- Email: [email protected]
Mis(t) information
Update Monitor Summaries of recently published papers of interest to cognitive scientists. Readers who would like to contribute to this section, by identifying appropriate papers and writing short summaries, should contact the Editor.
Mesmerizing waves A recent model of hypnosis proposed that this phenomenon could be induced by suppression of a frontal supervisory attentional system. Thus, subjects under hypnosis were conceived as having passed executive control to the hypnotist. Kaiser et al. have recently described the effects of hypnosis on subjects performing a Stroop-type task in which the subject had to press a left or
a right mouse button according to the colour and direction of an arrow on a VDU screen. If the arrow was green, the subject had to press the right-hand button when the arrow was pointing to the right, and the left button when the arrow was pointing to the left. If the arrow was red, the previous stimulus– response mapping was reversed and the subject had to respond with the right
button to an arrow pointing left and vice versa. As expected, subjects under hypnosis made more errors on the incongruent trials. Simultaneous recordings of event-related potentials indicated that these erroneous responses were accompanied by a normal early negativity waveform (100 ms after an error) and a reduced late positivity waveform (300 ms after an error) during hypnosis. These results are interpreted as a failure of context updating rather than a global loss of supervisory attention, and provide an interesting window into hypnotic states. Reference Kaiser, J. et al. (1997) Hypnosis and event-related potential correlates of error processing in a stroop-type paradigm: a test of the frontal hypothesis Int. J. Psychophysiol. 27, 215–222
Location, location, location Mis(t) A classical view of working memory is that this ability is used to maintain an active representation of information across a short time-delay. As such, it plays a critical role in many of the higher cognitive tasks, such as planning, that are believed to be associated with activity in the prefrontal cortex. Indeed, it has been postulated, on the basis of monkey studies, that there is a functional distinction between more dorsal areas of the prefrontal cortex, in and around the principal sulcus, and more ventral areas. The former areas appear to be largely concerned with spatial information while the more ventral areas are suggested to be involved with working memory for patterns, colours, objects and faces. In contrast, human neuroimaging studies have suggested that the spatial, verbal and visual information may activate a dorsolateral frontal region that would appear to be analogous to the dorsolateral area identified in monkeys. This
questions the location, and perhaps even the existence, of an area that is specialized for spatial working memory in man. Courtney et al. now report a possible resolution of this problem by proposing that the area specialized for spatial working memory is located more superior and posterior in humans, relative to its position in monkeys. In a complex study using fMRI with human subjects performing a variety of tasks, they suggest that the emergence of language could be related to the apparent displacement of functional areas in dorsal frontal cortex. This study might therefore have important theoretical implications for our understanding of the architecture of the prefrontal cortex and its functional parcellation. Reference Courtney, S.M. et al. (1998) An area specialized for working memory in human frontal cortex Science 279, 1347–1351
Monitor contributors for Trends in Cognitive Sciences A panel of monitor contributors assist the Editorial staff by suggesting appropriate articles and writing some of the short summaries that have appeared in this section of the journal. I would like to take this opportunity to express my sincere thanks for their efforts in providing an informative and imaginative addition to the journal. If you would like to contribute to Monitor, contact the Editor at [email protected]. Regular contributors receive a free subscription to the journal. Current panel members include: S. Bertolo N. George A. Grunewald S.R. Jackson E. Kaan I. McLaren
Cambridge, MA, USA London, UK Pasadena, CA, USA Bangor, UK Cambridge, MA, USA Cambridge, UK
A. Owen G. Rees M. Rushworth L. Wagner E. Wilding
Cambridge, UK London, UK Oxford, UK Philadelphia, PA, USA Oxford, UK
information Drivers in foggy conditions are frequently involved in accidents and are often ‘blamed’ for driving too fast for the weather conditions. But are these accidents solely caused by the recklessness of the drivers or are there other reasons? Clearly, when attempting to judge one’s speed during reduced visibility one is less likely to look away from the road to the speedometer as this might cause an accident in itself. This places an additional burden on the perceptual systems that can also provide clues to speed. Snowden, Stimpson and Ruddle have recently examined the ability of drivers to adjust their speed in a virtual environment that simulated the view from a car moving along a road. In one experiment they showed subjects two driving scenes, one with clear weather, the other with either clear or reduced visibility and calculated the speed at which the subjects reported that the two scenes appeared to be moving at the same speed. The results indicated that drivers perceived the foggy scene to be moving more slowly than the clear scene. In a second experiment the subjects were asked to try to match their speed to a target speed in a variety of weather conditions in a more realistic driving simulator involving a winding road, a steering wheel, and brake and accelerator pedals. Again, as the weather condition deteriorated the subjects drove faster. These results raise the question of the role of our perceptual systems in driver irresponsibility under poor visibility and may provide a test-bed for novel approaches to this problem. Reference Snowden, R.J., Stimpson, N. and Ruddle, R.A. (1998) Speed perception fogs up as visibility drops Nature 392, 450
Copyright © 1998, Elsevier Science Ltd. All rights reserved. 1364-6613/98/$19.00 Trends in Cognitive Sciences – Vol. 2, No. 5,
May 1998
167
Mesmerizing waves A recent model of hypnosis proposed that this phenomenon could be induced by suppression of a frontal supervisory attentional system. Thus, subjects under hypnosis were conceived as having passed executive control to the hypnotist. Kaiser et al. have recently described the effects of hypnosis on subjects performing a Stroop-type task in which the subject had to press a left or
a right mouse button according to the colour and direction of an arrow on a VDU screen. If the arrow was green, the subject had to press the right-hand button when the arrow was pointing to the right, and the left button when the arrow was pointing to the left. If the arrow was red, the previous stimulus– response mapping was reversed and the subject had to respond with the right
button to an arrow pointing left and vice versa. As expected, subjects under hypnosis made more errors on the incongruent trials. Simultaneous recordings of event-related potentials indicated that these erroneous responses were accompanied by a normal early negativity waveform (100 ms after an error) and a reduced late positivity waveform (300 ms after an error) during hypnosis. These results are interpreted as a failure of context updating rather than a global loss of supervisory attention, and provide an interesting window into hypnotic states. Reference Kaiser, J. et al. (1997) Hypnosis and event-related potential correlates of error processing in a stroop-type paradigm: a test of the frontal hypothesis Int. J. Psychophysiol. 27, 215–222
Location, location, location Mis(t) A classical view of working memory is that this ability is used to maintain an active representation of information across a short time-delay. As such, it plays a critical role in many of the higher cognitive tasks, such as planning, that are believed to be associated with activity in the prefrontal cortex. Indeed, it has been postulated, on the basis of monkey studies, that there is a functional distinction between more dorsal areas of the prefrontal cortex, in and around the principal sulcus, and more ventral areas. The former areas appear to be largely concerned with spatial information while the more ventral areas are suggested to be involved with working memory for patterns, colours, objects and faces. In contrast, human neuroimaging studies have suggested that the spatial, verbal and visual information may activate a dorsolateral frontal region that would appear to be analogous to the dorsolateral area identified in monkeys. This
questions the location, and perhaps even the existence, of an area that is specialized for spatial working memory in man. Courtney et al. now report a possible resolution of this problem by proposing that the area specialized for spatial working memory is located more superior and posterior in humans, relative to its position in monkeys. In a complex study using fMRI with human subjects performing a variety of tasks, they suggest that the emergence of language could be related to the apparent displacement of functional areas in dorsal frontal cortex. This study might therefore have important theoretical implications for our understanding of the architecture of the prefrontal cortex and its functional parcellation. Reference Courtney, S.M. et al. (1998) An area specialized for working memory in human frontal cortex Science 279, 1347–1351
Monitor contributors for Trends in Cognitive Sciences A panel of monitor contributors assist the Editorial staff by suggesting appropriate articles and writing some of the short summaries that have appeared in this section of the journal. I would like to take this opportunity to express my sincere thanks for their efforts in providing an informative and imaginative addition to the journal. If you would like to contribute to Monitor, contact the Editor at [email protected]. Regular contributors receive a free subscription to the journal. Current panel members include: S. Bertolo N. George A. Grunewald S.R. Jackson E. Kaan I. McLaren
Cambridge, MA, USA London, UK Pasadena, CA, USA Bangor, UK Cambridge, MA, USA Cambridge, UK
A. Owen G. Rees M. Rushworth L. Wagner E. Wilding
Cambridge, UK London, UK Oxford, UK Philadelphia, PA, USA Oxford, UK
information Drivers in foggy conditions are frequently involved in accidents and are often ‘blamed’ for driving too fast for the weather conditions. But are these accidents solely caused by the recklessness of the drivers or are there other reasons? Clearly, when attempting to judge one’s speed during reduced visibility one is less likely to look away from the road to the speedometer as this might cause an accident in itself. This places an additional burden on the perceptual systems that can also provide clues to speed. Snowden, Stimpson and Ruddle have recently examined the ability of drivers to adjust their speed in a virtual environment that simulated the view from a car moving along a road. In one experiment they showed subjects two driving scenes, one with clear weather, the other with either clear or reduced visibility and calculated the speed at which the subjects reported that the two scenes appeared to be moving at the same speed. The results indicated that drivers perceived the foggy scene to be moving more slowly than the clear scene. In a second experiment the subjects were asked to try to match their speed to a target speed in a variety of weather conditions in a more realistic driving simulator involving a winding road, a steering wheel, and brake and accelerator pedals. Again, as the weather condition deteriorated the subjects drove faster. These results raise the question of the role of our perceptual systems in driver irresponsibility under poor visibility and may provide a test-bed for novel approaches to this problem. Reference Snowden, R.J., Stimpson, N. and Ruddle, R.A. (1998) Speed perception fogs up as visibility drops Nature 392, 450
Copyright © 1998, Elsevier Science Ltd. All rights reserved. 1364-6613/98/$19.00 Trends in Cognitive Sciences – Vol. 2, No. 5,
May 1998
167