What are you looking at? Infants’ neural processing of an adult's object‐directed eye gaze

Previous research suggests that by 4 months of age infants use the eye gaze of adults to guide their attention and facilitate processing of environmental information. Here we address the question of how infants process the relation between another person and an external object. We applied an ERP paradigm to investigate the neural processes underlying the perception of the direction of an adult's eye gaze in 4-month-old infants. Infants showed differential processing of an adult's eye gaze, which was directed at a simultaneously presented object compared to non-object-directed eye gaze. This distinction was evident in two ERP components: The Negative component, reflecting attentional processes, and the positive slow wave, which is involved in memory encoding. The implications of these findings for the development of joint attention and related social cognitive functions are discussed.     

Should I believe this? Reality monitoring of accounts of self‐experienced and invented recent and distant autobiographical events

To examine personal and interpersonal reality monitoring, 240 participants wrote accounts of invented or self‐experienced autobiographical events. Half the participants wrote about a distant event that happened before the age of 15 and half wrote about a recent event that happened after the age of 15. Using a yoked design, participants rated the qualitative details of their own accounts and the details of other participants' accounts. Consistent with previous research, we found that self‐experienced accounts contained more qualitative details than invented accounts, and that accounts of recent events contained more qualitative details than accounts of distant events. Participants rated their own accounts as more qualitatively detailed than other participants' accounts, which suggests that they did not base their self‐ratings solely on the written details. We discuss the practical and theoretical importance of our findings. Copyright © 2006 John Wiley & Sons, Ltd.     

Psychotropic placebos create resistance to the misinformation effect

Can a placebo for a psychotropic drug help participants resist the misinformation effect? To answer this question, we gave participants a mixture of baking soda and water and told half of them that the mixture was a cognition-enhancing drug called R273 and told the other half that it was an inactive version of the drug. Shortly thereafter, all participants took part in a three-stage misinformation experiment. Compared with participants who were told that they had taken the placebo, the participants who were told that they had taken the drug reported improved cognitive abilities and were less susceptible to the misinformation effect. We provide sourcemonitoring and mindfulness accounts of our findings.     

Electrophysiological evidence for cognitive control during conflict processing in visual spatial attention

Event-related potentials were measured to investigate the role of visual spatial attention mechanisms in conflict processing. We suggested that a more difficult target selection leads to stronger attentional top-down control, thereby reducing the effects of arising conflicts. This hypothesis was tested by varying the selection difficulty in a location negative priming (NP) paradigm. The difficult task resulted in prolonged responses as compared to the easy task. A behavioral NP effect was only evident in the easy task. Psychophysiologically the easy task was associated with reduced parietal N1, enhanced frontocentral N2 and N2pc components and a prolonged P3 latency for the conflict as compared to the control condition. The N2pc effect was also obvious in the difficult task. Additionally frontocentral N2 amplitudes increased and latencies of N2pc and P3 were delayed compared to the easy task. The differences at frontocentral and parietal electrodes are consistent with previous studies ascribing activity in the prefrontal and parietal cortex as the source of top-down attentional control. Thus, we propose that stronger cognitive control is involved in the difficult task, resulting in a reduced behavioral NP conflict.     

Acquisition of lever-press responding in rats with delayed reinforcement: A comparison of three procedures

The present study examined the acquisition of lever pressing in rats under three procedures in which food delivery was delayed by 4, 8, and 16 seconds relative to the response. Under the nonresetting delay procedure, food followed the response selected for reinforcement after a specified interval elapsed; responses during this interval had no programmed effect. Under the resetting procedure, the response selected for reinforcement initiated an interval to food delivery that was reset by each subsequent response. Under the stacked delay procedure, every response programmed delivery of food t seconds after its occurrence. Two control groups were studied, one that received food immediately after each lever press and another that never received food. With the exception of the group that did not receive food, responding was established with every procedure at every delay value without autoshaping or shaping. Although responding was established under the resetting delay procedure, response rates were generally not as high as under the other two procedures. These findings support the results of other recent investigations in demonstrating that a response not previously reinforced can be brought to strength by delayed reinforcement in the absence of explicit training.     

On banishing ethics from our minds

The Journal of Value Inquiry -     

Clinical validation of a sleep assessment device

We have previously reported on the use of a sleep assessment device (SAD) with non-insomniac subjects. The SAD works by generating a brief, soft tone about every 10 min throughout the night and tape recording verbal responses to these cues. The sleep patterns reconstructed from the night's tape recordings proved highly concordant with EEG records. The present study tested the SAD against the EEG standard in 20 nights of monitoring chronic insomniacs. No significant differences were found between the SAD and EEG records with respect to sleep latency, duration of awakenings during the night, total sleep time and sleep efficiency percentage. The EEG detected many more very brief awakenings during the night than did the SAD due to the continuous monitoring by the former. The SAD proved to be a non-intrusive measure of sleep according to three independent measures. The usefulness of the SAD as a measure of sleep in the natural environment was discussed.