Attention and consciousness: two distinct brain processes

The close relationship between attention and consciousness has led many scholars to conflate these processes. This article summarizes psychophysical evidence, arguing that top-down attention and consciousness are distinct phenomena that need not occur together and that can be manipulated using distinct paradigms. Subjects can become conscious of an isolated object or the gist of a scene despite the near absence of top-down attention; conversely, subjects can attend to perceptually invisible objects. Furthermore, top-down attention and consciousness can have opposing effects. Such dissociations are easier to understand when the different functions of these two processes are considered. Untangling their tight relationship is necessary for the scientific elucidation of consciousness and its material substrate.     

An ironic effect of monitoring closeness

Most theories of goal pursuit underscore the beneficial consequences of monitoring progress towards goals. However, effects of affect labelling and dissociations between experience and meta-consciousness suggest that monitoring may not always facilitate goal pursuit. We predicted that in the case of pursuing interpersonal closeness, intense monitoring of progress would have a detrimental effect. We tested this hypothesis with the intimate conversation procedure, adapted from Aron, Melinat, Aron, Vallone, and Bator (1997). Participants in the closeness-monitoring condition asked themselves every five minutes in the course of a 45-minute interaction with a partner whether they felt any closer to their partner, whereas participants in the control condition monitored the room temperature. As predicted, intense monitoring interfered with achieving a feeling of closeness, as measured by sitting distance between pair members following the intimate conversation procedure. We discuss the possibility that monitoring would also be detrimental for achieving other goals that are internal states.     

Criteria for unconscious cognition: three types of dissociation

To demonstrate unconscious cognition, researchers commonly compare a direct measure (D) of awareness for a critical stimulus with an indirect measure (I) showing that the stimulus was cognitively processed at all. We discuss and empirically demonstrate three types of dissociation with distinct appearances in D-I plots, in which direct and indirect effects are plotted against each other in a shared effect size metric. Simple dissociations between D and I occur when I has some nonzero value and D is at chance level; the traditional requirement of zero awareness is necessary for this criterion only. Sensitivity dissociations only require that I be larger than D; double dissociations occur whensome experimental manipulation has opposite effects on I and D. We show that double dissociations require much weaker measurement assumptions than do other criteria. Several alternative approaches can be considered special cases of our framework.     

Graded representations in behavioral dissociations

Why do people sometimes seem to know things when they are tested in one way, while seeming unaware of this information when tested in a different way? Such task-dependent behaviors, or dissociations, often occur in infants and children, and in adults following brain damage. To explain these dissociations, researchers have posited separable knowledge systems that are differentially tapped by various tasks, develop at different rates and can be selectively impaired. There is an alternative account in which knowledge is viewed as graded in nature. Certain tasks tap weaker representations, while other tasks require stronger representations, leading to dissociations in behavior. The graded representations approach addresses dissociations observed in perception, attention, memory, executive functioning and language, and has implications for the organization, development and impairment of our cognitive systems.     

The consciousness continuum: from “qualia” to “free will”

The consciousness continuum is seen as extending from simple sensory experiences to complex subjective constructions resulting in the apparent exercise of conscious will. The phenomena between these two extremes include spontaneously occurring mental contents, unintended perceptual experiences, memory retrievals, and problem solving including feedback of conscious contents. Two factors describe this continuum: The presence or absence of intention (psychologically defined) and the complexity of the cognitive construction involved. Among other benefits, such an analysis is intended to provide an alternative to metaphysical and vague concepts such as qualia, free will, and intentionality.     

Implicit memory. Retention without remembering

Explicit measures of human memory, such as recall or recognition, reflect conscious recollection of the past. Implicit tests of retention measure transfer (or priming) from past experience on tasks that do not require conscious recollection of recent experiences for their performance. The article reviews research on the relation between explicit and implicit memory. The evidence points to substantial differences between standard explicit and implicit tests, because many variables create dissociations between these tests. For example, although pictures are remembered better than words on explicit tests, words produce more priming than do pictures on several implicit tests. These dissociations may implicate different memory systems that subserve distinct memorial functions, but the present argument is that many dissociations can be understood by appealing to general principles that apply to both explicit and implicit tests. Phenomena studied under the rubric of implicit memory may have important implications in many other fields, including social cognition, problem solving, and cognitive development.     

Using scissors to bisect a line: A perception–action dissociation in complex tool use

Previous research has shown that unilateral visual neglect is improved when patients are required to actively grasp an object at its center, rather than only pointing to its center. A similar dissociation between pointing and grasping responses has been reported for pseudoneglect, a spatial bias toward the left side of space that is normally exhibited by healthy participants. Among other theories, the two-visual-streams hypothesis has been offered as an explanation for these dissociations. According to this hypothesis, highly practiced actions that are performed under easily available visual input (e.g., grasping an object) are controlled by the dorsal stream and can resist perceptual judgment biases. We investigated whether, in pseudoneglect, dissociations between perceptual judgments and motor–manipulative responses occur when participants have to respond with complex tools that are highly practiced but that have been shown to rely on both ventral- and dorsal-stream processing. In a standard line bisection task, participants had to either mark the center of a line with a pencil or cut the line in two halves using a pair of scissors. The results indicated the typical leftward bias (pseudoneglect) in the pencil task, whereas performance was much more accurate in the scissors task. These results show that actions featuring complex tool use can resist perceptual judgment biases, and the findings are discussed with reference to existing accounts of perception–action dissociations.     

On the determinants of implicit evaluations: When the present weighs more than the past

It is often assumed that implicit evaluations are influenced by early childhood experiences, whereas explicit evaluations reflect recent experiences. However, previous findings supporting this assumption remain ambiguous as to whether the differential effects of early versus recent experiences are driven by their temporal distance or their affective versus cognitive nature. Controlling for affectivity by using a predominantly affective attitude object (i.e., religion), the present study found that both implicit and explicit evaluations were related to recent, but not early, experiences. This pattern consistently emerged for self-reported experiences as well as independent reports from parents. Moreover, the relation of recent experiences to one type of evaluation remained significant after controlling for the respective other type of evaluation, suggesting that recent experiences influenced implicit and explicit evaluations independently. Implications for attitudinal dissociations and processes of attitude change are discussed.     

Stochastic approaches to understanding dissociations in inflectional morphology

Computer modelling research has undermined the view that double dissociations in behaviour are sufficient to infer separability in the cognitive mechanisms underlying those behaviours. However, all these models employ multi-modal representational schemes, where functional specialisation of processing emerges from the training process. Targeted lesioning of different regions of functional specialisation leads to varied but predictable deficits in model performance. We argue that multi-modal representational schemes are not a necessary condition for the observation of double dissociations in an information processing system that shares resources across multiple tasks. Using a uni-modal representational system, we demonstrate that double dissociations may also result from stochastic processes. Lesioning experiments on a single-route, uni-modal connectionist model of regular and irregular noun and verb morphology confirm and extend earlier work demonstrating that selective impairment across tasks can result from damage to a distributed information processing system. A systematic investigation of the degree to which performance deteriorates across different inflectional classes reveals that simple and double dissociations can occur in this single-route, uni-modal model. An important prediction of the model is that double dissociations between regular and irregular inflection, resulting from stochastic processes should be extremely rare. However, they are particularly likely to occur when the researcher uses test batteries consisting of a small number of items. Given that cognitive neuropsychologists rarely provide details about the distribution of performance in a disordered population, it is concluded that a stochastic interpretation of double dissociations may have wider applicability than is normally supposed.     

Sitting through the emptiness

This article explores clinical encounters with experiences of the ‘empty ego’ which arise from early relational trauma. The ego’s emptiness is held in repetitious complexes and arises out of affectively charged experiences between self and other which remain split-off from awareness. This kind of consciousness is viewed as dualistic, separating non-dual subjectivity from its dualistic objects of consciousness. In contrast, what I am calling healing void states of non-dualistic consciousness, when admitted to awareness, allow the individual to dis-identify from the traumatizing representations of self and other through an experience of non-duality. In contrast to an objectified, dualistic emptiness of the ego, healing void states come about in moments of non-dual, unified consciousness. These states occur in the ego-Self relationship by linking the ego’s dualistic awareness in chronic subject/object splits to ones of non-dual pure consciousness. The healing void state is always incipiently present and potentially able to bridge the ego-Self connection in bogged-down treatment. The paper explores potential integrations with non-dual models of consciousness such as Vedantic and Kashmir Shaivism, among other mystical traditions. A combined Vedantic-Jungian understanding can provide a transcendent bridge that integrates Eastern concepts of non-duality in treating emptiness.     

Implicit and Explicit Evaluation: A Brief Review of the Associative–Propositional Evaluation Model

A central theme in contemporary psychology is the distinction between implicit and explicit evaluation. Research has shown various dissociations between the two kinds of evaluations, including different antecedents, different consequences, and discrepant evaluations of the same object. The current article provides a brief review of the associative–propositional evaluation (APE) model, which accounts for these dissociations by conceptualizing implicit and explicit evaluations as the behavioral outcomes of two functionally distinct, yet mutually interacting, mental processes. Whereas implicit evaluations are assumed to be the outcome of associative processes, explicit evaluations are conceptualized as the outcome of propositional processes. Associative processes determine the activation of mental contents on the basis of feature similarity and spatiotemporal contiguity; propositional processes involve the validation of activated mental contents on the basis of cognitive consistency. The APE model includes specific assumptions about mutual interactions between the two processes, implying precise predictions about converging versus diverging patterns of implicit and explicit evaluation.     

The temporally-integrated causality landscape: A theoretical framework for consciousness and meaning

Theoretical approaches to understanding consciousness have begun to converge upon areas of general agreement, yet substantive differences remain. Here, I introduce a new theoretical framework for the emergence of consciousness from the functional integration of the thalamocortical system: the Temporally-Integrated Causality Landscape (TICL). TICL presents a novel perspective which addresses important phenomenological characteristics of consciousness that other frameworks, such as IIT, do not. First, the TICL is based upon the observation that conscious experiences are temporally continuous, not discrete. Secondly, the TICL establishes a thalamocortical basis for the point-of-view. According to TICL, consciousness is composed of contents that arise from neuronal subsystems that have meaning from the point-of-view of the larger, integrated system in which they are nested. Meaningful contents emerge from the subsystems because they exhibit a level of temporally-integrated causality (TIC) that is distinguishable from that of the larger system.     

Consciousness during dreams

Two aspects of consciousness are first considered: consciousness as awareness (phenomenological meaning) and consciousness as strategic control (functional meaning). As to awareness, three types can be distinguished: first, awareness as the phenomenal experiences of objects and events; second, awareness as meta-awareness, i.e., the awareness of mental life itself; third, awareness as self-awareness, i.e., the awareness of being oneself. While phenomenal experience and self-awareness are usually present during dreaming (even if many modifications are possible), meta-awareness is usually absent (apart from some particular experiences of self-reflectiveness) with the major exception of lucid dreaming. Consciousness as strategic control may also be present in dreams. The functioning of consciousness is then analyzed, following a cognitive model of dream production. In such a model, the dream is supposed to be the product of the interaction of three components: (a) the bottom-up activation of mnemonic elements coming from LTM systems, (b) interpretative and elaborative top-down processes, and (c) monitoring of phenomenal experience. A feedback circulation is activated among the components, where the top-down interpretative organization and the conscious monitoring of the oneiric scene elicitates other mnemonic contents, according to the requirements of the dream plot. This dream productive activity is submitted to unconscious and conscious processes.     

Consciousness lost and found: subjective experiences in an unresponsive state

Anesthetic-induced changes in the neural activity of the brain have been recently utilized as a research model to investigate the neural mechanisms of phenomenal consciousness. However, the anesthesiologic definition of consciousness as “responsiveness to the environment” seems to sidestep the possibility that an unresponsive individual may have subjective experiences. The aim of the present study was to analyze subjective reports in sessions where sedation and the loss of responsiveness were induced by dexmedetomidine, propofol, sevoflurane or xenon in a nonsurgical experimental setting. After regaining responsiveness, participants recalled subjective experiences in almost 60% of sessions. During dexmedetomidine sessions, subjective experiences were associated with shallower “depth of sedation” as measured by an electroencephalography-derived anesthesia depth monitor. Results confirm that subjective experiences may occur during clinically defined unresponsiveness, and that studies aiming to investigate phenomenal consciousness under sedative and anesthetic effects should control the subjective state of unresponsive participants with post-recovery interviews.     

Phenomenal Concepts and Higher-Order Experiences

Relying on a range of now-familiar thought-experiments, it has seemed to many philosophers that phenomenal consciousness is beyond the scope of reductive explanation. (Phenomenal consciousness is a form of state-consciousness, which contrasts with creature-consciousness, or perceptual -consciousness. The different forms of state-consciousness include various kinds of access-consciousness, both first-order and higher-order–see Rosenthal, 1986; Block, 1995; Lycan, 1996; Carruthers, 2000. Phenomenal consciousness is the property that mental states have when it is like something to possess them, or when they have subjectively-accessible feels; or as some would say, when they have qualia (see fn. l below).) Others have thought that we can undermine the credibility of those thought-experiments by allowing that we possess purely recognitional concepts for the properties of our conscious mental states. This paper is concerned to explain, and then to meet, the challenge of showing how purely recognitional concepts are possible if there are no such things as qualia –in the strong sense of intrinsic (non relational, non-intentional) properties of experience. It argues that an appeal to higher-order experiences is necessary to meet this challenge, and then deploys a novel form of higher-order thought theory to explain how such experiences are generated.     

Temporal Experiences without the Specious Present

Most philosophers believe that we have experiences as of temporally extended phenomena like change, motion, and succession. Almost all theories of time consciousness explain these temporal experiences by subscribing to the doctrine of the specious present, the idea that the contents of our experiences embrace temporally extended intervals of time and are presented as temporally structured. Against these theories, I argue that the doctrine is false and present a theory that does not require the notion of a specious present. Furthermore, I argue that the different aspects of temporal experiences arise from different mechanisms operating separately. If the theory is true, then temporal experiences do not tell us anything special about the nature of consciousness and its temporal properties per se.     

国内近十年来意识和无意识关系研究的新成就

近十年来,国内掀起了从自然科学途径进行意识和无意识对比研究的新热潮,尤其在实验范式的引进、修正、完善和模型建构方面,做出了中国学者自己的贡献。错误记忆、内隐时间及不注意视盲等新领域的触及代表了国内学者在意识研究内容上的丰富。“钢筋水泥”、“意识涌现”及“车站监视室”等模型的提出,代表了中国学者在意识研究理论方面的创新。当前国内意识研究与国外基本同步,但存在着“研究领域泛化,神经机制探讨有限,跨学科整合力度有待深化”的问题。     

Attentional bias toward low-intensity stimuli: an explanation for the intensity dissociation between reaction time and temporal order judgment?

If two stimuli need different times to be processed, this difference should in principle be reflected both by response times (RT) and by judgments of their temporal order (TOJ). However, several dissociations have been reported between RT and TOJ, e.g., RT is more affected than TOJ when stimulus intensity decreases. One account for these dissociations is to assume differences in the allocation of attention induced by the two tasks. To test this hypothesis, different distributions of attention were induced in the present study between two stimulus positions (above and below fixation). Only bright stimuli appeared in one position and either bright or dim stimuli in the other. In the two RT experiments, participants had to respond to every stimulus appearing in one of the two positions. Reaction times to bright stimuli were faster when they appeared in the position where dim stimuli were likely to occur. This finding suggests that the allocation of attention was adapted to the asymmetrical arrangement of stimuli, not suggested by explicit instruction. In the two TOJ experiments, the temporal order of stimuli appearing in the two positions had to be judged. Although bright stimuli appearing at the bright-and-dim location were judged to be earlier, this effect was small and insignificant. Further, the intensity dissociation between RT and TOJ was insensitive to random vs blockwise presentations of intensities, therefore was not modified by attentional preferences. Thus, asymmetrical arrangement of stimuli has an impact on the allocation of attention, but only in the RT task. Therefore dissociations between TOJ and response times cannot be accounted for by an attentional bias in the TOJ task but probably by different use of temporal information in the two tasks.     

Pavlovian extinction,phobias, and the limits of the cognitive paradigm

The slow or total lack of decrease in some autonomic responses during extinction in aversive conditioning and concomitant verbalizations of fear have remained a problem for learning theories and psychophysiology. Removal of the aversive stimulus should result in a rapid decrement in responding, as it does in cognitive and somatic systems. In laboratory analogues of phobia and clinical neurosis, however, such decreases do not occur in some autonomic responses and reported fear. In this article three areas of research are presented in which dissociations occur between cognitive and autonomie responses: 1) relational learning, 2) phobia, and 3) incubation. The data indicate that there are some important distinctions to be made concerning the properties of different psychological and physiological systems. These distinctions pertain to the differences between cognitive and noncognitive systems, between the two branches of the ANS, and between acquisition and extinction processes. These distinctions lead to a number of hypotheses concerning dissociations between response systems and have important implications for the understanding and treatment of neurosis.