The International Brain Bee: Cultivating the next generation of neuroscientists.

Brain Bees are neuroscience competitions for teenagers (age 13 through 19) hosted around the world. This article provides the history of the Brain Bee initiative, the recent formation of the IBB organization, the IBB World Championship, and how scientists, educators, and other organizations can contribute.

Facilitating pipeline progress from doctoral degree to first job.

The sequence of professional development within psychology from doctoral education to first job represents a period of remarkable professional and personal growth for each trainee. However, this sequence also contains a variety of barriers that hinder progress through the pipeline. The myriad individual-, program-, and system-level barriers encountered by trainees in health service/other applied service psychology and in research basic/applied psychology are identified. To actively and systematically facilitate improved passage through major transition points, individual trainee and trainer, program- and system-level action steps are recommended. In addition, emphasis is placed on ensuring that the psychology education and training culture prioritizes the progress, creativity, and flourishing of trainees and supports their movement through branching pipelines in their training and in their careers. (PsycINFO Database Record

Dissociation of pursuit target selection from saccade execution.

Pursuit and saccades almost always select the same target. Is this the results of a common selection process or does smooth pursuit obligatorily follow the stimulus targeted by saccades? To address this question, we used microstimulation of the primate superior colliculus (SC) to redirect the eyes from a selected pursuit target to a distracter moving in the opposite direction. During each trial, monkeys pursued a horizontally moving array of colored target stimuli. In half of the trials, this target array was accompanied by a distracter array moving horizontally in the opposite direction, offset by the vertical amplitude of the stimulation-evoked saccade. We stimulated the SC during maintained pursuit on half of the trials, and measured pursuit eye velocity during the 50-ms interval immediately following the stimulation-evoked saccade to the distracter array. Saccades evoked by SC stimulation did not alter pursuit target selection. Pursuit velocity on average changed by less than 10% of that expected if the monkey had completely switched targets. Moreover, the same changes in velocity occurred when there was no distracter, indicating that even these small changes in pursuit velocity were a direct effect of the evoked saccade, not partial selection of the distracter. These results show that motor execution of saccades is not sufficient to select a pursuit target, and support the idea that the coordination of pursuit and saccades is accomplished by a shared target selection process.

Spatial allocation of attention during smooth pursuit eye movements.

We used a dual-task paradigm to investigate the spatial allocation of attention during smooth pursuit. Subjects tracked one character in a translating string of characters (block letter 8's), and during maintained pursuit, one of the characters briefly changed to an E or 3. Based on the ability of subjects to correctly discriminate the probed character, we found that the primary focus of attention during smooth pursuit is centered on the tracked target with no appreciable lead or lag. Spatial cues were only partly effective in directing attention to other locations in our task, and these cueing effects were biased for locations ahead of the tracked target.

Gaze during visually-guided locomotion in cats.

Visual guidance is often critical during locomotion. To understand how the visual system performs this function it is necessary to know what pattern of retinal image motion neurons experience. If a locomoting observer maintains an angle of gaze that is constant relative to his body, retinal image motion will resemble Gibson's (The Perception of the Visual World (1950)) well-known optic flow field. However, if a moving observer fixates and tracks a stationary feature of the environment, or shifts his gaze, retinal motion will be quite different. We have investigated gaze in cats during visually-guided locomotion. Because cats generally maintain their eyes centered in the orbits, their gaze can be monitored with reasonable accuracy by monitoring head position. Using a digital videocamera, we recorded head position in cats as they walked down a cluttered alley. For much of the time, cats maintained a downward angle of gaze that was constant relative to their body coordinates; these episodes averaged 240 ms in duration and occupied 48-71% of the total trial time. Constant gaze episodes were separated by gaze shifts, which often coincided with blinks. Only rarely did we observe instances when cats appeared to fixate and track stationary features of the alley. We hypothesize that walking cats acquire visual information primarily during episodes of constant gaze, when retinal image motion resembles Gibson's conventional optic flow field.

Lesions of extrastriate cortex and consequences for visual guidance during locomotion.

One of the functions of the putative motion pathway in visual cortex may be visual guidance during locomotion. Using cats, we have investigated the role of the first area in this pathway, the lateral suprasylvian visual area (LS, often considered analogous to the primate area MT). Visual function during locomotion was tested by looking at the accuracy of foot placement as cats walked down a cluttered alley. Cats were tested before and after LS was lesioned bilaterally using ibotenic acid. In all four cats tested, partial lesions of LS caused a significant deterioration in the accuracy of foot placement, though cats showed no deficit in acuity or in pattern discrimination. To determine whether the observed deficit was specific to the motion pathway, in two additional cats lesions were made in the central field representation in area 19, which lies adjacent to LS but belongs to the putative object recognition pathway. Surprisingly, both cats showed significant improvements in their accuracy of foot placement during locomotion. The reason for this improvement was unclear.