RESUMEN
Cerebral activations during olfactory mental imagery are fairly well investigated in healthy participants but little attention has been given to olfactory imagery in patients with olfactory loss. To explore whether olfactory loss leads to deficits in olfactory imagery, neural responses using functional magnetic resonance imaging (fMRI) and self-report measures were investigated in 16 participants with acquired olfactory loss and 19 control participants. Participants imagined both pleasant and unpleasant odors and their visual representations. Patients reported less vivid olfactory but not visual images than controls. Results from neuroimaging revealed that activation patterns differed between patients and controls. While the control group showed stronger activation in olfactory brain regions for unpleasant compared to pleasant odors, the patient group did not. Also, activation in critical areas for olfactory imagery was correlated with the duration of olfactory dysfunction, indicating that the longer the duration of dysfunction, the more the attentional resources were employed. This indicates that participants with olfactory loss have difficulties to perform olfactory imagery in the conventional way. Regular exposure to olfactory information may be necessary to maintain an olfactory imagery capacity.
Asunto(s)
Encéfalo/fisiopatología , Imaginación/fisiología , Trastornos del Olfato/fisiopatología , Trastornos del Olfato/psicología , Percepción Olfatoria/fisiología , Adulto , Anciano , Nivel de Alerta/fisiología , Atención/fisiología , Mapeo Encefálico , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Pruebas Neuropsicológicas , Autoinforme , Encuestas y Cuestionarios , Factores de Tiempo , Percepción Visual/fisiología , Adulto JovenRESUMEN
The present study examined the effects of repeated exposure of flight phobics to flights in virtual reality (VR). Flight phobics were randomly assigned either to complete one VR test flight followed by four VR exposure flights (VR group; N=15) in one lengthy session or to complete one VR test flight followed by a lengthy relaxation training session (relaxation group; N=15). All participants completed a second VR test flight at the end of the session. Fear reports and physiological fear reactions (heart rate, skin conductance level) during VR exposures were registered, and fear of flying was assessed psychometrically from 3 weeks before to 3 months after exposure. Exposure to VR flights elicited subjective and physiological fear responses in flight phobics, and these responses attenuated within and across VR flights. Fear reduction associated with repeated VR exposure was greater than fear reduction caused by relaxation training. Fear of flying improved in both treatment groups, but several outcome measures indicated greater effects in the VR treated group than in the relaxation group. These findings indicate that exposure in virtual reality may offer a new and promising approach for the treatment of fear of flying.