AntiReach

class braintools.cogtask.AntiReach(t_fixation=Quantity(500., 'ms'), t_stimulus=Quantity(500., 'ms'), t_delay=Quantity(500., 'ms'), t_response=Quantity(500., 'ms'), num_locations=8, anti_prob=0.5, noise_sigma=Quantity(1., 'ms^0.5'), **kwargs)

Anti-Reach (Anti-Saccade) task.

Agent must reach toward (pro) or away from (anti) a stimulus. Pro trials: respond toward stimulus location. Anti trials: respond opposite to stimulus location.

Structure: Fixation >> Stimulus >> Delay >> Response

Parameters:

• t_fixation (Quantity) – Fixation duration (default: 500ms).

• t_stimulus (Quantity) – Stimulus duration (default: 500ms).

• t_delay (Quantity) – Delay duration (default: 500ms).

• t_response (Quantity) – Response duration (default: 500ms).

• num_locations (int) – Number of possible stimulus/response locations (default: 8).

• anti_prob (float) – Probability of anti trial (default: 0.5).

• noise_sigma (Array | ndarray | bool | number | bool | int | float | complex | Quantity) – Stimulus noise (default: 1.0 * u.ms**0.5).

• seed (int, optional) – Random seed.

Examples

>>> task = AntiReach()
>>> task = AntiReach(num_locations=4, anti_prob=0.7)
>>> X, Y, info = task.sample_trial(0)

define_features()

Define input and output features.

Override in subclass for class-based task definition.

Return type:

Tuple

Returns:

• input_features (Feature or FeatureSet) – Input feature definitions.

• output_features (Feature or FeatureSet) – Output feature definitions.

define_phases()

Define the phase structure.

Override in subclass for class-based task definition.

Returns:

The task phase structure (single phase or composition).

Return type:

Phase

trial_init(ctx)

Initialize trial-level state.

Override in subclass to set up trial parameters like ground_truth, stimulus indices, etc.

Parameters:

ctx (Context) – Trial context to populate with state.

Return type:

None