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Josef Perner

Publications and source records attributed to Josef Perner.

10 recordsLinked to original sources
PubMed2005

Do visual perspective tasks need theory of mind?

Reviews [Frith, U., Frith, C.D., 2003. Development and neurophysiology of mentalising. Philos. Trans. R. Soc., B 358, 685-694.] of several imaging studies report robust involvement of medial prefrontal cortex (MPFC) in "theory of mind" (ToM) tasks. Surprisingly, this activation is notably absent when judging another person's visual perspective [Vogeley, K., May, M., Ritzl, A., Falkai, P., Zilles, K., Fink, G.R., 2004. Neural correlates of first-person perspective as one constituent of human self-consciousness. J. Cogn. Neurosci. 16, 817-827.]. The objective of our study was to see whether this activation can be recovered when the difference between what observers see is clearly one of perspectives (in front vs. behind) and not potentially a difference in what observers are looking at. Despite this change, there was still no apparent activation of MPFC. We did find activation in the temporo-parietal junction (TPJ) recently emphasized as centrally involved in processing false belief stories [Saxe, R., Kanwisher, N., 2003. People thinking about thinking people: The role of the temporo-parietal junction in "theory of mind". NeuroImage 19, 1835-1842.], which also create a stark contrast of perspectives. By integrating extant neurophysiological evidence on theory of mind processing, we suggest that the dorsal part of the TPJ region is responsible for representing perspective differences and making behavioral predictions, while the more ventral part of TPJ and the MPFC region is responsible for predicting behavioral consequences and the MPFC also emotional consequences of mental states.

Adult↗
PubMed2005

Dissociating size representation for action and for conscious judgment: Grasping visual illusions without apparent obstacles.

Visual illusions provide important evidence for the co-existence of unconscious and conscious representations. Objects surrounded by other figures (e.g., a disc surrounded by smaller or larger rings, Ebbinghaus/Titchener illusion) are consciously perceived as different in size, while the visuo-motor system supposedly uses an unconscious representation of the discs' true size for grip size scaling. Recent evidence suggests other factors than represented size, e.g., surrounding rings conceived as obstacles, affect grip size. Use of the diagonal illusion avoids visual obstacles in the path of the reaching hand. Results support the dual representation theory. Grip size scaling follows actual size independent of illusory effects, which clearly bias conscious perception in direct comparisons of lengths (Experiment 1) and in finger-thumb span indications of perceived length (Experiment 2).

Adult↗
PubMed2005

Disentangling dimensions in the dimensional change card-sorting task.

The dimensional change card-sorting task (DCCS task) is frequently used to assess young children's executive abilities. However, the source of children's difficulty with this task is still under debate. In the standard DCCS task, children have to sort, for example, test cards with a red cherry or a blue banana into two boxes marked with target cards showing a blue cherry and a red banana. Typically, 3-year-olds have severe problems switching from sorting by one dimension (e.g. color) to sorting by the other dimension (e.g. shape). Three experiments with 3- to 4-year-olds showed that separating the two dimensions as properties of a single object, and having them characterize two different objects (e.g. by displaying an outline of a cherry next to a red filled circle on the card) improves performance considerably. Results are discussed in relation to a number of alternative explanations for 3-year-olds' difficulty with the DCCS task.

Child Behavior↗
PubMed2003

Developmental aspects of consciousness: how much theory of mind do you need to be consciously aware?

When do children become consciously aware of events in the world? Five possible strategies are considered for their usefulness in determining the age in question. Three of these strategies ask when children show signs of engaging in activities for which conscious awareness seems necessary in adults (verbal communication, executive control, explicit memory), and two of the strategies consider when children have the ability to have the minimal form of higher-order thought necessary for access consciousness and phenomenal consciousness, respectively. The tentative answer to the guiding question is that children become consciously aware between 12 and 15 months (+/-3 months).

Awareness↗
PubMed2001

The Disjunction Effect: Does It Exist for Two-Step Gambles?

One of the basic axioms of the rational theory of decision under uncertainty is Savage's (1954) Sure Thing Principle. It states that if Prospect x is preferred to Prospect y knowing that Event A occurred, and if x is preferred to y knowing that A did not occur, then x should also be preferred to y when it is not known whether A occurred. Tversky and Shafir (1992) claim to have demonstrated a violation of this principle in two-step gambles, which is termed a disjunction effect. The present article evaluates the replicability of the disjunction effect for two-step gambles. The findings show that people do not violate the sure thing principle in repeated gambles. The validity of alleged violations in other paradigms is discussed. Copyright 2001 Academic Press.

Journal Article↗
PubMedDate not supplied

Training transfer between card sorting and false belief understanding: helping children apply conflicting descriptions.

Two studies investigated the parallel developmental progress in theory of mind and executive control, as exemplified by correlations between the Dimensional Change Card Sorting task (DCCS; Frye, Zelazo, & Palfai, 1995) and the false-belief task. Experiment 1 with sixty 3-year-old children confirmed earlier studies (e.g., Perner & Lang, 2002), suggesting that children's problem with the DCCS lies in the redescription of stimulus objects. Experiment 2 with forty-four 3- to 4-year-olds reinforced the correlational evidence for a developmental link by showing transfer of training: False-belief training improved DCCS performance, and DCCS training significantly increased children's performance on the false-belief task. Results are discussed in relation to 5 theories explaining the existing correlational evidence.

Awareness↗
PubMedDate not supplied

Theory of mind and self-control: more than a common problem of inhibition.

This study tested the theory that advances on theory-of-mind tasks and on executive function tasks show a strong correlation because the typically used theory-of-mind tasks pose the same executive demands. In Experiment 1 with fifty-six 3- to 6-year-old children, performance on the dimensional change card-sorting task as an executive function task was correlated with performance on the usual false-belief prediction task, r = .65, and the false-belief explanation task, r = .65, as measures of theory-of-mind development. Because the explanation version of the false-belief test is supposed to be free of the alleged executive demands inherent in the prediction version, the equally strong correlation with the executive function task suggests that this correlation cannot be due to common executive demands. In Experiment 2, the basic finding of Experiment 1 was replicated on another sample of 73 children, ages 3 to 5.5 years. The need for new theories to explain the developmental link between theory of mind and executive function development is discussed, and some existing candidates are evaluated.

Child↗
PubMedDate not supplied

Want that is understood well before say that, think that, and false belief: a test of de Villiers's linguistic determinism on German-speaking children.

Two experiments with 79 monolingual German speaking children between 2.5 and 4.5 years showed a consistent developmental gap between children's memory/inference of what someone wanted and what someone wrongly said or thought. For instance, when John is still playing and mother says, "John should be going to bed," more than 70% answered correctly that mother wanted John to go to bed. However, when mother said, "John is going to bed," about 70% answered wrongly that she thought/said that he was still playing. Correct answers emerged with the mastery of the false-belief task. In German, want sentences (about something to happen) obligatorily take the same grammatical that complement as say or think sentences. Therefore, the observed gap constrains de Villier's (1995) linguistic determinism, which claims that acquisition of the necessary grammatical structures for talking about the mind drives children's ability to think about the mind.

Child, Preschool↗