Type of Featural Attention Differentially Modulates hMT⁺ Responses to Illusory Motion Aftereffects

Abstract

Castelo-Branco M, Kozak LR, Formisano E, Teixeira J, Xavier J, Goebel R. Type of featural attention differentially modulates hMT ϩ responses to illusory motion aftereffects. J Neurophysiol 102: 3016-3025, 2009. First published August 26, 2009 doi:10.1152/jn.90812.2008. Activity in the human motion complex (hMT ϩ /V5) is related to the perception of motion, be it either real surface motion or an illusion of motion such as apparent motion (AM) or motion aftereffect (MAE). It is a longlasting debate whether illusory motion-related activations in hMT ϩ represent the motion itself or attention to it. We have asked whether hMT ϩ responses to MAEs are present when shifts in arousal are suppressed and attention is focused on concurrent motion versus nonmotion features. Significant enhancement of hMT ϩ activity was observed during MAEs when attention was focused either on concurrent spatial angle or color features. This observation was confirmed by direct comparison of adapting (MAE inducing) versus nonadapting conditions. In contrast, this effect was diminished when subjects had to report on concomitant speed changes of superimposed AM. The same finding was observed for concomitant orthogonal real motion (RM), suggesting that selective attention to concurrent illusory or real motion was interfering with the saliency of MAE signals in hMT ϩ . We conclude that MAE-related changes in the global activity of hMT ϩ are present provided selective attention is not focused on an interfering feature such as concurrent motion. Accordingly, there is a genuine MAE-related motion signal in hMT ϩ that is neither explained by shifts in arousal nor by selective attention.

Early Disrupted Neurovascular Coupling and Changed Event Level Hemodynamic Response Function in Type 2 Diabetes: An fMRI Study

“…The independent localizer (data not shown) is consistent with prior reports of its localization. 21,25 We defined two additional ROIs based on the thresholded RFX GLM statistical maps for further analysis of the HRF: one at the insula (top panel, peak voxel Talairach coordinates x = 36, y = 17, z = 7; t = 7.873521) because of its known role in decision making processes and one in the inferior frontal gyrus (middle panel, peak voxel Talairach coordinates x = 42, y = 2, z = 31; t = 9.717579) because of its role in executive function.…”

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Caffeine and Cognition in Functional Magnetic Resonance Imaging

“…As such, reasoning, problem solving, and decision-making rank among the "higher" functions. According to most theories, higher cognitive function entails the modulation of lower-level processes depending on abstract goals and intentions, by factors such as selective attention [12]. This modulation permits adaptation to novel or changing situations.…”

Visual Motion Processing and Visual Sensorimotor Control in Autism

“…First, we used passive viewing of visual motion to examine response to bottom–up visual motion input as well as adaptation to the input. Adaptation paradigms have been effective in examining one of the fundamental properties of visual systems, opponency (Castelo-Branco et al, 2009; Tootell et al, 1995). Opponency refers to gamma-aminobutyric acid (GABA) mediated mutual inhibition between neurons with different direction tuning (Bair, Cavanaugh, & Movshon, 2003; Spiegel, Hansen, Byblow, & Thompson, 2012), which determines how signals from single neurons become integrated to decide direction selectivity of the population response (Heeger, Boynton, Demb, Seidemann, & Newsome, 1999).…”