This review focuses on the theory of emotion outlined in Chapter 3 of Rolls's The brain and emotion. It is proposed that Rolls's emphasis on a relatively simple neurobiologically derived emotion scheme does not allow him to present a comprehensive account of emotion. Consequently, high-level cognitive processes, such as appraisal, end up being retained in the theory despite Rolls's skepticism about their utility. An argument is put forward that the concept of appraisal in the emotion literature is more than semantic convention and actually allows us to talk about multiple functional-level routes to the generation of emotion – a characteristic of the latest generation of theories in the cognition-emotion literature.

A broad evolutionary perspective is essential to fully reverse figure and ground in the rationality debate. Humans' evolved psychological architecture was designed to produce inferences that were adaptive, not normatively logical. This perspective points to several predictable sources of errors in modern laboratory reasoning tasks, including inherent, systematic biases in information-processing systems explained by Error Management Theory.

A problem with Stanovich & West's inference that there a nonintellectual processing system independent from an intellectual one from data in which they partialled out global intelligence is that they may have controlled for the wrong kind of intellectual intelligence. Research on cognitive-experiential self-theory over the past two decades provides much stronger support for two independent processing systems.

The Merge model suggests that lexical effects in phonemic processing reflect the activation of post-lexical phonemic representations that are distinct from prelexical phonemic input representations. This distinction seems to be unmotivated; the phoneme fails to capture the richness of prelexical representation. Increasing the information content of input representations minimizes the potential necessity for top-down processes.

In order to benefit from the advantages of localist coding, neural models that feature winner-take-all representations at the top level of a network hierarchy must still solve the computational problems inherent in distributed representations at the lower levels.

Three types of problems are raised in this commentary: On the linguistic side, we emphasize the importance of an appropriate definition of the different domains of linguistics. This is needed to define the domains (lexicon-syntax-semantics) to which transformational relations apply. We then question the concept of Broca's aphasia as a “functional” syndrome, associated with a specific lesion. Finally, we discuss evidence from functional brain imaging. The breadth and potential impact of such evidence has grown considerably in the last few years, expanding our knowledge of the multiple contributions of the “Broca's region” to phonological, lexical-semantic, and syntactic processing. “Lumping” under diagnostic labels, such as Broca's aphasia, should be replaced by more detailed linguistic and neurological descriptions of the clinical cases.

Although the work of Revonsuo is commendable for its attempt to use an evolutionary approach to formulate a hypothesis about the adaptive function of dreaming, the conclusions arrived at by this author cannot be fully shared. Particularly questionable is the idea that the specific function of dreaming is to simulate threatening events. I propose here a hypothesis in which the dream can have a different function.

[Revonsuo]

I express two concerns with the theory of emotion that Rolls provides: (1) rewards and punishers alone fail to explain the basic emotions; (2) Rolls needs to clarify his notion of the intentionality of emotions. I also criticize his theory of consciousness, arguing that it fails to explain qualia, and that ironically it is emotions which make this most evident.

The concept of emotion as defined by Rolls is based upon reinforcement mechanisms and their underlying neural networks. He shows how these networks process signals at many levels, through both separate and convergent pathways essential for adaptive action. While many behavioral issues related to emotion are omitted from his review, he succeeds admirably in summarizing both the “current state of the art” in single unit analyses and in pointing out how future research directions may be crafted.

In the Localist Manifesto, Page enumerated several computational advantages that localist representations have over distributed representations, but the most important difference between such networks concerns their theoretical clarity. Distributed representations are normally closed to theoretical interpretation and, for that reason, contribute little to psychology, whereas the meaning of the information processing in networks using localist representations can be transparent.

The model of phoneme monitoring proposed by Norris et al. is implausible when implemented in a localist connectionist network. Lexical representations mysteriously inform phoneme decision nodes as to the presence or absence of a target phoneme.

A prospective integration of evolutionary and other approaches to understanding rationality, as well as incorporation of individual difference concerns into the research agenda, are major contributions of Stanovich & West's analysis. This commentary focuses on issues of concern in detailing a dual-system or dual-process model of the sort they propose and using it as a basis for improving judgment.

Grodzinsky associates Broca's area with three kinds of deficit, relating to articulation, comprehension (involving trace deletion), and production (involving “tree pruning”). Could these be special cases of one deficit? Evidence from research on language evolution suggests that they may all involve syllable structure or those aspects of syntax that evolved through exploiting the neural mechanisms underlying syllable structure.

(1) Substituting (as Solms does) forebrain for brainstem in the search for a dream “controller” is counterproductive, since a distributed system need have no single controller. (2) Evidence against episodic memory consolidation does not show that REM sleep has no role in other types of memory, contra Vertes & Eastman. (3) A generalization of Revonsuo's “threat simulation” model in reverse is more plausible and is empirically testable.

[Hobson et al.; Solms; Revonsuo; Vertes & Eastman]

The brain contains ubiquitous reciprocal bottom-up and top-down intercortical and thalamocortical pathways. These resonating feedback pathways may be essential for stable learning of speech and language codes and for context-sensitive selection and completion of noisy speech sounds and word groupings. Context-sensitive speech data, notably interword backward effects in time, have been quantitatively modeled using these concepts but not with purely feedforward models.

Deficits observed in Broca's aphasia are much more general than Grodzinsky acknowledges. Broca's aphasics have a broad range of problems in lexical and morphological comprehension; furthermore, the classic “agrammatic” syntactic profile is observed over many populations. Finally, Broca's area is implicated in the performance of many linguistic and nonlinguistic tasks.

We contend that if efficiency and reliability are important factors in neural information processing then distributed, not localist, representations are “evolution's best bet.” We note that distributed codes are the most efficient method for representing information, and that this efficiency minimizes metabolic costs, providing adaptive advantage to an organism.

The book contains a masterly review of Rolls's single-neuron research reflecting rewards. It places that research in the context of the neo-behaviorist theory of emotions. That theory provides a useful first approximation to emotion-eliciting conditions but has little to tell about emotions as motivational states or response dispositions: nor does it give a rationale for what are considered to be primary rewarding stimuli.

Solms shows the cortical basis for why dreams reflect waking concerns and goals, but with deficient volition. I argue the latter relates to Hobson et al.'s process I as well as M. A memory function for REM sleep is possible, but may be irrelevant to dream characteristics, which, contrary to Revonsuo, mirror the range of waking emotions, positive and negative.

[Hobson et al.; Nielsen; Solms; Revonsuo; Vertes & Eastman]

I discuss several problems with Stanovich & West's research and suggest an alternative way to frame the rationality debate. The debate is about whether analytic (System 2) thinking is superior to intuitive (System 1) thinking or whether the two modes are complementary. I suggest that the System 1/System 2 distinction is equivalent to the Chinese concepts of yin and yang and that the two modes are complementary.