def get_probes(project_dict):
    """Gets the relevant probe ids from the project_dict

    Parameters
    ----------
    project_dict: dict
    A dictionary containing all the project's json values

    Returns
    -------
    probe_id_list_dict: dict
    a dictionary of lists of the session ids used by the project
    """
    probe_id_list_dict = project_dict['probes']
    return probe_id_list_dict