Are mental states reducible to neurobiological states?

Examining arguments of how neuroscience and psychology relate to philosophy by looking at how skeptics and enthusiasts have touched upon the subject. We’re going to take apart how psychology and cognitive science can be reduced to neuroscience.

Principled skepticism

These skeptics may argue there is a distinctive mental dimension that is not reducible to anything physical. Among them are those that argue this mental dimension actually harbors a separate mental substance as the nonphysical mind or the soul (substance dualism) or whether it’s limited to nonphysical properties of the physical brain (property dualism). There are also skeptics who argue a principled skepticism of reductionism uses the hypothesis that generalizations of psychology emerge with respect to the generalizations of neuroscience. Mental states and processes create a domain of study that’s autonomous with respect to neuroscience with functionalist arguments. They reject the dualist position.

Substance dualism

Mental states are not of the brain, but a different substance. It requires explanation for the way two different substances may interact and how the nonphysical mind creates those mental states. They must also account for free will in a nonphysical mind. Ultimately consciousness and qualities of felt experience may be explained with neurobiological terms or the logical-meaningful dimension may have a causal neurobiological explanation. Generally the dualist philosophers that attempt to explain the subjective experience may treat it as an irreducible property, in what we call property dualism.

These property dualists argue that, although there are nontrivial differences among the hypotheses advanced by assorted property dualists, they maintain that, even if the mind is the brain, subjective experience qualities are emergent with respect to the brain and its properties. The commonsense conceptual framework to understand psychological properties in a way that doesn’t reduce to any future neuroscience. Within intertheoretic reduction, we recognize subjective experiences won’t reduce to neuroscience. Property dualists don’t believe there’s a nonphysical substance inherent to experiences. They believe subjective experiences are produced by the brain and affect the brain even if they aren’t actual physical properties of the brain.

Philosopher Frank Jackson used the thought experiment of Mary the neuroscientist to show that differences between knowing our states through introspection and knowing through nonintrospection give the grounds to reduce psychology to neuroscience. The thought experiment supposes Mary is a neuroscientist who has lived her entire live in a room with no colors, yet she is still taught everything about how the brain works. Even if she knows everything about the brain, she still doesn’t have the experience of seeing color. There’s something in psychology not captured by neuroscience. It’s possible these two methods of knowing about the world are subject to different learning methods. Others may argue that Mary would still be able to identify the color red as it is an empirical question.

Dualist theories may include our capacity for introspection just as light still exists as a phenomena even if it may be reduced to electromagnetic radiation. A reductionist may also believe an evolved psychology can reduce to an evolved neuroscience.


Acknowledging there are categories of folk psychology that are incorrect for categorizing mental states, these categories delimit intentional states and logical processes, and they don’t reduce to categories are the neurobiological level of description. In this context, we introduce functionalism as the thesis that mental states are defined in terms of their abstract causal roles in the wider information-processing system. We characterize mental states as they relate to causal relations of environmental stimuli. Happiness is about the behavior associated with being happy and the way it relates to neurobiological phenomena that govern it. Mental states and processes are functional in a usually physicalist manner. We can describe causal and logical relations among perceptions, beliefs, desires, and behavior at the structural level. The same way switches in a computer govern the way it functions, a functionalist theory may believe that our physical phenomena of what goes on in the brain may govern behavior and actions.

One may argue that, if mental states and processes are functional, we can understand how to solve problems, think, reason, and perform similar actions by their functional organization. Neuroscientific methods of reasoning and theory need to focus on functional systems with knowledge of minutiae for other significant areas such as for neuropsychiatric disorders. Cognitive scientists determine the functional or cognitive theory of mind while neuroscientists figure out the physical devices that instantiate the cognitive “program.” Computational psychology is an autonomous science. This line of reasoning runs into issues with the Chinese room argument, as philosopher John Searle articulated, that one can copy intelligent action without interpretation or understanding through a purely functional system. An individual in a room with only Chinese symbols in a box with an English rule book for using the symbols in various ways may follow commands to send the symbols in a certain method without understanding the meaning of the symbols themselves. Philosopher Patricia Churchland continues to press functionalism that intertheoretic reductions aren’t conditional on a one-to-one mapping of higher-level theory to a reduced theory. One may argue against reductionism in this sense that there are fundamental differences between neuronal explanations and functional computational explanations.

Co-evolutionary research ideology

Cognitive psychology is autonomous with respect to neuroscience in the sense neurobiological data are irrelevant to the cognitive “program” the mind runs. We may argue this on the grounds that our mental state and processes are states and processes of our brains, the nervous system evolved from simpler nervous systems, brains are the classiest information processes available for study, neuroscience research cannot be ignored by cognitive scientists, and categories at levels that specify the fundamental kinds may need revision. This method of reasoning lets us use the mathematical development of statistical mechanics to, for example, expand to include temperature, equilibrium, entropy, and similar properties as discoveries at both lower and higher levels. We may deduce there are many relationships between genes and their functions, instead of a one-to-one mapping mentioned earlier. Similar co-evolution can show that genes have input-output functional properties we characterize through functions and laws that combine lower-level and higher-level discoveries.

Some functionalists believe input-output operations can be realized in no unitary mechanisms at intermediate or lower levels. We may be inclined to assume the abilities at the cognitive level are precise and the method of research influence will be from higher levels to
lower levels. Co-evolution is far from interactive.
Neuroscience and psychology need one another as neuroscience needs to know what the system does while psychology needs to know how those lower-level specifications emerge in input-output theory of functionalism. But the co-evolutionary development of neuroscience and psychology means reduction is bound to occur at some point or another. The practical difficulties, understanding how the mind brain works, lack of mathematical and computational theory, and the bare fact that it might be true that psychology isn’t reducible to neuroscience.


Much of what we discuss has an aboutness. When we believe, desire, think, intend, or anything similar we have a semantically coherent system such that these things have content and intention as they’re about things. If psychological explanations of human behavior rely on matching representational states to parts of the human being, we may object to reductionist ideas as mental states are identified in terms of logical and semantical relations.

Logical relations

Mental states have causal relations to other states, but mental representations have causal roles in virtue of their formal properties, as Fodor argues. There are arguments against reduction that don’t depend on giving a nonphysical status to representations. Psychological states for which these arguments are built upon are the sentiential attitudes (beliefs, desires, etc.). For these sentiential attidues, logic defines the relations between sentences.


That the philosophical tradition that espouses a logical-meaningful dimension of mental business isn’t naturalist may seem to support the idea logical relations between states can’t be explained with causal relations between neurobiological states. It also may seem this way given there are limitations of neuroscience such that no theory in neuroscience can tell us a lot of information. But it may be possible we explain neurobiologically what goes on in the brain unless the psychological phenomena are indeterministic with respect to the relevant neurophysical level.

In addition some criteria folk psychology uses in specifying content on features that are irrelevant to the causal role of the mental state as it interacts with other mental state. We may cite semantic features such as truth and justification as evidence of these interactions. Antireductionists may argue there are folk psychology categories that we cannot reduce representational states to, but these arguments lack the empirical evidence to support them.

Information processing

We may describe an information-processing theory as sentiential if the cognitively relevant internal states have content, the theoretically relevant relationships between cognitive states are characterized by logic, the state transitions are a function of logical relationships between sentences that identify the states, and we evaluate cognitive virtue as a function of the extent to which it succeeds in doing what the logical theory of state transition says it should do. We may also define cognitive processes as sentence-processing processes. Such an information-processing system should also have methods of determining which knowledge is relevant to its purpose. Such an artificial intelligence being would also have to do this