Coherence and recurrency: maintenance,control and integration in working memory

Working memory (WM), including a ‘central executive’, is used to guide behavior by internal goals or intentions. We suggest that WM is best described as a set of three interdependent functions which are implemented in the prefrontal cortex (PFC). These functions are maintenance, control of attention and integration. A model for the maintenance function is presented, and we will argue that this model can be extended to incorporate the other functions as well. Maintenance is the capacity to briefly maintain information in the absence of corresponding input, and even in the face of distracting information. We will argue that maintenance is based on recurrent loops between PFC and posterior parts of the brain, and probably within PFC as well. In these loops information can be held temporarily in an active form. We show that a model based on these structural ideas is capable of maintaining a limited number of neural patterns. Not the size, but the coherence of patterns (i.e., a chunking principle based on synchronous firing of interconnected cell assemblies) determines the maintenance capacity. A mechanism that optimizes coherent pattern segregation, also poses a limit to the number of assemblies (about four) that can concurrently reverberate. Top-down attentional control (in perception, action and memory retrieval) can be modelled by the modulation and re-entry of top-down information to posterior parts of the brain. Hierarchically organized modules in PFC create the possibility for information integration. We argue that large-scale multimodal integration of information creates an ‘episodic buffer’, and may even suffice for implementing a central executive.     

The ‘I’ and the ‘Me’ in self-referential awareness: a neurocognitive hypothesis

The nature of the ‘self’ and self-referential awareness has been one of the most debated issues in philosophy, psychology and cognitive neuroscience. Understanding the neurocognitive bases of self-related representation and processing is also crucial to research on the neural correlates of consciousness. The distinction between an ‘I’, corresponding to a subjective sense of the self as a thinker and causal agent, and a ‘Me’, as the objective sense of the self with the unique and identifiable features constituting one’s self-image or self-concept, suggested by William James, has been re-elaborated by authors from different theoretical perspectives. In this article, empirical studies and theories about the ‘I’ and the ‘Me’ in cognition and self-related awareness are reviewed, including the relationships between self and perception, self and memory, the development of the self, self-referential stimulus processing, as well as related neuroimaging studies. Subsequently, the relations between self and different aspects of consciousness are considered. On the basis of the reviewed literature and with reference to Block’s distinction between phenomenal and access consciousness, a neurocognitive hypothesis is formulated about ‘I’-related and ‘Me’-related self-referential awareness. This hypothesis is extended to metacognitive awareness and a form of non-transitive consciousness, characteristic of meditation experiences and studies, with particular reference to the notion of mindfulness and other Buddhist constructs.     

Visual marking and change detection

The preview benefit from prior exposure of response-irrelevant (distracter) objects in visual search has been accounted for in terms of top-down inhibition (i.e. visual marking), bottom-up abrupt onset capture, or asynchrony-dependent perceptual segregation. We assess the relative contribution of abrupt onset and visual marking in a paradigm combining visual search with a visual working memory task. We investigated time-based selection of multiple objects for storage in visual working memory, using a change detection paradigm (Luck and Vogel in Nature 390:279–281, 1997) with distracter preview. We varied preview exposure (short vs. long), in a series of three experiments. The contribution of asynchrony-related perceptual segregation was assessed across experiments by varying the complexity of the stimuli (colored squares, oriented bars and oriented T-shapes) and the type of change detection (color or orientation), resulting in different levels of perceptual segregation between visual elements. The results suggest that bottom-up abrupt onset, visual marking and perceptual segregation factors co-operate in time-based selection for storage in visual working memory.     

Narrative Derivatives of Alpha Elements: Clinical Implications

The author considers both the psychoanalytic field and the ways in which the characters of a psychoanalytic session can be understood. He then develops one of Bion's ideas, the dream in the waking state, by isolating the derivatives of such dreams or rather the alpha elements they consist of. The author implies a theory of technique which takes account of all the signals "the bi-personal field" gives the analyst about the functioning of the analytic couple by means of "narrative derivatives". This enables continual changes to be made in interpretation     

Interpretation: signals from the analytic field and emotional transformations

Through numerous clinical examples and from a point of view focused on field theory the author reflects upon what are the main characteristics of ‘transformative interpretations’ and upon the mental and affective conditions that support it. He especially centers his attention on difficult patients who have experienced cumulative affective traumas in their lives.     

Analysts in Search of an Author: Voltaire or Artemisia Gentileschi? Commentary on “Field Theory in Psychoanalysis,Part 2: Bionian Field Theory and Contemporary Interpersonal/Relational Psychoanalysis” by Donnel B. Stern

The authors comment on Stern's characterization of differences between interpersonal and relational psychoanalysis and Bionian field theory. The critical points on which a consensus is not, for the time being, readily possible concern the relationship between the external and internal worlds and the various conceptions of unconscious experience. They believe that, before forging a link with the external world (whose role we would be foolish to deny), it is clinically more useful to apprehend this internal world as rigorously and over as wide a range as possible—which they do by radically transforming the external world into a dream of the field. Conversely, in their view we may be reassured but partly misled by the concept of a dialectic between the external and internal worlds that fails to take account of the utter pervasiveness of the unconscious and the fact that it speaks even when seemingly silent—not only negatively in micro- and macroenactments but also positively in waking dream thought, which is an expression of its poetic activity that unceasingly confers meaning on experience.     

Disorganized Narratives: Problems In Treatment And Therapist Intervention Hierarchy

The way in which patients tell therapists their stories has an impact on treatment. They try to put their emotions and the events generating them, their goals and the behavior they adopt to achieve them, and so on, together in a coherent discourse. But some patients fail in organizing their narratives. They might describe a diffuse arousal without letting the reasons for their discomfort be known, switch from one subject to another without any apparent connection, or pile up one topic after another, thus overwhelming a listener, who is unable to see which is the main one. We call such narratives disorganized. They do not help a patient to make sense of experience or achieve consistency in behavior. A therapist listening has difficulty in planning treatment and often reacts negatively to such patients. Here we propose a series of interventions aimed at improving narrative coherence, creating a sound therapeutic relationship and making treatment effective. We will describe the therapy with a seriously dissociated patient in which this intervention has proven useful.     

Decay of Stimulus Spatial Code in Horizontal and Vertical Simon Tasks

Evidence on the processes underlying the horizontal and vertical Simon effect is still controversial. The present study uses experimental manipulations to selectively delay the stages of response execution, response selection, and stimulus identification in three experiments. A reduction is observed for both horizontal and vertical Simon effects when response execution is delayed by a go-signal presented 400–600 ms post-stimulus onset or when a spatial precue is presented 200–400 ms before the stimulus. When the overlap between stimulus spatial code formation and response selection is prevented by decreasing stimulus discriminability, the horizontal Simon effect decays, but the vertical Simon effect does not change. Activation theories, which propose a decay of the automatically activated response ipsilateral to the stimulus, mainly apply to the horizontal Simon effect. In contrast, translation theories, which propose that the effect occurs when stimulus features are translated into a response code, are more suitable to account for the vertical Simon effect.     

Acquiring contextualized concepts: a connectionist approach

Conceptual knowledge is acquired through recurrent experiences, by extracting statistical regularities at different levels of granularity. At a fine level, patterns of feature co-occurrence are categorized into objects. At a coarser level, patterns of concept co-occurrence are categorized into contexts. We present and test CONCAT, a connectionist model that simultaneously learns to categorize objects and contexts. The model contains two hierarchically organized CALM modules (Murre, Phaf, & Wolters, 1992). The first module, the Object Module, forms object representations based on co-occurrences between features. These representations are used as input for the second module, the Context Module, which categorizes contexts based on object co-occurrences. Feedback connections from the Context Module to the Object Module send activation from the active context to those objects that frequently occur within this context. We demonstrate that context feedback contributes to the successful categorization of objects, especially when bottom-up feature information is degraded or ambiguous.