Study on the A Not B Error

Study on the A Not B ErrorAfter being dis pass overed by Jean Piaget in 1954 doggedness labours became i of the main instrument of investigating in cognitive development psychology, signly in children and later in like manner in non- kind-hearted animals. The intimately gon of these is the, so called, A- non-B task, which even after legion(predicate) years of inquiry compose elicits debates about its underlying mechanisms. This paper aims to submit a review of existent empirical data in regulate to fare app bent motions of who and wherefore founders the A- non-B illusion. The rootage section of the review will split up a theoretical sternground by describing the absolute task utilize by Piaget, the splendour of such(prenominal) experiments. This will provide a return picture of what the A-not-B flaw is. The devil following parts will focus on the misgivings of who makes the computer flaw and why, by an epitome of a hardened of classic experiments. Each study will be bearvas in scathe of its cultures, results, and what the imp practice of these findings is. The last part will include general conclusions assemble on studies analyses from previous parts. In cast to answer the unbeliefs stated in the review title, what is the A-not-B erroneous belief, who makes it, and why?, classic data will be analyzed in order to get hold what the best freighterdidates for definition of the mechanisms responsible for the error ar (in the classic A-not-B task). The al closely convincing possible activity will be chosen based on its explanatory power (can it explain most of the existing data?) and its relation to other approaches (can it incorporate other ideas?). topic of the book The Construction of Reality in the Child in 1954 attach the beginning of question on perseverative tasks in babes. The causality, Jean Piaget, described galore(postnominal) hide and seek games, invented in order to investigate the learning of pe rmanency of headings in childs and its changes in time. One of these games became adept of the most widely utilize to explore infant cognition, the A-not-B task. The classic example of its process involved a 9 and a half calendar month old child called Laurent. Piaget put him on a sofa and presented him with two covert covers, one on the right, and one on the left. Then, he dedicated his watch under the cover A, and discover Laurent lift the cover to retrieve the watch. After this hiding and want was restate several times, Piaget hid his watch under the cover B. Laurent watched this go through attentively, simply when given a choice searched back at the localisation of function A. As the author put it, at the moment the watch has dis come to the foreed under the prune B, he Laurent turns back toward coverlet A, and searches for the inclination under the screen. From this wrong choice, Piaget concluded that Laurent did not understand the independence of disapprove g lasss from his own actions on them. Since these initial results, the A-not-B error has been constantly studied and proven to be a material and universal phenomenon in gracious infancy. However, the underlying mechanisms atomic number 18 still being debated, why the error happens and what it means. What is extender, are the crucial elements of the task to produce the A-not-B error (metalworker, 1999). In the superior agency an infant sits in front of two hiding places that are highly like and separated by a small distance. mend the infant watches, an attractive object lens (for example a act as) is hidden in one of the holes, described as A. After a clasp (which can vary), the infant is allowed to search for the object by attain to one of the two hiding localisation principles. This hiding and seeking is repeated several times, after which the object is hidden again, but this time in billet B. Again, after a foil the infant searches for the object. In this tradition al method, 8 to 10 month old infants keep range back to the initial fix A, in that respectfore making the A-not-B error. More recent data suggests that there faculty be to a fault other measurable elements of the experiment, including posture of an infant, social context of utilisation, or who the soulfulness interacting with subjects is. Before proceeding to a more(prenominal) detailed analysis of existing A-not-B task data, the significance of such research will be apprisely described.Investigations of A-not-B task are important for a couple of reasons. Firstly, it provides a clear paradigm to explore the development of infant cognition, how it changes in time. More specifically, it allows investigation how contrary processes involved in finding the object interact (such as smell, discriminating arrangements, posture control, and motor prep). Secondly, it similarly allows comparative experiments when the task is administered to bloodless animals. such research a llow comparisons of cognitive abilities of different species and how these abilities might put on evolved from common ancestors. However, after many years of research there is still no consensus on what is the meaning of the error and what its developmental importance is.The question of what the A-not-B error is has already been answered. The next question is about who makes the error. An answer to this question will be approached by analyzing a selection of studies on the A-not-B tasks which investigated forgiving beings infants (Homo sapiens), rhesus monkeys (Macaca mulatta), and dogs (Canis lupus familiaris).The predominant group of participants checked on the A-not-B task are kind-hearted infants of different ages. diamond and Goldman-Rakic (1989) investigated extensively how the age of infants and the length of go mingled with observing and inquisitory exercises the commitment rate of the error. The data-based procedure was based on the original task, designed by Pia get. However, several ends were also introduced. Instead of sitting freely, infants were held sitting on their parents lap, prevented from turning or looking at the hiding attitude during the delay. Care was taken to ensure that the infant was observing the whole hiding process. In order to prevent opthalmic fixation on remunerate hiding location, the infants were distracted by the experimenter employment them and counting aloud. Correct returnes were rewarded by gaining the hidden object (an attractive toy). In a gaucherie of an incorrect try, the experimenter showed the right choice by show the object, but did not allow the infant to clench for it. Testing for A-not-B began at present after the infant runner uncovered a hidden toy from one of the hiding places. Different lengths of delays amongst hiding and searching were introduced to the procedure to check what the crucial time to commit the error was. The first introduced delay was a 2 second one. Most infants belo w 8-8.5 months of age make the A-not-B error at these or smaller delays, whereas totally one infant above 11 months did so. The second delay was 5 seconds. By 8.5 months only half of infants make the error at delays of 5 +/- 2 seconds. By 9.5 months half of the infants required delays greater than 5 seconds for the error to appear. The last experimental delay was 10 seconds, where no infant below 8.5 months had passed, whereas by 12 months the average delay needed to be longer than 10 seconds. An raise observation from this experiment is that infants who maintained opthalmic fixation on the correct hiding location also reached correctly, while those who shifted their gaze, failed to do so (performed at chance levels). Another interesting fact is that infants tried to correct themselves when they made the A-not-B error (but not in the youngest ages). To sum up, the A-not-B error occurs in human infants at delays of 2-5 seconds at 7.5-9 months, and at delays greater than 10 seconds after one year. These findings also are consistent with studies conducted by Gratch and Landers (1971) and Fox et al. (1979) which both comprise that infants of 8 months made the error at a delay of 3 seconds, as well as with a study by Millar and Watson (1979) which showed that infants of 6-8 months could vitiate the error when there was no delay, but committed it with delays as brief as 3 seconds. This last finding corresponds sousedly with diamond and Goldman-Rakic who base that infants of 8 months will succeed on A-not-B task if there is no delay, but that they will also fail at delays of 3 seconds.Diamond and Goldman-Rakic used the same procedure to investigate ten rhesus monkeys with anterior lesions in comparison to monkeys with different brain lesions (parential), and ones with brains intact. Only animals with the prefrontal lesions committed the A-not-B errors at different delay lengths. There was no significant going in performance between unoperated and parentia lly lesioned monkeys. Their age ranged from 2 to 6 years. At the delay of 2 seconds, all monkeys with prefrontal lesions committed the error. At the delay level of 5 second results were similar, all monkeys with prefrontal lesions committed the error. At the delay of 10 seconds the performance of prefrontal animals did not meet criteria for the error (such as at least one error in the change trial, the error at least once repeated during the same trial), on the button like human infants below 9 months. Behaviour of prefrontally damaged monkeys was famed to be very similar to that of human infants described before.The last research analyzed in order to provide an answer to the question of who commits the A-not-B error was conducted by Topl et al. (2009) on dogs, wolves, and human infants. In a series of experiments a behavioural analogy between human infants and dogs was strand. The goal of the research was to investigate the functional nature of dogs sensitivity to communicative cues in a comparative framework, by the use of the A-not-B task. In one of the experiments dogs were shown to be influenced by the communicative context in their perseverative erroneous searches for hidden objects at a previously repeatedly baited (with a toy) location A, even when they observed the object being hidden at a different location (B). Such results are highly similar to those found in human infants. The task involved looking for a hidden object that the dogs apothegm being hidden so-and-so one of two identical screens. The first phase consisted of the dog being allowed to repeatedly sustain the object (toy) from behind of the screens (location A). In the tribulation phase, the experimenter hid the toy behind the alternative screen B. Dogs managed to fetch the hidden object correctly in all screen A trials. The main result from the test phase is that dogs in the social-communicative trial (the hider attracted the dogs attention) committed the A-not-B error more often than animals in the non-communicative (hiding with experimenters back turned toward the dog) or non-social (experimenter stayed still while the object was moved between screen by another experimenter, not visible to the dog) translation. Additionally, animals in the non-social condition were significantly more successful than chance during the test phases. To sum up, the error was eliminated when the hiding events were not accompanied by communicative signals from experimenters. Dogs were shown to be influenced by the communicative context in their perseverative erroneous searches for hidden objects at the previously repeatedly baited location A, even when they observed the object being hidden at a different location B. Such results are highly similar to those found in human infants. Thus, the A-not-B error was proven to also exist in dogs.Naturally this analysis does not exhaust all existing research on perseverative tasks. However, the aim of this review is to focus on A-not-B error only, in its classic version designed by Piaget. Other species, investigated in different variants of perseverative error tasks, included chimpanzees (Pan troglodytes), Japanese macaques (Macaca fuscata), cotton-top tamarin monkeys (Saguinus oedipus) (Hauser, 1999), as well as magpies (Pica pica) (Gmez, 2005).After the data of who makes the A-not-B error was summarized, an analysis of the underlying mechanisms should follow, to answer the question of why the error is made. In literature different hypotheses are present. virtuoso of these include areas such as object permanence, memory deficits, information influence, immatureness of prefrontal cerebral cerebral cortex, and action oriented responses ( make).The first write up was provided by the author of the A-not-B task himself, based on his initial research on perseverative errors. Piaget attributed this error to a lack of conception of object permanence in human infants. In his view infants commit the error because th ey do not understand that an object come ons to exist even when out of sight. Their reach back to location A is therefore seen as an attempt to bring that object back to existence. This is the first, historical account statement, which has been disproved by various studies. For example, Baillargeon (1987) has shown that some young infants (3.5-4.5 months) might pay some understanding of object permanence. When watching possible (a screen rotating and fish fillet at a box behind it) and impossible events (a screen rotating as though there was no box behind it), infants looked longer at the impossible ones, which can be understood that they were not expecting them to happen. Similar results were also reported by Ahmed and Ruffman (1998), where infants who made the A-not-B error in search tasks looked significantly longer at impossible events than possible ones in a non-search version of the task. Such behaviours required a comprehension that when objects are out of sight, they ha tch to exist. Infants did not expect the object to be retrieved from a wrong place and therefore they had to understand in some sense where the object was real located. Such results call into question Piagets claims about the age at which object permanence emerges.An alternative explanation focused on memory as a factor responsible for the error occurrence. In her research, Diamond (1985) found that different delay lengths between hiding and object searching impact the rate of the error. Thus the conclusion was that the recall memory was ca exploitation the A-not-B error. However, such view was disputed by Butterworth (1977), who found that use of logical covers in hiding locations does not decrease the error rates, which is inconsistent with the recall hypothesis. Seeing an object underneath a cover should create no need of using the recall memory and lead to the error not being committed, which did not happen. This study also can be used to argue against the hypothesis that co mpetition between different kinds of memory is responsible for the error. Harris (1989 after Ahmed Ruffman, 1998) proposed that infants make the A-not-B error because of two memory traces in combination with poor attention. In this view, information about the object at location A is held in the long-run memory, whereas information about the object at virgin location B is kept in a weaker short-term memory. However, the fact that infants continue to make the error even when provided with clear cues of the object location (transparent covers), suggests that the underlying cause is not related to memory issues.Another classic explanation placed the touchyy on the encryption of information. Bjork and Cummings (1984) suggested that encoding at new location B requires more processing (is more complex) than encoding repeated location A because B must be lordly from A. Sophian and Wellman (1983) also referred to information selection, where prior information was mistakenly selected ov er the new information about location B because infants forgot current information (which relates potently to the short-term memory limitations) or because infants did not know that current information should take over. These findings again can be debated in light of the transparent covers study by Butterworth (1977) and the violation-of-expectations study by Ahmed and Ruffman (1998). With the use of transparent covers, encoding new information does not pose major cognitive challenge since the desired object is visible all the time. The proposition of infants not wise to(p) which information should precede is enough ambiguous in itself (what know means in this context, do adults know which information from their environment should be the most valid one?) and is additionally contradicted by the findings that infants look longer at unexpected retrieval of objects from old locations. Therefore, they be crap as though they know where the object is currently hidden.All of the hitherto presented hypotheses have met their nemesis data. At this point, two major explanations of the A-not-B error will be presented that yielded wider acceptance. One of them, support by neuropsychological literature, is the importance of the prefrontal cortex, especially its relation with perseverance and inhibition. The prefrontal cortex is an anterior part of the frontal lobes of the brain, which is often associated with planning behaviours, decision making, and moderating social behaviour. As Hauser (1999) states it, the act of perseveration (a repeated production of particular action or thought) often represents the consequence of a particular cognitive problem, related to inhibition. In order to prevent perseveration such mechanism is required to reject some alternatives while favouring others, which whitethorn involve activation of the prefrontal cortex (Kimberg et al., 1997). Infants, therefore, are highly sensitive to the commitment of the A-not-B error because of their immatur e prefrontal cortex. The research by Diamond and Goldman-Rakic (1989) provided the first evidence that A-not-B performance depends upon the integrity of the prefrontal cortex and that ripening of this region underlies improvements in the task performance in human infants between 7.5 and 12 months of age. Further support comes from other groups of subjects of this study. Monkeys with lesions in the prefrontal cortex also committed the error, whereas monkeys with brains left intact, managed to choose the correct location B. As the authors noticed, the A-not-B task performance of operated monkeys and 7.5-9 month old human infants was highly like (both groups made errors at delays of 2-5 seconds). This significance of the prefrontal cortex can be explained by analyzing two main abilities required for the error to occur, which depend upon the dorsolateral prefrontal cortex temporal separation and inhibition of dominant response (Diamond Goldman-Rakic, 1989). The A-not-B task requires subjects to relate two temporally separate events hiding cue and searching action. With no delay between hiding and searching even 7.5-9 month old human infants and prefrontally operated monkeys can manage to choose the correct location B. However, even when a brief delay (2-5 seconds) is introduced, they start to fail in object searching. Therefore, the aspect of delay plays a crucial berth in committing the A-not-B error. This disadvantage can be overcome when subjects are allowed to maintain visual fixation or body orientation towards the new location during the delay. A similar effect is created by a visible cue which systematically indicates the correct choice (for example a mark on one of the locations). Those two findings indicate a possible involvement of short and long-term memory in the process of committing the error. In the grammatical case of fixation on the correct choice, a representation of this choice does not have to be held in short-term memory, and in the case of learning an association between a landmark and a reward, the long-term memory is activated, guiding reaching behaviour accordingly. This brings back the argument about the role of memory in explaining the A-not-B error. The second ability stemming from the prefrontal cortex, the inhibition of dominant response, is mostly related to the act of reaching for the hidden object. In the A-not-B task subjects are first repeatedly awarded for reaching to location A, which leads to strengthening of this response. However, such conditioned object to reach to A must be inhibited in the test trial if the subject is to succeed and reach correctly to new location B. The fact that subjects reach back to location A even when they appear to know where the object is hidden (by looking there) or should know where the object is placed (transparent covers with visible toys), adds validity to the notion that inhibiting the conditioned response is difficult and that memory might not play a major role in explaining the error (the problem is not simply forgetting location of an object). regular when the object is hidden, human infants and operated monkeys will often immediately correct themselves if their initial reach was incorrect. It appears therefore that subjects know the object is hidden in location B but still cannot inhibit the initial response of reaching to the previously rewarded location A. However, human infants often look in the charge of the correct hiding place, even when simultaneously reaching to the wrong one. It seems that the act of reaching itself might cause troubles, which relates to the next major explanation of the A-not-B error.metalworker et al. (1999) advocated a change in theoretical debates on possible explanations of the A-not-B error. Their explanation focuses on performance and behaviour during the task, which is described as reaching to back-to-back locations in visual space. Errors are made by returning to an original location when the goal location had changed. Reaching to a place consists of a series of ordered steps, beginning with cognition (perceiving the target, forming a goal) and ending with action (selecting a motor pattern, forming a trajectory of the reach). The proposition states that the A-not-B error is in the main a reaching error, emerging from a directional bias to location A created by previous looking and reaching, and because the visual input ready(prenominal) to guide the reaching hand is insufficient to overcome the bias (similar covers close to each other, not fully developed reaching skills of 8 to 10 month old infants). Crucial to this hypothesis is the idea of a around-the-clock interaction between looking, reaching, and memory of previous reaches. In other words, it is important that there are two similar potential reaching targets and that infants have a history of repeatedly reaching to one of the locations. Results from experiments by Smith et al. experiments indicated that goal-directe d reaches of infants stem from complex interactions of visual input, direction of gaze, posture, and memory (therefore indicating strong context effects). Such a system is inclined towards perseveration since it creates the reach based on current visual input and memories of recent reaches. This bias will prevail whenever the new information input is highly similar to previous reach information or whenever the systems memory of previous reaches is strong. Such an effect could be described as a version of a previously analyzed information bias. These general processes of goal-directed reaching are not specific to a particular moment in development, which suggests that old children and even adults are prone to commit the A-not-B error if placed in the appropriate situation. For example, when no visual cues are given, like in the case of hiding objects in sand (Spencer et al., 1997 after Smith et al., 1999). However, if these processes are not specific to a sure age, why then a orig in in making the error is observed? Authors point to two developmental changes that can contribute to an answer increasing infants ability to discriminate among visually similar locations, and increasing skill in reaching. Although Smith et al. state that there is no discrepancy between their results and data from investigations of the role of the prefrontal cortex, they do not agree with the explanation placing emphasis on inhibition loser in this region of the brain. In such a view, infants reach successfully to the correct location not because a dominant habit to reach to A was inhibited, but because the current visual information biasing the system in the B direction is stronger than the previously conditioned action towards A. Therefore, direction of the infants reach depends on internal and external dynamics shaping the goal-directed action (outside stimuli and previous experience).The goal of this review was to answer the questions of what the classic A-not-B error is, who m akes it, and for what reasons. The answer to the first two is a straightforward one. In order to determine who makes the error, it is enough to administer the original procedure devised by Piaget to various subjects (with gauzy modifications if used with nonhuman animals). The question of why the error is committed has a more complex nature. A range of proposed explanations have been presented, along with an analysis of how valid these hypotheses are in light of existing empirical data. referable to limitations of space, the review has focused on presenting a summary of the main hypotheses object permanence, memory deficits, information bias, immaturity of prefrontal cortex, and goal-oriented reaching. The two latter deliver the largest explanatory power, as they incorporate or explain elements of other approaches. The most important difference between them is present in the definition of who can commit the error. In the neuropsychological approach only subjects with immature or a damaged neocortex will make the error, whereas in the reaching approach this error is not so limited. Another main difference concerns the concept of inhibition. Described as a main element of the influence of the neocortex on choosing the right location, it is removed completely from the reaching approach. However, certain similarities are also present, since the neuropsychological hypothesis includes the aspect of programming a goal-oriented reach. Considering these characteristics together, as the best candidate for an explanation of the A-not-B task the immaturity of the neocortex will be chosen. It can provide sufficient explanation for why human infants with immature prefrontal cortex, prefrontally damaged monkeys, and dogs make the error. In the case of the latter, the inhibition process might play the major part. Dogs committed the error mostly in the communicative experimental condition, which might suggest that overcoming a bias created that way is too difficult, inhib ition in the prefrontal cortex (which is often assumed to organize social behaviour) is too weak. Of possible importance is the domestication process, during which dogs were selected to respond to human communicative signals. In terms of Marrs levels of explanation (Humpreys et at., 1994), the prefrontal cortex could be described as planning behaviours in order to act appropriately in the world (computational level), by the use of inhibition processes (algorithmic level) on the neuronal networks (implementional level). Additional empirical data, obtained in order to validate the prefrontal cortex hypothesis, should include studies on infant rhesus monkeys and other infant species, as well as autistic human children (due to their lack of social skills which could be attributed to malfunctioning prefrontal cortex). A set of such data would allow comparisons with existing findings. Naturally, new research might bring a change of focus in mechanisms underlying the A-not-B error, as the issue of perseverative errors is a complex one and requires further investigation.