Removal of epileptically compromised tissue in the frontal cortex restores oculomotor selection in the antisaccade task

The frontal cortex is heavily involved in oculomotor selection. Here, we investigated the neural correlates of eye movement selection during an antisaccade task in a young epileptic patient in whom the seizure focus included the frontal cortex and affected its function. Before resection surgery, the patient had difficulty in performing correct antisaccades towards the visual field contralateral to the seizure focus. Because the FEF is the only area in the human frontal cortex that is known to have a lateralized oculomotor function in the antisaccade task, this behavioural imbalance between the two visual fields suggests a disruption of FEF functioning by the nearby seizure focus. Electrocorticographic recordings at the seizure focus indeed showed that the seizure focus interfered with correct antisaccade performance. These results were in line with fMRI recordings revealing less task-related frontal activity for the hemisphere of the seizure focus, possibly reflecting diminished top-down engagement of the oculomotor system. Two months after removal of the compromised tissue, the seizures had disappeared, and antisaccade performance was the same for both visual hemifields. We conclude that a seizure focus in the frontal cortex can induce a dysfunction in the selection of eye movements, which is resolved after removal of interfering tissue.     

Observer-Relative Chances In Anthropic Reasoning?

John Leslie presents a thought experiment to show that chances are sometimes observer-relative in a paradoxical way. The pivotal assumption in his argument – a version of the weak anthropic principle – is the same as the one used to get the disturbing Doomsday argument off the ground. I show that Leslie's thought experiment trades on the sense/reference ambiguity and is fallacious. I then describe a related case where chances are observer-relative in an interesting way. But not in a paradoxical way. The result can be generalized: At least for a very wide range of cases, the weak anthropic principle does not giverise to paradoxical observer-relative chances. This finding could be taken to give new indirect support to the doomsday argument.     

Toward a Connectionist Model of Recursion in Human Linguistic Performance

Naturally occurring speech contains only a limited amount of complex recursive structure, and this is reflected in the empirically documented difficulties that people experience when processing such structures. We present a connectionist model of human performance in processing recursive language structures. The model is trained on simple artificial languages. We find that the qualitative performance profile of the model matches human behavior, both on the relative difficulty of center-embedding and cross-dependency, and between the processing of these complex recursive structures and right-branching recursive constructions. We analyze how these differences in performance are reflected in the internal representations of the model by performing discriminant analyses on these representations both before and after training. Furthermore, we show how a network trained to process recursive structures can also generate such structures in a probabilistic fashion. This work suggests a novel explanation of people's limited recursive performance, without assuming the existence of a mentally represented competence grammar allowing unbounded recursion.     

Conspiracist beliefs,intuitive thinking,and schizotypal facets: A further evaluation

This study examined whether thinking style mediated relationships between belief in conspiracy and schizotypy facets. A UK-based sample of 421 respondents completed the Generic Conspiracist Beliefs Scale (GCBS), Oxford-Liverpool Inventory of Feelings and Experiences Short (O-Life), and measures indexing preferential thinking style (proneness to reality testing deficits and Need for Cognition). Path analysis revealed direct and indirect relationships between Conspiracy Beliefs and schizotypy facets. Unusual Experiences had a direct effect on Conspiracy Beliefs and predicted Reality Testing and Need for Cognition. Preferential thinking style mediated the schizotypy-belief in conspiracy relationship. This pattern of results (higher experiential-based processing and lower Need for Cognition) was consistent with intuitive thinking. Introverted Anhedonia and Impulsive Nonconformity predicted Reality Testing and had indirect effects on Conspiracy Beliefs. Finally, Reality Testing predicted Conspiracy Beliefs, whereas Need for Cognition did not. These results confirm that cognitive processes related to thinking style mediate the schizotypy-conspiracist beliefs relationship.