The detection of visual signals by macaque frontal eye field during masking

Abstract

The neural link between a sensory signal and its behavioral report was investigated in macaques trained to locate an intermittently detectable visual target. Neurons in the frontal eye field, an area involved in converting the outcome of visual processing into motor commands, responded at short latencies to the target stimulus whether or not the monkey reported its presence. Neural activity immediately preceding the visual response to the mask was significantly greater on hits than on misses, and was significantly greater on false alarms than on correct rejections. The results show that visual signals masked by light are not filtered out at early stages of visual processing; furthermore, the magnitude of early visual responses in prefrontal cortex predicts the behavioral report.

A neuronal network model linking subjective reports and objective physiological data during conscious perception

“…4). Likewise, experiments that sort trials based on the presence or absence of a subsequent conscious report occasionally show early differences in neural activity in V1 or frontal eye field (34,35). In our interpretation, however, such early effects are only secondary correlates of consciousness because they are merely an indirect consequence of selective averaging over a fluctuating baseline.…”

Seeing properties of an invisible object: Feature inheritance and shine-through

“…Any neuronal explanation of this illusion has to account for the fact that the information pertaining to the vernier offset is present under both feature inheritance and shine-through conditions. Because of the simple and metric nature of our stimuli, they might lend themselves to studying these different states of feature binding in the awake behaving monkey (24)(25)(26)(27)(28). Even if the outer 2 ϫ 9 double-bars are presented only 10 ms later than the central five elements, a significant deterioration of performance is found.…”

Visual Selection and the Human Frontal Eye Fields: Effects of Frontal Transcranial Magnetic Stimulation on Partial Report Analyzed by Bundesen's Theory of Visual Attention

“…Early anatomical models of visual cortex (Maunsell and Van Essen, 1987) placed the FEF at the pinnacle of the visual system, but recent connectivity analyses (Barone et al, 2000) show intimate connections of FEF with extrastriate occipital cortices. Moreover, single-cell studies now show involvement of FEF in visual detection and priming (Schall and Hanes, 1993;Thompson et al, 1996Thompson et al, , 1997Schall and Bichot, 1998;Schall, 1999, 2002;Schall and Thompson, 1999;Thompson and Schall, 1999;Murthy et al, 2001). Microstimulation of monkey FEF during single-unit recordings from V4 has revealed influences of FEF on occipital activity (Moore and Fallah, 2001;Moore and Armstrong, 2003).…”