


































v1i2


Volume 1, Issue 2

The Conscious Unit (CU) model

A preliminary outline of a new approach to consciousness

Sam S. Rakover
DOI: 10.33014/issn.2640-5652.1.2.rakover.1

Abstract

The present paper attempts to handle the question how
an unconscious mental state (MS) is transformed into a
conscious-MS, by developing an outline of a new model,
the conscious unit (CU) model. The essential assumption
of this model is as follows: In the cognitive system exists
an inborn, special linking-mechanism that connects a MS
to a CU, i.e., a unit of consciousness (or a stream of such
units when represented by the MS is complex). As a re-
sult, the individual becomes aware (conscious) of the MS
representation. This model was applied successfully to cer-
tain empirical observations and to several problems, which
were directed toward the higher-order (HO) theories of con-
sciousness [especially the higher-order thought (HOT) the-
ory].

1 Introduction

Explaining consciousness is a core issue that has baffled
philosophers and psychologists for decades. There is cur-
rently no accepted theoretical solution to this issue and
the various existing explanatory attempts are under con-
tinuing debate (see Carruthers, 2016; Gennaro, 2004, 2017;
MacPhial, 1998; Rakover, 2007; Gulick, 2017). The present
paper discusses the following two related sub-questions:
what makes a mental state (MS) a conscious-MS? How is
an unconscious-MS transformed into conscious-MS?

Before beginning this discussion, I will clarify two impor-
tant concepts: MS and consciousness. For the present paper
a MS is described in the most general way by employing the
following delineation of representation. A system T repre-
sents a system O, when T’s symbols and their relations map
certain aspects of O and their relation. A MS can repre-
sent either an individual’s external world or inner private
world. For example, a blue and red parrot can be repre-
sented in one’s cognitive system by a hypothetical internal
symbol (the representation can be pictorial or propositional
but it cannot be a tiny bird in one’s head), the content of

a book, and even a chimera of a male body with a parrot’s
head singing the aria Casta Diva from Norma by Bellini
(e.g., Goldstein, 2011; Rakover, 1990). These representa-
tions mediate between the external world (the stimulus sit-
uation) and the individual’s response.

Consciousness is a very complex and controversial concept
(e.g., Gennaro, 2004, 2017; Gulick, 2017). In comparison,
the emotion of fear has, under different conditions, sev-
eral behavioral expressions (escape, freeze, or attack) (e.g.,
Rakover, 1975), but except in the extreme case where a
patient is not aware of an object that is detected easily
by a normal person, no such behavioral response exists for
consciousness. For the present paper I will refer to con-
sciousness as it is expressed by the following example. It
takes a few seconds to become conscious of the environment
in which I exist in, my body’s posture, some of my emo-
tions and thoughts that are running through my mind (I
am also aware of part of my consciousness) and above all, I
am conscious of being alive, i.e., I have the most basic com-
ponent of consciousness: the aliveness-feel. This feel gives
meaning to the representations. In view of this, I propose
that what differentiates a human being from a robot is not
the human’s behavior, which can be imitated by a robot,
but the aliveness-feel that a human being experiences but
which a robot does not.

Given these clarifications, I will now discuss the above
two questions. They have received elaborated answers in
higher-order (HO) theories of consciousness which appeal
to certain cognitive system ignoring brain neurophysiology.
Essentially, these theories are variations on the following
basic idea: a MS becomes a conscious-MS when it is related
by a higher-order MS. For example, my MS (desire to drink
hot tea) becomes conscious-MS when I think about my de-
sire (I become aware of my desire to drink hot tea). Two
important theoretical variations of HO theories are these:
the higher-order thought (HOT) is based on the idea that
higher-order MS is interpreted as a thought (e.g., Rosenthal,
2004), whereas the higher-order perception (HOP) inter-
prets higher-order MS as a perceptual state (Lycan, 2004).
The HO theories have encountered several objections (e.g.,
Byrne, 1997; Carruthers, 2016; Gennaro, 2004, 2017). Al-



6 The Conscious Unit (CU) model

Figure 1: Abbreviations and Nomenclature

MS mental state
CU conscious unit
Linkage CU/MS a connection between a

MS and a CU or a
stream of CUs when
the thing represented
by the MS is complex
is made by an inborn
special
cognitive-mechanism

Link-Condition the CU is linked to a
MS when the
link-condition is
realized in the
cognitive system

Connecting-System the connections among
MS, CU and the
Link-Condition

Linking-mechanism an inborn special
mechanism that
connects a CU to a MS

STM (LTM) short-term
(long-term)-memory

HO (LO) mental state higher-order
(low-order) mental
state

HO theories higher-order theories
HOP theory higher-order perception

theory
HOT theory higher-order thought

theory
Train Ride the example situation

demonstrating the
concepts related to the
CU

though these theories suggested replies to these objections,
the polemics continues. This paper concentrates on HOT
because the major part of the dispute targets HOT. The ob-
jections to this theory can be understood intuitively, and
most of these disagreements can be generalized to other HO
theories.

The present paper offers a preliminary CU sketch-model
that can propose explanations for certain empirical observa-
tions and solutions for some of the objections aimed against
HOT. It also sheds new light on the two questions raised
above. This CU model is not developed on Marr’s (1982)
realization (neurophysiological) level or the algorithm level,
but rather on the functional level. On this level, the model
is characterized in terms of its goals; how the model op-
erates (e.g., the stages in the information processing); and
the rationale and justification on which it is based.

The CU model is developed primarily as an explanation for
the following core empirical observation, called the "Train
Ride": David traveled from town A to town B by a train.
He sat in his compartment and thought about the goals of
his travel requiring him to get off the train at B-station
and meet the secretary of Dr. Arnold, Miss Smith, who
offered him a new job (this thought is called The Goal).
The journey took about two hours and during that time
David focused on a detective novel he was reading, and
ignored The Goal. At B-station David got off the train,
thought about The Goal, and was also aware that he was
thinking of The Goal. He was happy to see a Lady holding
a banner on which his name was written and immediately
realized that she must be Miss Smith, the secretary of Dr.
Arnold.

To explain the behavior of David on the Train Ride the
present CU model attempts to answer the following ques-
tions: what makes The Goal conscious (i.e., the MS (The
Goal) conscious)? How is the unconscious The Goal trans-
formed into a conscious one at the end of the journey? And
how was it possible for David to be aware of his awareness?

In the next section the UC sketch-model is presented and
the core observation is accounted for. Then it will examine
if it can tackle several objections presented to the HOT. If it
can provide simple and straightforward answers to several
problems with the HOT, this will support the suggestion
that the CU model is worthwhile. Finally, the advantages
vs. disadvantages and the model justifications will be dis-
cussed by describing the fundamental reasons and consid-
erations motivating the development of the CU model.



Volume 1, Issue 2

2. THE CONSCIOUS UNIT (CU) MODEL: A PRELIMINARY SKETCH 7

Figure 2: Notation for Representing Mental States
and Consciousness

MS(cat) a mental state
representing a cat

CU/MS(cat) a CU linked to the MS
representing a cat

MS*[CU/MS(cat)] the CU/MS(cat) is
represented by a
different symbol or by
a different representing
state called MS*(MS #
MS*)

CU/MS*[CU/MS(cat)] since the new
MS*[CU/MS(cat)] is in
the Link-Condition, a
CU is linked to
MS*[CU/MS(cat)], i.e.,
CU/MS*[CU/MS(cat)]

2 The Conscious Unit (CU) model:
A preliminary sketch

The CU model is based on several assumptions which
should be viewed as theoretical statements evaluated in
terms of the degree of success in proposing sound expla-
nations for different observations, and also to respond to
certain objections raised against other consciousness the-
ories (HOT). No theory that describes how brain activity
can be transformed into the processes of consciousness ex-
ists (e.g., Chalmers, 2007). Furthermore, I have no knowl-
edge of any association between certain neurophysiological
activity in the brain and what I term the conscious unit.
The CU model is based on purely theoretical concepts and
can be evaluated in terms of its explanatory usefulness.

Assumption (1). The conscious unit (CU). The individ-
ual becomes conscious (aware) of the content represented
by a MS in the following way. There is an inborn spe-
cial cognitive linking-mechanism that connects to a MS a
unit of consciousness (CU) or a stream of CUs when the
content represented by the MS is complex, called "linkage
CU/MS". That is, when the linkage CU/MS is activated,
the individual enters the state of being conscious of the
thing represented by the MS. One possible interpretation
of CU is as follows. CU may be viewed as the rudimentary
aliveness-feel. When this unit or a stream of units are linked
to a MS, the thing represented by it becomes conscious and
meaningful.

Assumption (2). The Link-Condition. The CU is linked to
a MS when a certain condition is realized in the cognitive

system called the "Link-Condition”. Five sub-assumptions
construct the connections among MS, CU and the Link-
Condition called the "Connecting-System":

(a) the CU can be linked to MS only when the MS enters,
or is in the Link-Condition;

(b) the CU cannot be linked to a MS more than once.
(Without this sub-assumption the same MS can be be-
stowed with CU infinitely.)

(c) when the Link-Condition ceases, the CU previously
linked to MS is now removed from that MS and it
becomes unconscious (a re-entrance of that MS to the
Link-Condition re-grants it CU)1;

(d) The linking of CU to MS or its removal from MS is
automatic, unconscious and a very fast cognitive oper-
ation;

(e) at a given time, the Link-Condition can encompass
a limited number of MSs. [Usually one MS (e.g., a
thought, an image, a view) at a time.]

Assumption (3). The entrance of a new-MS to the Link-
Condition. This situation is associated with three possibil-
ities:

(a) The new-MS acquires a CU. Thus the individual be-
comes conscious (aware) of what is represented by that
MS;

(b) Since the Link-Condition encompasses a limited num-
ber of MSs, the previous CU/MS makes room for the
new-MS and loses its CU. Thus the individual ceases
to be aware of the previous MS;

(c) If the new-MS supplements the information of the pre-
vious CU/MS, both the new and the previous MSs are
linked to CUs. Thus the individual becomes conscious
of both MSs as parts of a whole picture.

Here are two examples. First, I see a white-house in front
of me (I am aware of the white-house). I turn around and
see a black cat (I am now aware of the black cat). I do
not continue to be conscious of the white-house but only
of the black cat. (Usually, in daily life, I do not expe-
rience an afterimage. Furthermore, I do not develop the
belief that the white-house disappears, since when I turn

1Can assumption 2c be gradual? Theoretically the answer can be
yes, but for the sake of simplicity the Link-Condition is dichotomized.
Furthermore, this assumption fits the fact that one is conscious of
object A but when one turns the head she instantly becomes conscious
of object B and not of A.



8 The Conscious Unit (CU) model

around I see the house again and also I have the memory
of seeing this house before.). The CU is removed from the
MS (white-house) and it is transformed into an unconscious
MS. Secondly, I see a person before me, who says "What’s
up my dear friend?" After a second I become aware that
this is my good buddy from the army whom I haven’t seen
for many years, and I respond "Hey Dan, it’s good to see
you, how are you?" In this second case the conscious infor-
mation about Dan’s identity (good buddy) is added to the
information about the person I see in front of me, i.e., it
supplements the conscious information about that person.

Assumption (4). CU simplicity and MS complexity. The
CU is a uniform rudimentary unit. However, conscious
awareness changes in quality and degree as a result of
changes in the thing represented by the MS. For example,
one’s consciousness of a cat is different from one’s conscious-
ness of a dog; and one’s degree of awareness of the center
of a landscape picture is higher than of one’s awareness of
the picture’s margins. A CU can be linked to a MS com-
posed of one salient element (e.g., a black spot on a white
wall) or of many elements (e.g., landscape). In the latter
case, a CU is linked to each element of the landscape view
in a way similar to a stream of electrons running through
the TV screen to build an entire picture. Furthermore, one
may affect the thing represented by a MS (e.g., landscape)
by several simple manipulations, such as narrowing eyes,
staring, and concentrate one’s attention.

Assumption (5). Competition between external and internal
MSs. When two MSs, one from the external world and one
from the individual’s inner world, enter the Link-Condition,
only the external MS is linked with CU. However, certain
manipulations can change or block this linkage. For exam-
ple, if I see a cat and, at the same time, the face of a movie
star is retrieved from my Long-Term Memory, only the cat
is linked to CU. However, if I stare (have a glazed look) or
close my eyes and concentrate on the appropriate retrieved
memory, I can consciously remember the movie star’s face.

Assumption (6) Awareness of consciousness. One can be
aware of one’s consciousness in the following way, as il-
lustrated by an example. I consciously see a cat, i.e.,
my MS(cat) is linked to CU [i.e., CU/MS(cat)]. I can
be aware of being conscious of a cat (according to sub-
assumption (2b) a MS cannot grant a CU more than
once) if the CU/MS(cat) is represented by a different
symbol or by a different representing state called MS*,
i.e., MS*[CU/MS(cat)]. Since MS*[CU/MS(cat)] is in the
Link-Condition, a CU is linked to MS*[CU/MS(cat)], i.e.,
CU/MS*[CU/MS(cat)]. This means that I am aware of be-
ing conscious of a cat. This situation of being aware of
awareness can be achieved by concentrating my inner at-
tention on the CU/MS(cat). Usually, one becomes aware

of seeing a cat by 1) concentrating attention on being aware
of the cat, 2) by using a language to represent this event,
e.g., by thinking: I am aware that I am consciously seeing
a cat.

Given the description of the CU sketch-model, I shall at-
tempt (a) to interpret David’s behavior in the Train Ride
in terms of the model and (b) to show that the CU model
may suggest simple and straightforward explanations for
some of the objections to the HOT.

2.1 The Train Ride

According to assumptions (1), (2) and also (4) (since the
present observation deals with complex MSs) one may un-
derstand that David becomes conscious of The Goal (he has
to get off the train at B-station and meet Miss Smith, the
secretary of Dr. Arnold who has offered him a new job),
since this thought was in the Link-Condition and the CU
has been attached to it. That is, the Connecting-System
has been activated. (Note that the sketch-model does not
provide an explanation of how the Connecting-System has
been executed by specifying the appropriate mechanisms.
It is a description on the functional level. As mentioned no
theory exists that details the connection between the neuro-
physiological activity of the brain and this specific processes
of the mind.) These assumptions and assumption (3) may
account for the fact that David is not conscious of The Goal
while traveling in the train, since he is aware of the novel’s
new information and The Goal makes room for the new
information. When the train stops at B-station The Goal
re-enters the Link-Condition and it is re-granted CU (see
assumption 2c). The end of the Train Ride is as follows: "At
B-station David thought about The Goal, got off the train
and was thinking that he was thinking of The Goal. He was
happy to see a Lady holding a banner on which his name
was written and he immediately thought that she must be
Miss Smith." The situation in which David is aware of his
awareness can be handled by assumption (6) and the fact
he believes that the woman with the banner is Miss Smith
can be treated by assumptions (3), (4) and (5), which deal
with new vs. old MSs and the relation between external
(the lady with the banner) and internal information (the
stored information about Miss Smith).

2.2 Objections to the HOT

In this section I present several interesting objections pre-
sented to HOT and show how the CU sketch-model can
effectively cope with them. These disagreements are still
in dispute (for other disagreements see Byrne, 1997; Car-



Volume 1, Issue 2

2. THE CONSCIOUS UNIT (CU) MODEL: A PRELIMINARY SKETCH 9

ruthers, 2016; Gennaro, 2004, 2017). Note that my in-
tention is not to critically survey these objections, but to
emphasize that, because of the straightforwardness of the
present model’s explanations, it may be perceived as receiv-
ing methodological support.

(1) Logical problems: Since a MS becomes a conscious-MS
by its relation to a higher-order thought (HOT), a question
arises: how has HOT itself become a conscious-MS? This
question leads to an infinite regress. When HOT is con-
scious, the problem of circularity arises since consciousness
is explained by the fact that one is conscious. A possi-
ble reply is to suggest that HOT is unconscious. Unfor-
tunately, however, the assumption about unconsciousness
raises other problems, which I do not see how they can be
solved. It has been proposed that when two unconscious-
MSs are related [the HO mental-state is related to a lower-
order (LO) one] the LO mental state becomes conscious
(e.g., Gennaro, 2004, 2017). Given this, and the reasonable
hypothesis that there is a huge amount of unconscious-
MSs, one may wonder how it is that one’s mind is not
flooded with conscious-MSs caused by random relations
among these unconscious-MSs. Furthermore, if one ac-
cepts that a conscious-MS is not created randomly, then
one has to develop a very sophisticated unconscious mech-
anism which matches two relevant unconscious-MSs (one of
them HO and the other LO) without any inner conscious
guidance. In my view, this is difficult, if not impossible, to
achieve.

By contrast, the CU sketch-model is not bothered by these
objections because the linking of the CU to a MS is carried
out by an inborn automatic process, the activation of the
Connecting-System. Hence no need exists to attempt to
avoid infinite regress and circularity.

The Connecting-System (especially sub-assumption 2e) has
certain similarities to the well-known metaphors of short-
term-memory (STM), the inner visual spotlight, and Den-
nett’s (1991) Cartesian theater. The major focus of these
metaphors is to deal with the fact that a limited amount of
information can be encompassed in consciousness. While
the two first metaphors are anchored to experimental re-
sults (e.g., free recall in the case of STM and the distribu-
tion of spatial attention in the case of the visual spotlight)
Dennett’s Cartesian theater is a sarcastic concept used to
point out the fact that in the end, the explanation of con-
scious perception is based on a homunculus who sits in a
tiny theater in the head and consciously watches what is
staged there.

Nevertheless, the present model is different from these
metaphors because it is essentially founded on a functional
process. First, the CU sketch-model does not locate the

Link-Condition anywhere in the mind/brain – it is de-
lineated theoretically; secondly, as mentioned above, the
model does not attempt to suggest a theory of how con-
sciousness emerges from the neurophysiology of the brain –
it assumes that a rudimentary innate CU is linked to a MS
under a certain condition, the Link-Condition. Note that
the assumption about CU can be viewed as a necessary con-
dition for conferring consciousness, since only when a MS
is in the Link-Condition is it attached to the CU.

(2) Necessary and sufficient conditions: These objections
suggest that HOT is not a necessary or a sufficient condi-
tion for phenomenal consciousness. It is unnecessary, since
phenomenal consciousness can occur without high-order
thoughts; it is not sufficient, since high-order thoughts can,
and does, occur without phenomenal consciousness. [Note
that “phenomenal consciousness” is referred to in the liter-
ature by similar expressions such as “qualitative property
of consciousness,” “qualia,” "what it is like" (e.g., Nagel,
1974), “hard problem of consciousness” (e.g., Chalmers,
1996).]

Necessary condition – Animal consciousness: Today
many animal behavior researchers agree that at least the
“supreme” animals (e.g., apes, dogs, cats, dolphins, etc.)
have phenomenal consciousness, meaning they are con-
scious of the information detected by their senses (e.g.,
seeing, hearing, touching) and their emotions (e.g., pain,
fear, pleasure by tickling) (see Allen and Trestman, 2016;
Rakover, 2007; Seager, 2004). The problem for HOT is
that these MSs have to be enhanced with consciousness by
HOTs, but there are major doubts whether animals (also
infants) possess such advanced higher-order MSs. How one
can explain the consciousness attributed to animals with-
out having HOTs has sparked a hot dispute. What I would
like to do here is not critically review this controversy, but
show that the CU sketch-model can handle this problem
quite straightforwardly.

Since it is assumed that CU is rudimentary, uniform and
innate, in accordance with the evolution theory one may
suggest that the Connecting-System can be found also
in animals’ cognitive systems, hence these animals may
have consciousness (e.g., Rakover, 2007). But, as men-
tioned, it is doubtful that animals possess the ability of self-
consciousness or of being aware of awareness. For example,
continuing debate exists whether Gallup’s Mirror Test can
provide unequivocal experimental results that indicate self-
recognition in animals (e.g., a chimpanzee recognizes itself
in the mirror) (see e.g. Allen and Trestman, 2016; Gallup,
Jr., 1998; Povinelli, 1998). According to the CU sketch-
model [assumption (6)], to be aware of awareness another
system for representing the CU/MS is required. While em-
pirical observations indicate emotions and sensory informa-



10 The Conscious Unit (CU) model

tion are conscious in animals, it is difficult to find experi-
mental evidence that support the hypothesis that animals
can be aware of their awareness. While a human can use
his/her natural language to represent a CU/MS, a similar
language has not been found in animals.

Sufficient condition – phenomenal consciousness: Accord-
ing to HOT, the HO mental state relates to the LO mental
state and thereby the LO mental state acquires the quali-
tative property of consciousness. This raises the following
problem: How can HOT handle the possibility that one
thinks that one now sees a red flour when in fact one sees a
white wall? The HOT may find this question hard to deal
with, perhaps because the question is anchored to the re-
quest to give a complete explanation of how consciousness
is generated, whereas HOT aims only to explain how an
unconscious-MS becomes a conscious one.

The present model deals with this question in two parts.
In the first one the present model does not provide an an-
swer how consciousness arises from the neurophysiology of
the brain. The present answer is similar to HOT’s answer.
But the second part of the answer emphasizes that the CU
model presents some new and interesting information re-
garding the question how an unconscious-MS is transformed
into a conscious one. This helps the present model skip over
some of the potholes into which the HOT has stumbled.

First, while according to HOT consciousness depends on
the relationship between two mental states (HO and LO),
according to the present model the relationship between
CU and MS depends on the Connecting-System. Given
this, it doesn’t matter what kind of MS is at issue (HO or
LO mental states) since the same CU is linked to any MS
when the Link-Condition is realized. According to the CU
sketch-model, the difference between a HO and LO mental
states lies not in the conscious experience itself (since the
same CU is linked to any MS) but in the content, in what
is represented by these two different MSs.

Secondly, it seems that there is a point of similarity between
HOT and the present model, assumption (6). But this is
only a seeming similarity. The situation "I am thinking that
I am conscious of that beautiful cat" is not interpreted as
illustrating that I am conscious of the beautiful cat since
this MS was related by a higher-order thought; instead, ac-
cording to the present model, it is interpreted as a CU/MS
that was represented by MS* that was linked to a CU.

3 Disadvantages vs. advantages
and the CU Model Justifications

Disadvantages: As mentioned above, the present model
does not provide an explanation of how consciousness arises
from the neurophysiology of the brain. Nor does it provide
a neurophysiological explanatory foundation for CU and
Link-Condition. As stated, the best way to conceive these
assumptions is as theoretical statements which provide us
with efficient explanations. The CU sketch-model was con-
structed on the functional level by a description of how it
has to operate.

Advantages: First, as can be seen from the above, the CU
sketch-model has succeeded in explaining certain empirical
observations and also several objections leveled at HOT.

Secondly, the CU sketch-model is based on six basic as-
sumptions that raise several important questions regarding
their rationales. The answers to these questions will high-
light the qualities of the present model. I will now deal with
the following fundamental queries.

Question (1): Why is the transformation of an unconscious-
MS into a conscious-MS done by linking a CU to a MS?

The answer is based on the assumption that the linking-
mechanism (see assumption (1)) bestows consciousness on
each MS. The bestowal of consciousness depends on the
realization of a specific condition (the Link-Condition) in
the cognitive system. This bestowal can be achieved in the
following two possible ways.

First, the linking-mechanism bestows on a MS conscious-
ness that varies in quality and intensity. The change in
conscious experience is matched to the complexity in qual-
ity and intensity of what is represented by that MS.

Secondly, the linking-mechanism bestows on each MS the
same unit of consciousness (CU). If so, how does the model
explain the changes in the conscious experience? The
changes do not originate from consciousness itself but from
the changes in the content (quality and degree) represented
by a MS.

Given these two options, the second was chosen as the in-
frastructure for the present model for the following reasons.

Simplicity. To develop a theory that will match variations
in consciousness to variations in the thing represented by a
MS is more complex than constructing a theory that links
each MS with the same CU (when the changes in conscious
experience are determined by the complexity of the repre-



Volume 1, Issue 2

3. DISADVANTAGES VS. ADVANTAGES AND THE CU MODEL JUSTIFICATIONS 11

sented).

Consciousness uniformity. Since the same CU is linked to
any MS, the thing represented by that MS is unified to
a higher degree in this case than in the case where various
qualities and degrees of consciousness are linked to that MS.
The reason is that the same CU creates in the perceiver’s
mind a uniform conscious-feel of the thing represented by
that MS (e.g., one perceives a whole picture of a landscape
which includes a house, trees, a lake, ducks and birds).

Generalization. Since the second option paves the way for
the development of a possible durable linking-mechanism
for consciousness grant, one may propose the following. Ac-
cording to the evolutionary approach, it possible to suggest
that supreme animals may also possess the Connecting-
System, and therefore have phenomenal consciousness. Ac-
cording to the present model, this proposal rests on animals
also having the ability to represent the world, i.e., they have
MSs which can be linked to a CU.

Aliveness-feel. It is simpler to interpret a CU as an
aliveness-feel than a complex consciousness that varies over
the dimensions of quality and degree (intensity). Further-
more, this interpretation can be generalized to animals and
one may propose that the crucial difference between an ani-
mal and a machine is, while an animal can be endowed with
an aliveness-feel a machine cannot.

Question (2): Why assume the Link-Condition?

If the CU sketch-model consisted only of the linking-
mechanism (without the Link-Condition) one would not be
able to explain the following objections: first, the same MS
can be conscious at one moment and unconscious at an-
other; secondly, if the activation of the linking-mechanism
were non-stop (since the Link-Condition does not exist) the
result would be that the cognitive system would be flooded
with conscious MSs.

The condition of the Link-Condition provides appropriate
answers to these objections: it explains both the linkage to
MS and the removal of a CU from that MS by restricting
these operations to the cases where MS enters the Link-
Condition and where the MS is not under that condition.

Question (3): Why does the Link-Condition handle only a
limited number of MSs?

The Link-Condition is a theoretical construct which allows
the linking-mechanism to join a CU to a MS. In a given
time, it can handle a limited number of MSs. This restric-
tion is based on the following observations and experimental
results.

First, if the Link-Condition allowed the linkage of CU
to many MSs, one’s mind would be flooded with many
CU/MSs that would interfere with conducting appropri-
ate behavior, and one’s chances of survival would plummet.
This is called information overload.

Secondly, many instances indicate that one can be aware
of limited visual information. Consider the following case.
I am aware of all the items that appear in visual field A.
When I turn my head I am aware of all the items in visual
field B but no longer of those in visual field A. In this case,
the domain of consciousness is restricted: it can encompass
only what is represented by MS (field A) or MS (field B).
However, according to assumption (3), if I see a face in front
of me, I am conscious of the following MSs: I am aware of
that face; I am also aware that I saw this face in the past,
and that I cannot remember the name of the face’s owner.
That is, in this case different CU/MSs are joined together
to form a unified conscious picture.

Thirdly, the present restriction may be viewed as analogous
to the well-known hypothesis that the short-term memory
(STM) can handle limited chunks of information (about
four). Although there are several criticisms of the distinc-
tion between the STM and long-term memory (LTM), most
researchers accept that the STM is limited in capacity and
can preserve information for about 20 seconds. By contrast,
the LTM stores an infinite amount of information for many
years (see Sternberg, 2009). Despite this similarity, it is im-
portant to emphasize the following crucial difference. While
the STM is conceived metaphorically as a storage with lim-
ited space, the Link-Condition is a theoretical construct,
which can be viewed as part of the cognitive system, and
its function is to allow the CU linking to a MS. (Note that
as a storage, the STM is not granted cognitive operations;
these are bestowed on the “working memory.”)

Question (4): When two MSs (one representing the ex-
ternal world and the other one’s internal world) enter the
Link-Condition, why is the CU linked to the external MS
and not to the internal MS?

If the external MS were not preferred to the internal MS,
the following intolerable possible situation would be created
in the cognitive system: the mind would be flooded with a
huge number of internal unconscious-MSs that immediately
would be transformed into conscious ones. The assumption
regarding the preference of the external over the internal
MS prevents the occurrence of this undesirable possibility,
simply because a live creature receives continuously exter-
nal stimulations that are represented in the cognitive sys-
tem by their appropriate MSs. If the external stimulation
was reduced or blocked, as in the case with the experiments
in “sensory deprivation,” the chances of unconscious-MS ap-



12 The Conscious Unit (CU) model

pearing in the Link-Condition and being transformed into
conscious-MS would increase. And indeed, the results of
experiments in sensory deprivation in which the sensory
stimulation of seeing, hearing, touching, etc. is reduced or
blocked show detrimental effects such as visual hallucina-
tions, disorientation in time and space, inability to concen-
trate and think clearly, and restless behavior (see Zubek,
1969).

In light of the above, one may propose that, although the
present paper has not offered a theory of consciousness an-
chored to the neurophysiological level, but only to the func-
tional level, the CU sketch-model has succeeded in explain-
ing particular empirical observations and also in solving
certain problems connected with other theories.

Acknowledgements

I am grateful to Jonathan Bartlett and two anonymous re-
viewers who read the paper and made helpful suggestions.

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