Hemifield-specific control of spatial attention and working memory: Evidence from hemifield crossover costs

Abstract

Attentional tracking and working memory tasks are often performed better when targets are divided evenly between the left and right visual hemifields, rather than contained within a single hemifield (Alvarez & Cavanagh, 2005; Delvenne, 2005). However, this bilateral field advantage does not provide conclusive evidence of hemifield-specific control of attention and working memory, as it can be explained solely from hemifield-limited spatial interference at early stages of visual processing. If control of attention and working memory is specific to each hemifield, maintaining target information should become more difficult as targets move between the two hemifields. Observers in the present study maintained targets that moved either within or between the left and right hemifields, using either attention (Experiment 1) or working memory (Experiment 2). Maintaining spatial information was more difficult when target items moved between the hemifields compared to when target items moved within their original hemifields, consistent with hemifield-specific control of spatial attention and working memory. However, this pattern was not found for maintaining identity information (e.g., color) in working memory (Experiment 3). Together, these results provide evidence that control of spatial attention and working memory is specific to each hemifield, and that hemifield-specific control is a unique signature of spatial processing.

Development of multiple object tracking via multifocal attention.

“…We did not observe any hemifield-specific tracking deficits at any of the age groups investigated, including adults, contrary to previous research (Minami et al, 2019; Strong & Alvarez, 2019). However, our task was designed for children, so both the rotational (225°/s) and crossover (45°/s) speeds were slower than in previous adult studies, which averaged 371°/s rotational speed and 208°/s degrees/second crossover speed (Strong & Alvarez, 2019).…”

“…Once reaching their final locations, the dot pairs orbited for another 2,000 ms, spinning in the same direction as they did during the shift between quadrants for at least 833 ms before again having a 1/75 chance of changing direction on each frame (following the same parameters as the first 2,000 ms of motion). Total movement lasted for 6.0 s. These parameters were selected based on a previous study using a similar design with adult participants (Strong & Alvarez, 2019). Critically, display parameters encouraged the use of multifocal attention over other potential strategies.…”

“…Adult participants clicked the target themselves. Note that participants did not know which pair would be probed; the probed pair was randomly selected on each trial (Strong & Alvarez, 2019). Participants received feedback on each trial.…”

“…Children may exhibit a bilateral field advantage similar to or greater than adults when tracking objects in separate hemifields. However, when the task requires integration of information across the hemifields, like when objects move between the hemifields (Minami et al, 2019; Strong & Alvarez, 2019), children may have more difficulty tracking that information.…”

“…We leveraged two previously used methods for investigating hemifield-specific processing in adults. In Experiment 1, we asked whether children and adults would show a “crossover cost” for tracking objects that move between compared to within hemifields, after Minami et al (2019) and Strong and Alvarez (2019). In Experiment 2, we asked whether children and adults would show a bilateral field advantage in tracking objects presented in separate hemifields compared to within the same hemifield, after Alvarez and Cavanagh (2005).…”