PSYCHOPHYSIOLOGY: WHAT IT STUDIES, OBJECTIVES AND METHODS - NEUROPSYCHOLOGY - 2025

The psychophysiology or physiological psychology is the branch of psychology that is responsible for studying the biological elements of behavior. It is a discipline that is related to the physiological bases of psychological processes and brain functioning.

Psychology is a broad science that, for example, is interested in knowing the reasons why certain people fear spiders. Instead, psychophysiology is a more concrete discipline that would be interested in the mental and physiological processes responsible for fear of spiders.

Psychophysiology is therefore a branch that developed from psychology. In fact, the first scientific psychology text written by the famous German psychologist Wilhem Wundt in the late 19th century was titled Principles of Physiological Psychology.

In recent years, the large amount of information obtained in experimental biology and in scientific studies of other disciplines, have contributed significantly to the investigation of human behavior.

In this way, psychophysiological studies are essential for the development of psychology as a science. More and more information is available about the functioning of the nervous system and brain structures.

In the modern history of research in the physiology of human behavior, the experimental methods of psychology have been combined with those of physiology, thus giving rise to what is now known as psychophysiology.

History of psychophysiology

The branch of psychophysiology was started and developed by Wilhem Wundt at the end of the 19th century through the publication of the book "Principles of Physiological Psychology". However, the interest in the most relevant concepts of psychophysiology were taken into account much earlier, despite not constituting a research discipline.

In this sense, the most relevant historical aspects of psychophysiology are:

Plato

Plato sculpture.

During the years 428 and 347 BC, the well-known philosopher postulated three different regions in human functioning: reason and perception located in the head, noble passions such as courage or pride located in the heart, and lower passions such as greed and lust located in the liver and intestines.

Aristotle

Later, Aristotle postulated that the brain did not originate any sensation and understood that the heart should be where the sensations were produced.

Likewise, Aristotle hypothesized a structure of the anima in three dimensions: vegetative, sensitive and intellectual.

Herphilus

Contemporaneously with Aristotle, Herophilus dedicated himself to dissecting the bodies of animals and people for the study of the nervous system, tracing nerves from the muscles and the skin to the regions of the spinal cord.

Galen

In 157 BC, Galen made an important appreciation by reporting that changes in the behavior of gladiators were caused by injuries received to the head. For the first time, the brain is beginning to be associated with mental functioning.

Nemesius

In 400 AD, Nemesisus formulated a theory of location in the brain, elaborating the idea that cognition is in the ventricles.

Thomas willis

During the 18th century, Thomas Willis provided valuable information about brain function. He was the first author to locate the functions in the cerebral cortex. Specifically, the author located sensation in the striatum, perception in the corpus callosum, and memory in the cortex.

Likewise, during the same period, La Peroynie placed intelligence in the corpus callosum since an injury to the hemisphere did not cause significant deficits.

Joseph Gall

At the beginning of the 19th century, Joseph Gall promoted the study of the location of the brain in the different cognitive functions. Likewise, at the same time, Flourens postulated a theory antagonistic to Gall's, arguing that mental processes depended on the global functioning of the brain.

Golden years

The golden years of psychophysiology emerged in the mid-nineteenth century. Broca, a Swiss neurologist discovered the broca area through the TAN-TAN case. 5 years later, the Wernicke area is discovered.

60's

During the 60s of the last century two authors stood out. Geshwind demonstrated the importance of connections in complex tasks and described the disconnection syndrome, referring to the damage to the connections between different brain areas.

For his part, Luria devoted himself to studying World War II patients and described disorders located in the prefrontal cortex of the brain.

What does psychophysiology study? (object of study)

Psychophysiology is in charge of analyzing the physiological bases of psychological processes. That is, it focuses on examining the way in which psychological activities produce physiological responses.

Historically, most authors have tended to examine the physiological responses and organs innervated by the autonomic nervous system.

Instead, more recently, psychophysiologists have become interested in the central nervous system, exploring cortical potentials and event-related potentials, brain waves, and functional neuroimaging.

In this sense, psychophysiology can investigate, for example, how being exposed to a stressful situation produces a result in the cardiovascular system such as an alteration in heart rhythm or ventricular vasodilation.

In general, the main aspects on which psychophysiology focuses are:

Sensation and perception

The general principles of sensory information processing are one of the foundations of psychophysiology as a science.

The functioning of the mind, consciousness and perception are the main elements investigated and examined by this branch of psychology.

Somatic senses

The functioning of the bodily senses and their integration with mental processes are also studied from psychophysiology.

Somatic modalities, receptors, somastic pathways and transduction would be the main topics of interest. Likewise, psychophysiology examines the processes of pain and analgesia, and the functioning of somatic information in the cerebral cortex.

View

Specifically, the functioning of the visual sense is one of the topics of special interest in psychophysiology. The particularities of the eye, retina and optical pathways are examined, as well as the transduction and coding of visual information.

In addition, psychophysiology is in charge of analyzing visual information in the striated cortex and the association cortex of the brain.

Hearing and balance

As with the visual sense, the auditory sense is another research aspect of psychophysiology.

Determining the particularities of the ear, the organ of corti and the auditory pathways are activities carried out from this branch of psychology. Likewise, the transduction, coding and analysis of auditory information in brain regions are examined.

Movement control

Psychophysiology is in charge of investigating the organization of the sensory-motor function, the effector systems, the control of reflex responses and the cerebral control of movement.

Sleep and wakefulness

On the other hand, psychophysiology is the discipline that is responsible for investigating circadian rhythms and their regulation, the behavioral and physiological characteristics of sleep and wakefulness, as well as their neural mechanisms and functions.

Reinforcement

The biological and physiological nature of motivational systems are also aspects of study in psychophysiology. The reinforcing nervous substrate, incentive motivation and addiction would be the elements of special interest.

Hunger and thirst

Digestion and metabolism are physiological aspects that are also of interest to psychophysiology. This branch of psychology focuses on examining the mechanisms of peripheral regulation of intake, neural control of hunger and water balance.

Sexual conduct

Regarding sexual behavior, psychophysiology studies the organizing and activating effects of sex hormones, the neural control of sexual behavior, and the functioning of pheromones.

Emotion

Emotional processes are probably the elements that are most related to psychophysiology today.

The nature of emotions and feelings, neural functions and systems of emotions, aggressive and violent behaviors, and the physiological response to stress would be the main aspects.

Learning and memory

Finally, psychophysiology has recently gained importance in the study of higher cognitive processes.

The nature of learning and memory, synaptic plasticity, basic forms of learning and implicit memory, relational learning and the neural functioning of working memory are elements studied by psychophysiology.

Research objectives

The objective of scientific research is based on explaining the phenomena that are studied. In psychophysiology, reduction is often used. In this way, an attempt is made to explain complex phenomena in terms of more specific ones.

However, psychophysiology does not focus solely on providing reductionist responses. That is, it is not based solely on observing behaviors and correlating them with physiological events.

Thus, psychophysiology uses both generalization and reductionism. Reduction refers to the explanation of phenomena in terms of more basic physical processes. Instead, in generalization, psychophysiology uses the traditional methods of psychology.

In this sense, reduction focuses on explaining behaviors in terms of physiological events within the body, specifically within the nervous system, and generalization focuses on relating that information to the psychological processes that are studied.

More specifically, several authors conclude that the main objectives of psychophysiology are:

1. Analyze the nervous processes that intervene in the transformation of the physical stimulation of the sensory organs.

1. Study the influence exerted by biological modifications on the formation of certain psychological manifestations.

Methods of psychophysiology

Psychological methods

This method seeks to study the behavior of an individual. For this, an artificial situation (stimulus) is provoked that allows to determine in a more objective way if the behavior is normal or abnormal.

Anatomical methods

It is about the study of the morphological characteristics of the nervous system and its activity through stimulation. This method can help determine the link between brain and cognitive activity. It is not invasive and does not cause injury. It is a harmful and invasive process.

Chemical methods

This technique is invasive. It consists of introducing a series of chemicals through a cannula. This serves as stimulation to determine the changes that occur in brain activity.

Electrical methods

The electrical method requires a series of electrodes that are applied to the tissues to emit voltages and thus determine the damaged structure and its relationship with the behavior of the individual.

Differences between psychophysiology and physiological psychology

Although they are two concepts that are often used interchangeably, psychophysiology and physiological psychology are not the same branch of psychology.

Both disciplines focus on studying the physiological functioning of the organism and relating it to psychological processes. However, they differ in their way of working.

Psychophysiology focuses on analyzing the way in which psychological activities produce physiological responses. Instead, physiological psychology focuses on analyzing the physiological mechanisms that lead to psychological activity.

The study components of the two disciplines are often the same. However, they are distinguished through the point of view from which they are investigated and analyzed.

For example, physiological psychology focuses on studying what physiological processes are responsible for producing the sensation of thirst, while psychophysiology would focus on examining what modifications in physiological functioning originate the sensation of thirst itself.

Applications

Beyond the research function, psychophysiology has other types of applications. Specifically, psychophysiological measures are often used to study emotion and attention.

Likewise, psychophysiology could play an important role in improving the conceptualization of cognitive processes. In fact, certain psychophysiological sensors have already been used to detect emotions in schools and to develop intelligent tutoring systems.

Signals used

Psychophysiological study requires the use of electronic mechanisms, and modern psychophysiology uses many different types of signals.

Those most commonly used are evoked potentials, event-related potentials, and brain waves (electroencephalography).

Likewise, other types of signals are also used such as functional magnetic resonance imaging (fMRI), measurements of the conductivity of the skin, the galvanic response of the skin, measurements of the cardiovascular system, measurements of the heart rate and signals of the variability of the HRV heart rate.

Finally, eye movements recorded by electro-oculogromas (EOG), gaze tracking methods or changes in the diameter of the pupil are other signals commonly used in psychophysiology.

References

1. Bear, MF, Connors, B. i Paradiso, M. (2008) Neuroscience: exploring the brain (3rd edition) Barcelona: Wolters Kluwer.
2. Carlson, NR (2014) Physiology of behavior (11 edition) Madrid: Pearson Education.
3. Cacioppo, John; Tassinary, Louis; Berntson, Gary (2007). "25". Handbook of Psychophysiology (3rd ed.). Cambridge University Press. pp. 581–607.
4. Glynn, Laura; Christenfeld, Nicholas; Gerin, William (2002). «The Role of Rumination in Recovery From Reactivity; Cardiovascular Consequences of Emotional States ”. Psychosomatic Medicine. 64 (5): 714–726.
5. Purves, D., Augustine, GJ, Fitzpatrick, D., Hall, WC, Lamantia, AS. Mcnamara, JO i Williams, SM (2006) Neuroscience (3rd edition) Madrid: Editorial Médica Panamericana.
6. Rosenzweig, MR, Breedlove, SM i Watson, NV i. (2005) Psychobiology. An Introduction to Behavioral, Cognitive, and Clinical Neuroscience (2nd edition updated). Barcelona: Ariel.