Jittery Capabilities in Remembering in Newborns - Essay Example

Memory in Infants (Author’s Name) (Professor’s Name) (Subject) (Date of Submission) Introduction The formal study of memory has a long and distinguished history, dating back (at least) to the mid-nineteenth century. Three themes common to research conducted form the mid-1800s through to the latter half of the twentieth century were concerns with the limits of memory, the contents of memory, and increasingly, the cognitive architecture of memory. However, relatively ignored until the late twentieth century was a concern with the ontogeny of memory, and interest in the biological bases of memory. As will be evident here, there is now a plethora of research on memory development, due in large measure to the development of methods amenable to the study of the infant and child. In addition, the biological bases of memory have also received considerable study of late. However, as will become apparent in this discussion, the juxtaposition of these themes – the biological bases of early memory development – has received relatively little attention. It is the goal of this discussion to review what is currently known about this topic, and to put forth a number of theoretical proposals on the relation between brain and memory development (Cowan, 1997). Memory It is obviously important that infants attend to stimuli and events in their environment, but it is also crucial that they be able to store, retrieve, and use that information later. Memory representations underlie that infant’s awareness, experience, knowledge, and interpretation of the world. Developmentalists are interested in all dimensions of infant memory, in what infants can remember, and the nature of their memory representations, in the ways in which infants remember, and in how good infant memory is. Memory plays a key role in the general model of mental functioning. This model is traditionally believed to involve (at least) three stages: 1. The sensory register temporarily stores attended-to information. 2. Short-term memory has limited and momentary capacity for information. 3. Long-term memory represents a limitless, permanent storehouse of knowledge, but one that depends on “control” processes that are generally unavailable to infants or even very young children. (Failure to remember is more likely to result from an inability to retrieve information from long-term store rather than actual loss of information; as a consequence, memory strategies play a key role in long-term memory.) Learning and memory are interrelated but not identical phenomena. In conditioned head turning, for example, the infant must recognize a sound and remember to turn to one side when that sound is heard. It is quite conceivable, however, that the infant will remember the sound and perhaps even remembers the response contingency, yet choose not to perform. Alternately, the baby may be incapable of a response yet recognize the learning situation very well. Therefore, the study of memory development is important in its own right (Lamb et al., 2002). Tasks for Infants For many years, researchers have studied infant memory using novelty-preference tasks. Although there are many variants of these tasks, all are based on the fact that infants usually orient to novel but not familiar stimuli (2000). In the simplest form of the paradigm, infants might be shown a picture; their looking time is recorded. Immediately thereafter, infants are shown the same picture, suggesting that they recognize the other picture from its prior presentation. Another method of assessing infant memory relies on conjugate reinforcement (Bauer, 2006). A mobile is mounted temporarily above an infant’s crib and a ribbon connects the mobile in the infant’s leg. Within a few minutes, 2- to 3- month-olds learn to kick to make the mobile move. The mobile is then removed but, at various intervals, reattached. Infants often kick spontaneously, suggesting that they remember the contingency between leg movement and the mobile’s motion. Both of these paradigms have been used successfully to study many aspects of memory during infancy. It should be noted, however, each technique measures a broad collection of memory processes, not simply working memory. Measures of infant memory typically have not included the concurrent processing component that is the hallmark of working memory tasks for older children, adolescents, and adults. Processing speed has been studies less extensively that memory in infants. Consequently, suitable tasks are still emerging. One approach relies on the novelty-preference paradigm and simply records the amount of time that infants spend looking a novel stimulus. Infants differ substantially, in their average looking, and when tested on their cognitive tasks, “short-looking” infants rend to perform better than “long-looking” infants (Novak and Pelaez, 2004). These results suggest that infants who look at novel stimuli briefly are processing them more rapidly than infants who look longer. Another method, known as the visual expectation paradigm, involves rapid presentation of pictures to an infant’s peripheral visual field (Chen and Siegler, 2000). Typically, the infant’s eye moves rapidly and directly toward the picture, a motion known as saccade. These eye movements are videotaped, and these tapes are scored to measure saccade RT, the time elapsed from the appearance of a picture until the start of the eye’s movement toward the picture. Several caveats are associated with these methods for estimating processing speed; 1) both methods, but particularly the visual expectation paradigm, require elaborate apparatus and complex scoring, 2) the saccade RTs, from the visual expectation paradigm can be ineterpreted in much the same way in infants, children, and adolescents, but this not likely to be true for looking times obtained from novelty-preference tasks, and 3) estimates of processing speed from novelty preference and visual-expectation paradigms are related, but not substantially (Bornstein, 2003). Other Techniques Used to Study Infant Memory Students of memory capacity in infancy have used five different techniques. Two are habituation and novelty-responsiveness procedures, which specifically tap recognition memory. When an infant looks at a repeated study stimulus less on its fifth showing than on its first, the loss of interest – barring artifact – strongly suggests that the baby is coming to recognize the stimulus. Presumably, the baby is comparing each new stimulus presentation with a memory, or mental representation of the study stimulus based on previous exposures. A recovery in attention to a novel or test stimulus following familiarization necessarily indicates differential treatment of study from test stimuli based on prior study experience. Once habituation is complete, the study stimulus and a new or test stimulus is presented. If the baby looks more at the test than at the study stimulus, researchers infer that the baby has recognized the study stimulus and so in some rudimentary and unspecified way has remembered something about the study stimulus. That is, a low level of looking ay the study stimulus on retest is usually interpreted as recognition, or memory of the study stimulus on retest is usually interpreted as recognition, or memory of the study stimulus, whereas recovery of looking at the study stimulus is interpreted as forgetting. Strictly speaking, however, if the baby regards the test and the study stimuli equally, researchers cannot assume that the baby failed to remember. Instead, the infant may simply find the familiar stimulus as interesting as the novel stimulus. Because “ interestingness” is determined by many factors (other than novelty), the absence of recovery is always difficult to interpret (Reder, 1996). Habituation and novelty responsiveness are taken to involve development of both mental representation and memory, and students of infancy have transformed the two paradigms into versatile and powerful tools with which to investigate the ontogeny of memory (Woll, 2002). Using habituation, for example, it is possible to track the rate at which a stimulus is encoded; presumably, faster habituation is an index of quicker encoding. It is also possible to monitor the course of mental construction because one can “probe” during habituation for discrimination to assess the ongoing development or consolidation of memory structures. By habituating or familiarizing infants and testing them immediately afterward with the same stimulus, it is also possible to study short-term recognition memory, just as it is possible to impose a delay between habituation and a later test in order to assess long-term recognition memory. Similarly, a “savings method” that compares the rate of habituation to a stimulus at one time with habituation to the same stimulus but at a later time can be used to assess short or long-term retention of a stimulus depending on the length of time between the two tests. Lastly, an approach designed to tap into infant recognition memory involves a variety of operant conditioning techniques. This paradigm is particularly useful with very young infants who have not yet developed fine-motor control and manual search skills (Lamb et al., 2002). Summary and Conclusions Attention and memory are intricately related, although in the context of studying infants and children, these abilities are often difficult to disentangle experimentally. As should be evident, there is some similarity between the time course for the development of attentional abilities, and for memorial abilities. It is unclear whether this similarity is due to development of those neural abilities. It is not clear whether this similarity is due to development of those neural systems that support attention and memory coming online at the same times, or is an artifact of our methods for studying both behavioral and neurological development. Regarding the former, it is entirely possible that the neural systems involved in, for example, vigilance, happen to develop on the same time scale as those that are involved in the development of explicit memory. Accordingly, it would appear that both vigilance and explicit memory come online together. On the other hand, our methods for studying memory development, particularly in the earliest portions of the life span, are severely limited. As a result, it is also possible that the crudeness of our methods contributes most to our observations about similarities in developmental course. Clearly, then, developmental science would profit from expanding the methodological armamentarium for studying memory (Richards, 1998). List of References: (2000) Progress in Infancy Research, Mahwah, New Jersey, Lawrence Erlbaum Associates. BAUER, P. J. (2006) Remembering the Times of Our Lives: Memory in Infancy And Beyond, London and New York, Routledge. BORNSTEIN, M. H. (2003) Well-Being: Positive Development Across the Life Course, Mahwah, New Jersey, Lawrence Erlbaum Associates. CHEN, Z. & SIEGLER, R. S. (2000) Across the Great Divide: Bridging the Gap Between Understanding of Toddlers Michigan, US, Blackwell Publishing. COWAN, N. (1997) The Development of Memory in Childhood, New York, Psychology Press. LAMB, M. E., BORNSTEIN, M. H. & TETI, D. M. (2002) Development in Infancy: An Introduction, Mahwah, New Jersey, Lawrence Erlbaum Associates. NOVAK, G. & PELAEZ, M. B. (2004) Child and Adolescent Development: A Behavioral Systems Approach, New York, SAGE. REDER, L. M. (1996) Implicit Memory and Metacognition, Mahwah, New Jersey, Lawrence Erlbaum Associates. RICHARDS, J. E. (1998) Cognitive Neuroscience of Attention: A Developmental Perspective, Mahwah, New Jersey, Lawrence Erlbaum Associates. WOLL, S. (2002) Everyday Thinking: Memory, Reasoning, and Judgment in the Real World, Mahwah, New Jersey, Lawrence Erlbaum Associates.  Read More