Memories defining the self in Alzheimer’s disease

ABSTRACT

There is a debate over the extent to which personal identity or the self is preserved in patients with Alzheimer’s disease (AD). Autobiographical memory deficits at early stages of AD could contribute to altering patients’ self. However, the nature of the relationship between autobiographical memory deficits and the self in AD has not been much investigated experimentally. In the present study, we aimed to investigate the integrative meaning of self-defining memories (SDMs) in early stages of AD and to analyse its relationship with the self-concept. The results showed that, when compared to the control group, AD patients less frequently extracted meaning from their SDMs and the meaning was less frequently tied to the self. Patients exhibited some altered aspects of the self-concept (i.e., complexity and strength), though some other components still persisted (i.e., valence and certainty). Correlation analyses showed that the impaired integrative meaning in the AD group was correlated with some changes in self-concept. We suggest that integrative meaning may act as a bridge between autobiographical memories and the self-concept, with reduced integration abilities appearing as a potential mechanism for the deterioration of the self-concept in AD.     

Overcoming fixation with repeated memory suppression

Fixation (blocks to memories or ideas) can be alleviated not only by encouraging productive work towards a solution, but, as the present experiments show, by reducing counterproductive work. Two experiments examined relief from fixation in a word-fragment completion task. Blockers, orthographically similar negative primes (e.g., ANALOGY), blocked solutions to word fragments (e.g., A_L_ _GY) in both experiments. After priming, but before the fragment completion test, participants repeatedly suppressed half of the blockers using the Think/No-Think paradigm, which results in memory inhibition. Inhibiting blockers did not alleviate fixation in Experiment 1 when conscious recollection of negative primes was not encouraged on the fragment completion test. In Experiment 2, however, when participants were encouraged to remember negative primes at fragment completion, relief from fixation was observed. Repeated suppression may nullify fixation effects, and promote creative thinking, particularly when fixation is caused by conscious recollection of counterproductive information.     

Perception,Judgment and Individuation: Towards a Metaphysics of Particularity

Abstract

The aim of this paper is to develop a new theory of particularity. In so doing it redefines the concepts ‘perception’ and ‘judgment’. The redefinition occurs once perception is understood as recognition. The move to recognition entails the centrality of repetition. Recognition, it is argued, is a form of repetition. Allowing for repetition necessitates changing the way the relationship between universals and particulars is understood. This is developed via an engagement with Hume and Plato. The article concludes with the outline for a rethinking of the metaphysics of particularity.     

Father and daughter: Identification with difference—a contribution to gender heterodoxy

This paper reinterprets the historical problem of penis envy, that is, the girl's wish to be masculine, in terms of a developmental need to identify with father. Many of the problems posed by earlier analyses of femininity can be clarified by recognizing that before the girl “turns”; to the oedipal father as love object, she looks to the rapprochement father for identification. Identification is not merely an internal structure, it is a relationship in which the subject recognizes herself or himself in the other. In rapprochement, love of the father, who symbolically represents the outside world, takes the place of the practicing toddler's “love affair with the world.”; This identificatory love of the father, initially noticed in boys by Freud and later authors, is often frustrated by the father's absence or inability to recognize the daughter. This frustrated longing takes the penis as its symbol of likeness. The pre‐oedipal over‐inclusive phase of identification with the other sex parent is not superceded by the oedipal constellation, but is integrated with it. Thus identification becomes an important basis of the love of the other: it is not so much the opposite of object love as an important precursor and ongoing constituent of it. Case material illustrates the multiple possibilities of identificatory love and use of phallic symbolism to represent them.     

Knowing at Second Hand

Participants on both sides of the contemporary debate between reductionism and anti‐reductionism about testimony commonly describe testimonial knowledge as knowledge acquired at second hand. I argue that fully appreciating the distinctive sense in which testimonial knowledge is secondhand supports anti‐reductionism over reductionism but also that it supports a particular kind of anti‐reductionism very different from that typically offered in the literature. Testimonial knowledge is secondhand in the demanding sense of being justified by the authority of a speaker where this requires that epistemic responsibility for meeting challenges to the audience's testimonial knowledge is shared between speaker and audience. The epistemic credentials of testimonial knowledge are in this sense importantly interpersonal.     

Strategie Calibration and Spatial Alignment: A Model From Prism Adaptation

Two types of adaptive processes involved in prism adaptation have been identified: slower spatial realignment among the several unique sensorimotor coordinate systems (spatial maps) and faster strategic motor control responses (including skill learning and calibration) to spatial misalignment. One measures the 1st process by assessing the aftereffects of prism exposure, whereas direct effects of the prism during exposure are a measure of the 2nd process. A model is described that relates those adaptive processes and distinguishes between extraordinary alignment and ordinary calibration. A conformal translation algorithm that operates on the hypothesized circuitry is proposed. The authors apply the model to explain the advantage of visual calibration when the limb is seen in the starting position prior to movement initiation. Implications of the model for the use of prism adaptation as a tool for investigation of motor control and learning are discussed.     

Prism Exposure Aftereffects and Direct Effects for Different Movement and Feedback Times

The effects of movement time and time to visual feedback (feedback time) on prism exposure aftereffects and direct effects were studied. In Experiment 1, the participants' (N = 60) pointing limb became visible early in the movement (.2-s feedback time, and eye-head aftereffects increased with increasing movement time (.5 to 3.0 s), but larger hand-head aftereffects showed little change. Direct effects (terminal error during exposure) showed near-perfect compensation for the prismatic displacement (11.4 diopters) when movement time was short but decreasing compensation with longer movement times. In Experiment 2, participants' (N = 48) eye-head aftereffects increased and their larger hand-head aftereffects decreased with increasing movement time (2.0 and 3.0 s), especially when feedback time increased (.25 and 1.5 s). Direct effects showed increasing overcompensation for longer movement and feedback times. Those results suggest that aftereffects and direct effects measure distinct adaptive processes, namely, spatial realignment and strategic control, respectively. Differences in movement and feedback times evoke different eye -hand coordination strategies and consequent direct effects. Realignment aftereffects also depend upon the coordination strategy deployed, but not all strategies support realignment. Moreover, realignment is transparent to strategic control and, when added to strategic correction, may produce nonadaptive performance.     

Effects on Prism Adaptation of Duration and Timing of Visual Feedback During Pointing

In two experiments, we investigated the effects of duration of visual feedback of the pointing limb and the time (early to late) in the movement when the limb first becomes visible (timing of visual feedback). Timing, rather than duration of visual feedback, proved to have the greater effect on the relative magnitude of visual and proprioceptive adaptation. Visual adaptation increased smoothly with feedback delay, but corresponding decreases in proprioceptive adaptation underwent an additional sharp change when feedback was delayed until about three-fourths of the way to the terminal limb position. These results are consistent with the idea that visual and proprioceptive adaptation are mediated by exclusive processes. Change in the limb position sense (i.e., proprioceptive adaptation) may be produced by visual guidance of the pointing limb, and view of the limb early in the pointing movement seems to be critical for such visual guidance. The limb may be ballistically “released“ as it nears the terminal position, and, thereafter, any opportunity for visual guidance (i.e., view of the limb) is not effective. On the other hand, change in the eye position sense (i.e., visual adaptation) may be mediated by proprioceptive guidance of the eye; the eyes may track the imaged position of the nonvisible limb. Such proprioceptive guidance seems to be solely a function of the distance moved before the limb becomes visible.