After a lot of search and trial & errors, I figured out this (semi) solution: simply generate abstract and keywords manually, i.e., do not provide this `fields' in preamble. However, I added small preamble-snippet for changing margins to make abstract prettier. This will cause warning messages, but the output will look nicer. Here is the corrected code from the above:
\documentclass[doc,11pt,a4paper,natbib,floatsintext]{apa6}
\usepackage[german,serbian,american]{babel}
\usepackage[T1]{fontenc}
\usepackage{graphicx}
\usepackage{tabulary}
\usepackage{multirow}
\usepackage{rotating}
\usepackage{xspace}
\usepackage{color}
\usepackage{url}
\usepackage{times}
\usepackage{amssymb}
\usepackage{amsmath}
\usepackage{csquotes}
%-- Margins change
\def\changemargin#1#2{\list{}{\rightmargin#2\leftmargin#1}\item[]}
\let\endchangemargin=\endlist
\shorttitle{Revision revisited}
\leftheader{Myname, Hername, Hisname, Hername, Hisname}
\title
{Processing parts and a whole:
\protect\\
An information-theoretic approach to some interesting stuffs}
\fiveauthors
{Myname Mysurname}{Hername Hersurname}{Hisname Hissurname}
{Hername Hersurname}{Hisname Hissurname}
\fiveaffiliations
{My affiliation at the University of something \&
My second affiliation at the University of something else}
{Her affiliation at the University of something}
{His affiliation at the University of something}
{Her affiliation at the University of something \&
Her second affiliation at the University of something else}
{His affiliation at the University of something \&
His second affiliation at the University of something else}
\authornote{
Please send correspondence to me: \\
Email: first.author@something.edu \\ \ \\
\noindent
This research was supported some guys.
}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\begin{document}
\maketitle
\vspace*{2\baselineskip}
\begin{changemargin}{2cm}{2cm}
{\small{
\begin{center}
{\bf Abstract}
\end{center}
Converting light into matter may sound like alchemy, but it's a natural outcome
of physics – one that scientists have been demonstrating to varying degrees for
decades. Now, a team of European physicists is proposing a way to do it much
more simply.
If the approach works as the researcher's initial calculations suggest, the
results are unlikely immediately answer any vexing question, physicists say. The
fundamental science behind the process of turning light to matter is already
well understood. But it would be a new tool in physicists' toolkit.
Currently, the process of getting packets of light, known as photons, to collide
and make particles can be a complicated business, requiring a few tricks. But
the new technology might enable a range of new experiments, which could lead to
unexpected answers or uses.
The tool is a collider for photons, the subatomic particles associated with
visible light and other forms of electromagnetic radiation, such as radio waves
and gamma rays. By crashing them head-on, the collider would turn the photons
into electrons and their anti-matter counterparts, positrons. Calculations
suggesting how this might work appear in the current issue of the journal
Nature Photonics.
The theory behind this was first proposed in 1934 by two American physicists,
Gregory Breit and John Wheeler. But it wasn't until 1997 that scientists
working at the Stanford Linear Accelerator Center (SLAC) in Stanford, Calif.,
were able to successfully carry out the first true photon-to-photon collision
and create the two particles.
They did it by using electrons to ricochet light back into itself. The team
accelerated a beam of electrons to high energies, then blasted the beam with a
laser. Some of the photons in the laser scattered off these electrons, traveling
back toward the laser beam and picking up energy in the process. When these
higher-energy photons collided with additional photons the laser was sending
out, the collisions produced pairs of electrons and their antimatter
counterparts, positrons.
Keywords: one, two, three, four, five
}}
\end{changemargin}
\vspace*{4\baselineskip}
\section{Introduction}
Converting light into matter may sound like alchemy, but it's a natural outcome
of physics – one that scientists have been demonstrating to varying degrees for
decades. Now, a team of European physicists is proposing a way to do it much
more simply.
If the approach works as the researcher's initial calculations suggest, the results
are unlikely immediately answer any vexing question, physicists say. The fundamental
science behind the process of turning light to matter is already well understood.
But it would be a new tool in physicists' toolkit.
Currently, the process of getting packets of light, known as photons, to collide
and make particles can be a complicated business, requiring a few tricks. But the
new technology might enable a range of new experiments, which could lead to
unexpected answers or uses.
The tool is a collider for photons, the subatomic particles associated with visible
light and other forms of electromagnetic radiation, such as radio waves and gamma
rays. By crashing them head-on, the collider would turn the photons into electrons
and their anti-matter counterparts, positrons. Calculations suggesting how this
might work appear in the current issue of the journal Nature Photonics.
The theory behind this was first proposed in 1934 by two American physicists,
Gregory Breit and John Wheeler. But it wasn't until 1997 that scientists working
at the Stanford Linear Accelerator Center (SLAC) in Stanford, Calif., were able to
successfully carry out the first true photon-to-photon collision and create the two
particles.
They did it by using electrons to ricochet light back into itself. The team
accelerated a beam of electrons to high energies, then blasted the beam with a
laser. Some of the photons in the laser scattered off these electrons, traveling
back toward the laser beam and picking up energy in the process. When these
higher-energy photons collided with additional photons the laser was sending out,
the collisions produced pairs of electrons and their antimatter counterparts,
positrons.
\end{document}
And now, the first page looks better (I think):
Best Answer
The
apa6class defines two page styles:titlepageandotherpage. The phrase "RUNNING HEAD" will appear only on pages with thetitlepagestyle. Assuming you want this phrase to appear only on theapa6title page and not on your extra title page, we can do this by using\thispagestyle{titlepage}before the\maketitlecommand: