at the child so they can see where they are and then the parent hides. Then the baby gets turned around a few times, disorientated. Then the baby is put back in the arena and see if they go to where the mum way. Babies can crawl to locate their hidden mother using distal landmarks from 11 months but fail at 8 months.

Question 19

Maze tasks: locating a hidden toy

Answer 19

Balcomb et al (2011) Children have little success locating a hidden toy in a different adaptation of Morris water maze task until over 20 months. 16-20 months searched in the correct or near correct location in 20% of trials. 21-24 months searched in correct or near correct location on 83% of trials. Seems to suggest that in this early stage, the root of this memory is there (because they can find their mum) but isn’t solidified until about 2 (because they can’t find a toy)

Question 20

Delayed imitation: 6 months

Answer 20

Cuevas et al (2006) Children are shown an action or series of actions on an object. After a delay, they are provided with the object and encouraged to repeat/imitate the actions. Children from around 6 months can imitate at least part of an action sequence and recall this for up to two days.

Question 21

Delayed imitation: 2 years

Answer 21

Burns et al (2015) showed that children from 2 years show some evidence of remembering integrated features of the action sequence such as what actions were applied where and in what order. Show kids a table with handles that can be tuned like a wheel or pumped up and down like a piston. Show children a sequence of pumps and twists on certain ones that made a tune play. Introduced different delays and recorded what mistakes the babies made with repeating the actions. Where the action is done and in what order it is done is not developed until a bit later on. They could do the action, just weren’t very good at doing it on the right piston in the right order. They can remember an action but the ability to remember an episode doesn’t develop until later.

Question 22

Neural responses to familiar or unfamiliar

Answer 22

Benavides-Varela et al (2011) From 2 days of age infants demonstrate differential neural responses to familiar and unfamiliar stimuli. Increased frontal, temporal and parietal activity in response to novel words in 2 day old infants.

Question 23

Neural responses and behavioural responses

Answer 23

Bauer et al (2003) Neural responses to stimuli predict behavioural responses to memory tests in 9 month olds. Increased EEG responses to photos of familiar sequences of actions in 9 month olds but only in those that could subsequently imitate the actions correctly.

Question 24

Theoretical positions in developmental psychology

Answer 24

Conceptualist - posit that for episodic memory to be defined as such, it must be accompanied by a conceptual grasp of what is being experienced. There is however, no absolute agreement about the specific concept that needs to be grasped.
Minimalist - suggest that episodic memory should be defined in more simple terms, either by emphasising behavioural and content criteria or by suggesting that experiences may not require understanding.

Question 25

The sense of self

Answer 25

Fivush and Nelson (2004) suggests that maturation of the sense of self is fundamentally in the development of episodic memory. This allows memory traces to be organised around a me who experienced them.

Question 26

Temporally extended self

Answer 26

Nelson (2001) Expanded the sense of self to the temporally extended self, a self identity that extends into the personal past and personal future. It is only the self with a specific past that is endowed with the unique capacity to re experience the past.

Question 27

Self awareness over time

Answer 27

Povinelli et al (1996) This temporally extended self is thought to develop at around the age of 4. Parent played with child and put sticker on the kids head without them knowing. This was videoed and played back to them later and see whether they try and take the sticker off their head. Kids don't try and take the sticker off their head until age 4. Do they not realise it is themselves until that age? This has been taken by many as evidence that episodic memory cannot exist before the age of 4.

Question 28

Meta representation

Answer 28

Perner et al (1991) For episodic memory to exist, children must recognise a memory trace as a representation of an event previously experienced by a past self. This requires understanding that what is being experienced is not direct experience or imagination but a memory, that is a representation, of past experience. Thus they must be able to mentally represent a representation. He thus theorised that episodic memory development depends on the development of representation theory of mind which is thought to develop around age 4.

Question 29

Minimalist theories

Answer 29

Russell et al (2011) proposed an alternative approach to conceptualist theories. A more tractable way of defining episodic memory when dealing with young children and animals.

Question 30

Episodic like minimalism

Answer 30

Clayton et al (2003) Emphasises the binding of spatiotemporal features, focus on content and structure of memory, no assumptions or claims about about phenomenology or subjective experience. Based on work with animals. Episodic like in acknowledgement that doesn't address the questions/definitions around the subjective experience of remembering. Does the memory represent a single coherent episode.

Question 31

Kantian minimalism

Answer 31

Russell et al (2011) emphasises that memory must be experienced from a first person perspective. They argue that children lacking adults sophisticated conceptual apparatus might still exhibit some legitimate form of episodic memory and foresight. That is that children do not need to understand what is going on in their heads for it to be going on in their heads. Doesn't make claims about self awareness but focusses on what the member would look like to a naïve rememberer. The most important factor is not so much the content of the memory or the understanding of it but that it is experienced as a first person replay of the direct perceptual experience.

Question 32

Preschool years episodic like memory

Answer 32

Hayne and Imuta (2011) asked 3 and 4 year old children to hide 3 toys around their own homes. They had a delay period where they were read two story books. They were then tested: Behavioural - lead experimenter to the room and search for the toy Verbal - name the toy Rated children on which questions they got correct: What - what toy Where - what room and what location in that room When - in what order 3 year olds can find the objects again at a rate above chance but they are a lot worse at it than 4 year olds who do it quite well.

Question 33

Preschool years language

Answer 33

Busby and Suddendorf (2005) Children asked to tell experimenter something they did yesterday. These answers were coded by parents as correct or incorrect. There was significant improvement between ages 3 and 4 but no significant change between ages 4 and 5.

Question 34

What, where, which context

Answer 34

Newcomb et al (2014) Two rooms, each with the same four containers but in different places. One toy hidden in a different container in each room. Children explore each room to find the toy and briefly play with it. Then clean and put the toy back in the container. AT test, they enter each room and asked if they know where the toy is. This requires them to have separate representations of what is where and in which context. Before 4, they are above chance with their accuracy of picking containers but they are much better at it after 4. If they were getting it wrong, they were more often only getting half of it wrong, so the correct container but the wrong room. This shows they had some level of learning and memory of it but they didn’t have the full conception of it. This experiment allowed for an assessment of degree of accuracy than just right or wrong.

Question 35

Source memory and theory of mind

Answer 35

Naito (2003) when age and verbal competence are controlled for, source memory ability correlates with theory of mind in 6 but not 4 and 5 year olds. This suggests memory development may be more associated with the development of theory of mind later in a child's development than age 4.

Question 36

Gradual development of episodic memory.

Answer 36

Cheke et al (2015) Performance on episodic memory tasks improved between 3 and 7. Some tasks are easier than others but there is no sudden jump in performance at age 4 in any of them. This shows that memory development may be more gradual and there is not something special about age 4.