“John thinks that Mary thinks that…” attribution of second-order beliefs by 5- to 10-year-old children

Understanding of second-order belief structures by 5- and 10-year-old children was assessed in acted stories in which two characters (John and Mary) were independently informed about an object's (ice-cream van's) unexpected transfer to a new location. Hence both John and Mary knew where the van was but there was a mistake in John's second-order belief about Mary's belief: “John thinks Mary thinks the van is still at the old place”. Children's understanding of this second-order belief was tested by asking “Where does John think Mary will go for ice cream?” Correct answers could only be given if John's second-order belief was represented, since all shortcut reasoning based on first-order beliefs would have led to the wrong answer. Results suggested unexpected early competence around the age of 6 and 7 years, shown under optimal conditions when inference of second-order beliefs was prompted.     

Optic aphasia, optic apraxia, and loss of dreaming

A 47-year-old man with a left temporo-occipital infarct in the area of the posterior cerebral artery is presented. The neuropsychological examination did not reveal aphasia or gross mental deficits. The patient presented with alexia without agraphia, color agnosia, but few visual perceptual deficits. The main impairment was in confrontation naming; he was incapable of naming objects and pictures, not from lack of recognition (excluding visual agnosia) but from lack of access to the appropriate word (optic aphasia). The patient also exhibited a deficit in the evocation of gesture from the visual presentation of an object (optic apraxia) and a difficulty in "conjuring up" visual images of objects (impaired visual imagery) and loss of dreams. The fundamental deficit of this patient is tentatively explained in terms of visuoverbal and visuogestural disconnection and a deficit of mental imagery.     

Integrating velocity,time, and distance information: A developmental study

The development of understanding the relationships between velocity, time, and distance was investigated in three tasks. In each task, values of two dimensions were given, and 5-year-olds, 10-year-olds, and adults had to infer values of the third dimension. These inferences were made in all age groups. The integration rules were found to depend upon age and task. In the distance = time × velocity task, all age groups obeyed the normative multiplication rule. In the time = distance ÷ velocity task, the two older age groups obeyed the normative division rule, but the 5-year-olds shifted to a simpler subtraction rule. In the velocity = distance ÷ time task, which was the most difficult, the two older age groups simplified to use of a subtraction rule, and the 5-year-olds simplified even further to use of a distance-only rule. The knowledge level revealed for young children contrasts sharply with results from previous studies using Piagetian choice tasks, which apparently investigate selective attention to one dimension rather than conceptual understanding of relations.     

Postdecisional preference for decision-relevant information as a function of the competence of its source and the degree of familiarity with this information

Three experiments are reported concerning the determinants of postdecisional preferences for decision-relevant information. Two factors were considered: the competence of the source of the information and the degree of prior familiarity with the contents of the information. The first two experiments showed that the competence of the source of decision-supporting information affected the desirability of reading both types of information, whereas the competence of the source of decision-opposing information had very little effect on the desirability of reading either type. In the third experiment, the effects of giving subjects access to prior information supporting or opposing their view on their preferences for further information were investigated under conditions in which the number of choices of this later information were either limited or unlimited. The effects of prior information on choices of decision-supporting information were identical regardless of whether the total amount of information available was limited or unlimited: Less decision-supporting information was chosen when subjects had previously been exposed to decision-supporting information than when they had not, and this difference was greater when they had not previously been exposed to decision-opposing information. However, the choices of decision-opposing information under unlimited choice conditions increased with the amount of decision-supporting information previously read, but decreased with the amount of decision-opposing information previously read. The processes that underlie the choices of information under conditions in which several types are available are discussed.     

Beliefs about beliefs: representation and constraining function of wrong beliefs in young children's understanding of deception

Understanding of another person's wrong belief requires explicit representation of the wrongness of this person's belief in relation to one's own knowledge. Three to nine year old children's understanding of two sketches was tested. In each sketch subjects observed how a protagonist put an object into a location x and then witnessed that in the absence of the protagonist the object was transferred from x to location y. Since this transfer came as a surprise they had to assume that the protagonist still believed that the object was in x. Subjects had to indicate where the protagonist will look for the object at his return. None of the 3–4-year old, 57% of 4–6-year old, and 86% of 6–9-year old children pointed correctly to location x in both sketches. Of the many cases where 4–6-year olds made an error they failed in only about 20% to remember the initial location correctly. As a test of the stability of children's representation of the protagonist's wrong belief the sketches continued with a statement about the protagonist's intention to either deceive an antagonist or truthfully inform a friend about the object's location. Independent of age, of those children who correctly thought that the protagonist would search in x, 85% of the time they also correctly thought that he would direct his antagonist to location y and his friend to location x. This shows that once children can represent a person's beliefs they can constrain their interpretation of this person's stated intentions to the person's beliefs. In a more story-like situation another group of children had to infer a deceptive plan from the depiction of a goal conflict between two story characters and one character's expedient utterance. At the age of 4–5 years children correctly judged this utterance as a lie only 28% of the time while 5–6-year olds did so 94% of the time. These results suggest that around the ages of 4 to 6 years the ability to represent the relationship between two or more person's epistemic states emerges and becomes firmly established.     

A characterization of stochastic independence by association,with an application to random utility theory

A characterization of stochastic independence in terms of association of random variables is given. The result is applied to yield a simple proof of the Sattath-Tversky inequality without continuity assumptions.     

Experimentally induced phonological paraphasias.

A motor aphasic patient had to repeat word lists that contained, among other things, words with the sequences r - r - l and l - l - r. These sequences were often repeated as l - r - l (anticipatory distant assimilation) and r - l - r (same type, but less frequently), respectively. These assimilations violate the cross-over constraint (or relevancy condition or adjacency principle) and thus represent another instance of a flagrant contradiction between pathological and normal (natural) phonological processes.     

The short-term storage as a buffer memory between long-term storage and the motor system: A simultaneous-processing model

It is assumed that in a free-recall task the short-term store serves as a memory buffer between the long-term store and a final motor stage of word production. Because of this the retrieval process in long-term store is not hindered by the final motor stage of word production since continued output from the long-term store queues in the buffer for motoric processing. Otherwise a time consuming communication between the two processes would be necessary. A stochastic model of this conceptualization is provided to predict the temporal course of free recall as well as a paradigm in which the contribution of the short-term store in free recall can be studied. The experimental results from this paradigm were used to test the model and to estimate short-term storage capacity on the basis of the time course of free recall. The model predictions were in good agreement with the data and the capacity estimate coincides well with estimates found by totally different methods reported in the literature.     

The effect of negative feedback about oneself and cost of information on preferences for information about the source of this feedback

The present paper reports an experiment in which different amounts of negative self-discrepant information were induced and its effects on information seeking were tested. In addition, the monetary cost of the information available was manipulated. Subjects received fictitious intelligence test results that were negatively discrepant from their self-evaluation. They were then given the opportunity to choose among several articles containing information that either derogated intelligence tests (test-disparaging information) or argued for their validity (test-supporting information). The relative preference for test-disparaging over test-supporting information increased with feedback discrepancy up to a point, but then decreased as this discrepancy became more extreme. The relative preference in reading desirability for test-disparaging over test-supporting articles was also higher when the information cost money than when it did not. In addition, the difference between the desire for the two types of information was greater under cost than under no cost conditions, particularly at the extreme levels of feedback discrepancy.