Biomedical subjects

George Andrew Michael

Publications and source records attributed to George Andrew Michael.

3 recordsLinked to original sources

PubMed2005

Ambient odors influence the amplitude and time course of visual distraction.

Behavioral performance was examined in a task of attentional capture by luminance under conditions of ambient odors (phenyl ethyl alcohol [PEA], olfactory stimulus, and allyl isothiocyanate [AIC], mixed olfactory/trigeminal stimulus). The AIC increased the amplitude and duration of capture, whereas the presence of PEA led capture to disappear. Furthermore, the PEA caused a general slowing in the speed of information processing. The amplitude and time course of capture were correlated to the irritating components of these odorants, whereas a control experiment showed that the general slowing caused by the PEA was correlated to a drop-off of the subjects' arousal level. These results suggest that ambient odors may exert differential influence of visual-attentional processes and that this influence may depend on the odor's properties.

Adult↗

PubMed2004

The human pulvinar and attentional processing of visual distractors.

The processing of a target is degraded when noise is present in proximity, and performance increases as the target-noise distance increases. We tested a group of healthy volunteers and a group of patients, who suffered strokes in the posterior thalamus, in a task where the target-noise distance was manipulated. Whilst controls exhibited the expected pattern of results, thalamic patients exhibited little signs of noise interference. Interference occurred when the target-noise distance was 0 degrees (the target and noise were superimposed), but it was absent for distances equal to and bigger than 1 degree. The results suggest that the coarse grain of visual attention reported previously might be due to some aspects of attention processing underlain by the pulvinar and acting to grab the visual context or background of a target.

Adult↗

PubMed2003

Ambient odors modulate visual attentional capture.

Sudden visual events capture attention involuntarily because they may signal potential threats. Some theoretical accounts consider that the biological significance of these events is established through the limbic structures. Thus, the manipulation of the limbic activity would affect attentional capture. Since these structures are directly linked to the olfactory system, we have tended to modulate their activity with olfactory stimulations. We have examined behavioral performance in a task of attentional capture by luminance under conditions of ambient odors. Our results show that attentional capture is indeed modulated by ambient odors, and that this modulation may depend on the odor's properties.

Adult↗