One hypothesis concerning the human dorsal anterior cingulate cortex (ACC) is that it functions, in part, to signal the occurrence of conflicts in information processing, thereby triggering compensatory adjustments in cognitive control. Since this idea was first proposed, a great deal of relevant empirical evidence has accrued. This evidence has largely corroborated the conflict-monitoring hypothesis, and some very recent work has provided striking new support for the theory. At the same time, other findings have posed specific challenges, especially concerning the (...) way the theory addresses the processing of errors. Recent research has also begun to shed light on the larger function of the ACC, suggesting some new possibilities concerning how conflict monitoring might fit into the cingulate's overall role in cognition and action. (shrink)

Anterior cingulate cortex (ACC) is a part of the brain's limbic system. Classically, this region has been related to affect, on the basis of lesion studies in humans and in animals. In the late 1980s, neuroimaging research indicated that ACC was active in many studies of cognition. The findings from EEG studies of a focal area of negativity in scalp electrodes following an error response led to the idea that ACC might be the brain's error detection and correction device. In (...) this article, these various findings are reviewed in relation to the idea that ACC is a part of a circuit involved in a form of attention that serves to regulate both cognitive and emotional processing. Neuroimaging studies showing that separate areas of ACC are involved in cognition and emotion are discussed and related to results showing that the error negativity is influenced by affect and motivation. In addition, the development of the emotional and cognitive roles of ACC are discussed, and how the success of this regulation in controlling responses might be correlated with cingulate size. Finally, some theories are considered about how the different subdivisions of ACC might interact with other cortical structures as a part of the circuits involved in the regulation of mental and emotional activity. (shrink)

Children tend to extend object names on the basis of sameness of shape, rather than size, color, or materialFa tendency that has been dubbed the ‘‘shape bias.’’ Is the shape bias the result of well-learned associations between words and objects? Or does it exist because of a general belief that shape is a good indicator of object category membership? The present three studies addressed this debate by exploring whether the shape bias is specific to naming. In Study 1, 3-year-olds showed (...) the shape bias both when asked to extend a novel name and when asked to select an object of the same kind as a target object. Study 2 found the same shape bias when children were asked to generalize properties relevant to category membership. Study 3 replicated the findings from Study 1 with 2-year-olds. These findings suggest that the shape bias derives from children’s beliefs about object kinds and is not the product of associative learning. (shrink)

This is a book about how we see: the environment around us (its surfaces, their layout, and their colors and textures); where we are in the environment; whether or not we are moving and, if we are, where we are going; what things are good for; how to do things (to thread a needle or drive an automobile); or why things look as they do.The basic assumption is that vision depends on the eye which is connected to the brain. The (...) author suggests that natural vision depends on the eyes in the head on a body supported by the ground, the brain being only the central organ of a complete visual system. When no constraints are put on the visual system, people look around, walk up to something interesting and move around it so as to see it from all sides, and go from one vista to another. That is natural vision—and what this book is about. (shrink)

Using an explicit task cuing paradigm, we tested whether masked cues can trigger task-set activation, which would suggest that unconsciously presented stimuli can impact cognitive control processes. Based on a critical assessment of previous findings on the priming of task-set activation, we present two experiments with a new method to approach this subject. Instead of using a prime, we varied the visibility of the cue. These cues either directly signaled particular tasks in Experiment 1, or certain task transitions in Experiment (...) 2. While both masked task and transition cues affected task choice, only task cues affected the speed of task performance. This observation suggests that task-specific stimulus–response rules can be activated only by masked cues that are uniquely associated with a particular task. Taken together, these results demonstrate that unconsciously presented stimuli have the power to activate corresponding task sets. (shrink)

The results of four experiments provide evidence for controlled processing in the absence of awareness. Participants identified the colour of a neutral distracter word. Each of four words was presented in one of the four colours 75% of the time or 50% of the time . Colour identification was faster when the words appeared in the colour they were most often presented in relative to when they appeared in another colour, even for participants who were subjectively unaware of any contingencies (...) between the words and the colours. An analysis of sequence effects showed that participants who were unaware of the relation between distracter words and colours nonetheless controlled the impact of the word on performance depending on the nature of the previous trial. A block analysis of contingency-unaware participants revealed that contingencies were learned rapidly in the first block of trials. Experiment 3 showed that the contingency effect does not depend on the level of awareness, thus ruling out explicit strategy accounts. Finally, Experiment 4 showed that the contingency effect results from behavioural control and not from semantic association or stimulus familiarity. These results thus provide evidence for implicit control. (shrink)

The Stroop effect is composed of interference and facilitation effects. The facilitation is less stable and thus many times is referred to as a “fragile effect”. Here we suggest the facilitation effect is highly vulnerable to individual differences in control over the task conflict . We replicated previous findings of a significant correlation between stop-signal reaction time and Stroop interference, and also found a significant correlation between SSRT and the Stroop facilitation effect—participants with low inhibitory control had no facilitation effect (...) or even a reversed one. These results shed new light on the “fragile” facilitation effect and highlight the necessity of awareness of task conflict, especially in the Stroop task. (shrink)