Vegetarian Discussion: Slavery/AR Analogy

Slavery/AR Analogy
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Seabird
2006-05-09 11:28:40 EST
As I'm sure everyone on this list knows, an analogy is often drawn
between slavery and animal abuse. This morning on a morning news
shows, there was a segment in a fish market, with a son and his mother,
throwing fish around. The subject of the segment was how the mother
could get her son to eat more fish.

But what was disturbing was that they were tossing around these what
appeared to be live fish, and laughing. No thought whatsoever was
given to how the fish may have felt about this, what a horror it was to
them, etc. This is, granted, not as serious as, but still --it seems
to be -- plausibly analogous to the photos of African-Americans being
hung in the south, with people standing around, drinking beer and
laughing, as if they were at a picnic. Of course, with these
unfortunate human beings, I put that at a far greater level of tragedy.
But still.

How can people be so insensitive? Fish, I am sure, have feelings. I
think you can become close to them, I think they have a very high level
of awareness, and they suffer, like all living creatures. I know this
sounds absurd to some people.


C*@yahoo.com
2006-05-13 05:40:14 EST
seabird wrote:
> As I'm sure everyone on this list knows, an analogy is often drawn
> between slavery and animal abuse. This morning on a morning news
> shows, there was a segment in a fish market, with a son and his mother,
> throwing fish around. The subject of the segment was how the mother
> could get her son to eat more fish.
>
> But what was disturbing was that they were tossing around these what
> appeared to be live fish, and laughing. No thought whatsoever was
> given to how the fish may have felt about this, what a horror it was to
> them, etc. This is, granted, not as serious as, but still --it seems
> to be -- plausibly analogous to the photos of African-Americans being
> hung in the south, with people standing around, drinking beer and
> laughing, as if they were at a picnic. Of course, with these
> unfortunate human beings, I put that at a far greater level of tragedy.
> But still.
>
> How can people be so insensitive? Fish, I am sure, have feelings. I
> think you can become close to them, I think they have a very high level
> of awareness, and they suffer, like all living creatures. I know this
> sounds absurd to some people.


Fish don't have the right parts of the cerebral cortex to feel pain
like mammals do. Fish go mostly by brain stem, which means that their
actions occur without "thinking" in the mamalian/human sense.

Responce to stimulation is not the same as the experience of pain.


Pearl
2006-05-31 06:15:54 EST
<chris_h_fleming@yahoo.com> wrote in message news:1147513214.043458.30630@j73g2000cwa.googlegroups.com...
> seabird wrote:
> > As I'm sure everyone on this list knows, an analogy is often drawn
> > between slavery and animal abuse. This morning on a morning news
> > shows, there was a segment in a fish market, with a son and his mother,
> > throwing fish around. The subject of the segment was how the mother
> > could get her son to eat more fish.
> >
> > But what was disturbing was that they were tossing around these what
> > appeared to be live fish, and laughing. No thought whatsoever was
> > given to how the fish may have felt about this, what a horror it was to
> > them, etc. This is, granted, not as serious as, but still --it seems
> > to be -- plausibly analogous to the photos of African-Americans being
> > hung in the south, with people standing around, drinking beer and
> > laughing, as if they were at a picnic. Of course, with these
> > unfortunate human beings, I put that at a far greater level of tragedy.
> > But still.
> >
> > How can people be so insensitive? Fish, I am sure, have feelings. I
> > think you can become close to them, I think they have a very high level
> > of awareness, and they suffer, like all living creatures. I know this
> > sounds absurd to some people.
>
>
> Fish don't have the right parts of the cerebral cortex to feel pain
> like mammals do. Fish go mostly by brain stem, which means that their
> actions occur without "thinking" in the mamalian/human sense.
>
> Responce to stimulation is not the same as the experience of pain.

'An evaluation of current perspectives on consciousness and pain in fishes

Kristopher Paul Chandroo, Stephanie Yue & Richard David Moccia
Aquaculture Centre, Department of Animal and Poultry Sciences,
University of Guelph, Guelph, ON, Canada N1G 2W1

Introduction 282
The neocortex and the neural correlates of consciousness
Convergence, homology and evolutionary psychology
Pain perception and brain structure
Cognition and behaviour in fishes
Conclusions
Acknowledgements
References

Abstract

There is growing societal and scientific interest in the welfare status of fish
used for commercial enterprise. As animal welfare is primarily concerned
with the quality of life of a conscious, sentient organism, the question of
whether fishes are even capable of consciousness must first be addressed
in order to assess their welfare status.Recently, there has been a resurgence
of research investigating the biological basis for human consciousness, and
our current understanding of the cognitive mechanisms underlying fish
behaviour has likewise improved significantly. Combined, these research
perspectives create an opportunity to better comprehend the phylogeny of
traits associated with consciousness, as well as the emergence of
consciousness itself during vertebrate evolution. Despite the availability of
this literature, contemporary reviews or published studies investigating the
probability of conscious states occurring in fishes often do so without
considering new perspectives or data. In this paper, we review and critique
recent publications that report equivocal conclusions favouring the absence
or presence of consciousness in various fishes. By introducing other data
into these analyses, we demonstrate that there are alternative perspectives
which support the existence of consciousness in fishes as a plausible concept.
An accurate assessment of the mental capacity of fishes will require enhanced
knowledge of their forebrain neuroanatomy, an understanding of how such
structures mediate behavioural responses, and an analysis of that information
within the context of contemporary theory related to the evolution of
consciousness in higher vertebrates.

Keywords animal welfare, consciousness, fish, pain, sentience

....

Introduction

There is growing societal and scientific interest in the welfare status of fish
used in commercial enterprise. As animal welfare is concerned with the
quality of life of a conscious and sentient organism, the question of whether
or not fishes are capable of conscious states must be addressed in order to
evaluate their welfare status. Surprisingly, there is no universally accepted
definition of consciousness as it applies across the spectrum of vertebrate
phyla (Searle 2000). However, it is generally agreed among researchers
that consciousness refers to a mental state of awareness of internal and
external stimuli. Depending upon the quantitative or qualitative degree of
awareness that is present in an organism, consciousness can also be
described as existing in a primary or extended state (Lindahl 1997).
Primary consciousness may be defined as the ability to generate a mental
scene in which diverse information is integrated for the purpose of directing
behaviour of self (Edelman and Tononi 2000). Extended consciousness is
thought to involve 'higher order', advanced cognitive abilities that involve,
for example, a linguistic capability or self-consciousness as self-knowledge
(Zeman 2001). Regardless of whether an animal is thought to have primary
or extended consciousness, both designations imply that they are sentient
or self-aware organisms. The probability of consciousness occurring in
animals is typically assessed by comparing their neuroanatomical,
behavioural and physiological characteristics with an array of human
(or other well-studied mammalian) biological features that are closely
associated with consciousness and emotional states.

Comparative investigations of this kind have recently been published
for fish species (Rose2002; Sneddon 2003; Chandroo et al. 2004).
The conclusions attained by simplistic, comparative assessment are often
controversial, and much debate exists with respect to the accuracy of this
analytical approach (Rolls 2000). This is especially true when such
evaluations are focused on ancestral or 'primitive' vertebrate species, such
as fish. Reasons for this controversy are wide ranging, and include
philosophical disagreement concerningwhat comprises a legitimate form of
scientific study (Searle 1998), as well as an historical bias regarding the
interpretation of results derived from animal behaviour research (Griffin
1998; Schilhab 2002). Of equal controversy, is the disagreement with
regard to the phylogenetic relationships between similar biological structures
and their putative functions among distantly related species (Striedter2002).

Until recently, the scientific investigation into the existence of conscious
states in fishes has been compromised due to a lack of primary research
investigating the aetiology of human consciousness, as well as a limited
supply of comparative studies examining brain structure and cognition in fish
species. However, a simultaneous resurgence of research investigating the
neurophysiological basis of human consciousness, including telencephalic
neuroanatomy and the underlying cognitive mechanisms of fish behaviour,
has provided basic information that permits the phylogeny of biological
traits associated with consciousness and consciousness itself to be studied
more objectively (Butler and Hodos 1996; Baars 002). Despite the
availability of this information, current reviews or published studies
investigating the probability of conscious states occurring in fishes, often
do so without considering innovative, applicable data or alternative
perspectives in its interpretation.

In this paper, we review and critique a number of recent publications that
have reported equivocal conclusions on the existence of consciousness in
fishes. We primarily critique the work of Rose (2002), and also address
the work of Cabanac(1999), Sneddon (2003), Sneddon et al. (2003) and
Cabanac and Cabanac (2000). Rose (2002) argues that it is most likely
impossible for fish to experience pain or fear, while in contrast, Sneddon
et al.(2003) provide anatomical, physiological and behavioural evidence
that demonstrates nociception in fish, concluding that fish can also perceive
pain. Based on empirical studies focused on physiological and behavioural
responses, Cabanac (1999) suggests that fish do not have the ability for
consciousness and emotion. The introductory list of issues and concepts
found within (Rose 2002, p. 2) illustrate Rose's position that 'anthropomorphic
thinking undermines our understanding of other species',and that 'an evolutionary
perspective is essential to understanding the neurobehavioural differences
between fishes and humans.' We agree with Rose that an unjustified ascribing
of mental abilities to animals and the lack of an evolutionary perspective will
lead to inaccurate conclusions with regard to the mental life of any animal.
However, the evolutionary perspective that Rose presents is heavily dependent
upon contrasts and anthropocentric arguments. Primary literature on the
neurobiological features and learning behaviour of fishes seem lacking in Rose's
review, despite the fact that there is a plethora of suitable papers available
(Moccia and Chandroo 2003). Within his review, one can find many discussions
where neurobiological literature pertaining to consciousness and pain perception
in humans are utilized as if they were well-established facts, whereas the actual
research behind those subjects or 'facts' are often hypothetical, preliminary or
controversial. But it is our hope that his foundation paper, in addition to this
current review, will help to open up the meaningful and critical dialogue relevant
to a better understandingof consciousness and pain perception in fish.

The neocortex and the neural correlates ofconsciousness

The neocortex is a heterogeneous, laminated brain structure that comprises
much of the cerebral cortex in humans (Nieuwenhuys 1994). The neocortex
allows for sophisticated sensory processing, motor functions and is associated
with distinctive human cognitive abilities. The role of cortical and non-cortical
brain structures in the generation of conscious states in humans has been the
subject of intense debate and study (Kanwisher 2001; Baars 2002). We
interpret the central thesis in Rose (2002) to be that conscious animals have a
neocortex and animals without a neocortex, such as fishes, are by default,
incapable of consciousness.The information presented in Rose (2002)
pertaining to nociception, fear and learning processes in fish are eventually
tied to the central theme that the neocortex is a prerequisite for any of these
processes to 'reach' consciousness. Edelman and Tononi (2000), a reference
source cited frequently within Rose (2002), states that, 'Many neuroscientists
have emphasized particular neural structures whose activity correlates with
conscious experiences. It is not surprising that different neuroscientists end
up favouring different structures. As we shall see in a number of cases, it is
likely that the workings of each structure may contribute to consciousness,
but it is a mistake to expect that pinpointing particular locations in the brain or
understanding intrinsic properties of particular neurons themselves, will explain
why their activity does or does not contribute to conscious experience. Such
an expectation is a prime example of a category error, in the specific sense of
ascribing to things properties they cannot have' (Edelman and Tononi 2000,
p. 19). Rose clearly, and for good reason favours the human neocortex as the
structure of choice when it comesto attributing consciousness to a particular
brain region, and suggests that specific areas of theneocortex are crucial for
consciousness to occur (Rose 2002, p. 31). In order to support this claim,
Rose primarily presents 'global workspace' theory (Baars 2002) or the
'dynamic core hypothesis' of Edelman and Tononi (2000), as well as evidence
from clinical studies of humans afflicted with chronic vegetative states due to
catastrophic brain injury (Laureys et al. 2000).

Although providing a brief, generalized description, Rose never sufficiently
explains how, or why, the neocortex is thought to be responsible for
consciousness, and careful examination of the neural-based theories of
consciousness yields a viewpoint that does not necessarily support his arguments.
Edelman and Tononi (2000), Laureys et al. (2000) and other work cited within
Rose(2002) commonly implicate the thalamocortical system, and not the
neocortex per se as the essential neural substrate required for consciousness.
This is not a trivial detail, because as we explain later, it is precisely this
interpretational difference that permits valid, alternative suggestions with regard
to the neural requirements and evolutionary history of neural systems hypothesized
to support consciousness. Theories proposed by Edelman and Tononi(2000) or
tested by Laureys et al. (2000), account for the fundamental properties of
consciousness by linking them to a particular type of neuronal process found
primarily within the thalamocortical system (Tononi and Edelman 1998). The
neuronal process within the thalamocortical system that may account for key
properties of consciousness, is essentially described as the widespread
integration of differentiated brain areas or functions (Baars2002). A key tenet
of the dynamic core hypothesis or other theories describing related neuronal
processes, is that consciousness is 'generated' by a neural process per se, and
as such is not accurately characterized as a specific thing or a location (Tononi
and Edelman 1998). Therefore, if a nervous system has the appropriate
characteristics that can support this process in theory, then it is appropriate,
from a neurobiological perspective, to consider that this nervous system has
the potential to 'generate' consciousness. Depending upon which hypothesis one
ascribes to, the appropriate neuronal characteristics could include a variable
level of complexity that reflects the interplay between functional segregation and
integration within a neural system (Tononi et al. 1994), the level of degeneracy
or redundancy within a neural system (Tononi et al.1999), the process of neural
signal re-entry (S****set al. 1991), particular thalamic functions (Llin\ufffdset al.
1998), specific neural activity synchronized at a particular gamma frequency
(Sewards andSewards 2001) and other features exhibited by vertebrate brains
(Zeman 2001). It seems that Rose(2002) offers no cyto-architectural or
neurophysiological data on the forebrain of fishes that can be used to argue
whether or not this brain region can support any of the neuronal process
mentioned above. Without this analysis, Rose's conclusion that, 'It is a
neurophysiological impossibility for fish to have consciousness', is at best,
unsubstantiated. Instead of a data-based or theoretical analysis, Rose relies on
the belief that the fish brain is well understood and thus it is highly implausible
that it could support consciousness (Rose 2002, p. 24). The argument suggests
that fish forebrains have 'diminutive' dimensions (Rose 2002, p. 10), or 'poor
differentiation' (Rose 2002, p. 28). Perplexingly, the discussion presented in
Rose (2002) that does incorporate a selection of primary literature concerning
the central nervous system of fishes is focused on the spinal cord and brain stem
(Rose 2002, pp. 9-10, 22-23). Preliminary investigations into fish neurobiology
suggest that adequate information currently exists to equally include or exclude
the fish forebrain from having the capacity to support consciousness as defined
by contemporary theory (Chandroo et al. 2004). Thus, the question of whether
or not the nervous system of fish permits consciousness, from a purely
neurobiological perspective, remains a very open question in our opinion.
Innovative application of brain imaging techniques (Baars 2002) to fish
species may provide new insights into the function of the fish telencephalon as
it relates to neural processes associated with conscious states.

Many arguments within Rose (2002) rely upon controversial or untested
interpretations of the neural-based theories of consciousness. In explaining why
the neocortex exclusively is critical for consciousness, Rose asserts that there is
clear and extensive evidence demonstrating that the human neocortex satisfies
several, essential 'functional criteria', namely its unique structural features, that
permit the existence of 'widely distributed brain activity that is simultaneously
diverse, temporally coordinated and of high informational complexity'(Rose
2002, p. 7). However, it seems this argument is entirely circular: the human
neocortex satisfies the critical, 'functional criteria' for consciousness,because the
'functional criteria' for consciousness are directly derived from the anatomy of
the human neocortex. The majority of studies examining the neural correlates of
consciousness do not support Rose's claim that 'the neurological basis of human
consciousness is becoming increasingly well understood and is known to depend
on functions of the neocortex' (Rose 2002, p. 31), or that 'the fundamental neural
requirements for pain and suffering are now known' (Rose 2002, p. 33) (Damasio
1998; Llin\ufffds et al. 1998; Searle 1998; Tononi and Edelman 1998; Searle 2000;
Jack and Shallice2001; Kanwisher 2001; Parvizi and Damasio 2001; Zeman 2001;
Baars 2002). Exactly how or why certain brain areas are associated with
consciousness or pain perception is still largely controversial (Block 2001; Dennett
2001), and explanations for the associations are not by any means exclusive to a
single theory or particular brain region (Sewards and Sewards 2000; John 2001).
Rose reports that consciousness 'requires structurally differentiated neocortical
regions with great numbers of exactly interconnected neurons' (Rose 2002, p. 24),
and that 'the type of neocortex most essential to consciousness, i.e. the non-sensory
association cortex, comprises the vast majority of the human cerebral cortex' (Rose
2002, p. 7, 31). However, the dynamic core hypothesis as proposed by Tononi and
Edelman (1998), and cited by Rose to defend his argument, actually reports that the
term dynamic core deliberately does not refer to a unique, invariant set of brain areas
and that the core may change in composition over time. The dynamic core is also not
necessarily restricted to the thalamocortical system, which is an important concept.
Tononi and Edelman (1998) state that as neural participation in the dynamic core
depends upon shifting functional connectivity among groups of neurones, rather than
on anatomical proximity, the composition of the core can transcend traditional
anatomical boundaries. As Rose equates consciousness exclusively with the neocortex,
we suggest that his use of theoretical neurobiology is misleading and may be unsuitable
for comparative assessment of fish brain function.

In other attempts to single out the neocortex as the exclusive structure enabling
consciousness, Rose uses the literature to dissect the thalamocortical system (Rose
2002, p. 7, 13, 18). This is carried out to distinguish the neocortex from subcortical
brain areas, implying that it is not significant that many animals have strikingly similar
subcortical brain anatomy and function because they are not especially essential for
the generation of consciousness. For example, Rose states that 'these [neocortical]
structures and functional features are not present in subcortical regions of the brain,
which is probably the main reason that activity confined to subcortical brain systems
can't support consciousness' (Rose2002, p. 7). He also states that '.consciousness
also requires the operation of subcortical support systems such as the brainstem
reticular formation and the thalamus, that enable a working condition of the cortex.
However, in the absence of cortical operations, activity limited to these subcortical
systems cannot generate consciousness' (Rose 2002, pp. 6-7). Although Rose cites
data that reasonably support his claims, we again find that other variations in
interpretation exist. Contemporary studies on the neural correlates of consciousness
does not seem to support the suggestion that the thalamus behaves as a 'support
system', so that the neocortex is enabled to generate consciousness. In fact, the role
of subcortical activity within the human thalamocortical system is sometimes deemed
as just as important for the 'generation' of consciousness per se, as is neocortical
function (Llin\ufffds et al. 1998). In addition, Rose (2002), cites other works (Tononi
and Edelman1998; Edelman and Tononi 2000; Laureys et al.2000) and commentary
that just as clearly suggests that consciousness is more accurately described as a
global functioning state of the brain, rather than a function of neocortical activity alone.

To further support his suggestion that the neo-cortex is the exclusive domain of
consciousness, Rose extends a defence to include clinical studies pertaining to human
patients in chronic, vegetative states. Rose describes a clinical condition that is
intended to demonstrate that damage to the human neocortex renders a person
vegetative and non-conscious (Rose 2002; pp. 13-14, 21), thus the neocortex must
be responsible for any type of conscious state. This is a reasonable interpretation and
hypothesis. However, there are three points of information that illustrate a possible
contradiction in this logic. The first is that Rose fails to report that all of his examples
refer to a pathological condition that radically affects the cerebral cortex in a way that
also compromises thalamocortical activity. That is, thalamocortical activity and
neocortical function are confounded in Rose's analysis. Secondly, Rose only reports
cases of the persistent vegetative condition in which damage has occurred mostly to
the neocortex, which permits an argument that the neocortex and not subcortical
regions are therefore responsible for consciousness. However, vegetative patients
demonstrating near-normal cortical metabolic rates (i.e. preserved cerebralfunction),
but with damaged thalamic nuclei, have been documented (Schiff et al. 2002). Our
last point refers to the effect of restricted neocortical lesions on consciousness.
Edelman and Tononi (2000, p. 54) readily point out that 'despite occasional claims
to the contrary, it has never been conclusively shown that a lesion of a restricted
portion of the cerebral cortex leads to unconsciousness.... no single area seems to
hold the key to consciousness'. In fact, the only localized brain lesion that results in
loss of consciousness typically affects the reticular activating system, a non-cortical
structure found in all vertebrates. Again, it seems risky to equate consciousness as
the exclusive domain of the neocortex.

Rose constructs several concise arguments contrasting the neurobiology of humans
with that of other animals, and it therefore seems reasonable to suggest that the human
forebrain is both quantitatively and qualitatively different on most accounts that matter
to consciousness. These arguments suggest a unique, causative link between the
physical size of the human neocortex, human intelligence and the fundamental aspects
of brain organization that are supposedly specific to laminated mammalian brains.
Rose emphasizes that it is not just the presence of the neocortex that is critical to
consciousness, but a massive amount of neocortical expansion is also required (Rose
2002, p. 7,10). And it continues that this massive neocortical expansion has allowed
for the development of certain anatomical and cognitive traits that are distinctly human,
including the lateralization of functions between the cerebral hemispheres (Rose2002,
p.13), or the ability to have a psychological capacity (Rose 2002, p. 3). While there
is no dispute that humans possess greatly expanded mental capacities that are associated
with our brain structure, the application of this data to the analogous question of mental
capacity in fish and other animals seems biased in our view. Consider the assertion that
a massive expansion of neocortex must be present in order for consciousness to occur,
and that this neurological requirement is essential for a psychological capacity (Rose
2002, p. 3, 29, 31). Edelman and Tononi (2000, p. 53) mention several clinical reports
of human patients, who have lost (via surgery), or failed to develop, massive neocortical
expansion, and yet have reasonably normal cognitive abilities and intelligence quotients.
These anomalous observations, considered together with the reality that there is still little
consensus among neurobiologists as to how consciousness is actually 'generated', point
to the fact that modern theories of the neural correlates of consciousness are still just
tentative explanations. But, we suppose that this is fair enough at such an early stage of
debate of these complex paradigms. But Rose subtly portrays some of these theories as
biological facts, without explaining the necessary caveats and underlying assumptions
inherent in these theories. The observation is made that the majority of the activity in our
extensive brain matter is 'unavailable' to our conscious awareness, and therefore, for an
organism like a fish (i.e. having a smaller, less complex brain), it is entirely logical that
none of their brain activity could be dedicated to conscious experience (Rose 2002,
p. 15). However, as pointed out by Griffin (1998), the implied assumption within Rose's
reasoning is that the proportion of conscious to unconscious activity must be even smaller
in the non-human, animal brain. Rose fails to provide any neurobiological data that could
justify that assumption (perhaps because such data does not exist?), yet studies of human
subjects whose brain development or size had been limited also do not support that
premise (Edelman and Tononi 2000). As Griffin (1998) remarks, 'perhaps only in
''megabrains'' is most of the information processing unconscious.... insofar as simple
conscious thinking is effective and adaptive, it may be one of the important functions [of]
a central nervous system.' Rose states that 'expansion of the cerebral hemispheres has
also allowed lateralized functionsof the two cerebral hemispheres.' and alludes to the
fact that certain lateralized cognitive functions are manifestations of higher-order
consciousness (Rose 2002, p. 13). The idea that massive cortical expansion is necessary
for the lateralization of cerebral functions seems simplistic. A brain is considered to be
cerebrally lateralized if one hemisphere performs a different set of cognitive functions, or
is anatomically distinguishable from the other (Bisazza et al. 1998). There are many
studies that show lateralization of cognitive functions involved in social interactions,
learning and perceptual categorization occurs in many vertebrate species, including fishes
(Bisazza et al. 1998; Vallortigara 2000), and that fundamental similarities between the
cerebral structures of all vertebrates exist. Clearly, the association between absolute
brain size, brain organization, cognition and consciousness is not as clear-cut as Rose
argues, and as such, his application of these concepts to the question of consciousness
in fish is divisive.

Convergence, homology and evolutionary psychology

Rose (2002) emphasizes the impressive differences between the brain structure
of fish and humans. However, when the analysis of brain structure and function is
extended to all major vertebrate groups, the vertebrate central nervous system appears
to have had a rather conservative evolution. The structural or functional differences
between species can be accurately described as specialized adaptations within a
consistent overall organization(Butler and Hodos 1996). We believe that Rose would
consider the neural substrate for 'primary' or 'extended' consciousness to be a
specialized adaptation exclusive to humans (Rose 2002, p. 6). However, notably
absent from Rose's evolutionary perspective is a consideration of the process of
convergent evolution. Convergent evolution appears at all level of biological
organization, and is a process by which similarity between unrelated species occurs
because of adaptation to similar environmental pressures (Wray 2002). Convergence
can occur on a functional level without the complete convergence of underlying
structural elements.

If Rose's analysis is correct, and human neocortical structure is the only neural
substrate capable of producing consciousness beyond a rudimentary extent, then
different neuroanatomical arrangements of the forebrain should result in animals
with very dissimilar cognitive capabilities and little or no manifestations of primary
or extended consciousness. Marino (2002) provides data and analysis that test this
hypothesis and compares primate and cetacean biology, and describes aspects of
their independent evolutionary history such as adaptations to drastically different
physical environments (terrestrial vs. aquatic), as well as pronounced differences in
body shape and physiology. He also demonstrates that cetacean forebrains are
organized in fundamentally different patterns from that observed in the brains of
primates, to the extent that cetaceans can be considered as having a completely
different mode of cortical elaboration. Interestingly, cetaceans demonstrate cognitive
abilities that are elsewhere only found in humans or the great apes - abilities that
were traditionally assumed to be solely the result of human neocortical structure and
function. Marino (2002) clearly shows that cognitive and behavioural convergence
can occur, even in the face of profound neuroanatomical divergence. The cognitive
abilities shown by cetaceans are also widely accepted as manifestations of primary
or extended consciousness (Marino 2002). As cetaceans do not show the 'extensive
frontal and parietal lobe of neocortex', or,'expansive, specialized six-layered type
of cortex' that Rose suggests is the most important brain level requirement for
conscious awareness and other cognitive abilities (Rose 2002, p. 32), it would seem
that his argument can be challenged at the conceptual level. Namely, the specific
neurobiological way that a species arrives at a functional solution is not the only level
by which to understand it, especially when comparing disparate species of animals.
Thus, the neural substrate of consciousness does not necessarily invoke the
involvement of a six-layered laminar structure, but instead needs to fulfil some other
aspect of a specific neural process, such as those described within Searle (2000) or
Baars (2002). An examination of brain structure and function between distantly
related species, which demonstrate cognitive adaptations characteristic of primary
consciousness may further reveal the nature of these neural processes.

We review the work of Marino (2002) as one example of how different species
have evolved alternate mechanisms to increase their brain mass and function.
Enlargement and elaboration of the forebrain has independently occurred multiple
times within different lineages of vertebrates, within fish and mammalian species
(Butler and Hodos 1996). Contrary to the suggestions found in Rose (2002), the
forebrains of some fish do, in fact, represent complex, elaborated structures within
the vertebrate radiation. Anatomical features and functions of the fish forebrain may
be homologous or convergently related to similar structures and functions in mammals.
Despite evidence to the contrary, Rose strongly denies that any functional homologies
(especially limbic brain regions implicated in conscious states) exist in the fish brain
(Rose 2002,p. 28). His reasoning is that such homologies are simply structural, and
therefore it is misleading to ascribe a comparable function with those structures. He
also favours the thesis that functional equivalency for any limbic structure found both
in fish and mammals is impossible, because fish do not have a neocortex. We find the
first reason perplexing, because the majority of limbic structures in the fish brain have
not been defined simply because their structures have been conserved during evolution,
but specifically because they have similar physiological and behavioural function as in
other vertebrates (L\ufffdpez et al. 2000; Portavella et al.2002). It is to be expected that
limbic structures will have modified interaction and function within the fish and human
cerebrum because those cerebral structures must mediate different cognitive tasks.
However, the assertion that functional equivalency of limbic structures is impossible
because fish do not have a neocortex implies that the influence of the neocortex on
other brain structures is to make those brain structures functionally dissimilar. That
conclusion seems unsupported by others (Butler and Hodos 1996), and demonstrates
an anatomical bias in Rose's reasoning. Many limbic brain structures found in mammals
have functionally similar counterparts within the brains of fish (reviewed in Chandroo
et al. 2004).

Although Rose suggests that some mammals have a primary, rudimentary form of
consciousness (because their cerebral hemispheres show limited neocortical structure),
he gives little indication as to what primary consciousness actually implies in terms of
an animal's psychological capacity. This is significant, because delineating the exact
nature of the psychological differences between humans and other species is necessary
if we are to develop a valid understanding of how and why a psychological capacity
arose during vertebrate evolution. In the discussion that appears to address the question
of psychological capacities within vertebrate phyla, it seems that Rose adopts an overly
anthropocentric view (Rose 2002, p. 3). That is, any psychological capacity that can be
observed in humans is assumed to be uniquely human, so any suggestion that animals
have similar mental capacities can be immediately dismissed as anthropomorphic. Rose
goes on to describe unique aspects of human psychology, such as our capability for
creativity including art, science and the existence of religious beliefs. He uses these
specific human abilities as examples that would make us seem so distinct, that it would
be highly inappropriate and misleading to project any human-like psychological
characteristic whatsoever onto other species. And this may be a reasonable premise.
Yet, he then presents examples of electroreception and signalling by electric fish,
or echolocation in bats and dolphins as unique capacities endowed to these animals
that have no equal counterpart in humans. This also sets the stage for Rose's opinion
of consciousness (and therefore psychological abilities as well), being likewise a
unique capacity, has no counterpart in most animals.

The opinions expressed by Rose reflect one of two competing philosophical
paradigms that characterize the approach to understanding the evolution of the
human mind. These approaches are termed theCartesian and Darwinian perspectives
(Gibson2002). Rose apparently ascribes to the Cartesian perspective, which postulates
that human and animal minds are separated by major qualitative differences in mental
abilities. The Darwinian perspective postulates more continuity between animal and
human mental capacities; in other words, the differences between the animal and
human mind is more a matter of degree rather than kind (Gibson2002). As empirical
data from comparative neuro-biology and ethological studies have revealed limitations
in the explanatory value of the Cartesian perspective for a number biological
phenomenon, including the learning behaviour of animals, we tend to favour the later
conceptual approach to understanding the animal mind.

Animal behaviour research suggests that rudiments of most human cognitive abilities
also exist ingreat apes (reviewed in Gibson 2002). These cognitive abilities, many of
which cannot be explained by traditional associative theory, are thought to occur
through a process that is termed 'mental construction'. Mental construction refers to
the brain's ability to generate a representation of internal and external events. These
mental representations function as a predictive model of the environment, allowing for
the construction of new knowledge. Utilization of this knowledge permits an animal to
express novel, adaptive behaviour (Top\ufffdland Cs\ufffdnyi 1999; Edelman and Tononi 2000;
Gibson 2002). As cognitive abilities that are better explained by means of mental
construction have been shown to exist in both animal and human minds, it has been
hypothesized that enhanced human mental constructional capacities underlie human
creativity and mental flexibility (Gibson2002). According to Gibson (2002), the
improved information processing abilities of the enlarged human brain endows our
species with greater abilities to break concepts and actions into fine component parts,
and to combine these differentiated components into higher order behavioural and
mental constructs. It is these mental construction capacities that serve as a common
foundation for the wide-ranging behavioural domains in which human intellectual
abilities resemble and improve on those of other primates (Gibson 2002). If we
assume that the capacity for mental construction is associated with a psychological
capacity, or is characteristic of primary consciousness, then the observation that
mental construction occurs in a variety of distantly related vertebrate taxa would
argue that basic psychological capacities, as well as primary consciousness, is
phylogenetically old. We suggest that the 'building blocks' for psychological capacity
and primary consciousness may exist within certain fundamental neural attributes
and processes shared by many vertebrate animals (Chandroo et al. 2004). The
hypothesis that the ability for mental construction was associated with the emergence
of primary consciousness in animals pecies, has also been proposed within tenets of
certain neural theories of consciousness (Edelmanand Tononi 2000). Rose (2002)
contains no data that enable us to determine whether or not mental representation
occurs in fish species, or that mental constructs of a lesser complexity are not
associated with primary consciousness. The issue of mental constructs in fish has
been reviewed in Chandroo et al. (2004), and we suggest that such a cognitive ability
is indeed feasible for fish species.

Pain perception and brain structure

Following the initial discussion on the neocortex and consciousness, Rose (2002)
gives a review of pain perception in humans, with an eventual application to the
question of pain perception in fish. Rose begins the pain perception review with
an analysis of nociception and pain in humans, appropriately making the distinction
between transduction of tissue trauma into neural signals (i.e.nociception), and
central registration of nociception (i.e. the processes involved in consciously
experiencing pain). Rose states that 'pain is a psychological experience that is
separate from behavioural reactions to injurious stimuli' (Rose 2002, p. 15) and
we accept this definition. However, for Rose, subcortical events (e.g. behavioural
reactions, and presumably their accompanying autonomic nervous system processes)
involved with nociception have nothing to do with the conscious awareness of pain,
because, '..the behavioural displays related to noxious stimuli or emotion in humans,
as in other animals, are stereotyped, automatic behavioural programs controlled by
lower levels of the central nervous system.' (Rose 2002, p. 17) The supporting
evidence given for these suggestions is that one can observe 'pain-like' responses
in humans and animals with neocortical damage or impaired nociceptive transmission
preventing signals from reaching the neocortex. Eventually, Rose's argument reduces
to the premise that lack of a neocortex essentially means that there can be no pain
perception.

Conceptually, Rose's view of the mechanisms of pain perception is questionable.
For example, consider his reasoning behind the claim, 'pain is a psychological
experience that is separate from behavioural reactions to injurious stimuli.' Contrary
to Rose's assertions, the arousal of the subcortical autonomic nervous system (and
the associated defensive behaviour response) plays a paramount role in creating the
psychological experience of pain, and is not a functionally separate entity in normal
humans (Chapman and Nakamura 1999; Saper2002; Craig 2003). Although it is
perfectly acceptable from an instructive point of view to subdivide pain perception
into anatomic categories (e.g. cortical and subcortical), this dichotomous portrayal
is ultimately limited as far as gaining an accurate understanding of human pain
perception, as well as in its application to the question of pain perception in other
species (Price et al. 2002). Although Rose's conception of the neural mechanisms
of pain perception can be demonstrated with humans or animals with damaged,
impaired central nervous systems, one must ask - how does this relate to pain
perception in normal human subjects, and what, if anything, does it say about the
evolution of pain perception in lower vertebrates?

Pain perception in humans is not simply a series of reflexive behavioural responses
accompanied by a non-functional, distinctly separate, cortical-mediated subjective
feeling. Rose does not acknowledge this concept, and as such, his arguments reflect
a dualistic perspective to pain perception. In addition to his 'consciousness as a
computer monitor' analogy in which consciousness is portrayed as a passive window
in which brain processes may come to awareness (Rose 2002, p. 15), Rose cites a
passage from LeDoux (1996) that states, 'the brain states and bodily responses are
the fundamental facts of an emotion, and the conscious feelings are the frills that have
added icing to the emotional cake' (Rose 2002,p. 26). Rose seems to suggest that
the conscious, subjective aspects of pain perception have no tangible or adaptive
function, but are epiphenomenal. The hypothesis that pain is a sensory end product
of a passive information transmission process has largely been rejected among pain
researchers (Chapman and Nakamura 1999). It is curious how Rose can present a
dualistic perspective for a conscious state because the work he cites in order to report
that the neocortex is the exclusive structure responsible for consciousness explicitly
requires the underlying assumption that consciousness is not epiphenomenal, but
functional and adaptive (Edelman and Tononi 2000). Although Rose argues that an
evolutionary perspective is necessary for examining the question of pain perception
in fish species, his apparent dualistic view of pain perception is largely incompatible
with an evolutionary account for its existence.

Although it is easy to gain the perception from Rose (2002) that it is becoming very
clear as to why and how the neocortex is responsible for pain perception, this portrayal
does not fully reflect the current scientific literature (Besson 1999; Chapman and
Nakamura 1999; Treede et al.1999). In brain imaging studies, only the anterior cingulate
gyrus (a 'limbic' system brain component) has demonstrated a consistent response during
the conscious experience of pain in humans (Derbyshire et al.1997). Interestingly, the
anterior cingulate gyrus does not show the classical neocortical, six-layered structure,
but its cellular conformation resembles a five-layered structure, with other distinctions
(Nimchinsky et al. 1997). Although we could argue that this neurophysiological fact casts
doubt on Rose's claim that only specific, specialized neocortex can be responsible for
conscious perception of pain in humans or animals, we instead suggest that this line of
reasoning in general is fruitless in any event. Tononi and Edelman (1998) and others (Baars
2002) advocate that it is not any specific structure (e.g. a cortex with five or six layers) or
particular location that is associated with the generation of consciousness, but rather, it is
the type of neuronal activity per se that the structure participates in that is critical for the
generation of consciousness. While Rose's review brings forth some pertinent issues needed
to assess the question of pain perception in fish, his interpretations of the neurobiological
underpinnings of human pain perception combined with a lack of primary literature
concerning fish neurobiology and behaviour preclude him from making any firm conclusions
on the existence of pain perception in those species.

We address the question of pain perception in fish by first accepting the assumption
that it is unlikely that the conscious perception of pain evolved to simply guide reactions
to noxious events, or to provide an experiential dimension to accompany reflexes, but
rather it allowed an organism to discriminate their environment in ways that permitted
adaptive and flexible behaviour (Chandrooet al. 2004). The neural systems involved in
nociception and pain perception, and the cognitive processes resulting in flexible
behaviour function, probably evolved as an interactive dynamic system within the central
nervous system (Chapman and Nakamura 1999). The creation of a subjective feeling of
pain is arguably a complex affair, including spinal, brainstem, thalamic and cerebral
structures, as well as essential autonomic nervous system feedback (Willis and Westlund
1997; Chapman and Nakamura 1999; Saper 2002). Spinal, thalamic and forebrain
system interdevelopment has been a primary mode of central nervous system evolution
in vertebrate species (Kevetter and Willis1984; Butler 1994). Accordingly, it is reasonable
to suggest that the evolution of pain perception should show concomitant developments in
all those neural structures, and these developments should be reflected within an animal's
cognitive abilities. Therefore, a pertinent question to ask when attempting to determine
the origins of pain perception during vertebrate evolution is when, and in what form, does
this unified, integrative system appear? How do we recognize when nociceptive signals
arrive at the forebrain and participate in the cognitive processes characteristic of conscious,
adaptive behaviour?

Work performed by Sneddon (2003) and Sneddon et al. (2003) are a step in the right
direction to provide insights for the questions we pose. Sneddon et al. (2003), Sneddon
(2003) and Ide and Hoffmann (2002) report experimental studies that contribute
significantly to the question of nociception and pain perception in fish species.Their studies
contain data that describes the function of peripheral and central nervous system structures
involved in nociception, and the correlation of nociceptor activation with autonomic and
behavioural responses. Sneddon (2003) and Sneddon et al. (2003) interpret their work
within an ethological and physiological framework that allows them to conclude that their
results fulfil 'the criteria' for demonstrating pain in animals, and that accordingly, fish can
perceive pain. After defining pain in humans as an 'unpleasant sensory and emotional
experience associated with actual or potential tissue damage,' Sneddon et al. (2003) state
that, 'it is impossible to truly know whether an animal has an emotion because we cannot
measure emotion directly. Therefore, emotion does not feature in the definition of pain in
animals.' They further describe their criterion for pain perception by stating '..if a noxious
event has sufficient adverse effects on behaviour and physiology in an animal, and this
experience is painful in humans, then it is likely to be painful in the animal' (Sneddon et al.
2003, p. 2). The criterion that Sneddon et al. (2003) describe is adequate for assessing
clinical pain responses in animals whose pain system is well understood (e.g. domestic
mammals). However, when this criterion is used for the purpose of elucidating the existence
of pain perception in animals that are significantly less understood (e.g. fish), subjective leaps
in the interpretation of the results are required to come to firm conclusions on the issue.

Sneddon (2003) shows that injection of a known noxious substance into peripheral
tissue innervated by nociceptors, causes several physiological and behavioural reactions
not found in control fish, such as a significantly increased respiratory rate, a delay in the
time it takes for fish to resume feeding, and rocking and rubbing behaviour. Sneddon
(2003) also shows that these induced responses greatly diminish when morphine is
administered intramuscularly. Clearly, the responses of fish to noxious stimuli and
morphine require the integration of peripheral and central nervous system structures.
However, we must ask what relevance these results have to the question of actual
pain perception. Sneddon (2003) first attempts to address that question by suggesting
that rocking behaviour of fish may be similar to the rocking behaviour shown by primates
and zoo animals which are exhibiting signs of poor welfare. Beyond the superficial
similarity, this suggestion is not further supported by any other data presented. There is
no effort made to include or exclude alternative accounts for the rocking behaviour that
do not require the involvement of consciousness for its explanation (e.g. the effect of
metabolic alterations caused by prolonged hyperventilation, subsequent swim bladder
or equilibrium reactions, the effect of corticosteroid and catecholamine responses, as
well as the effect of trigeminal nerve input on brainstem controlled motor behaviour). In
addition, Sneddon makes no attempt to explain or compare the putative proximate and
ultimate causes for rocking behaviour in primates and fish. Such a comparison would need
to address the question of why rocking, primarily a primate behaviour elicited by diverse
aetiologies (Nash et al. 1999), should have the same cognitive underpinnings and social
function in a rainbow trout. This seems highly unlikely. Similarly, Sneddon compares the
rubbing behaviour of fish to the act of rubbing an injured area to ameliorate the intensity
of pain as observed in humans and mammals. She also states that rubbing behaviour and
rocking, may be potential pain-coping strategies in fish (Sneddon 2003, p. 7). Again, the
data or analysis needed to confirm these suggestions are absent, and as such, she cannot
exclude non-cognitive or non-conscious explanations for such behaviour. Although
Sneddon et al. (2003) have described the composition and response characteristics of
fish nociceptors, they have not presented any anatomical or physiological data to suggest
that afferent inhibition occurs in fish species (i.e. the process behind pain amelioration via
rubbing).

Sneddon suggests that the rocking and rubbing behaviour of fish is complex in nature,
and therefore higher processing is involved (Sneddon 2003, p. 8). This leads her to conclude
that fish can perceive pain. In light of the critique we have presented, we suggest that this
interpretation is premature. Based on the information presented in Sneddon (2003), labelling
such behaviour as complex is a simple value judgment. Even if nociception-induced rocking
and rubbing behaviour was complex, the assumption that complex behaviour per se must
be indicative of 'higher processing' is incorrect (Shettleworth 2001). Furthermore, the concept
that higher cognitive processing is synonymous with conscious cognition is misleading (Bargh
andFerguson 2000). We suggest that alternative criteria should be used to determine if
behavioural responses are reflective of pain perception in fish. The behaviour meeting this
criterion should permit the distinction between responses that involve the integration of brain
structures that are hypothesized to be involved in the process of conscious cognition and of
those that do not. Such behaviour might include those that are observed as the result of
interactive or declarative learning processes (Chandroo et al. 2004). Other studies that use
autonomic and behavioural responses of fish to assess whether they are conscious have
been performed by Cabanac (1999). Based on empirical studies focused on autonomic
physiological responses, Cabanac(1999), as well as Cabanac and Cabanac (2000) suggest
that consciousness and emotion evolved with the appearance of amphibians or reptiles.
They reason that as fish do not show autonomic responses to 'emotional stress'
(i.e. tachycardia or behavioural fever) in the same way terrestrial animals do, they probably
are not conscious. There are factual and conceptual errors with this argument. Fish do in fact
exhibit tachycardia in response to circumstances that one might expect a similar emotional
response to occur in mammals (H\ufffdjesj\ufffd et al. 1999). Cabanac's hypothesis does not account
for the observation that emotionally influenced autonomic responses are associated with
behaviour that is relevant to surviving species-specific environmental challenges. For example,
an animal that evolved a 'freeze' strategy to a predation threat likely have altered autonomic
responses to an animal that evolved a 'flight response'. The autonomic response to specific
stimuli can even change with age within single species (H\ufffdjesj\ufffd et al. 1999). The expectation
that certain autonomic or behavioural responses should be similarly associated with specific
emotions among diverse vertebrate groups is unwarranted at this time, although it is a useful
paradigm to examine. Future work should aim to account for the mechanism by which
behavioural or autonomic responses are seated within cerebral processes that may be
associated with the existence of conscious states.

Cognition and behaviour in fishes

Rose has reviewed a subset of the extensive contemporary knowledge available on the
neurobehavioural nature of fish. The primary literature concerning the neurobiological
features and learning behaviour of fish and other non-human vertebrates is somewhat
weakly presented in Rose (2002), and it undoubtedly is the reason for many of the
arguments that support his conclusions. He argues that '.most behaviour of fishes is
not dependent greatly on learning.' (Rose 2002,p. 8), '...instrumental and Pavlovian
conditioning are forms of associative, implicit learning that occur in fishes...as cases of
implicit learning, they operate without awareness.' (Rose 2002, p. 27), '..nothing about
the behaviour of a fish requires a capacity for conscious awareness for its explanation'
(Rose Consciousness and pain perception in fish K P Chandroo et al. 2004 Blackwell
Publishing Ltd, FISH and FISHERIES, 5, 281-295291 2002, p. 24), '...avoidance
conditioning occurs unconsciously and is not evidence of awareness of pain or any other
experience' (Rose 2002, p. 29),'.. in fishes, our brainstem-spinal systems are adequate
for generation of overt reactions' (Rose2002, p. 25) and '..behavioural specialization in
fishes is associated with expanded brainstem as opposed to cerebral hemisphere
development' (Rose2002, p. 10). All of those statements are misleading in our opinion.

Rose claims that fish behaviour in general is not greatly dependent on learning, except
for the initial development of species-typical behaviour (Rose2002, p. 9). The idea that
fish behaviour is dominated by pre-programmed, invariant responses to the environment,
and that the main significanceof learning is to 'prime' the development of such responses
is perhaps more reflective of a historical view of fish behaviour rather than of any current
data (Laland et al. 2003). The relevance of learning to fish behaviour at various life-history
stages has been increasingly investigated over the past decade(Overmier and Hollis 1990;
Kieffer and Colgan1992; Cs\ufffdnyi and D\ufffdka 1993; Bshary et al. 2002).The learning
processes shown by fish include observational (McGregor et al. 2001), interactive (Top\ufffdl
and Cs\ufffdnyi 1999), Pavlovian (Hollis 1984) and avoidance (Zerbolio and Royalty 1983).
Current work shows that learning processes demonstrated by fish are multifaceted
phenomenon that have clear fitness implications to fish species at various developmental
stages (Brown and Laland 2003; Griffiths 2003; Hoare and Krause 2003; Kelley and
Magurran 2003; Odling-Smee andBraithwaite 2003).

Rose presents Pavlovian (i.e. classical conditioning) and avoidance learning exclusively
to describe learning processes in fish. He further defines Pavlovian and avoidance learning
as examples of implicit learning. The argument then goes on to state that implicit learning
has no relationship to any conscious process, and must therefore occur without conscious
awareness. The suggestion that implicit learning has no relationship to higher order cognition,
or is inherently an unconscious process is a concept that is not universally accepted because
there is empirical data that show otherwise (Maren2001; Lovibond and Shanks 2002).
Similarly, the suggestion that avoidance learning in fish species is purely a form of implicit
learning with no other significance to cognition is incorrect according to Overmier and Hollis
(1990). We suggest that observational, avoidance and interactive learning processes may
require the formation of declarative memories. The relationship between learning processes
demonstrated by fish, declarative memory and conscious cognition has been reviewed in
Chandroo et al. (2004), and there is, in fact, an objective basis for suggesting that some fish
behaviour is better explained within a theoretical framework that includes primary
consciousness as a function of their nervous system. Given the fact that none of the learning
processes we mention are considered in Rose (2002), his statement that 'nothing about a
fish's behaviour could be conscious' seems unqualified and incomplete.

There are several arguments found within Rose(2002) that suggest that fish are unique
among vertebrates in that their behavioural specialization is dependent heavily upon
brainstem development, and that the fish cerebrum has little significance to their behaviour
beyond olfaction, or to 'refine the expression' of brainstem functions (Rose 2002,p. 9).
He further states that, 'the neurobehavioral evolution of fishes has resulted in a highly
diversified array of species in which the essentials of neurobehavioral function are
mediated mainly by a neural system below the cerebral hemispheres'(Rose 2002, p. 9).
To support these claims, he suggests that fish function, learn and behave essentially
normally (except for functions requiring olfaction, which Rose claims is processed
entirely within their forebrain) after their cerebrum is ablated. The logic here is misleading.
The concept that the fish cerebrum functions primarily as a 'smell brain' has been rejected
by most comparative neurologists for some time (Echteler and Saidel 1981). Although
Rose brings forth the valid notion that one function of the fish cerebrum is to modulate
behavioural expression, he fails to acknowledge the implications of this function in terms
of fish cognition. Ablation of the fish cerebrum does in fact impair learning and behaviour
that are hypothesized to involve expectancies, complex spatial cognition, declarative
memory or mental construction processes (Overmier and Hollis1990; Broglio et al. 2003;
Chandroo et al. 2004). Rose chooses to report only the learning and behavioural
processes that do not require the involvement of such cognitive processes for their
explanation, and distorts the definition of avoidance learning to suit his arguments. Rose's
theoretical argument that evolution of the central nervous system of fishes has resulted in
mainly brainstem development, and that their success as a species has little to do with
cerebral modification is refuted by empirical evidence. All teleost fish have elaborate
forebrains (Butler and Hodos 1996), and the degree of forebrain development is correlated
with social behaviour, communication abilities and other environmental factors that may
require integrative cognitive capacities (Kotrschal et al. 1998). Fish have evolved to
exploit diverse environmental niches, and show concomitant development within all
relevant brain areas. This brain development may consist of increases or decreases in
brain stem, cerebellar, optic, olfactory, diencephalic and telencephalic structural mass
or complexity (Kotrschalet al. 1998). The morphological changes that may comprise the
representative brain for any given species are diverse, and contrary to Rose's generalized
assumption, some phylogenetic radiations(e.g. actinoperygians) show a shift in brain mass
from primary sensory areas towards higher order integration centres (Kotrschal et al. 1998).
In addition, the integration of cerebellar, optic and telencephalic functions to produce
cognitive responses to the environment may be similar in fish and mammals (Broglio et al.
2003). Although Rose briefly comments on the great morphological variation of fish brains
and the putative functions of the fish cerebrum (Rose 2002, p. 9, 10), he fails to give a
balanced account of the implication that such diversity and development have to cognitive
functions, and the question of consciousness in fish species.

Conclusions

If the debate regarding the existence of sentience in fish is to have valid conclusions, the
basis of the arguments must be made upon sound biological principles, taking into account
all sources of relevant data. Our critique has demonstrated that the input of recent
behavioural, neurological or physiological findings into the analysis can profoundly change
the possible conclusions reached about the mental capacity of fishes. We have argued that
if one adopts a Darwinian perspective to the study of animal minds, it is not simply a matter
of more, less, or no neocortex present that permits the existence ofa neural system that
may support primary consciousness. A current limitation of theories describing the neural
basis of consciousness in humans is that it essentially examines the intrinsic properties of
complex neural systems, often without considering the question of how those characteristics
arose during evolution (Tononi et al. 1994). If a neural process, whether its substrate is
laminated or otherwise, allows some degree of mental construction to occur, and then it
may be reasonable to suggest that those animals may have evolved primary consciousness.
Autonomic and behavioural responses that are used to prove or refute the existence of
conscious states in fish species need to be assessed for their involvement within integrative
cognitive processes that are associated with mental construction, declarative memory or
other possible indicators of primary consciousness. A sound assessment of the probability
that conscious states occur in fish species will require expanded knowledge of their forebrain
neuroanatomy, an understanding of how such structures mediate behavioural responses to
environmental challenges and an analysis of that information within the context of contemporary
theory on the evolution of consciousness.

Acknowledgements
...
References
...
http://www.aquanet.ca/English/research/fish/rm-perspective.pdf




D*@.
2006-05-31 11:16:51 EST
On 13 May 2006 02:40:14 -0700, chris_h_fleming@yahoo.com wrote:

>seabird wrote:
>> As I'm sure everyone on this list knows, an analogy is often drawn
>> between slavery and animal abuse. This morning on a morning news
>> shows, there was a segment in a fish market, with a son and his mother,
>> throwing fish around. The subject of the segment was how the mother
>> could get her son to eat more fish.
>>
>> But what was disturbing was that they were tossing around these what
>> appeared to be live fish, and laughing. No thought whatsoever was
>> given to how the fish may have felt about this, what a horror it was to
>> them, etc. This is, granted, not as serious as, but still --it seems
>> to be -- plausibly analogous to the photos of African-Americans being
>> hung in the south, with people standing around, drinking beer and
>> laughing, as if they were at a picnic. Of course, with these
>> unfortunate human beings, I put that at a far greater level of tragedy.
>> But still.
>>
>> How can people be so insensitive? Fish, I am sure, have feelings. I
>> think you can become close to them, I think they have a very high level
>> of awareness, and they suffer, like all living creatures. I know this
>> sounds absurd to some people.
>
>
>Fish don't have the right parts of the cerebral cortex to feel pain
>like mammals do.

Maybe not like mammals do, but we have no reason to believe they
can't experience pain at all. We know fish can see, hear and smell.
I feel certain that people have demonstrated that fish can taste, and
take it into consideration when feeding and baiting them. Since their
brain (or whatever) is capable of those four senses, it would be absurd
to think of it as capable of all senses except physical feeling.

>Fish go mostly by brain stem, which means that their
>actions occur without "thinking" in the mamalian/human sense.

They are still capable of learning, as well as the other things we
know they're capable of.

>Responce to stimulation is not the same as the experience of pain.

It often is to me. You must have a lot of scarring if it's not to you :-)

Leif Erikson
2006-05-31 11:59:43 EST
Fuckwit David Harrison, ignorant lying pig-sodomizing goober cracker,
lied:
> On 13 May 2006 02:40:14 -0700, chris_h_fleming@yahoo.com wrote:
>
> >seabird wrote:
> >> As I'm sure everyone on this list knows, an analogy is often drawn
> >> between slavery and animal abuse. This morning on a morning news
> >> shows, there was a segment in a fish market, with a son and his mother,
> >> throwing fish around. The subject of the segment was how the mother
> >> could get her son to eat more fish.
> >>
> >> But what was disturbing was that they were tossing around these what
> >> appeared to be live fish, and laughing. No thought whatsoever was
> >> given to how the fish may have felt about this, what a horror it was to
> >> them, etc. This is, granted, not as serious as, but still --it seems
> >> to be -- plausibly analogous to the photos of African-Americans being
> >> hung in the south, with people standing around, drinking beer and
> >> laughing, as if they were at a picnic. Of course, with these
> >> unfortunate human beings, I put that at a far greater level of tragedy.
> >> But still.
> >>
> >> How can people be so insensitive? Fish, I am sure, have feelings. I
> >> think you can become close to them, I think they have a very high level
> >> of awareness, and they suffer, like all living creatures. I know this
> >> sounds absurd to some people.
> >
> >
> >Fish don't have the right parts of the cerebral cortex to feel pain
> >like mammals do.
>
> Maybe not like mammals do, but we have no reason to believe they
> can't experience pain at all. We know fish can see, hear and smell.

Can they experience disappointment, pride, loyalty, Schadenfreude,
reverence and shame, Fuckwit? You stupid pig-sodomizing goober cracker.


Kevan
2006-06-01 14:09:05 EST
"Leif Erikson" <notgenx32@yahoo.com> wrote in
news:1149091183.706786.89740@j55g2000cwa.googlegroups.com:

>
> Can they experience disappointment, pride, loyalty, Schadenfreude,
> reverence and shame, Fuckwit? You stupid pig-sodomizing goober cracker.

Thankfully, they can't experience you.


Leif Erikson
2006-06-01 15:51:08 EST
Kevan wrote:
> "Leif Erikson" <notgenx32@yahoo.com> wrote in
> news:1149091183.706786.89740@j55g2000cwa.googlegroups.com:
>
> >
> > Can they experience disappointment, pride, loyalty, Schadenfreude,
> > reverence and shame, Fuckwit? You stupid pig-sodomizing goober cracker.
>
> Thankfully, they can't experience you.

They do.

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