json unserialize or something else?

I have this in my usermeta table:

a:2:{s:5:"yesno";s:3:"yes";s:6:"updown";s:2:"up";}

How can I grab the values from it using php??

I have this but it produces nothing:

$jsonS2 = get_user_meta($user_ID,'wp_s2member_custom_fields');
$decoded = unserialize($jsonS2);
foreach ($decoded as $key => $val)
{
if($key==$field)
{
return "<span class=\"userinfo\">" . $val . "</span>";
}
}

any help would be appreciated.