He frontal eye fields also responded most strongly to targets in : Différence entre versions

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This O-Propargylpuromycin site result supports the concept that FBA modifications activity throughout the visual-field representation within a valuable way for title= ece3.2353 visual search. Neural adaptation tends to boost with stronger neuronal response towards the adapting stimulus (Gardner et al., 2005; Sclar et al., 1989). Correspondingly, the magnitude of adaptation increases with all the intensity in the adapter stimulus. As an illustration, adapting to higher contrast gratings results in higher threshold elevation (Langley, 20.He frontal eye fields also responded most strongly to targets in conjunction search, and more strongly to distractors that shared one particular target feature than to distractors that shared none (Bichot Schall, 1999).NIH-PA Author Manuscript NIH-PA Author Manuscript NIH-PA Author ManuscriptVision Res. Author manuscript; obtainable in PMC 2012 July 05.CarrascoPageNeurophysiological studies have also shown that shifting interest involving unique feature dimensions (e.g., color or orientation) modulates activity in cortical regions specialized for processing those dimensions. For example, in a single study making use of delayed match to sample the responses of most V4 neurons were affected by whether or not the monkey was attending to the orientation or color of a stimulus distant in the receptive field (McAdams Maunsell, 2000). This outcome supports the idea that FBA adjustments activity all through the visual-field representation within a useful way for title= ece3.2353 visual search. 6.2. Feature-based effects at attended locations Notwithstanding advances in electrophysiological research of visual search, this paradigm will not be title= s12864-016-2896-7 best to assess regardless of whether and how attention affects sensory representations. In most human research of visual search the role of attention has been inferred as opposed to directly manipulated, and only a few studies have taken into account standard title= bmjopen-2016-012517 visual and stimulus components (e.g., Carrasco Frieder, 1997; Carrasco et al., 1995; Carrasco, McLean, et al., 1998; Geisler Chou, 1995; Palmer, 1995; Palmer et al., 2000; Verghese, 2001; Verghese Nakayama, 1994). Moreover, search tasks often involve spatial focus (either covert or overt) thus complicating the assessment of FBA per se in these tasks. Due to the fact a visual stimulus usually occupies a specific spatial location, it truly is important to control spatial selection when studying feature-based selection. Thus, research of FBA usually use compound stimuli that contain a number of characteristics superimposed more than the same spatial location, and observers are necessary to attend to a single of these attributes. This section reviews research that investigate FBA in the attended location, i.e. at the regional level. The subsequent section evaluations the consequences of these manipulations, whereby feature-related activity spreads to locations apart from the attended one. 6.2.1. Behavioral studies 6.two.1.1. Adaptation aftereffects: The effects of selectively attending to a relevant feature presented simultaneously with other features happen to be investigated in behavioral studies of aftereffects following selective adaptation. This technique allows researchers to address no matter whether attending to a feature enhances selective responses to that function. Selective adaptation is defined as decreased sensitivity following prolonged exposure to a stimulus, and equivalent stimuli, resulting in aftereffects (Carrasco, Figueroa, Willen, 1986; Kohn, 2007; Movshon Blakemore, 1973; Ohzawa, Sclar, Freeman, 1982; Pantle Sekuler, 1968). Neurophysiologically, this decreased sensitivity has been attributed to a contrast gain manage mechanism, whereby adaptation decreases the acquire of detectors tuned to the adapter stimulus (Ohzawa et al., 1982).