Week 3 - Cognitive Development in Infancy

Cognitive Development in Infancy

Perceptual Narrowing

Language General Capacity

Infants possess a language-general capacity, allowing them to discriminate between any two speech sounds from any of the world's languages. This phonetic perception is universal, unlike adults who are more attuned to their native language.

Language-Specific Speech Perception

As infants develop, they hone in on speech contrasts specific to their native language.

Universal Phonetic Perception: Developmental Change

Werker and Tees (1984) conducted research demonstrating that newborns are initially capable of non-native sound discrimination but become specialists in their native language by 12 months. This study involved:

• Three age groups: 6-8 months, 8-10 months, and 10-12 months.

• Three languages: English, Hindi, and Salish.

• Phoneme distinction: consonant contrasts (native vs. non-native).

They used a conditioned head-turn procedure where infants heard a repeating background sound and were trained to turn their head to a visual reinforcer when there was a change in speech sound category.

Perceptual Reorganisation

Perceptual reorganisation is domain-general. With age and experience, infants become uniquely sensitive to native language speech features, including:

• Native language prosody.

• Native language stress patterns.

• Native language phonotactics (order of sounds).

Perceptual narrowing results from neuroplasticity, a domain-general, multisensory cognitive mechanism. It also applies to face perception (native and non-native race).

Pascalis, de Haan, and Nelson (2002) found that 6-month-olds discriminate between two human faces or two macaque monkey faces equally well, but 9-month-olds and adults only discriminate between human faces, showing tuning into relevant distinctions.

Object Permanence

Piaget's Stages of Object Permanence

Piaget outlined the following stages:

• < 1 month: Only look at objects in front of them.

• 1-4 months: Dropped objects not looked for.

• By 4 months: Visually search for fallen object. Search for partially visible object, not an entirely hidden one.

• 8-12 months: Search for entirely concealed objects.

• 12-18 months: Permanence of invisible objects; visual tracking of moving objects, search for disappeared object.

• 18-24 months: Full object permanence acquired; understands object as existing independent of sensory-motor action.

The A-not-B Error

The A-not-B task requires an infant to search for a hidden object. The object is initially found in location A, but then the researcher hides it in location B.

• Infants below 8 months will not search for the object at all due to a lack of object permanence.

• Infants between 9-12 months will search, but usually in the wrong location (A), where they last found it, despite watching it being moved.

Object Permanence: Violation of Expectations (VoE)

Babies realize that objects are entities, and impossible things cannot happen to them. The VoE paradigm investigates object permanence in infants younger than 9 months.

Infants are shown an event, then two new events: one consistent with everyday reality (possible) and the other inconsistent (impossible). Infants typically look longer at the impossible event, assuming they have a sensitivity/representation of the event.

Possible Explanations for A-not-B Error

While VoE studies suggest object permanence exists earlier than Piaget proposed, younger infants still struggle with searching tasks. Possible explanations for the A-not-B error include:

• Lack of inhibition/response perseveration: Searching repeatedly at location A makes location A part of the object identity. Studies have shown the error occurs even with purely observational trials (Butterworth, 1974; Evans, 1973; Landers, 1971).

• Memory deficiency: Infants might struggle to remember the object's location. This is unlikely because the error occurs even when containers are transparent (Butterworth, 1977; Bremner & Knowles, 1984).

• Integrative executive functioning explanation: Frontal cortex immaturity is involved in planning and guiding actions (executive functions) (Diamond, 1988). The frontal cortex matures slowly and is involved in maintaining the representation of a hidden object and inhibiting incorrect responses. To succeed in the A-not-B task, the frontal cortex has to accomplish two different tasks at the same time, but its immaturity does not allow that.

• Dynamic systems theory explanation: The two locations are in competition with each other in the child's mind (Smith & Thelen, 2003). Repeatedly hiding the object in location A highlights the importance of location A. When the object is unexpectedly hidden in location B, this new visual cue initially competes with the memory of location A, but it decays after the object is hidden and the memory of location A wins! If infants can immediately search without delay, they indeed reach for location B (Wellman, Cross, Bartsch & Harris, 1986). Highlighting differences in locations helps; when infants were sitting during trials A and standing during trials B, they correctly searched in location B!

• Role of communication: Ostensive communication promotes the search error!

Object Permanence: Take-Home Messages

• VoE studies suggest that infants below 8 months already have knowledge of object permanence, contrasting with Piaget's view.

• However, this knowledge may not be sufficiently engrained to guide action, or the links between knowledge and action haven't been developed.

• Several proposals explain the A-not-B error: lack of inhibition, memory, executive function, and communicative cues.

Memory and Infantile Amnesia

Content of Early Memories

Significant events, such as the birth of a sibling or hospitalization/accident, can be remembered. Remembering increases depending on the age when the event occurred. When re-questioned one year later, memories proved quite stable, but this was less true of those who had only just turned two at the time

Mobile Contingency Experiments

• 3-month-olds can remember how to make a mobile move by kicking it one week after training/conditioning.

• By 6 months, they remember the same task two weeks later.

Infantile Amnesia: Explanations

Explanations for why most people do not have memories of early childhood, despite infants having memory for events, include:

• Brain development: Immaturity of the hippocampus until 3-4 years prevents memory formation; frontal lobe growth allows for explicit or conscious memories.

• Linguistic development: Inability to form memories/encode events without language.

• Emotional development: Inability to form memories without emotion schemes.

• Profound memory limitations: Infants can develop long-term memories for causal events! But when tested in a different crib that presents different visual cues, they can no longer remember how to make the mobile move, even after short delays (Boller et al., 1995).

• A not B error: infants rarely made errors if they were allowed to search immediately for the hidden object at B, with interference occurring between memory of object at A location and at new location (Harris, 1973)

Long-Term Recall – Reactivating Reminders

Infants at 6.5 months reaching in the light and dark for a sounding object – single exposure. When retested at 2.5 years old in the same procedure, those who had experience of reaching in the dark, and those who were given leading instructions, reached and grasped the sounding object significantly more (Perris, Myers, & Clifton, 1990).

Longer-Term Recall – Emotional Interpersonal Interaction

When presented with a photo of a person who did the still face experiments with them when they were 5 months, 20-month-olds could remember it (Bornstein et al., 2004).

Memories Can Be Scaffolded

Guiding questions and comments can help (Vygotskyan account). Recollection is the type of conversation children engage in before reminiscing independently. Elaboration is more effective than repeating the same question (Reese et al., 1994; Engel, 1986).

Procedural vs. Conceptual Memories

• Procedural memories: Specific to the initial event's situation, embodied, and disrupted by even slight differences.

• Conceptual memories: Rooted in verbal descriptions, dependent on semantic knowledge and adults' scaffolding.

Infant Memory: Take-Home Message

Even young infants can remember events but are limited to procedural memories. It's difficult for older infants and adults to translate earlier procedural memories into higher-order conceptual memories, thus it may seem that most people forget their infant experiences. Scaffolding by others can increase the rate and quality of recall.

Conclusions

These are just some pieces of the puzzle – distinct aspects of cognitive development in infancy. Limitations include the difficulty of investigating a complex phenomenon in its entirety; research usually investigates one or a few aspects.

Social Interaction and Communication in Infancy

Born to Communicate? Piaget vs. Vygotsky

• Piaget:

  • Egocentric stage: Language not aimed at communication of thought; self-directed speech as a monologue, which disappears with development.

  • Socialized stage: Language clearly directed towards someone else; exchange of thoughts - dialogues.

• Vygotsky:

  • Language is inherently communicative.

  • Self-directed and social language are initially merged, then divide into egocentric and communicative language; both remain present throughout life.

  • Internalized language also remains as a private monologue – shortened, fragmentary and unintelligible, an evolutionary product of egocentric language.

Early Language Development

• Cooing and gurgling: Starts around 3 months old.

• Reception and production of speech:

  • Infants prefer speech over other types of complex sounds.

  • Greater involvement of the left hemisphere in areas specialized for processing “communicative” sounds.

  • As early as 3 months of age, neural responses indicate rapid learning of the association of words and objects.

  • 6-month-olds look longer at very common referents (specifically feet vs hands and other body parts).

• Babbling: Starts around 6 months old.

  • Canonical babbling: Syllables, such as “ba ba” or “di da,” including a consonant and a vowel, either repeated or combined.

• Speech production: first words: Starts around 12 months.

  • Refer to individual objects, categories of objects, properties of objects, and actions.

Development of Speech Perception and Production

• Verbal communication:

  • 18 months: Knows 5-40 words; starts to use 2-word sentences.

  • 24 months: Knows 150-300 words; uses 2-3 word sentences; first efforts to combine different types of words (e.g., nouns, verbs, adjectives).

Pragmatics in Early Communication

Use of language to communicate in social interactions, focusing on the quality, relevance, and manner in which language is used. It includes efficient communication by avoiding repetition or irrelevant information, providing clarification, making adjustments, turn-taking, eye contact, facial expressions, body language, intonation, etc.

Types of Social Interaction

Starts with early attention to faces, sensitivity to various social cues (gaze, voice, emotional expressions, gesture, contingency), seeking and using others’ social cues to guide their behavior, and actively initiating communicative bids.

Still Face Paradigm

Infants become very distressed when the normality of the social interaction is impaired. They aim to restore effective communication by using their own communicative cues (Ed Tronick, 1970s). The goal is contingent, positive, informative, and directed communication.

Ostensive Communication

Humans are uniquely predisposed to learn from social partners who use communicative cues. Human communication is ostensive: it communicates not just the message to influence the recipient but also the very fact that this message is being intentionally communicated to her.

Infant-Directed Speech

Motherese/parentese or baby talk = infant and child-directed speech, which includes higher pitch, exaggerated intonation, and slow and stretchy speech repetition.

Social Referencing

Using the parent’s emotions to assess a novel situation (e.g., parent reacts negatively towards a new toy; infant avoids playing with it). It enables infants to quickly learn about emotions and about the world. A classic example is demonstrated with the visual cliff paradigm.

Joint Attention (JA)

JA emerges between 9 to 12 months of age, appears unique to humans, and is significantly associated with later language development. It includes:

• RJA (Responding to JA): Following JA bids from others.

• IJA (Initiating JA): Via developmentally available communicative behaviors: social referencing, pointing, vocalizing.

• IBR (Initiating Behavioral Regulation/Requests): Instrumental function (via reaching, pointing, vocalizing).

• RBR (Responding to Behavioral Requests):Via reaching, pointing

Impact of Early JA skills

Long term positive effects:

• Early JA skills and the amount of time spent engaging in child-parent book reading are related to later vocabulary development.

• Gaze following at 9-11 months predicts language comprehension (but not production) at 18 months of age.

• 12-month-olds initiating JA and 18-month-olds’ response to JA predicts vocabulary at 24 months.

• Infants who were better at gaze following at 10.5 months used more words to describe their feelings and thoughts (e.g., “mad” or “think”) when they were 2.5 years old.

• Those 2.5-year-olds who used more words to describe their mental states were better at figuring out what other people were thinking when they were re-tested at 4.5 years of age.
  Conversational turns affect brain connectivity and are predictive of later language development outcomes and IQ

Contingent Talk

There is no right way to talk. Parents from different cultures talk to their children differently, and small changes in talking to toddlers are unlikely to affect a child's language long-term.

Gestural Communication

Communicative intentions:

• Socio-emotional – non-informational needs.

• Imperative – instrumental, or requestive (« Get me that! »).

• Declarative – sharing attention or interest («Look at that!»).

• Information-seeking – e.g., from more knowledgeable others.

• Informative – providing information to less knowledgeable others.

Pointing with declarative intention emerges around 12 months.Decorated room paradigm shows that pointing is a prelinguistic gestural universal of human communication

Pointing as information-seeking:

• 12-month-olds pointed more when an adult was Informing rather than Sharing attention.

• 16-month-olds pointed more when adult was Informative rather than Ignorant about toy labels and functions
  Social referencing as information seeking occurs

• when their expectations are violated/unexpected information given

• when can obtain information from others about the location of hidden objects or novel words

• when presented with two novel objects and only one novel label (referential uncertainty)

• when detecting humor

In informational uncertainty, 12-month-olds use social referencing to selectively seek information from more knowledgeable adults when facing referential uncertainty.

Preschool Years

• ~3 years: 900-1000 words; ask short questions.

• ~4 years: 2000+ words; 5-word sentences; lots of questions!

Question-Asking as Active Learning

Intentions:

• Attention

• Permission

• Help

• Clarification

• Information

In “passages of intellectual search” (~4 years), extended bouts of questioning, sustained curiosity on a single topic, follow-up questions about explanations, detecting inconsistencies in responses, and building up inquiry occur with a responsive caregiver (Tizard & Hughes, 1984).
What kind of information-seeking?
Existential/teleological explanations and resolution to puzzling events are sought