Academic journal article The Spanish Journal of Psychology

Presaccadic Brain Potentials in Conditions of Covert Attention Orienting

Academic journal article The Spanish Journal of Psychology

Presaccadic Brain Potentials in Conditions of Covert Attention Orienting

Article excerpt

Twelve healthy subjects underwent investigation of averaged (electroencephalogram) EEG potentials during preparation for motor activity and in the latent period (LP) of visually evoked saccades by presentation of stimuli using Posner's (1980) design of "cost-benefit." It has been shown that covert spatial attention orientation leads to an increase in amplitude and decrease in latency of presaccadic initiation potential peaks within the saccadic latent period (LP) (P-100, N -50). Processes of covert orientation of attention during the interstimulus interval period of anticipation of the target stimulus correlate with the increase of slow negativity of fronto-parietal-temporal localization. Spatial-temporal changes of presaccadic potentials are evidence of the fact that orientation of attention during motor preparation and saccadic initiation is reflected in intensification of fronto-parietal networks of saccadic control and attention, activating the fronto-medio-thalamic and thalamo-parietal modulating systems.

Keywords: orienting of attention, saccades, latent period, presaccadic potentials

Se examinaron los potenciales EEG promediados de doce sujetos sanos durante su preparación para actividad motor y en el período latente de sacádicos evocados visualmente por la presentación de estímulos según el diseño de "coste-beneficio" de Posner (1980). Se ha mostrado que la orientación de la atención espacial encubierto lleva a un incremento en la amplitud y un decremento en la latencia de los picos potenciales de iniciación presacádica dentro del período sacádico latente (P-100, N -50). Los procesos encubiertos de orientación de la atención durante el período del intervalo inter-estímulo de anticipación del estímulo meta correlacionan con el incremento de la negatividad lenta de localización fronto-parietal. Cambios espacio-temporales de potenciales presacádicos son evidencia del hecho de que la orientación de la atención durante la preparación motora y la iniciación sacádica se refleja en la intensificación de las redes fronto-parietales de control y atención, activando los sistemas de modulación fronto-medio-talámicos y tálamo-parietales.

Palabras clave: orientación de la atención, movimientos sacádicos, periodo latente, potenciales presacádicos

Despite a multitude of studies over the past 40 years, the nature of attention remains poorly understood. An important contribution to the comprehension of attention mechanisms has been made by studies of evoked potentials (Naatanen, 1998; Rutman, 1979), clinical studies using positron emission (PET) and magnetic resonance tomography (fMRT) (Coull, 1998; Mangun, Jha, Hopfinger, & Handy, 2000; Posner, 1980), as well as neurophysiological studies on monkey neurons (Andersen & Gnadt, 1989; Robinson, Bowman, & Kertzman, 1995). The knowledge acquired has permitted the development of hypothetic designs of the interaction of brain structures when attending (Machinskaya, 2003; Coull, 1998; Laberge, 2000; Posner, 1980).

The intimate interrelation of spatial attention and saccadic eye movements is well known, as is their anatomic sharing of these mechanisms (Posner, 1980; Rizzolatti, Riggio, Dascola, & Umilta, 1987). Several experimental paradigms have been developed in psychophysiology to study the influence of attention on saccadic programming. One of the most adequate paradigms is the method probability of presentation of visual targets of Posner's "cost-benefit" or the "spatial cued task," which permits the quantitative assessment of spatial orientation of attention within a visual field according to the LP of saccadic or manual reaction (Posner, 1980). This method requires the use of signal stimuli to attract attention to one of the visual half-fields. The appearance of peripheral target stimuli (PTS) in the half-field at which attention is aimed leads to a decrease in the LP (benefit) and, in the opposite half-field, to its increase (cost). …

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