Developmental perception
A cognitive neuroscience perspective
Course overview
1)
2)
3)
4)
5)
6)
7)
8)
9)
Prenatal development and perceptual abilities
Neural plasticity and perceptual development
Development of tactile and vestibular perception
Development of low-level visual perception
Development of high-level visual perception
Development of auditory and speech perception
Multisensory perception: innate or acquired?
Perceptual processing and ageing
Development of social perception
•
Nelson & Luciana (2008). Handbook of Developmental Cognitive Neurscience. MIT Press.
•
Gazzaniga, Ivry & Mangun (2002). Cognitive Neuroscience: the biology of the mind.
•
McCartney & Phillips (2008). Early childhood development. Blackwell publishers
•
Bremner & Fogel (2004). Infant development. Blackwell publishers
•
Nelson, de Haan & Thomas (2006). Neuroscience of Cognitive Development. Wiley publishers.
•
Atkinson, J. (2000). The developing visual brain. Oxford Psychology Series.
•
Other primary source material recommended during lectures.
Recommended reading
Lecture 1: Pre-natal sensation and perception
Brain development in the foetus
•
8 distinct stages of brain development
–
1.
2.
3.
4.
5.
6.
7.
8.
Herschkowitz, (1988). Neonate 54, pp. 1–19.
neural induction
neuronal proliferation (neurogenesis)
neuronal migration
neuronal selective aggression
neuronal differentiation
neuronal death (apoptosis)
selective synapse elimination (pruning)
myelination
– Some of these processes start as early as 3–4 weeks of gestation and can even continue until 20 years of age.
Development of nervous system
• At birth, foetal brain already well developed
– Cortical layers, neuronal connectivity, myelination
• Within 5 days following fertilization - cell differentiation
– Multicellular blastula
• Ectoderm
– Nervous system and outer skin
• Mesoderm
– Skeletal system and muscle
• Endoderm
– Internal organs and digestive system
– Ectodermal cells form the neural plate
Development of nervous system
•
Week 3 of gestation
•
Neural plate grooves to form neural tube
– Rostral section closes to form cortex and other brain structures
– Caudal section forms spinal chord
Neuronal proliferation
•
From week 7
– More elaborate structures develop from neural tube
– Massive proliferation of new neurons
•
100,000+ per minute at its peak
– In primates neurogenesis in cerebral cortex begins in first 10 weeks and generally completed within 2 months
•
Different areas of brain finish process at different stages
–
E.g. V1 slow
– No further neurogenesis in post-natal cortex
•
Exceptions of dendate gyrus in hippocampus
•
•
olfactory bulb
Prefrontal and parietal cortices
–
–
(Gage and colleagues - Eriksson et al, 1998)
(Gould & Gross, 1999)
Synaptogenesis and pruning
•
First synapses generally appear about week 23
•
Spontaneous overproduction
– Peaks during first year of life
•
Post-natal pruning is experience dependent
•
•
continues into adulthood
Synaptic pruning varies by cortical region
•
•
Occipital lobe synapses peak at 4 to 8 months and are pruned to adult level by age 5
Prefontal cortex peaks at 1 to 2 years and pruned to adult levels in late adolescence
Prenatal development and perceptual abilities
•
Before birth
– Different brain regions develop at different rates
• Mainly independently of development of sensory organs
– Connections between brain regions and peripheral sensory organs develop after 25th week
– Sensory learning can begin in utero after this time
• Brain development influenced by external stimulation
Prenatal development and perceptual abilities
– The first projections from the thalamus to cortex appear at 12-16 weeks' gestation.
– The major afferent fibres (thalamocortical, basal forebrain, and corticocortical) penetrate
and form synapses within the cortical plate from 23-25 weeks' gestation.
Measuring foetal behaviour
•
Brain structure and ontongeny
– Postmortem studies of foetus
– Comparative studies
•
Brain function of foetus
– Derived from ultrasound observations
– visual evoked response (VER) recordings on preterm human infants
• VERs recorded from neonates delivered as early as 26 weeks GA
–
E.g. Birch & O’connor, 2001
– noninvasive magnetoencephalography (MEG) technique
• Auditory responses
–
Naatenen and colleagues
• Visual responses
–
E.g. Using visual flashes that can penetrate uterine wall
»
Eswaran and colleagues, Experimental Neurology, 2004
Magnetoencephalography
Foetal sensory development
The Appearance of Fetal Movements
in Early Pregnancy
Movement
Lateral head movement
Startle
Generalized movements
Hiccups
Isolated arm movements
Head retroflexion
Hand—face contact
Breathing
Jaw opening
Stretching
Head anteflexion
Yawn
Suck and swallow
First Appearance
(Wks. Gestation)
7
8
8
8
9
9
10
10
10
10
10
11
12
Note. From De Vries et al. (1982).
The emergence of fetal behavior:
I. Qualitative Aspects.
Early Hum. Dev., 7, 301-322.
Foetal sensory development
Somatosensation
7 wk
8-9 wk
11 wk
15 wk
13-14 wk
first responses to upper lip
peribuccal free nerve endings found 8-9 wk
face, palmar, plantar
trunk
whole body responds
20-25 wk
vestibular
4 wk
11 wk
20-30 wk
trigeminal
ciliated receptors
functional olfaction
12 wk
taste buds
4 wk
8 wk
18-20 wk
20 wk
20-25 wk
23-29 wk
24-28 wk
27-28 wk
20-25 wk
33 wk
cochlea begins to differentiate
organ of Corti begins to develop
organ of Corti begins to function
cochlea appears mature
first cardiac responses to sound
first responses obtained
first responses to vibro-acoustic stimuli
first responses to pure tones
first cardiac responses to sound
inner ear mature
30-32 d
13 wk
20 wk
optic vesicles form
rods, cones, begin to form, not complete until after birth
eyes open
Proprioception
Chemosensation
Olfaction
Gustation
Audition
Vision
Foetal sensory development
–
–
Graph of onset and duration of sensory development
Gottlieb (1971) The biopsychology of development. Tobach, Aronson & Shaw (Eds.)
Tactile perception
•
Fetal face and hand movements suggest preadaptation for manual and oral grasping
• Trevarthen, 1974
•
Spelt (1948) investigated tactile senstitivity in foetus between 7-9 months
– Vibrotactile stimulation caused regular feotal movement
•
Week 38
– habituation to repeated vibrotactile stimulation
•
Precocious development of tactile sense
– System reaches structural maturity and functional competence early in ontogenesis
• Post-natal tactile stimulation associated with weight gain and growth in high risk neonates
–
Goldberg & diVitto 2002
Foetal vestibular system
•
Structure of vestibular system progresses rapidly
– as seen by the active movement of the fetus in utero
– floats, kicks, turns, sighs, grabs at umbilicus, gets excited at sudden noises, movement reduction
when the mother talks quietly
– As early as the first trimester, regular exercise patterns have been observed with ultra-sound:
• rolling, flexing, turning, etc. (Van Dongen & Goudie, 1980).
•
Foetus responds to self-generated movement
– Movement in utero associated with heartbeat acceleration
• DeMause (1982)
Foetal vestibular system
•
Vestibular system consists of the bony labyrinth
– the inner ear, including the sense organ of hearing in the cochlea, the vestibule and the semicircular
canals
•
The modern human bony labyrinth is morphologically distinct from that of all other primates
(Hyrtl, 1845)
– thought to relate functionally to sensory control of modern human bipedal locomotion and support of
larger cranium
• (Spoor (1993) and Spoor & Zonneveld (1998)
– Maturation peaks at weeks 17-19
– the prenatal labyrinth same equivalent size as adult
– shape changes to all or most of the labyrinth cease
• Fully encapsulated by bone a few weeks later
–
Jeffrey & Spoor (2004). J Anat. 2004 February; 204(2): 71–92.