Based on animal head positions in a V-shaped tunnel, calc_sf_V() calculates how the animal perceives the spatial frequency of lateral visual stimuli as modulated by distance to the stimulus.

calc_sf_V(
  obj_name,
  vertex_angle,
  stim_param_pos,
  stim_param_neg,
  simplify_output = FALSE
)

Arguments

obj_name

The input viewr object; a tibble or data.frame with attribute pathviewR_steps that includes "viewr"

vertex_angle

The angle (in degrees) subtended by a vertical axis and the sides of the tunnel. Equivalent to the angle of the "V" divided by 2. vertex_angle) defaults to 45.

stim_param_pos

The length (in meters) of the visual stimulus presented on the positive side of the tunnel (i.e. position_width >= 0). For example, a sinusoidal grating 10cm wide is stim_param_pos = 0.1

stim_param_neg

The same convention as stim_param_pos but for stimuli presented on the negative side of the tunnel (i.e. position_width < 0).

simplify_output

If TRUE, the returned object includes minimum distance as well as the spatial frequencies perceived on either side of the tunnel. If FALSE, the returned object includes all variables internal to the calculation.

Value

A tibble or data.frame with added variables for s_freq_pos and s_freq_neg reported in cycles per 1deg of visual angle.

Details

cal_sf_V assumes fixed gaze at the point on the either side of the tunnel that minimizes the distance to visual stimuli and thereby minimizes spatial frequencies.

See also

Other visual perception functions: calc_sf_box(), calc_vis_angle_V(), calc_vis_angle_box()

Author

Eric R. Press