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Anatomical connectivity of color-processing modules in monkey inferior temporal cortex
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Abstracts / Neuroscience Research 68S (2010) e55–e108
O2-8-3-1 Anatomical connectivity of color-processing modules in monkey inferior temporal cortex Taku Banno 1,2 , Noritaka Ichinohe 3,5 , Kathleen S. Rockland 4,5 , Hidehiko Komatsu 1,2 1
Division of Sensory and Cognitive Information, NIPS, Okazaki, Japan 2 SOKENDAI 3 Department of Neuroanat, Hirosaki Univ, Hirosaki, Japan 4 RIKEN-MIT Center for Neural Circuit Genetics, MIT, USA 5 Lab for Cort Org System, BSI, RIKEN, Wako, Japan Recent imaging and electrophysiological studies have revealed the presence of several distinct patches of color-selective regions in the anterior and posterior IT cortex (AIT and PIT). Although accumulating evidence from lesion and electrophysiological studies suggests that the color-selective region in AIT (AITC) is important for color vision, less is known about the input sources to AITC, and especially how these contribute to the color-related signals. In the present study, we combined anatomical tracing methods with electrophysiological identification of two color-selective regions in monkey IT cortex and investigated their anatomical connectivity. We found that AITC forms a strong reciprocal connection with the previously reported color-selective region in PIT (PITC), but mainly with its ventral part. The AITC also received inputs from discrete clusters of cells in other occipito-temporal areas, in superior temporal sulcus, and in prefrontal and parietal cortices. The distribution of the labeled cells is consistent with some of the color-selective regions revealed by recent imaging studies. By contrast, the dorsal part of PITC strongly projected to a separate AIT region, slightly posterior and dorsal to the AITC. These results suggest architecture of parallel color-processing pathways, demonstrated by an anatomically interconnected network of distributed color-processing modules in the monkey IT cortex. doi:10.1016/j.neures.2010.07.204
O2-8-3-2 Prediction of transient states during and after long-term chromatic adaptation Chihiro Imai 1 , Hideyuki Suzuki 1,2 1
Grad Sch Info & Sci., Univ of Tokyo, Tokyo 2 Inst Ind Sci., Univ of Tokyo, Tokyo
The visual system makes adaptive adjustments to maintain a stable color perception in chromatic environments changing in various time scales ranging from tens of milliseconds to several decades as senescent changes in ocular media density. Although the equilibrium yellow, the color perceived as neither reddish nor greenish, is profoundly changed by short-term adaptations, it returns to the normal perception immediately after the release from adaptations (Jameson, 1979). In contrast, recent studies report that long-term adaptations continuing for weeks shift the yellow perception progressively away from the normal, and the changed perceptions persist for weeks in the absence of exposure to chromatic alteration (Neitz, 2002; Blemore, 2008). However, existing computational studies are not enough to provide a unified model which accounts for both the brief and the sustained shifts in chromatic perception led by short- and long-term adaptations, respectively. Moreover, many of those models assume that the color appearances are already in the steady state, little focusing on the dynamics and the plasticity of the visual nervous system during the chromatic adaptation. In the present study, we propose a computational model of the primate visual pathway, which explains the change in color appearance during and after the adaptation with a broad range of temporal scales. Based on anatomical and physiological knowledge, the model assumes that the neuronal plasticity plays a key role in the long-term adaptations. Our model reproduces the dynamic properties of color vision reported in the previous experimental studies. Additionally, we applied the current model to various conditions of chromatic illumination, providing testable predictions on the color appearances and their dynamics in changing environments. doi:10.1016/j.neures.2010.07.205
O2-8-3-3 Visually guided eye movements based on color saliency in monkeys with unilateral lesion of primary visual cortex Masatoshi Yoshdia 1,2 , Launrent Itti 3 , David Berg 3 , Takuro Ikeda 1 , Rikako Kato 1 , Kana Takaura 1,2 , Tadashi Isa 1,2 1
Dept Dev Physiol, Nat’l Inst Physiol Sci, Okazaki, Japan 2 Sch. Life Sci., Grad. University Adv. Stud., Hayama, Japan 3 Viterbi school of engineering, University of Southern California, Los Angeles, USA We investigated residual visually-guided behavior in monkeys after unilateral ablation of primary visual cortex (V1), to unravel the contributions of V1 to salience computation. We analyzed eye movements of monkeys watching video stimuli and a computational model of saliency-based, bottom-up attention quantified the monkeys’ propensity to attend to salient targets. All monkeys were attracted towards salient stimuli, significantly above chance, for saccades directed both into normal and affected hemifields. We also quantified the contribution of visual attributes (intensity, color, motion and so on) to the saliency-based eye movements and obtained evidence that the guidance of gaze was influenced by color saliency in the V1-lesioned monkeys. Here we directly examined residual visuomotor processing based on color saliency with color discrimination tasks. In two monkeys after unilateral ablation of V1, the isoluminant, chromatic stimuli was presented in one of the two positions in their affected hemifield. The monkeys were rewarded by making saccade to the target. The CRT monitor (Mitsubishi DZ21) was used for stimulus presentation and was calibrated with a colorimeter (PR650). The stimuli were defined by the DKL color space, that is, the luminance axis, the L-M axis and the S-(L+M) axis. In both monkeys, the correct ratio was significantly above chance for stimuli with the L-M component and the S(L+M) component. Control experiments were done to exclude the possibility that a small luminance difference from background may contribute to the above-chance performance. When a small positive or negative luminance difference (<5%) was added to the chromatic stimuli, the correct ratio was not decreased. On the other hand, the correct ratio was near the chance level when the achromatic stimuli with the same luminance difference were used. Our results suggest that unilateral ablation of V1 does not abolish the computation of color saliency. doi:10.1016/j.neures.2010.07.206
O2-8-3-4 Pairwise interactions account for correlated activity of neurons in the inferior temporal cortex of macaque monkeys Hiroshi Shiozaki 1 Fujita 1
, Taku Motonaga 2 , Hiroshi Tamura 1 , Ichiro
1
Grad Sch Frontier Biosciences, Osaka Univ, Osaka 2 Sch Engineering Science, Osaka Univ, Osaka Characterization of the activity of populations of neurons provides clues for the computation performed by neural circuits. Recent studies have shown spatial patterns that describe the activity of tens of retinal ganglion cells and neurons in the primary visual cortex can be explained by a model that incorporates firing rates of individual cells and pairwise interactions but ignores higher-order interactions. However, it remains unclear whether pairwise interactions account for the concerted activity of neurons in higher-order visual areas where dendritic morphology and local anatomical connections differ from those in the early visual processing stages. To address this issue, we simultaneously recorded the spike activity of a population of neurons in the inferior temporal cortex (ITC), a higher-order visual area, of two monkeys under analgesia. We obtained data from four populations consisting of 23, 25, 32, and 37 neurons over 15 to 60 minutes. The probability of the number of neurons that were active in the same 5-ms time bin systematically deviated from the prediction of a model that assumes statistical independence between the activity of different neurons. This deviation was largely explained by a model that takes into account pairwise interactions in addition to the firing rates of individual neurons. The pairwise model captured 94% of the deviations seen in the statistical independence model. To further test the pairwise model, we randomly selected subpopulations consisting of 10 neurons and examined the probability of the individual activity patterns of these subpopulations in a 5-ms time bin. The pairwise model predicted 88% of the deviations seen in the statistical independence model. From these results, we suggest that pairwise interactions account for correlated activity
Abstracts / Neuroscience Research 68S (2010) e55–e108
O2-8-3-1 Anatomical connectivity of color-processing modules in monkey inferior temporal cortex Taku Banno 1,2 , Noritaka Ichinohe 3,5 , Kathleen S. Rockland 4,5 , Hidehiko Komatsu 1,2 1
Division of Sensory and Cognitive Information, NIPS, Okazaki, Japan 2 SOKENDAI 3 Department of Neuroanat, Hirosaki Univ, Hirosaki, Japan 4 RIKEN-MIT Center for Neural Circuit Genetics, MIT, USA 5 Lab for Cort Org System, BSI, RIKEN, Wako, Japan Recent imaging and electrophysiological studies have revealed the presence of several distinct patches of color-selective regions in the anterior and posterior IT cortex (AIT and PIT). Although accumulating evidence from lesion and electrophysiological studies suggests that the color-selective region in AIT (AITC) is important for color vision, less is known about the input sources to AITC, and especially how these contribute to the color-related signals. In the present study, we combined anatomical tracing methods with electrophysiological identification of two color-selective regions in monkey IT cortex and investigated their anatomical connectivity. We found that AITC forms a strong reciprocal connection with the previously reported color-selective region in PIT (PITC), but mainly with its ventral part. The AITC also received inputs from discrete clusters of cells in other occipito-temporal areas, in superior temporal sulcus, and in prefrontal and parietal cortices. The distribution of the labeled cells is consistent with some of the color-selective regions revealed by recent imaging studies. By contrast, the dorsal part of PITC strongly projected to a separate AIT region, slightly posterior and dorsal to the AITC. These results suggest architecture of parallel color-processing pathways, demonstrated by an anatomically interconnected network of distributed color-processing modules in the monkey IT cortex. doi:10.1016/j.neures.2010.07.204
O2-8-3-2 Prediction of transient states during and after long-term chromatic adaptation Chihiro Imai 1 , Hideyuki Suzuki 1,2 1
Grad Sch Info & Sci., Univ of Tokyo, Tokyo 2 Inst Ind Sci., Univ of Tokyo, Tokyo
The visual system makes adaptive adjustments to maintain a stable color perception in chromatic environments changing in various time scales ranging from tens of milliseconds to several decades as senescent changes in ocular media density. Although the equilibrium yellow, the color perceived as neither reddish nor greenish, is profoundly changed by short-term adaptations, it returns to the normal perception immediately after the release from adaptations (Jameson, 1979). In contrast, recent studies report that long-term adaptations continuing for weeks shift the yellow perception progressively away from the normal, and the changed perceptions persist for weeks in the absence of exposure to chromatic alteration (Neitz, 2002; Blemore, 2008). However, existing computational studies are not enough to provide a unified model which accounts for both the brief and the sustained shifts in chromatic perception led by short- and long-term adaptations, respectively. Moreover, many of those models assume that the color appearances are already in the steady state, little focusing on the dynamics and the plasticity of the visual nervous system during the chromatic adaptation. In the present study, we propose a computational model of the primate visual pathway, which explains the change in color appearance during and after the adaptation with a broad range of temporal scales. Based on anatomical and physiological knowledge, the model assumes that the neuronal plasticity plays a key role in the long-term adaptations. Our model reproduces the dynamic properties of color vision reported in the previous experimental studies. Additionally, we applied the current model to various conditions of chromatic illumination, providing testable predictions on the color appearances and their dynamics in changing environments. doi:10.1016/j.neures.2010.07.205
O2-8-3-3 Visually guided eye movements based on color saliency in monkeys with unilateral lesion of primary visual cortex Masatoshi Yoshdia 1,2 , Launrent Itti 3 , David Berg 3 , Takuro Ikeda 1 , Rikako Kato 1 , Kana Takaura 1,2 , Tadashi Isa 1,2 1
Dept Dev Physiol, Nat’l Inst Physiol Sci, Okazaki, Japan 2 Sch. Life Sci., Grad. University Adv. Stud., Hayama, Japan 3 Viterbi school of engineering, University of Southern California, Los Angeles, USA We investigated residual visually-guided behavior in monkeys after unilateral ablation of primary visual cortex (V1), to unravel the contributions of V1 to salience computation. We analyzed eye movements of monkeys watching video stimuli and a computational model of saliency-based, bottom-up attention quantified the monkeys’ propensity to attend to salient targets. All monkeys were attracted towards salient stimuli, significantly above chance, for saccades directed both into normal and affected hemifields. We also quantified the contribution of visual attributes (intensity, color, motion and so on) to the saliency-based eye movements and obtained evidence that the guidance of gaze was influenced by color saliency in the V1-lesioned monkeys. Here we directly examined residual visuomotor processing based on color saliency with color discrimination tasks. In two monkeys after unilateral ablation of V1, the isoluminant, chromatic stimuli was presented in one of the two positions in their affected hemifield. The monkeys were rewarded by making saccade to the target. The CRT monitor (Mitsubishi DZ21) was used for stimulus presentation and was calibrated with a colorimeter (PR650). The stimuli were defined by the DKL color space, that is, the luminance axis, the L-M axis and the S-(L+M) axis. In both monkeys, the correct ratio was significantly above chance for stimuli with the L-M component and the S(L+M) component. Control experiments were done to exclude the possibility that a small luminance difference from background may contribute to the above-chance performance. When a small positive or negative luminance difference (<5%) was added to the chromatic stimuli, the correct ratio was not decreased. On the other hand, the correct ratio was near the chance level when the achromatic stimuli with the same luminance difference were used. Our results suggest that unilateral ablation of V1 does not abolish the computation of color saliency. doi:10.1016/j.neures.2010.07.206
O2-8-3-4 Pairwise interactions account for correlated activity of neurons in the inferior temporal cortex of macaque monkeys Hiroshi Shiozaki 1 Fujita 1
, Taku Motonaga 2 , Hiroshi Tamura 1 , Ichiro
1
Grad Sch Frontier Biosciences, Osaka Univ, Osaka 2 Sch Engineering Science, Osaka Univ, Osaka Characterization of the activity of populations of neurons provides clues for the computation performed by neural circuits. Recent studies have shown spatial patterns that describe the activity of tens of retinal ganglion cells and neurons in the primary visual cortex can be explained by a model that incorporates firing rates of individual cells and pairwise interactions but ignores higher-order interactions. However, it remains unclear whether pairwise interactions account for the concerted activity of neurons in higher-order visual areas where dendritic morphology and local anatomical connections differ from those in the early visual processing stages. To address this issue, we simultaneously recorded the spike activity of a population of neurons in the inferior temporal cortex (ITC), a higher-order visual area, of two monkeys under analgesia. We obtained data from four populations consisting of 23, 25, 32, and 37 neurons over 15 to 60 minutes. The probability of the number of neurons that were active in the same 5-ms time bin systematically deviated from the prediction of a model that assumes statistical independence between the activity of different neurons. This deviation was largely explained by a model that takes into account pairwise interactions in addition to the firing rates of individual neurons. The pairwise model captured 94% of the deviations seen in the statistical independence model. To further test the pairwise model, we randomly selected subpopulations consisting of 10 neurons and examined the probability of the individual activity patterns of these subpopulations in a 5-ms time bin. The pairwise model predicted 88% of the deviations seen in the statistical independence model. From these results, we suggest that pairwise interactions account for correlated activity