Images of mindsuperbly summarizes work on cognitive neuroscienee using PET scanning. Some of the data emphasized suggests that parietal cortex is involved in the disengagement of attention. We have discovered neurons in awake monkeys which could perform this function. Another point of emphasis is the concept of neutral cues. Although an appealing concept, it is extremely difficult to define what is actually neutral.

While it is known that reward induces attentional prioritization, it is not clear what effect reward-learning has when associated with stimuli that are not fully perceived. The masked priming paradigm has been extensively used to investigate the indirect impact of brief stimuli on response behavior. Interestingly, the effect of masked primes is observed even when participants choose their responses freely. While classical theories assume this process to be automatic, recent studies have provided evidence for attentional modulations of masked priming effects. (...) Most such studies have manipulated bottom-up or top-down modes of attentional selection, but the role of “newer” forms of attentional control such as reward-learning and selection history remains unclear. In two experiments, with number and arrow primes, we examined whether reward-mediated attentional selection modulates masked priming when responses are chosen freely. In both experiments, we observed that primes associated with high-reward lead to enhanced free-choice priming compared to primes associated with no-reward. The effect was seen on both proportion of choices and response times, and was more evident in the faster responses. In the slower responses, the effect was diminished. Our study adds to the growing literature showing the susceptibility of masked priming to factors related to attention and executive control. (shrink)

This volume explores how functional brain imaging techniques like positron emission tomography have influenced cognitive studies. The first chapter outlines efforts to relate human thought and cognition in terms of great books from the late 1800s through the present. Chapter 2 describes mental operations as they are measured in cognitive science studies. It develops a framework for relating mental operations to activity in nerve cells. In Chapter 3, the PET method is reviewed and studies are presented that use PET to (...) map the striate cortex and to activate extrastriate motion, color, and form areas. Chapter 4 shows how top down processes involving attention can lead to activation of these same areas in the detection of targets, visual search, and visual imagery. This chapter reveals complex networks of activations. Chapters 5 and 6 deal with the presentation of words. Chapter 5 illustrates PET studies of the anatomy of visual word processing and shows how the circuitry used for generating novel uses of words changes as the task becomes automated. Chapter 6 applies high density electrical recording to explore these activations in real time and to show how a constant anatomy can be reprogrammed by task instructions to produce and perform different cognitive tasks. Chapter 7 shows how studies of brain lesions and PET converge on common networks underlying attentional functions such as visual orienting, target detection, and maintenance of the alert state. Chapters 8 and 9 apply the network approach to examine normal development of attention in infants and pathological conditions resulting from brain damage, and psychiatric pathologies of depression, schizophrenia, and attention deficit disorder. In Chapter 10, new developments such as functional MRI are discussed in terms of future developments and integration of cognitive neuroscience. (shrink)

We divided the many diverse comments on our book into categories. These are: theory, scope and goals of our project, methods, comments on specific anatomical areas, the concept of attention, consciousness and cognitive control, and finally other issues. Although many of the points of the critics are certainly well taken, we believe studies that have emerged since our book provide strong evidence that the general approach taken in our book is now yielding important new data on the relation of cognitive (...) processes to underlying brain activity. (shrink)

PET studies in domains like vision and attention have been successful because the experiments are the product of highly articulated theories. In contrast, the results of PET studies investigating language processing are difficult to interpret. We suggest that this difficulty is due to the more tentative connection of these experiments with the insights of psycholinguistics and linguistic theory.

The aim of this study was to investigate unconscious priming by the use of a spatial mirror-masking paradigm. Words and nonwords with no under-length letters are mirrored at their horizontal axis. The results are figures of geometric-like forms that contain letters in their upper part. In the three experiments reported in this study, a priming procedure used such mirrored words and nonwords as primes. Participants were ignorant of the nature of the construction of the stimuli. Perceptual reports of the participants (...) revealed that they did not realize that words were hidden in the primes. Nevertheless, they showed priming in all three experiments. Priming effects were replicated with prime–target SOAs of between 1 and 3 s. Functional dissociations were found between ignorant and informed participants. Informed groups showed perceptual and semantic priming, while ignorant groups showed only perceptual priming. (shrink)

In Posner & Raichle's (1994) book, two essential and strictly related limitations of cognitive neurophysiology are not sufficiently enhanced: (1) The problem of “coding,” namely the capability of a natural brain to redefine its own “basic symbols” as a function of a changing environment; (2) the inadequacy of a Hebbian rule to reckon with complex computational problems such as those solved by real brains.

Can we build endogenous expectations about the locus of occurrence of a target without being able to describe them? Participants performed cue–target detection tasks with different proportions of valid and invalid trials, without being informed of these proportions, and demonstrated typical endogenous effects. About half were subsequently able to correctly describe the cue–target relationships . However, even non-verbalizer participants showed endogenous orienting with peripheral cues , not depending solely on practice . Explicit instructions did not bring about dramatic advantages in (...) performance .With central symbolic cues, only verbalizers showed reliable endogenous effects . We concluded that endogenous orienting with peripheral cues can occur independently of participants developing explicit hypotheses about the cue–target relationships. (shrink)

Pictures of normal brain activity during human thought can be worth a great deal. Electrophysiology and functional neuroimaging together allow both temporal and spatial dimensions of neurocognitive functions to be explored. Although these techniqueshave their limitations, the Cognitive Neuroscience approach is well-suited to pursuing questions about how words are perceived, understood, and remembered.

The objective of this paper is to characterize the rich interplay between automatic and cognitive control processes that we propose is the hallmark of skill, in contrast to habit, and what accounts for its flexibility. We argue that this interplay isn't entirely hierarchical and static, but rather heterarchical and dynamic. We further argue that it crucially depends on the acquisition of detailed and well-structured action representations and internal models, as well as the concomitant development of metacontrol processes that can be (...) used to shape and balance it. (shrink)

Posner & Raichle's book is a superbly presented and wellwritten overview of a fast-developing and important field in contemporary neuroscience. It suffers from being an overview, however, because it does not go into sufficient detail or depth in many of the issues that it raises. It also neglects many other important areas of current research, for example, technical advances in other areas, learning and memory, and lesion analysis of brain function.

The results of two experiments provide the first direct demonstration that subjects can process a word lexically despite concurrently being engaged in decoding a task cue telling them which of two tasks to perform. These results, taken together with others, point to qualitative differences between the mind‘s ability to engage in lexical versus sublexical processing during the time they are engaged with other tasks. The emerging picture is one in which some form of resource plays little role during lexical processing (...) whereas the need for some form of resource during sublexical processing serves to bottleneck performance. (shrink)

Priming effects have been used widely as a tool to study attentional processes. However, inferences regarding attention depend on how priming effects are interpreted. In the case of negative priming, an activation-based framework for interpreting priming suggests that attention inhibits the representation of prime distractors and that this inhibition is measured in performance to subsequent probes. Data summarized in this article point out that negative priming does not depend on selection of one of two primes and that attentional influences during (...) retrieval play an important role in determining negative priming. Also, two experiments are described that demonstrate a correlation between priming effects and knowledge of the relation between primes and probes. We suggest that negative priming is not determined directly by a process of ignoring, but instead occurs because a repeated probe is less temporally distinct when ignored as a prime than when attended. (shrink)

A distributed neural network model called SPEC for processing sentences with recursive relative clauses is described. The model is based on separating the tasks of segmenting the input word sequence into clauses, forming the case‐role representations, and keeping track of the recursive embeddings into different modules. The system needs to be trained only with the basic sentence constructs, and it generalizes not only to new instances of familiar relative clause structures but to novel structures as well. SPEC exhibits plausible memory (...) degradation as the depth of the center embeddings increases, its memory is primed by earlier constituents, and its performance is aided by semantic constraints between the constituents. The ability to process structure is largely due to a central executive network that monitors and controls the execution of the entire system. This way, in contrast to earlier subsymbolic systems, parsing is modeled as a controlled high‐level process rather than one based on automatic reflex responses. (shrink)

In “Mercier and Sperber’s Argumentative Theory of Reasoning: From Psychology of Reasoning to Argumentation Studies” (2012) Santibáñez Yañez offers constructive comments and criticisms of the argumentative theory of reasoning. The purpose of this reply is twofold. First, it seeks to clarify two points broached by Yanez: (1) the relation between reasoning (in this specific theory) and dual process accounts in general and (2) the benefits that can be derived from reasoning and argumentation (again, in this specific theory). Second, it suggests (...) one domain—the categorization of arguments—in which argumentation studies and the argumentative theory of reasoning could usefully complement each other to yield a better understanding of the processes of argumentation. (shrink)