Max coltheart

INTRODUCTION: Koro is a delusion whereby a man believes his penis is shrinking into his abdomen and this may result in his death. This socially-transmitted non-neuropsychological delusional belief occurs (in epidemic form) in South-East and South Asia. We investigated whether the two-factor theory of delusion could be applied to epidemic Koro. METHODS: We scrutinised the literature on epidemic Koro to isolate features relevant to the two questions that must be answered to provide a two-factor account: What could initially prompt the Koro delusional hypothesis? Why is this hypothesis adopted as a belief? RESULTS: We concluded that the Koro hypothesis is usually prompted by the surprising observation of actual penis shrinkage-but only if the man has access to background beliefs about Koro...

INTRODUCTION: Cotard delusion-the delusional belief "I am dead"-is named after the French psychiatrist who first described it: Jules Cotard. Ramachandran and Blakeslee proposed that the idea "I am dead" comes to mind when a neuropathological condition has resulted in complete abolition of emotional responsivity to the world. The idea would arise as a putative explanation: if "I am dead" were true, there would be no emotional responsivity to the world. METHODS: We scrutinised the literature on people who expressed the delusional belief "I am dead", looking for data on whether such patients are reported as entirely lacking in emotional responsivity...

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INTRODUCTION: Capgras delusion is sometimes defined as believing that close relatives have been replaced by strangers. But such replacement beliefs also occur in response to encountering an acquaintance, or the voice of a familiar person, or a pet, or some personal possession. All five scenarios involve believing something familiar has been replaced by something unfamiliar. METHODS: We evaluate the proposal that these five kinds of delusional belief should count as subtypes of the same delusion...

Tests of nonword reading have been instrumental in adjudicating between theories of reading and in assessing individuals' reading skill in educational and clinical practice. It is generally assumed that the way in which readers pronounce nonwords reflects their long-term knowledge of spelling-sound correspondences that exist in the writing system. The present study found considerable variability in how the same adults read the same 50 nonwords across five sessions. This variability was not all random: Nonwords that consisted of graphemes that had multiple possible pronunciations in English elicited more intraparticipant variation...

INTRODUCTION: In accounts of the two-factor theory of delusional belief, the second factor in this theory has been referred to only in the most general terms, as a failure in the processes of hypothesis evaluation, with no attempt to characterise those processes in any detail. Coltheart and Davies ([2021]. How unexpected observations lead to new beliefs: A Peircean pathway. Consciousness and Cognition , 87 , 103037. https://doi.org/10.1016/j.concog.2020.103037) attempted such a characterisation, proposing a detailed eight-step model of how unexpected observations lead to new beliefs based on the concept of abductive inference as introduced by Charles Sanders Peirce...

A key method for studying articulatory planning at different levels of phonological organization is masked-onset priming. In previous work using that paradigm the dependent variable has been acoustic response time (RT). We used electromagnetic articulography to measure articulatory RTs and the articulatory properties of speech gestures in non-word production in a masked-onset priming experiment. Initiation of articulation preceded acoustic response onset by 199 ms, but the acoustic lag varied by up to 63 ms, depending on the phonological structure of the target...

People acquire new beliefs in various ways. One of the most important of these is that new beliefs are acquired as a response to experiencing events that one did not expect. This involves a form of inference distinct from both deductive and inductive inference: abductive inference. The concept of abduction is due to the American pragmatist philosopher C. S. Peirce. Davies and Coltheart (in press) elucidated what Peirce meant by abduction, and identified two problems in his otherwise promising account requiring solution if that account were to become fully workable...

No abstract text is available yet for this article.

Loss of foveal vision with sparing of peripheral vision, as in macular degeneration, is often associated with visual hallucinations: it has been suggested that these occur because deafferentation of neurons in regions of visual cortex results in local neuronal hyperexcitability, and new evidence supports this hypothesis.

Surface dyslexia is characterised by poor reading of irregular words while nonword reading can be completely normal. Previous work has identified several theoretical possibilities for the underlying locus of impairment in surface dyslexia. In this study, we systematically investigated whether children with surface dyslexia showed different patterns of reading performance that could be traced back to different underlying levels of impairment. To do this, we tested 12 English readers, replicating previous work in Hebrew (Gvion & Friedmann, 2013; 2016; Friedmann & Lukov, 2008; Friedmann & Gvion, 2016)...

When the task is reading nonwords aloud, skilled adult readers are very variable in the responses they produce: a nonword can evoke as many as 24 different responses in a group of such readers. Why is nonword reading so variable? We analysed a large database of reading responses to nonwords, which documented that two factors contribute to this variability. The first factor is variability in graphemic parsing (the parsing of a letter string into its constituent graphemes): the same nonword can be graphemically parsed in different ways by different readers...

The self-teaching hypothesis describes how children progress toward skilled sight-word reading. It proposes that children do this via phonological recoding with assistance from contextual cues, to identify the target pronunciation for a novel letter string, and in so doing create an opportunity to self-teach new orthographic knowledge. We present a new computational implementation of self-teaching within the dual-route cascaded (DRC) model of reading aloud, and we explore how decoding and contextual cues can work together to enable accurate self-teaching under a variety of circumstances...

According to the Two-Factor theory of delusional belief (see e.g. Coltheart at al., 2011), there exists a cognitive system dedicated to the generation, evaluation, and acceptance or rejection of beliefs. Studies of the neuropsychology of delusion provide evidence that this system is neurally realized in right dorsolateral prefrontal cortex (rDLPFC). Furthermore, we have shown that convincing analogues of many specific delusional beliefs can be created in nonclinical subjects by hypnotic suggestion and we think of hypnosis as having the effect of temporarily interfering with the operation of the belief system, which allows acceptance of the delusional suggestions...

In English, the size of the regularity effect on word reading-aloud latency decreases across position of irregularity. This has been explained by a sublexical serially operating reading mechanism. It is unclear whether sublexical serial processing occurs in reading two-character kanji words aloud. To investigate this issue, we studied how the position of atypical character-to-sound correspondences influenced reading performance. When participants read inconsistent-atypical words aloud mixed randomly with nonwords, reading latencies of words with an inconsistent-atypical correspondence in the initial position were significantly longer than words with an inconsistent-atypical correspondence in the second position...

Previous studies have indicated that the relationship between magnocellular-dorsal (M-D) function and reading-related skills may vary with reading development in readers of alphabetic languages. Since this relationship could be affected by the orthographic depth of writing systems, the present study explored the relationship between M-D function and reading-related skills in Chinese, a writing system with a deeper orthography than alphabetic languages. Thirty-seven primary school students and fifty-one undergraduate students participated...

Approximately 30 years ago, Caramazza (1984. The logic of neuropsychological research and the problem of patient classification in aphasia. Brain and Language, 21, 9-20; 1986. On drawing inferences about the structure of normal cognitive systems from the analysis of patterns of impaired performance. Brain and Language, 5, 41-66) proposed that cognitive neuropsychology needs to make four assumptions in order for its inferences from pathological performance to the structure of intact cognitive systems to be justifiable...

In déjà vu, the feeling that what we are currently experiencing we have experienced before is fleeting and is not accepted as true. In contrast, in déjà vecu or "recollective confabulation", the sense of déjà vu is persistent and convincing, and patients genuinely believe that they have lived through the current moment at some previous time. In previous reports of cases of déjà vecu, both personal events and non-personal, world events gave rise to this experience. In this paper we describe a patient whose déjà vecu experiences are entirely restricted to non-personal events, suggesting that autobiographical and non-autobiographical episodic memory processing can dissociate...

BACKGROUND: Impaired ability to make inferences about what another person might think or feel (i.e., social cognition impairment) is recognised as a core feature of schizophrenia and a key determinant of the poor social functioning that characterizes this illness. The development of treatments to target social cognitive impairments as a causal factor of impaired functioning in schizophrenia is of high priority. In this study, we investigated the acceptability, feasibility, and limited efficacy of 2 programs targeted at specific domains of social cognition in schizophrenia: "SoCog" Mental-State Reasoning Training (SoCog-MSRT) and "SoCog" Emotion Recognition Training (SoCog-ERT)...

Confabulation is sometimes defined - by Berlyne, for example - as a symptom that is seen only in one neuropsychological condition, amnesia. In this paper I argue for a somewhat more liberal - and, I contend, more productive - conception of confabulation, according to which it is seen not only in amnesia but also in other neuropsychological conditions such as delusion - and, indeed, even in healthy people. I also argue that it follows from this that in neuropsychological conditions where confabulations are seen, these are responses to abnormal experiences brought about by brain damage, but the occurrence of confabulation itself need not be seen as due to any impairment of cognitive processes due to the brain damage...