Video_3_The Dominant Role of Visual Motion Cues in Bumblebee Flight Control Revealed Through Virtual Reality.MP4

<p>Flying bees make extensive use of optic flow: the apparent motion in the visual scene generated by their own movement. Much of what is known about bees' visually-guided flight comes from experiments employing real physical objects, which constrains the types of cues that can be presented. Here we implement a virtual reality system allowing us to create the visual illusion of objects in 3D space. We trained bumblebees, Bombus ignitus, to feed from a static target displayed on the floor of a flight arena, and then observed their responses to various interposing virtual objects. When a virtual floor was presented above the physical floor, bees were reluctant to descend through it, indicating that they perceived the virtual floor as a real surface. To reach a target at ground level, they flew through a hole in a virtual surface above the ground, and around an elevated virtual platform, despite receiving no reward for avoiding the virtual obstacles. These behaviors persisted even when the target was made (unrealistically) visible through the obstructing object. Finally, we challenged the bees with physically impossible ambiguous stimuli, which give conflicting motion and occlusion cues. In such cases, they behaved in accordance with the motion information, seemingly ignoring occlusion.</p

Video_8_The Dominant Role of Visual Motion Cues in Bumblebee Flight Control Revealed Through Virtual Reality.MP4

<p>Flying bees make extensive use of optic flow: the apparent motion in the visual scene generated by their own movement. Much of what is known about bees' visually-guided flight comes from experiments employing real physical objects, which constrains the types of cues that can be presented. Here we implement a virtual reality system allowing us to create the visual illusion of objects in 3D space. We trained bumblebees, Bombus ignitus, to feed from a static target displayed on the floor of a flight arena, and then observed their responses to various interposing virtual objects. When a virtual floor was presented above the physical floor, bees were reluctant to descend through it, indicating that they perceived the virtual floor as a real surface. To reach a target at ground level, they flew through a hole in a virtual surface above the ground, and around an elevated virtual platform, despite receiving no reward for avoiding the virtual obstacles. These behaviors persisted even when the target was made (unrealistically) visible through the obstructing object. Finally, we challenged the bees with physically impossible ambiguous stimuli, which give conflicting motion and occlusion cues. In such cases, they behaved in accordance with the motion information, seemingly ignoring occlusion.</p

Video_9_The Dominant Role of Visual Motion Cues in Bumblebee Flight Control Revealed Through Virtual Reality.MP4

<p>Flying bees make extensive use of optic flow: the apparent motion in the visual scene generated by their own movement. Much of what is known about bees' visually-guided flight comes from experiments employing real physical objects, which constrains the types of cues that can be presented. Here we implement a virtual reality system allowing us to create the visual illusion of objects in 3D space. We trained bumblebees, Bombus ignitus, to feed from a static target displayed on the floor of a flight arena, and then observed their responses to various interposing virtual objects. When a virtual floor was presented above the physical floor, bees were reluctant to descend through it, indicating that they perceived the virtual floor as a real surface. To reach a target at ground level, they flew through a hole in a virtual surface above the ground, and around an elevated virtual platform, despite receiving no reward for avoiding the virtual obstacles. These behaviors persisted even when the target was made (unrealistically) visible through the obstructing object. Finally, we challenged the bees with physically impossible ambiguous stimuli, which give conflicting motion and occlusion cues. In such cases, they behaved in accordance with the motion information, seemingly ignoring occlusion.</p

Video_6_The Dominant Role of Visual Motion Cues in Bumblebee Flight Control Revealed Through Virtual Reality.MP4

<p>Flying bees make extensive use of optic flow: the apparent motion in the visual scene generated by their own movement. Much of what is known about bees' visually-guided flight comes from experiments employing real physical objects, which constrains the types of cues that can be presented. Here we implement a virtual reality system allowing us to create the visual illusion of objects in 3D space. We trained bumblebees, Bombus ignitus, to feed from a static target displayed on the floor of a flight arena, and then observed their responses to various interposing virtual objects. When a virtual floor was presented above the physical floor, bees were reluctant to descend through it, indicating that they perceived the virtual floor as a real surface. To reach a target at ground level, they flew through a hole in a virtual surface above the ground, and around an elevated virtual platform, despite receiving no reward for avoiding the virtual obstacles. These behaviors persisted even when the target was made (unrealistically) visible through the obstructing object. Finally, we challenged the bees with physically impossible ambiguous stimuli, which give conflicting motion and occlusion cues. In such cases, they behaved in accordance with the motion information, seemingly ignoring occlusion.</p

Video_2_The Dominant Role of Visual Motion Cues in Bumblebee Flight Control Revealed Through Virtual Reality.MP4

<p>Flying bees make extensive use of optic flow: the apparent motion in the visual scene generated by their own movement. Much of what is known about bees' visually-guided flight comes from experiments employing real physical objects, which constrains the types of cues that can be presented. Here we implement a virtual reality system allowing us to create the visual illusion of objects in 3D space. We trained bumblebees, Bombus ignitus, to feed from a static target displayed on the floor of a flight arena, and then observed their responses to various interposing virtual objects. When a virtual floor was presented above the physical floor, bees were reluctant to descend through it, indicating that they perceived the virtual floor as a real surface. To reach a target at ground level, they flew through a hole in a virtual surface above the ground, and around an elevated virtual platform, despite receiving no reward for avoiding the virtual obstacles. These behaviors persisted even when the target was made (unrealistically) visible through the obstructing object. Finally, we challenged the bees with physically impossible ambiguous stimuli, which give conflicting motion and occlusion cues. In such cases, they behaved in accordance with the motion information, seemingly ignoring occlusion.</p

Video_4_The Dominant Role of Visual Motion Cues in Bumblebee Flight Control Revealed Through Virtual Reality.MP4

<p>Flying bees make extensive use of optic flow: the apparent motion in the visual scene generated by their own movement. Much of what is known about bees' visually-guided flight comes from experiments employing real physical objects, which constrains the types of cues that can be presented. Here we implement a virtual reality system allowing us to create the visual illusion of objects in 3D space. We trained bumblebees, Bombus ignitus, to feed from a static target displayed on the floor of a flight arena, and then observed their responses to various interposing virtual objects. When a virtual floor was presented above the physical floor, bees were reluctant to descend through it, indicating that they perceived the virtual floor as a real surface. To reach a target at ground level, they flew through a hole in a virtual surface above the ground, and around an elevated virtual platform, despite receiving no reward for avoiding the virtual obstacles. These behaviors persisted even when the target was made (unrealistically) visible through the obstructing object. Finally, we challenged the bees with physically impossible ambiguous stimuli, which give conflicting motion and occlusion cues. In such cases, they behaved in accordance with the motion information, seemingly ignoring occlusion.</p

Mean number ± SE of sensilla for the right antenna (white bars) and for the left antenna (grey bars) of <i>Bombus terrestris</i> foragers in function of the segment number.

<p>Putative olfactory sensilla: placodea, trichodea type A, basiconica, coeloconica (upper graphs). Non-olfactory sensilla: trichodea type B, ampullacea (lower graphs). Data were analyzed by ANOVA with antenna, segment and sensilla as within-subjects factor. An overall antenna effect emerged (F_1,13 = 22.56, p<0.001). A significant effect of segment (F_7,91 = 43.20, p<0.001), sensillum type (F_5,65 = 396.40, p<0.001) and antenna per sensillum type interaction (F_5,65 = 17.89, p<0.001) was revealed. Asterisks indicate a significant right antenna dominance in the number of olfactory sensilla trichodea type A (F_1,13 = 21.26, p<0.001). No significant antenna effects were found in the number of sensilla basiconica (F_1,13 = 1.47, p = 0.247), sensilla coeloconica (F_1,13 = 3.61, p = 0.08) and sensilla placodea (F_1,13 = 0.97, p = 0.342). Analyses of non-olfactory sensilla did not reveal any significant difference between right and left antennae in the number of sensilla trichodea type B (F_1,13 = 3.45, p = 0.086) and sensilla ampullacea (F_1,13 = 0.10, p = 0.755).</p

Mean EAG ± SE absolute responses (mV) of right (unbroken lines with black squares) and left (dotted lines with empty squares) antenna of <i>Bombus terrestris</i> foragers (N = 20) to isoamyl acetate (left) and (-)-linalool (right) at five different doses (Log₁₀ µg/µl).

<p>No significant differences were found between the antennae (ANOVA: F_1,19 = 2.72, p = 0.12). Significant effects of both dose (ANOVA: F_4,16 = 42.52, p<0.001) and scent (ANOVA: F_1,76 = 107.61, p<0.001) were revealed.</p

Behavioural asymmetry during recall of short-term odour memory in <i>Bombus terrestris</i> foragers, after trained on the proboscis extension reflex.

<p>Mean percent correct responses ± SE 1 h after (-)-linalool conditioning with both antennae in use (white bars), right antenna in use only (grey bars), or left antenna in use only (black bars). A significant effect of the antenna in use was found (ANOVA: F_2,27 = 80.86, p<0.001). Post hoc comparison using Tukey HSD test revealed a significant difference between bees using their right and their left antenna (p<0.001), and between bees using their left antenna and those using both antennae (p<0.001) and between bees using their right antenna and bees using both antennae (p<0.01).</p

Scanning electron micrographs of <i>Bombus terrestris</i> foragers.

<p>(a) ventral view of a medial segment of the flagellum; (b) details of sensillum trichodeum type A, type B and sensillum placodeum; (c) details of sensillum coeloconicum, ampullaceum, trichodeum type B and setae; (d) detail of sensillum basiconicum. Am, sensillum ampullaceum; Ba, sensillum basiconicum; Co, sensillum coeloconicum; Pl, sensillum placodeum; Se, seta; TA, sensillum trichodeum type A; TB, sensillum trichodeum type B.</p