Development of Mental Representation

Five Characteristics of Representations (from Perner, 1991, Understanding the Representational Mind)

(1) Aboutness:  The picture is about them at Oxford.
(2) Asymetry:  Picture represents them at Oxford, but them being at Oxford does not represent the picture.
(3) Singularity:  Picture represents them at Oxford, not others doing identical things at same time at Oxford or them doing same thing at different time.
(4) Nonexistence:  Pictures can represent that which does not exist (e.g., unicorns).
(5) Misrepresentation:  Must be possible (e.g., representing something as being different than it really is).

Piaget (from Mandler, 1983, Handbook of Child Psychology)

Before 18-24 months:
•	infants couldn't be said to "think"
•	know something about world but knowledge in form of "perceptual schemas" and actions  -->  schema includes stable behavioural patterns underlaid by stable cognitive structures, triggered by certain environmental conditions
Example 1: sucking schema = innate tendency to suck all that is within vicinity of mouth
Example 2: door opens and infant looks expecting someone will come through
•	knowledge can be accessed only with respect to the immediate context
•	can recognize an object (i.e., object elicits stereotypical motor response) but can't recall it when object disappears from immediate perceptual field (no stored representation)

After 18-24 months:
•	the beginning of representation
•	can now access (think about) things in their absence (freed from context in which learned, no longer needs the environmental trigger)
•	no longer is cognitive activity tied to schemas and actions

Piaget's four characteristics of representations:
	(a)  internalized (things can be accessed when not present, freed from context in which learned)
	(b)  mentally evoked (not simply a schema or action)
	(c)  able to be used retrospectively for purposes of recall
	(d)  able to be used prospectively for anticipating the future

Contemporary View on Cognition (as Opposed to Perception):
(a) interpretation:
•	perception  may involve inference but inferences are constrained through evolution and learning
•	cognition  inferences may be much more elaborate in thinking
 (b) here & now:
•	perception  restricted to here & now
•	cognition  not restricted to here & now

Note: description of cognition sounds very much like Piaget’s description of representation  representation = cognition;  representation = perception
But: is representation possible without equating it with cognition?

Evaluating Piaget:
(1)  What constitutes representation?
•	Perner (1991) argues that many "schemes" are representations
Example:
	- nutritive vs. non-nutritive sucking: within 1st month of life infant differentiates objects for nutritive sucking (breast) from objects for non-nutritive sucking (pacifier) by sucking differently on each
	- oral information creates an internal (mental) scheme which leads to different behaviour
	- so scheme represents object in mouth as being in a certain way (e.g., nutritive) --> is "about" object because different schemes for different objects
	- so even such "schemes" are representations
- most other criteria of representation fit also
(2)   Meltzoff & Borton:   inter-modal matching  abstract representation
•	at least some 1-month-olds can do this
(3)  Baillargeon:  some understanding of object permanence by 3.5 to 4.5 months
•	is this the same as what Piaget was concerned with?  maybe
For:  infant representing object that not currently present
Against:  involves looking rather than reaching

Implicit - Explicit:
•	looking more implicit than reaching?  looking more automatic whereas reaching involves a commitment to a particular location
•	Dienes & Perner (1996) criteria for implicitness: (a) a lack of metaknowledge, (b) lack of control over applying the knowledge, (c) knowledge not revealed in free recall, & (d) knowledge that shows itself only in indirect tests
•	looking is more implicit on last three criteria

Graded Representations:
•	Munakata et al. (in press)  reaching requires stronger representations than looking (representation strength = connection strength)

Semantic Network:

•	could be distinct from implicit-explicit
•	e.g., looking could be correct and reaching incorrect, yet both are equally implicit

Perner’s Levels (1991)
0-18 Months:  Single Updating Model (representation possible)
18 Months - 4 Years:  Multiple Models
•	allows:
1. pretence: model of banana as (a) banana & (b) telephone
•	if only have (a)  not pretending
•	if only have (b)  are confused
2. freeing up from present: invisible displacement
•	model of present: “object in hand”  but object not there  updated: “hand empty”
•	model of past: “object under cloth”  model of present updated: object under cloth

4 Years +:  Modeling models (representing a representation {metarepresentation} possible)