Principles of Cognition: Finding Minds - A book review by Brenda Walker

PRINCIPLES OF COGNITION; Finding Minds                 

Princetown University Press. Princeton and Oxford 2024, Eduardo Mercado III                     

Eduardo Mercado III is a professor of psychology and of ecology, evolution and behaviour at the University of Buffalo. The State University of New York, where he is Director of the Center for Cognitive Science.  During 2023, in his role as a behavioural neuroscientist he received a Grass Fellowship from the Harvard Radcliffe Institute where he studied the nature, functions, and plasticity of whale songs with a Fellowship grant from the John Simon Guggenheim Memorial Foundation. This innovative research scientist has now produced this attractive six-hundred page volume, published by Princeton University Press in New Jersey and their European office in Banbury Road, Oxford. Designed as a textbook, it presents as a high quality publication with full colour diagrams and photographs throughout. There are two tables of contents: one in brief on a single page to enable the reader to absorb key headers and chapters at a glance. This information is then extended into an eleven page complete list of the twelve chapters. Within this book’s attractively arranged pages, user-friendly language is found throughout, even for headings and sub-headings, which promotes interest and clarity of the subject matter. There is an eleven page detailed glossary, an excellent reference section and index.

Mercado’s very personal preface opens with a quotation from page two of the 1890 publication, The Principles of Psychology  by William James that poses questions for the modern reader on trying ‘to make sense of  the peculiarities associated with the operations of mind’.  It was this book and James’ abridged version, Psychology: The Brief Course, that led Mercado to build on James’ legacy by writing a textbook which would provide ‘a modern, comprehensive overview of what psychologists currently know about the nature of cognition’. Mercado mentions how many critics considered James out of date; considering the work of Ulner Neisser, Cognitive Psychology, more relevant. However, Mercado allows the reader to compare the summarised table of contents for both these authors and then states why he thinks James provides the more modern and comprehensive overview ‘of the fields of cognitive psychology and cognitive neuroscience’. He then explains how for this latest volume, he has deviated from the usual textbook structure, which in consequence omits many details, but is more manageable and concise. His reasoning being that in this way the reader is still able to attain ‘insights into the science of cognition,’ without being weighed down by too many facts. These insights vary in length and many are contracted into short sections which invite, rather than overwhelm the reader.

The author recalls his exciting and confusing work exploring cognition and minds with dolphins and how, when looking back on this, he realised that ‘confusion is not your enemy, when trying to understand cognition, or when trying to understand anything really – but complacency, boredom and certainty will most likely do you in’. Mercado then adds that in the planning stage of this book he has done everything to avoid this and hopes the reader will capture some of the excitement of learning that he himself felt after his hands-on experience with such intelligent cetaceans. He acknowledges that today more is known regarding cognition processes and underlying mechanisms than in 1800, but states that many ideas on certain areas are not very different from those subscribed to Aristotle more than two thousand years ago. Mercado then queries whether this volume will provide a ‘leap forward’ or a ‘scientific side step’, and advises readers to decide for themselves, suggesting they question their understanding of relevant data as well as explanations given by others regarding the essence of cognition and the principals of mental function. 

The author’s detailed and engaging list of acknowledgements describes the journey of this book from conception to production. William James took twelve years and Eduardo Mercado III, ten. Among his appreciation for collaborators, friends and family, he particularly comments on those university students who ‘left their mark on the contents’ either by comments, questions arising in class or by their responses to earlier drafts.

The opening text of Principles of Cognition. Finding Minds is titled BEGINNINGS and it is here where a page and a half is given to the career projectory of William James. A career that began in the world of the artist, but shifted towards scientific subjects: chemistry, medicine, physiology, and eventually, cognitive psychology. All of which makes fascinating reading, providing a starting point to explore the path ‘blazed’ by James who expounded on the experiential elements of thought in contrast to current thinking, where the focus of cognitive research tends to be on ‘the collection, organization, and manipulation of information.’ The following three opening chapters: The Science of Minds; Mechanisms of Mind; and Conscious Cognitive Processes, explore the idea that ‘behaviour, brains and consciousness are all fundamental components of cognition and to truly understand minds one needs to experimentally explore how all change over time.’  Spread through every chapter in this large volume, the student’s attention is captured and held both by clear and informative photographs and figures; contracted small two to three line sections called SIGHT BITES, that highlight ongoing key points; a SNEAK PEEK at various approaches; list of words such as Cognitive LINGO; strange facts gathered under the heading, WIERD, TRUE, FREAKY; and finally, each chapter ends with a CHAPTER SUMMARY, REVIEW EXERCISES and CRITICAL THINKING QUESTIONS.

By referring to the TV game, Jeopardy, the author describes how the IBM’s computer WATSON is able to improve over time by utilising a trial and error system and how this ability suggests it may be the first cognitive computer. ‘Cognitive’, as it can solve problems ‘by assessing and conveying facts’.  Human cognition however, has the additional ability to remember feelings of familiarity as well as personal events; an awareness that comes from watching others and a linked in memory. Mercado defines The Principles of Cognition. Finding Minds, as THE SCIENTIFIC STUDY OF COGNITION that sets out to describe not only how such studies are carried out, but what they have revealed. As researchers find the ‘mind’ hard to define, they conclude it to be the ‘hidden parts of a mental activity’. Comparing athletic skills to mental ones he introduces ‘cognizing’, and gives various examples of how conceptual models of mind, both quantitative and qualitative, can help reveal some essential elements of – ‘what is involved’ in cognizing, and just ‘how cognitive processes’ might work,  (Cognition: ‘It’s what you think’ and Intelligence:  ‘Knowing how to think’). Some key facts from these early chapters are contracted in the SNEAK PEAKS, but the reader is also introduced to comparisons across species; the value of self-reflection; reasoning versus instinct; the relationship between language and thought; nature versus nurture versus computational power; and many aspects regarding the measuring of intelligence, behaviour and learning. To conclude this section, Mercado illuminates current practises of cognitive psychologists with an illustration delineating the format of a scientific method of enquiry.

Often, Mercado deviates from the reader’s expectation. For instance, the opening sentence of the chapter ‘Mechanisms of Mind,’ starts with:  ‘Over fifteen languages are at Christopher Taylor’s disposal. Yet he cannot find his way to the local grocery store and back.’ What a great way to capture a student’s interest when discussing both a polyglot and a savant; a mystery to solve, with questions regarding memory, language, intelligence and cognition.  Mercado states that some psychologists might think: “Aha! Genius level language capacities combined with low-level intelligence. The mechanisms for language must be separate from those of other cognitive abilities!”  He then goes on to describe how the number of abilities one has depends on brain structure and function; mainly controlled by genes. However, they ‘do not determine what brains ultimately do.’   He follows the questions he poses by discussing how genes ‘set the stage’ for cognition, and how both ‘Genes and brains are dynamic and their activity is strongly influenced by environmental events.’ The author goes on to state: ‘Your experiences early in life, in particular, can strongly affect the kinds of cognitive feats you are likely to be able to achieve.’ A SNEAK PEAK then explains how genes can affect cognitive processes ‘in ways more complex than determining the presence or absence of cognitive ability’.

Looking at the idea of ranking across primate minds from ‘primordial monkey to hyper-advanced hominoid’, another question is posed, “Why might such brain sorting misrepresent how evolution has shaped cognition?” (After Sousa et al. 2017) Then follows paragraphs on breeding intelligence, heritability of aptitudes, genetic engineering, eugenics and savants. The reader is then asked to consider yet another question, “Are genes relevant to understanding cognition?”  An explanation of how cognitive neuroscience differs from cognitive psychology introduces comments on brain qualities and brain basics, functions of brain regions, cortical complexity, and the final question in this section set for students, “Does size matter?”

There is so much valuable and interesting material in this book which includes further key chapters on:                                                                                                      

• Perception, Recognition and Attention     
• Categorization and Discrimination             
• Time, Space and Number                               
• Acquiring and Applying Memories                
• Remembering                                                                                                                                                  
• Imagery, Planning and cognition                                                                                                                                                                                       
• Communication and Language

Every page in this volume invites the reader’s attention with its conversational style and wealth of knowledge, the carefully thought out illustrations and figures, finely produced coloured photographs, and well chosen personal comments. Following in James’ footsteps, whilst acknowledging past heritage, Mercado lll has achieved a textbook described on its back cover as a modern ‘comprehensive overview of what psychologists know about the nature of cognition’.  With the undergraduate or graduate student in mind, he enthusiastically connects topics across chapters to aid retention of the subject matter, and provides many areas seldom covered in a single volume. The reader will find enrichment by discovering information about animal cognition, the perception of time and space, consciousness, and the functional dynamics of cognitive processes in everyday life  one such as:  reading and maths’ skills, intelligence, social cognition, and emotions.  Each chapter engages in some kind of practical application from cognitive research, whether experimental, naturalistic or applied, and the introduction to neuroscience and brain structure quite early on in the book is a definite asset enabling the mechanism of cognition to be viewed from a more neurally grounded framework.

The whole volume could be of particular interest for a browser or anyone in the teaching profession, as Mercado emphasises learning and its interactions with memory and cognition while integrating findings about animals and children with traditional studies of adults.

Brenda Walker   
July 2025