Hemispheric asymmetries for simple visual judgments in the split brain

Automatic attention lateral asymmetry in visual discrimination tasks

“…This result does not support the idea that the visual processing hemispheric asymmetries (Sergent et al 1992;Köhler et al 1995;Corballis et al 1999Corballis et al , 2002Shen et al 1999) contribute to behavioral asymmetries. It is possible that the visual processing hemispheric asymmetries are too weak to modulate the lateral asymmetry of attention.…”

“…Performance was more accurate for the left hemifield stimuli in the spatial matching condition and tended to be more accurate for the right hemifield stimuli in the identity matching condition. In a subsequent study performed with the same patients, Corballis et al (2002) confirmed the dominance of the right hemisphere for spatial processing. They presented a pair of lines with the same or different orientations, a pair of vertical lines which were collinear or not, a pair of circles of the same or different sizes or a pair of circles with the same or different luminances in the left or right visual field.…”

“…Since the right hemisphere would be more involved in discrimination of the location of visual stimuli and the left hemisphere in the discrimination of the shape of visual stimuli (Sergent et al 1992;Köhler et al 1995;Corballis et al 1999Corballis et al , 2002Shen et al 1999), it could be supposed that the right side favoring by attention would be partially compensated in location discrimination tasks and be potentiated in shape discrimination tasks. In this case, greater differences between the attentional effects produced by a right hemifield prime stimulus and a left hemifield prime stimulus should be observed in the latter tasks than in the former.…”

Assimetria interlateral da atenção visuoespacial automática em tarefas de discriminação de forma e de localização.

“…Ela é considerada a principal responsável pelo processamento de movimento, posição espacial e orientação dos objetos (Ungerleider e Mishkin¹, 1982apud Milner e Goodale, 2008Haxby et al, 1991;Ungerleider e Haxby, 1994;Schwartz, 2004;Valyear et al, 2006 (Sergent et al, 1992;Köhler et al, 1995;Liotti e Tucker, 1995;Shen et al, 1999). Por outro lado o hemisfério direito seria capaz de desempenhar de maneira mais eficiente, em relação ao esquerdo, tarefas em que a via visual dorsal está preferencialmente envolvida (Sergent et al, 1992;Köhler et al, 1995;Liotti e Tucker, 1995;Funnel et al, 1999;Shen et al, 1999;Corballis et al, 2002 …”

“…O hemisfério direito seria mais eficiente que o hemisfério esquerdo quanto ao processamento deste estímulo visual (Sergent et al, 1992;Köhler et al, 1995;Liotti e Tucker, 1995;Funnel et al, 1999;Shen et al, 1999;Corballis et al, 2002). Assim quando este aparecesse no hemicampo esquerdo seu processamento seria mais eficiente do que quando aparecesse no hemicampo direito.…”