Representation of the Visual Field in the Human Occipital Cortex

Abstract

To evaluate the retinotopic map of the human occipital cortex by correlating magnetic resonance imaging (MRI) findings with visual field defects in patients with occipital lobe infarcts and to assess the compatibility between our cliniconeuroimaging findings and the location of lesions predicted by the classic Holmes map and a revised map. Methods: Magnetic resonance images were obtained in 14 patients with occipital lobe infarcts. Visual field analysis was performed with tangent screen, the Goldmann perimeter, and the Humphrey Field Analyzer. Based on the pattern of visual field deficit, the location of the lesion in the mesial occipital lobe in each patient was predicted using the Holmes map and other retinotopic maps of the occipital cortex. The predicted location of the lesion was then compared with its actual location shown on MRI to assess the compatibility between our data and the other maps. These maps determine retinotopic correlates of the medial occipital lobe, but they cannot establish correlates of the striate cortex (V1). The medial occipital representation of central vision was evaluated by regression analysis. Results: The MRI correlations in this study confirmed gross estimates of the retinotopic organization of the occipital cortex. However, our findings did not correlate exactly with the Holmes map. We determined that the central 15 o of vision occupies 37% of the total surface area of the human medial occipital lobe. Based on our data, a refined retinotopic map is presented. Conclusions: The resolution of conventional MRI testifies to its considerable value in localizing occipital lobe lesions. Our findings support, and refine, the Holmes map of the human occipital cortex.

Clinical Study of the Visual Field Defects Caused by Occipital Lobe Lesions

“…One patient with a lesion in the posterior portion of the medial area showed central homonymous hemianopia without peripheral visual field disturbance. These results suggested that the responsible lesion for central visual field disturbance extended to the posterior portion of the medial area in the striate cortex, which was consistent with recent studies that reported the responsible lesion for central visual field disturbance [3,4,5,6]. Bilateral superior altitudinal hemianopia in 1 patient correlated well with the bilateral involvement of the anterior and posterior portions of the medial area below the calcarine fissure.…”

“…In conclusion, central visual field disturbance was induced by lesions in the posterior portion of the medial area as well as occipital tip lesions in our study, as reported in previous studies [3,4,5,6]. Central visual field disturbances caused by lesions in the posterior portion of the medial area tended to be incomplete homonymous hemianopia, while complete homonymous hemianopia or quadrantanopia occurred due to occipital tip lesions.…”

Clinical Study of the Visual Field Defects Caused by Occipital Lobe Lesions

“…One patient with a lesion in the posterior portion of the medial area showed central homonymous hemianopia without peripheral visual field disturbance. These results suggested that the responsible lesion for central visual field disturbance extended to the posterior portion of the medial area in the striate cortex, which was consistent with recent studies that reported the responsible lesion for central visual field disturbance [3,4,5,6]. Bilateral superior altitudinal hemianopia in 1 patient correlated well with the bilateral involvement of the anterior and posterior portions of the medial area below the calcarine fissure.…”

“…In conclusion, central visual field disturbance was induced by lesions in the posterior portion of the medial area as well as occipital tip lesions in our study, as reported in previous studies [3,4,5,6]. Central visual field disturbances caused by lesions in the posterior portion of the medial area tended to be incomplete homonymous hemianopia, while complete homonymous hemianopia or quadrantanopia occurred due to occipital tip lesions.…”

Occipital gamma-oscillations modulated during eye movement tasks: Simultaneous eye tracking and electrocorticography recording in epileptic patients

“…This finding can be explained by the realigned images in the peripheral field following such a saccade (Wong and Sharpe, 1999; Yoshor et al, 2007). Otherwise, the word reading task elicited gamma-augmentation sequentially involving the widespread occipital region, left parietal, left prefrontal, left premotor and Rolandic regions, as described in previous ECoG studies (Lachaux et al, 2008; Vidal et al, 2010; Wu et al, 2011).…”

Gamma-oscillations modulated by picture naming and word reading: Intracranial recording in epileptic patients

“…We found that the effect of word length on gamma-augmentation was largest in the medial occipital lobe. This finding suggests that longer words, compared to shorter ones, activate the primary visual cortex for the peripheral field (Wong and Sharpe, 1999; Levy et al, 2001; Rols et al, 2001; Stenbacka and Vanni, 2007; Yoshor et al, 2007). …”

Clinical Study of the Visual Field Defects Caused by Occipital Lobe Lesions

“…One patient with a lesion in the posterior portion of the medial area showed central homonymous hemianopia without peripheral visual field disturbance. These results suggested that the responsible lesion for central visual field disturbance extended to the posterior portion of the medial area in the striate cortex, which was consistent with recent studies that reported the responsible lesion for central visual field disturbance [3,4,5,6]. Bilateral superior altitudinal hemianopia in 1 patient correlated well with the bilateral involvement of the anterior and posterior portions of the medial area below the calcarine fissure.…”

“…In conclusion, central visual field disturbance was induced by lesions in the posterior portion of the medial area as well as occipital tip lesions in our study, as reported in previous studies [3,4,5,6]. Central visual field disturbances caused by lesions in the posterior portion of the medial area tended to be incomplete homonymous hemianopia, while complete homonymous hemianopia or quadrantanopia occurred due to occipital tip lesions.…”

Occipital gamma-oscillations modulated during eye movement tasks: Simultaneous eye tracking and electrocorticography recording in epileptic patients

“…This finding can be explained by the realigned images in the peripheral field following such a saccade (Wong and Sharpe, 1999; Yoshor et al, 2007). Otherwise, the word reading task elicited gamma-augmentation sequentially involving the widespread occipital region, left parietal, left prefrontal, left premotor and Rolandic regions, as described in previous ECoG studies (Lachaux et al, 2008; Vidal et al, 2010; Wu et al, 2011).…”

Gamma-oscillations modulated by picture naming and word reading: Intracranial recording in epileptic patients

“…We found that the effect of word length on gamma-augmentation was largest in the medial occipital lobe. This finding suggests that longer words, compared to shorter ones, activate the primary visual cortex for the peripheral field (Wong and Sharpe, 1999; Levy et al, 2001; Rols et al, 2001; Stenbacka and Vanni, 2007; Yoshor et al, 2007). …”

Clinical Study of the Visual Field Defects Caused by Occipital Lobe Lesions

“…One patient with a lesion in the posterior portion of the medial area showed central homonymous hemianopia without peripheral visual field disturbance. These results suggested that the responsible lesion for central visual field disturbance extended to the posterior portion of the medial area in the striate cortex, which was consistent with recent studies that reported the responsible lesion for central visual field disturbance [3,4,5,6]. Bilateral superior altitudinal hemianopia in 1 patient correlated well with the bilateral involvement of the anterior and posterior portions of the medial area below the calcarine fissure.…”

“…In conclusion, central visual field disturbance was induced by lesions in the posterior portion of the medial area as well as occipital tip lesions in our study, as reported in previous studies [3,4,5,6]. Central visual field disturbances caused by lesions in the posterior portion of the medial area tended to be incomplete homonymous hemianopia, while complete homonymous hemianopia or quadrantanopia occurred due to occipital tip lesions.…”

Occipital gamma-oscillations modulated during eye movement tasks: Simultaneous eye tracking and electrocorticography recording in epileptic patients

“…This finding can be explained by the realigned images in the peripheral field following such a saccade (Wong and Sharpe, 1999; Yoshor et al, 2007). Otherwise, the word reading task elicited gamma-augmentation sequentially involving the widespread occipital region, left parietal, left prefrontal, left premotor and Rolandic regions, as described in previous ECoG studies (Lachaux et al, 2008; Vidal et al, 2010; Wu et al, 2011).…”

Gamma-oscillations modulated by picture naming and word reading: Intracranial recording in epileptic patients

“…We found that the effect of word length on gamma-augmentation was largest in the medial occipital lobe. This finding suggests that longer words, compared to shorter ones, activate the primary visual cortex for the peripheral field (Wong and Sharpe, 1999; Levy et al, 2001; Rols et al, 2001; Stenbacka and Vanni, 2007; Yoshor et al, 2007). …”