We aimed to clarify the importance of early visual processing deficits for the formation of cognitive deficits in the schizophrenia spectrum. We carried out an event-related potential (ERP) study using a computerised delayed matching to sample working memory (WM) task on a sample of volunteers with high and low scores on the Schizotypal…

I investigate how and whether a heterogeneous group of first-year university mathematics students in South Africa harness the potential power of a computer algebra system (CAS) when doing a specific mathematics task. In order to do this, I develop a framework for deconstructing a mathematics task requiring the use of CAS, into its primary…

Source monitoring is made difficult when the similarity between candidate sources increases. The current work examines how individual differences in social intelligence and perspective-taking abilities serve to increase source similarity and thus negatively impact source memory. Strangers first engaged in a cooperative storytelling task. On each…

The neural correlates of recollection were examined using event-related functional MRI. We examined how the presence of different visual context information during encoding of target words influenced later recollection for the words presented alone at retrieval. Participants studied words presented with different pictures of faces or scrambled…

Set shifting provokes specific alterations of cerebral hemodynamics in basal cerebral arteries. However, no gender differences have been reported. In the following functional transcranial Doppler study, we introduced cerebral hemodynamic modulation to the aspects of set shifting during Wisconsin Card Sorting Test (WCST). Twenty-one subjects…

As literate adults, we appreciate numerical values as abstract entities that can be represented by a numeral, a word, a number of lines on a scorecard, or a sequence of chimes from a clock. This abstract, notation-independent appreciation of numbers develops gradually over the first several years of life. Here, using functional magnetic resonance…

Evidence from neuropsychology suggests that the distinction between animate and inanimate kinds is fundamental to human cognition. Previous neuroimaging studies have reported that viewing animate objects activates ventrolateral visual brain regions, whereas inanimate objects activate ventromedial regions. However, these studies have typically…

When rapidly switching between two tasks, bivalent stimuli can accidentally trigger the previously executed and therefore still activated response. Recently, it has been suggested that behavioral response-repetition effects reflect response inhibition that reduces the risk of such erroneous response repetitions. The present study investigated…

Task-cueing studies suggest that the updating of sensory and task representations both contribute to behavioral task-switch costs [Forstmann, B. U., Brass, M., & Koch, I. (2007). "Methodological and empirical issues when dissociating cue-related from task-related processes in the explicit task-cuing procedure." "Psychological Research, 71"(4),…

The acquisition of volitional control depends, in part, on developing the ability to countermand a planned action. Many tasks have been used to tap the efficiency of this process, but few studies have investigated how it may be modulated by participants' motivation. Multiple mechanisms may be involved in the deliberate exercise of caution when…

The current study examined basic cognitive abilities that are related to or included in the concept of working memory (WM): different WM components, three executive functions, simple short-term storage (STM), and sustained attention. Tasks were selected from well-established models and balanced in terms of content. The predictive power of storage…

We conducted three experiments to study the role of instrumental (e.g. "knife-bread") and categorical (e.g. "cake-bread") relations in the development of conceptual organization with a priming paradigm, by varying the nature of the task (naming--Experiment 1--or categorical decision--Experiments 2 and 3). The participants were 5-, 7- and…

Categorical perception (CP) is said to occur when a continuum of equally spaced physical changes is perceived as unequally spaced as a function of category membership (Harnad, S. (Ed.) (1987). Psychophysical and cognitive aspects of categorical perception: A critical overview. Cambridge: Cambridge University Press). A common suggestion is that CP…

This study extends Duff and Hampson's [Duff, S., & Hampson, E. (2001). A sex difference on a novel spatial working memory task in humans. "Brain and Cognition, 47," 470-493] finding of a sex-related difference in favor of females for an object location memory task. Twenty female and 20 male undergraduate students performed both manual and…

New granule cells are born throughout life in the dentate gyrus of the hippocampal formation. Given the fundamental role of the hippocampus in processes underlying certain forms of learning and memory, it has been speculated that newborn granule cells contribute to cognition. However, previous strategies aiming to causally link newborn neurons…