Introduction

To better answer the question, this post will illustrate how the study of mental processes has evolved through three significant phases: before Biological studies, this “era” focuses on the early philosophical and introspective approaches; the Stimulus-reaction period, this is the “era” of behaviourism and early neurophysiological models, which characterised brain as a stimulus-response machine; Predictive Processing, the current “era”, which provides a more integrated and dynamic understanding of mental processes as proactive, prediction-based processes.

Brain’s function and structure across the time

Before going into a detailed exploration of the study of mental processes across the history of psychology, it’s important to look at the evolution of understanding brain functions and structures across the mentioned periods; to see the profound changes in the conceptualisation of the brain in psychology and neuroscience. 

Before Biological contribution: in this era, the understanding of the brain function and structure was rudimentary and relayed on philosophical speculations. The anatomical knowledge was limited and the brain’s importance was overlooked. Aristotle for instance thought that the heart has a more crucial role and is the primary organ of sensation (Aristotle, 350 BCE). The brain’s function, for example was often explained through metaphysical concepts, like the Humoral theory, which suggests that bodily fluids influenced behaviour and temperament (Hippocrates, 400 BCE). Later in the 17th century, Descartes proposed a new theory “Mind-Body Dualism”, where he distinctly separates the nature of the mind and the nature of the body, arguing that one can exist without another. Although he assigns a function of consciousness and reason to the brain. 

Stimulus-Reaction Era: shaped by the rise of behaviourism and early neuroscience, the understanding of the brain shifted towards more empirical and anatomical forms. Which led to a clearer understanding of the brain’s structure and functions. One of the most significant findings was Broca’s discovery of the speech production centre in the brain, known as Broca’s area, which linked specific brain areas to cognitive function (Broca, 1861). This was the beginning of a new field- neurophysiology. Later Wernickle (1874) developed even further the brain-behaviour relationship, by identifying the brain’s area responsible for language comprehension. During the same period, the brain’s function was understood as a stimulus-response mechanism, (where specific inputs led to certain outputs.) This era was dominated by the behaviourists’ perspective that all behaviours could be understood as reflexes conditioned by environmental stimuli (Watson, 1913; Pavlov 1927).

The Predictive Processing Era: views the brain as an active participant that doesn’t just passively respond to the external world but proactively simulates and predicts the environment. The distinction of understanding brain structure in this era is neuroimaging technologies such as fMRI and PET scans which allowed to examine hierarchical organisation of the brain, showing how different layers of neural circuits predict sensory inputs at various levels of abstraction (Friston, 2005). The brain’s function is understood as a continuous prediction process, to minimise the error between its predictions and sensory inputs and by adjusting its predictions, shapes cognitive functions. As well as, construct and maintain perceptual reality (Clark, 2013). Unlike earlier theories which often separated mind and body, the modern approach emphasises the inseparability of cognitive processes from their biological bases, aligning psychology more closely with biological science.

References

• Aristotle. (circa 350 BCE). De Anima (On the Soul).
•  Broca, P. (1861). Remarks on the seat of the faculty of articulated language, following an observation of aphemia (loss of speech). Bulletin de la Société Anatomique.
• Clark, A. (2013). “Whatever next? Predictive brains, situated agents, and the future of cognitive science.” Behavioral and Brain Sciences.
• Friston, K. (2005). “A theory of cortical responses.” Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences.
• Hippocrates. (460-370 BCE). On the Sacred Disease.
• Pavlov, I.P. (1927). Conditioned Reflexes. London: Oxford University Press.
• Watson, J.B. (1913). “Psychology as the behaviorist views it.” Psychological Review
• Wernicke, C. (1874). Der aphasische Symptomencomplex: Eine psychologische Studie auf anatomischer Basis. Cohn & Weigert.