Person:
Jakob, Elizabeth

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Professor, Department of Psychology, College of Natural Sciences
Last Name
Jakob
First Name
Elizabeth
Discipline
Psychology
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Introduction
I am a behavioral ecologist. My main study organisms are spiders. Questions that my students and I work on include the role of learning in spider behavior, the evolution of group living, and the role of behavior in the establishment of invasive species.
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Now showing 1 - 6 of 6
  • Publication
    Design of a Retinal Tracking System for Jumping Spiders
    (2011-01-01) Canavesi, Cristina; Long, Skye; Fantone, Dennis; Jakob, Elizabeth; Jackson, Robert; Harland, Duanne; Rolland, Jannick
    We designed an optical system for tracking the retinal movement of a jumping spider as a stimulus is presented to it. The system, using all off-the-shelf optical components except for one custom aspheric plate, consists of three sub-systems that share a common path: a visible stimuli presentation sub-system, a NIR illumination sub-system, and a NIR retinal imaging sub-system. A 25 mm clearance between the last element and the spider ensures a stable positioning of the spider. The stimuli presentation system relays an image from a display to the spider eye, matching the 15 arcmin resolution of the two principal eyes and producing a virtual image at a distance of 255 mm from the spider, with a visual full field of view of 52o . When viewing a stimulus, the spider moves its retinas, which cover a full field of view of only 0.6o , and directs them to view different places in the visual field. The retinal imaging system uses a NIR camera to track changes of 0.5o in the field of view seen by the spider. By tracking retinal movement across images presented to spiders, we will learn how they search for visual cues to identify prey, rivals, and potential mates.
  • Publication
    Retinal Imaging with Virtual Reality Stimulus for Studying Salticidae Retinas
    (2014-01-01) Schiesser, Eric; Canavesi, Cristina; Long, Skye; Jakob, Elizabeth; Rolland, Jannick
    We present a 3-path optical system for studying the retinal movement of jumping spiders: a visible OLED virtual reality system presents stimulus, while NIR illumination and imaging systems observe retinal movement.
  • Publication
    Plasticity, Learning and Cognition
    (2011-01-01) Jakob, Elizabeth; Skow, Christa Danielle; Long, Skye M
    As is becoming increasingly clear, spiders are not entirely instinct driven and inflexible in their behaviour. Here we review evidence for behavioural plasticity, learning and other cognitive processes such as attentional priming and memory. We first examine these attributes in several natural contexts: predation, interactions with conspecifics and potential predators, and spatial navigation. Next we examine two somewhat more artificial experimental approaches, heat aversion and rearing in enriched versus impoverished environments. We briefly describe the neurobiological underpinnings of these behaviours. Finally, we point to areas where our knowledge gaps are greatest, and we offer advice for researchers beginning their own studies of spider learning.
  • Publication
    The effect of visual features on jumping spider movements across gaps
    (2009-01-01) Baker, Liv; Kelty, Emma; Jakob, Elizabeth
    Our objective was to determine whether an animal’s decisions to cross inhospitable open space are influenced by the visual characteristics of targets it can see across the space. We studied jumping spiders (Salticidae) in the genus Phidippus. We considered the effect of target size (short vs. tall) and distance (close vs. distant) in no-choice experiments. How often spiders approached close targets, regardless of target size, was not significantly different from how often they approached tall, distant targets, but they approached close targets of either size significantly more often than short, distant targets. When presented simultaneously with short, close and tall, distant targets the spiders’ choices did not differ significantly from random. We also tested for the effects of the contrast of targets with their background and found that the spiders crossed open space to reach green, but not white, targets, regardless of background. Finally, spiders were more likely to approach a green grass-like target rather than a target composed of geometric shapes. We conclude that target size, distance and appearance all influence the spiders’ willingness to cross open space.
  • Publication
    Ontogenetic Shifts in the Costs of Living in Groups: Focal Observations of a Pholcid Spider (Holocnemus pluchei)
    (2000-01-01) Jakob, Elizabeth; Blanchong, Julie; Popson, Mary; Sedey, Kristine; Summerfield, Michael
    Holocnemus pluchei spiders (Family Pholcidae) facultatively live in groups: sometimes they live alone and sometimes they share webs. In the field groups vary in size and composition and include spiders of all ages and either sex. Group membership is flexible and individuals move frequently among groups. To understand group formation and maintenance it is necessary to understand the costs of group membership. We used focal animal sampling to investigate the cost of group living for spiders of different ages across a range of group sizes. Both spider age and group size affected the costs incurred by group-living spiders. There was no variation among groups of different sizes in the percentage of time focal small or large spiders spent in costly behaviors (moving, web maintenance, bouncing or interactions with conspecifics), but medium-sized spiders spent more time engaged in costly behaviors with increasing group size. Medium and large spiders also had more interactions with greater numbers of different conspecifics when they were in groups larger than three, whereas small spiders interacted rarely with conspecifics regardless of group size. These results suggest that there are significant ontogenetic shifts in the costs of group living in H. pluchei.