Conceptualise the sensory overload of information and movements after being born. Moreover, how these sensations, experiences are processed, interpreted and reassessed by a newborn on a daily basis. With this in mind, this chapter will be dedicated to understanding sensory and perceptual development. That is, how empirically based evidence allows us to gain a historical and modern-day understanding of what is meant by ‘Sensory & Perceptual Development.’ But before we can continue let’s distinguish between what is meant by ‘sensation’ and ‘perception’ as these two terms are frequently misused. Sensation relates to one’s ability to detect and distinguish between sensory information, for example; the difference between local and soft noises. Whereas, perception refers to how a person interprets each sensation.
Note: $74.99 (+ Shipping / Price subject to change by Amazon) Video Baby Monitor with Camera, ANMEATE Digital 2.4 Ghz Wireless Video Monitor, 960ft Transmission Range, 2-Way Talk, Night Vision, High Capacity Battery. (White)
Theories on Sensory & Perceptual Development
Although there are multiple theories on Sensory & Perceptual Development, it’s clear that there is one common principle within each theory, namely, that one’s development is based on the interaction between nature and nurture. ‘Learning’ theorists Shapley, Caelli, Grosberg, Morgan & Rentschler (1990) referred to an infant’s first reaction to a face as a collection of unorganised features, moreover, that it’s the infant’s experiences and ability to distinguish different sensory inputs that determine how the infant perceives their environment. With this in mind, facial features like the nose, mouth and eyes can be recognised as a face by the infant. In addition, how objects of the same shape can consist of multiple surface textures.
Furthermore, in Sangrigoli, Pallier, Afenti, Ventureyra & Schonen’s (2005) view repetition by association might explain how ‘own-race bias’s’ occurs, namely, how individuals find it easier to recognise others of the same racial or ethnic heritage. Moreover, Ethological theorist Bremner (1997) theorised how perceptual systems are developed as one’s knowledge of the world increases.
Theories on Cognition Development
Cognitive developmental theories are based on how knowledge affects one’s perception. Moreover, how higher complex cognitive processes like thinking and reasoning are organised from the ‘top-down.’ Noticeably, this concept is self-evident as a child interprets sensory information from their environment. It also explains according to Jerome Bruner (1957) how the cognitive process proceeds perception as individuals recognise and categorise objects within their environment before conceptualising the meaning or perception of the object. In addition, Schyns, Goldstone & Thibaut (1998) argued that one’s interpretation or the perception of an object is formulated as the child tries to understand what the object is used for. Therefore, cognitive development refers to a child’s interaction and interpretation of their environment. It also relates to the child’s sensory information and experiences that increase throughout a child’s life. With this in mind, perception via vision will be explained in the next section.
Historically speaking, little was known about infants and their vision within the first few months of development. In fact, according to Bendersky & Sullivan (2007) advances in technology along with improved research techniques has allowed us to gain a greater insight into infant vision. Knowing of this, Robert Frantz’s (1961) ‘preferential-looking’ technique was considered a breakthrough in early infant psychology as Frantz’s technique had identified a child’s preference or increased duration of focus to a new stimulus over a known stimulus.
The infant would then be subjected to alternating images on each screen. It was an observation that an infant’s duration of focus was longer towards the new images. Therefore, Frantz concluded that infant’s in the early stages of development are able to distinguish changes in their environment. One other infant perceptual technique that is frequently implemented by developmental psychologist today is the ‘habitual-dis-habituation’ procedure which is based on the premise that infants (like adults) are generally attracted to new ‘dis-habituated’ or novel stimuli over repetitive ‘habitual’ stimuli.
Measuring Visual acuity & Colour vision
Visual acuity refers to the clarity or perception of one’s vision and is assessed by the ‘preferential-looking’ method as previously mentioned. For example; vertical black and grey lines of equal width would be presented to a child along with a picture of equal brightness. Typically, the novelty of the lines will hold the attention of the infant for longer. In addition, as this procedure is repeated the black lines become thicker until no grey lines are perceived by the infant. This will be self-evident as the infant’s attention span decreases along with its novelty. In other words, the limit of the infant’s visual acuity has been reached. Moreover, research has revealed that infant visual acuity is limited in the early stages of development.
With this in mind, a computerised representation of infant visual acuity has been expressed in this diagram to illustrate how infants perceive the world between the first and third months of life. In comparison, in the ‘preferential-looking’ procedure the ‘Snellen fractional’ system is another visual acuity method designed for young children and adults. It’s also known to many as a ‘visual eye chart’ and is commonly found displayed on the wall within an optometrist or doctors consulting room. Furthermore, normal visual acuity for adults is 6/6 or 20/20 in a higher denominator of this fraction. For example; according to Slater (2004) a three-month-old infant’s visual acuity is around 6/30.
How do we define colour? The perception of a wavelength of light is how individuals interpret colour, more precisely, how colour-sensitive receptors known as ‘cone’ are sensitive to specific wavelengths, like blue or red. Knowing of this, Kellman & Arterberry’s (2000) argued that the maturation of cone receptors can account for a newborn’s progressive ability to perceive colour.
The perception of patterns and contrast
With the maturation of basic low-level processes like ‘visual-acuity’ and ‘colourvison,’ a baby’s ability to identify objects within their environment increases significantly. However, according to Kellman & Arterberry (2006) ‘pattern recognition’ is more complex and involves a higher cognitive process known as ‘visual scanning’ which involves tracking of eye movements of infants as they learn to identify differences in geometric shapes, like squares, triangles and circles. It also explains how a child at one month will focus on individual and therefore less complicated features of an object. For example; the outline or edges of the object. Moreover, how maturation is reflected in a two-month-olds ability to distinguish between more complex internal features.
With this in mind, one example of ‘visual-scanning’ might be the recognition of individual facial features by a child in order to identify between known or unfamiliar faces. Noticeably, older babies acquire more comprehensive scanning strategies to identify complex patterns, textures, colours and shapes. It also allows a baby to perceive depth as these features are often associated with the structure of an object.
In addition, Quinn & Slater (2003) conceptualised that the development of perception is normal and advantageous to a child when identifying one’s parents. Moreover, that ‘parent-recognition’ is achieved in Pascal’s De Schoman, Morton & Deruelle’s (1995) view by discriminating between different facial features of each parent and the features associated with a stranger. Noticeably, these features according to Kellman & Arterberry (2006) are represented as a smile or frown and can be identified by an infant by the age of three months. The infant will also at this developmental stage have the ability to respond appropriately to different facial stimuli, namely, a happy, surprise, or angry face. This reaction according to Serrano, Iglesias and Loeches (1995) also reflects the infant’s ability to learn from their social environment, in other words, how others react to the same or similar facial expressions.
How infants perceive & interact with objects
As previously mentioned visual perception is based on ‘visual acuity,’ ‘colour vision’ and ‘pattern-recognition.’ However, to mobilise towards and to physically interact with objects infants need to acquire a more comprehensive understanding of other visual properties. One such visual perception property is ‘size-constancy.’ Size constancy refers to our ability to recognise shapes via our ‘retina’ and to conceptualise that these shapes regardless of distance will remain unaltered in physical size. Noticeably, Bower’s (1965) research revealed that babies between 40 and 60 days of age were capable of displaying such perceptual tendencies. Moreover, Cohen & Cashon’s (2008) habitual research methods had identified another stable perceptual property, namely, ‘Shape constancy.’ Shape constancy refers to one’s ability to understand how objects remain consistent in shape regardless of their perceived rotation or obscurity behind other objects.
The perception of Space, Depth & Distance
Although our world is perceived in three-dimensions, it’s our perception system that allows us to interpret two-dimensional images that are projected onto our retina into logical visual-spatial cues. With this in mind, Gibson & Walk’s (1960) depth perception experiment was based on the premise that infants process the ability to perceive depth at an early age. They also conceptualised that infants would demonstrate this ability by avoiding a ‘visual cliff.’ Here is a representation of Gibson & Walk’s (1960) ‘visual-cliff’ experiment.
Here is a representation of Gibson & Walk’s (1960) ‘visual-cliff’
A rectangular enclosed glass table was constructed with a checkerboard pattern displayed beneath one-half of the table. On the other half of the table, a transparent glass platform reveals a ‘visual-cliff’ that falls away to a checkerboard floor below. Noticeably, on the side of the visual cliff, the table is also enclosed with a checkerboard pattern. Gibson & Walk’s reasoned that a child who has developed a cognitive understanding of depth perception will try to avoid the ‘cliff’ and remain on the shallow end of the table.
As a result, the ‘visual-cliff’ experiment demonstrated that infants at six months of age have the ability to perceive distance and depth. In contrast, Cohen & Cashon (2006) attributed ‘depth perception’ to a child’s ability to interpret observable differences between each eye. That is, to implement ‘Binocular depth cues’ to perceive depth. In addition, one other ‘kinetic cue’ that is important to depth perception is ‘motion parallax.’ Motion parallax refers to the relative distance and observable changes of an object as it passes through one’s environment. With this in mind, one’s visual experiences are considered to be greater if the object is close and moving towards one’s self. Whereas, observable distant objects that move are less visually stimulating as distance and size are perceived as being small.
Sensitivity to pictorial cues
Early research into ‘pictorial distance cues’ by DeLoache, Strauss & Maynard (1979) indicated that newborns have the ability to distinguish between real objects and two-dimensional pictures of the same object. However, DeLoache & Ganea (2009) suggested that evidence indicates a child’s full conceptual understanding of a picture develops during the second and third year of life. It also explains why a nine-month-old will attempt to grasp a life like a toy from a picture according to DeLoache, Pierroutsakos, Uttal, Rosengren, & Gottlieb (1998).
Hearing and Auditory Perception
Auditory development is based on one’s ability to detect and perceive auditable environmental changes. This, in turn, allows the individual to quantify the relative distance of objects in relation to one’s self. It also acts as a defence mechanism when trying to avoid objects in motion, namely, a moving vehicle from behind or an approaching cyclist on the road. Therefore, ‘sound recognition’ is vital to one’s development as it also helps a newborn to distinguish between the voice of its mother and father. In addition, this identification is critical for reassurance and survival on a nutritional level in the early years of development. Moreover, according to Sloutsky & Napolitan’s (2003) it’s more important than vision.
But how are the development of hearing and auditory perception assessed in infants, young children? The answer lies in a child’s normal reaction to sound. Namely, the infant’s physiological increased heart rate and breathing in Aslin, Jusczyk, & Pisoni’s (1998) view. It also includes the rotation of an infant’s head towards a new auditory stimulus. Noticeably, habituation, dishabituation also will occur as the infant becomes familiar with the repetition and source of the auditory sound. This will become self-evident in Aslin et al. view as the infant’s attention span will diminish over time.
Remarkably, research by Lecanuet, Granier-Deferre, & Bunsnel (1995) had revealed that a foetus at 24 weeks has the ability to acknowledge outside audible stimuli as electrical activity of the foetus’s brain. With this in mind, Lecanuet et al. conceptualised that infants might be able to discern between individual sounds. Moreover, that pattern recognition of voices might aid in the infant’s ability to identify their own mother’s voice. This premise was also the foundation of DeCasper & Spence’s (1986) auditory experiment with a pregnant woman. The mothers would read aloud one of three stories each day and by strangers three days after the birth of the child. The results indicated a significant measurable difference in the rhyme of sucking by the infant when the mother’s voice was presented.
Therefore, in DeCasper et al. view ‘parental exposure’ during the prenatal stage of development is associated with ‘vocal pattern recognition’ by the child after birth. Similarly, as indicated by DeCasper, Lecanuet, Bunsnel, Granier-Deferre, & Mangeais (1994) infants show a preference for known rhythmic sounds like melodies. This conclusion was reached after the monitoring of newborns and their declining heart rates after the introduction of familiar prenatal rhythmic sounds like melodies. This conclusion was reached after the monitoring of newborns and their declining heart rates after the introduction of familiar prenatal rhythmic sounds.
Sound sensitivity and sound discrimination
How sensitive are we to sound? By definition ‘sound sensitivity’ refers to one’s ability to detect ‘pitch,’ that is, a frequency or vibration of a wavelength of sound at a certain level. Noticeably, this is in contrast to ‘sound discrimination’ which refers to the identification of individual sounds. With this in mind, according to Saffran et al. (2006) adults unlike newborns are more sensitive to sound and are capable of detecting a whisper at one meter. In contrast, a newborn within the same environment would require a level of sound that is four times as loud to achieve the same detection.
Moreover, as identified by Eisenberg (1976) newborns are more sensitive to ‘lowfrequencies.’ However, research by Saffran et al (2006) had revealed that a newborn’s rapid development of sound sensitivity to different frequencies increase up until the child reaches 10 years of age. Furthermore, that a newborns sensitivity to high-frequencies is approximately equal to an adult at the chronological age of six months. More importantly, that infants at one month, in Vouloumanos & Walker’s (2007) view, can distinguish between multiple frequencies that fall within the normal vocal range of human speech.
Sound localisation and the perception of music
Fernald’s (2004) ‘eye-movement recognition’ approach to sound localisation allows us as individuals to comprehend how newborns are more likely to focus their attention on human voices or sounds that last for more than a few seconds. With this in mind, according to LaGasse, VanVorst Brunnert, & Zucker (1999) infants also have the ability to track audible moving objects in the dark and are capable of determining the objects final resting place. Moreover, as conceptualised by Muir & Hain’s (2004) a newborns ability to detect and locate sounds within their environment can be attributed to the maturation of the ‘subcortical,’ cortex during the first year of life.
In addition, in Frehub & Hannon’s (2006) view, the implementation of rhythmic tones, melodies and tempos by parents are represented within all cultures as a part of a newborn’s audible development. Noticeably, this premise also reinforces research by Plantinga & Trainor (2005) as infants at six months were found to have the ability to identify individual structural features like tone, tempo within music. More importantly, according to Balaban, Anderson & Wisniewski (1998), on a biological level, the detection of melody changes can be related to the maturation and cognitive processes of the right ‘cerebral hemisphere’ of the brain.
Sensory perception continued….
During early child development infants will experience pain as a result of an injury, illness or medical procedure, like immunisation. Knowing of this, Sweet, McGrath, & Symons (1999) suggested that a child’s physiological reaction to a painful stimulus might also be influenced by the reaction of others within their immediate environment. Moreover, research by Piira, Champain, Bustos, Donnelly, & Lui (2007) had identified higher blood levels of ‘cortisol’ after infant immunisation. Noticeably, this occurs in their view as an indicator of physiological distress to pain. In addition, Guinsberg et al. (2000) also contributed to the field of pain reaction by suggesting that babies, namely, boys and girls react differently while under physical distress. With this in mind, individual researchers like Blount, Piira, Cohen, & Cheng (2006) have indicated that the implementation of essential coping mechanisms can be designed to help relieve distress and pain in children.
One’s perception of Touch, Taste, & Smell
Sensation, that is, one’s perception and response to an environmental tactile experience can according to Gentaz (2008) occur early in the foetal developmental stage. Namely, when Foetal reflexive responses are noticeable two months after conception as a result of pressure being applied on the surface of the mother’s skin. Knowing of this, touching in Gallace & Spence’s (2009) opinion might act as a positive emotional reinforcement, moreover, that the response to the stimuli can be observed as a smile or gaze towards the caregiver. In addition, ‘Haptic perception’ can be referred to as a child’s acquired tactile knowledge and experience of objects over time.
With this in mind, Streri (2003) attributed ‘oral exploration’ by infants as one example of ‘Haptic perception’ as infants will suck on fingers during the early stages of development. Moreover, research by Streri, Lhote, & Dutilleul (2000) suggests that infants have the ability to discriminate between tactile objects. Noticeably, Streri et al. methodology within their experiment included subjecting infants to two different identifiable tactile objects, namely, a ‘wooden cylinder’ and a novel ‘wooden prism.’ The results of the trial indicated that the attention span of infants who were repeatedly subjected to the same object had declined over time. In contrast, when infants were introduced to a new tactile the infant’s attention span towards the object was found to be quantitatively longer.
Therefore, in their view, infants can perceive and discriminate between known, unknown objects. Striano & Bushnell’s (2005) ‘fine-grained discrimination’ experiment also explored the concept of ‘Haptic perception.’ Their results indicated that infants as young as three months of age are capable of perceiving and discriminating between almost identical object by touch alone. Noticeably, the weight of each object was the only discriminating variable that the infant could perceive. Moreover, that this perception according to Striano & Bushnell had dominated all other sensors. In addition, with ‘increased manual dexterity’ infants were able to explore new objects on hard surfaces.
Therefore, in Jovanovic, Demmier, & Schwarzer’s (2008) opinion manual exploration accounts for the turning over, the passing of objects from one hand to the other.
Early prenatal development research by Lamb et al. (2002) had identified the presence of taste receptors on the tongue, mouth and throats of foetuses before birth. More importantly, that taste discrimination might also occur as a Foetus appears to prefer the sweet taste of foods that are found within the mother’s ‘amniotic fluid.’ In addition, according to Smith & Blass (1996), a positive reaction to sweet substances is evident and observable in
the newborn’s increased rate of sucking. Conversely, when bitter sour liquids are consumed by the newborn, the newborn’s reaction, in Rosenstein & Oster’s (1998) view appears to be negative. However, as identified by Mennella & Beauchamp (1997) infants will at four months transfer their preference of taste from sweet to salty.
More significantly, how ‘oral medications’ can be engineered to include trace amounts of salt for the ease of consumption for children. Mennella, Pepino, & Beauchamp (2003) researched this premise and discovered that children between seven to 10 years of age had found the consumption of medication with salt more acceptable. It also one example of how developmental psychology contributes to our society.
Lamb Bornstein, & Teti (2002) hypothesised that ‘olfaction’ or the sense of smell is one of the earliest sensory systems to develop. Physiological research by Schaal, Orgeur, & Rognon (1995) reinforces this premise as their research had revealed that a foetus during the final few months of gestation was able to distinguish between smells found in the amniotic fluid. Moreover, according to Porter, Makin, Davis, & Christensen (1992) ‘olfactory receptor maturation,’ is evident in the first few weeks of life as newborns prefer the odour of breast milk. In addition, previous research by Lipsitt, Engen, & Kaye (1963) found that newborns react differently to unpleasant, pleasant odours. With this in mind, newborns would lick and make sucking movements of the lips to indicate a relaxed reaction to pleasant odours. Noticeably, this was in contrast to splitting like gestures when offensive, unpleasant odours were presented.
As previously mentioned each sensory modality occurs independently. However, ‘inter-model perception’ as identified by Cohen & Cashon (2003) refers to the simultaneous stimulation of all sensors at the same time to form a new perception or ‘a-modal’ representation of an object or event. Historically speaking this premise of intermodal perception has been controversial as cognitive developmental theorist Piaget and ‘learning’ theorist Hebb (1949) adhered to the cognitive separation of all sensors at birth theory. Moreover, how individuals learn to integrate each sensory system to gain a new perspective. Whereas, recent research by Gibson and his colleagues (1996) had conceptualised that cognitive integration of the sensory information system occurs in the early stages of infancy.
Noticeably, this concept is evident according to Hofeten (2001) when infants implement ‘intermodal exploration.’
That is when information that’s acquired by one sense leads to the exploration of an object by another sense. Note: One example of this might be the visual orientation shift towards a novel soft toy or familiar voice. More importantly, research by Woodward & Needham (2009) had revealed that a ‘cross-modal response’ to a stimulus has a significant adaptive value as an infant’s elementary modification of development by the employment of ‘intermodal perception’ and ‘exploration’ is essential during the first 12 months of life.
Cognitive & Stage developmental theorist Jean Piaget
Let’s first define what is meant by cognition. Cognition refers to the mental processes involved in understanding and adapting to one’s environment. Whereas, ‘cognitive development’ refers to one’s mental adaptation over the course of one’s lifetime. With this in mind, Piaget conceptualised that cognition progresses through a number of a systematic integrated developmental stage. Namely, the ‘sensorimotor,’ ‘pre-operational,’ ‘operational,’ and ‘formal operational’ stage. Piaget also suggested that ‘stage variance’ occurs when children transition from one stage to the next as one’s genetic endowment and environmental conditions will determine when one stage overlaps the other. Moreover, that cognition consists of one’s ability to reason, to solve problems by understanding time, space, memory language, and the movement of objects, fantasy play, and one’s moral judgement from birth to early adulthood.
Noticeably, each stage according to Piaget adheres to a ‘Universal pattern of development,’ which all children regardless of their culture, educational background or family context will progress through each stage. Piaget also believed that one’s mental & physical development is constructed by learning from one’s experiences. That acquired knowledge from birth is stored and organised into ‘schemes’ or common properties of specific behavioural patterns, objects and experiences.
With this in mind, Piaget referred to schemes as being ‘dynamic’ as each scheme or mental structure is open to ‘adaptation.’ Noticeably, as identified by Piaget, adaptation is based on the individual’s mental ability to ‘assimilate’ new information into known schemes or categories. Moreover, how another cognitive process is known as ‘accommodation’ allows the individual to formulate a new scheme in order to construct a greater perspective of the world. Piaget also suggested that each is connected and is affected when a new conceptual understanding of their environment occurs. Let’s now look at the first developmental stage.