The neural bases of the constructive nature of autobiographical memories studied with a self-paced fMRI design

In Conway and Pleydell-Pearce's model (2000), autobiographical memories are viewed as transitory mental representations, more often generated in an effortful way. An important claim of the model concerns the dynamic process that evolves over time, from the left prefrontal areas to posterior regions, to retrieve specific memories. The present work aims at investigating, using fMRI, the temporal distribution of effortful autobiographical memory construction. In addition, a self-paced design was implemented to elucidate the question of the timing window required to evoke recollections. The results showed a large pattern of brain regions, which included the two major poles of activation predicted by Conway and Pleydell-Pearce's model. Likewise, we were able to detect the earlier implication of the left dorso-lateral prefrontal cortex, by comparison with posterior structures, which seemed to confirm its involvement in the effortful retrieval process. Finally, the self-paced procedure allowed us to refine the timing window necessary to construct past events.     

The neural bases of the constructive nature of autobiographical memories studied with a self-paced fMRI design

In Conway and Pleydell-Pearce's model (2000), autobiographical memories are viewed as transitory mental representations, more often generated in an effortful way. An important claim of the model concerns the dynamic process that evolves over time, from the left prefrontal areas to posterior regions, to retrieve specific memories. The present work aims at investigating, using fMRI, the temporal distribution of effortful autobiographical memory construction. In addition, a self-paced design was implemented to elucidate the question of the timing window required to evoke recollections. The results showed a large pattern of brain regions, which included the two major poles of activation predicted by Conway and Pleydell-Pearce's model. Likewise, we were able to detect the earlier implication of the left dorso-lateral prefrontal cortex, by comparison with posterior structures, which seemed to confirm its involvement in the effortful retrieval process. Finally, the self-paced procedure allowed us to refine the timing window necessary to construct past events.     

Cultural and linguistic influence on neural bases of 'Theory of Mind': an fMRI study with Japanese bilinguals

Theory of mind (ToM)-our ability to predict behaviors of others in terms of their underlying intentions-has been thought to be universal and invariant across different cultures. However, several ToM studies conducted outside the Anglo-American cultural or linguistic boundaries have obtained mixed results. To examine the influence of culture/language on neural bases of ToM, we studied 16 American English-speaking monolinguals and 16 Japanese-English bilinguals with second-order false-belief story tasks, using functional magnetic resonance imaging (fMRI). Several neural correlates of ToM including medial prefrontal cortex (mPFC) and anterior cingulate cortex (ACC) were recruited by both cultural/linguistic groups. However, some other brain areas including inferior frontal gyrus (IFG) were employed in a culture/language-specific manner, during the ToM tasks. These results suggest that the ways in which adults understand ToM are not entirely universal.     

The neural correlates of happiness: A review of PET and fMRI studies using autobiographical recall methods

Although very difficult to define, happiness is becoming a core concept within contemporary psychology and affective neuroscience. In the last two decades, the increased use of neuroimaging techniques has facilitated empirical study of the neural correlates of happiness. This area of research utilizes procedures that induce positive emotion and mood, and autobiographical recall is one of the most widely used and effective approaches. In this article, we review eight positron emission tomography and seven functional magnetic resonance imaging studies that have investigated happiness by using autobiographical recall to induce emotion. Regardless of the neuroimaging technique used, the studies conducted so far have shown that remembering happy events is primarily associated with the activation of many areas, including anterior cingulate cortex, prefrontal cortex, and insula. Importantly, these areas are also found to be connected with other basic emotions, such as sadness and anger. In the conclusion, we integrate these findings, discussing important limitations of the extant literature and suggesting new research directions.     

Adaptive mechanisms in perceptual-motor coordination: components of prism adaptation

Aftereffect measures of visual shift and proprioceptive shift were obtained for prism exposure conditions in which, at the end of a sagittal pointing movement, most of the arm was visible (concurrent exposure) or only the first finger joint was visible (terminal exposure). Intermediate exposure conditions permitted view of the hand or the first two finger joints. Under the concurrent exposure condition, proprioceptive shift was greater than visual shift but, as view of the pointing hand decreased, the relative magnitude of the two components gradually reversed so that, under the terminal exposure condition, visual shift was greater than proprioceptive shift. These results are discussed in terms of a model of perceptual-motor organization (Redding, Clark, & Wallace, 1985) in which the direction of coordinative linkage between eye-head and hand-head systems determines the locus of discordance and adaptive recalibration.     

Individual differences in the visual component of prism adaptation

The centrality of individual differences in the visual component of perceptual adaptation was examined in a massed-practice-terminal-exposure, prism-viewing paradigm. With positive (adaptive) adjustments in the judgment of the visual straight-ahead, target-pointing aftereffects were found to be equivalent to the sum of the visual and proprioceptive (head-arm) aftereffects. For subjects showing negative visual adjustments to prism exposure, the target-pointing aftereffect was not significantly different from the change in proprioception alone. Implications of these findings for hypotheses concerning the process of perceptual adaptation are discussed.     

First-trial adaptation to prism exposure: artifact of visual capture

Terminal target-pointing error on the 1st trial of exposure to optical displacement is usually less than is expected from the optical displacement magnitude. The authors confirmed 1st-trial adaptation in the task of pointing toward optically displaced targets while visual feedback was delayed until movement completion. Measurement of head-shoulder posture while participants (N = 24) viewed the optically displaced field revealed that their shoulders felt turned in the direction opposite to the displacement (visual capture), accounting for all but about 4% to 10% of 1st-trial adaptation. First-trial adaptation was unrelated to realignment aftereffects. First-trial adaptation is largely an artifact of the asymmetry of the structured visual field produced by optical displacement, which induces a felt body rotation, thereby reducing the effective optical displacement.     

Strategic calibration and spatial alignment: a model from prism adaptation

Two types of adaptive processes involved in prism adaptation have been identified&colon: 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 to 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.     

An examination of the relationship between visual capture and prism adaptation

The phenomena of prismatically induced “visual capture” and adaptation of the hand were compared. In Experiment 1, it was demonstrated that when the subject’s hand was transported for him by the experimenter (passive movement) immediately preceding the measure of visual capture, the magnitude of the immediate shift in felt limb position (visual capture) was enhanced relative to when the subject moved the hand himself (active movement). In Experiment 2, where the dependent measure was adaptation of the prism-exposed hand, the opposite effect was produced by the active/passive manipulation. It appears, then, that different processes operate to produce visual capture and adaptation. It was speculated that visual capture represents an immediate weighting of visual over proprioceptive input as a result of the greater precision of vision and/or the subject’s tendency to direct his attention more heavily to this modality. In contrast, prism adaptation is probably a recalibration of felt limb position in the direction of vision, induced by the presence of a registered discordance between visual and proprioceptive inputs.     

Does prism adaptation affect visual search in spatial neglect patients: A systematic review

Prism adaptation (PA) is a widely used intervention for (visuo‐)spatial neglect. PA‐induced improvements can be assessed by visual search tasks. It remains unclear which outcome measures are the most sensitive for the effects of PA in neglect. In this review, we aimed to evaluate PA effects on visual search measures. A systematic literature search was completed regarding PA intervention studies focusing on patients with neglect using visual search tasks. Information about study content and effectiveness was extracted. Out of 403 identified studies, 30 met the inclusion criteria. The quality of the studies was evaluated: Rankings were moderate‐to‐high for 7, and low for 23 studies. As feature search was only performed by five studies, low‐to‐moderate ranking, we were limited in drawing firm conclusions about the PA effect on feature search. All moderate‐to‐high‐ranking studies investigated cancellation by measuring only omissions or hits. These studies found an overall improvement after PA. Measuring perseverations and total task duration provides more specific information about visual search. The two (low ranking) studies that measured this found an improvement after PA on perseverations and duration (while accuracy improved for one study and remained the same for the other). This review suggests there is an overall effect of PA on visual search, although complex visual search tasks and specific visual search measures are lacking. Suggestions for search measures that give insight in subcomponents of visual search are provided for future studies, such as perseverations, search path intersections, search consistency and using a speed–accuracy trade‐off.     

Sentimental perceptualism and the challenge from cognitive bases

According to a historically popular view, emotions are normative experiences that ground moral knowledge much as perceptual experiences ground empirical knowledge. Given the analogy it draws between emotion and perception, sentimental perceptualism constitutes a promising, naturalist-friendly alternative to classical rationalist accounts of moral knowledge. In this paper, we consider an important but underappreciated objection to the view, namely that in contrast with perception, emotions depend for their occurrence on prior representational states, with the result that emotions cannot give perceptual-like access to normative properties. We argue that underlying this objection are several specific problems, rooted in the different types of mental states to which emotions may respond, that the sentimental perceptualist must tackle for her view to be successful. We argue, moreover, that the problems can be answered by filling out the theory with several independently motivated yet highly controversial commitments, which we carefully catalogue. The plausibility of sentimental perceptualism, as a result, hinges on further claims sentimental perceptualists should not ignore.

     

Development of the third component in prism adaptation: effects of active and passive movement

Adaptation to prismatically displaced vision was assessed using a factorial design involving active or passive exposure movement, active or passive test movement, and target location. Tests of visual shift, ipsilateral and contralateral proprioceptive shift, and ipsilateral and contralateral target-pointing shift were made at the completion of 6, 12, 24, 48, and 96 exposure trials. During the early stages of adaptation (< 48 exposure trials), changes in ipsilateral target pointing were completely accounted for by the sum of the visual and ipsilateral proprioceptive changes. Following longer exposure durations, evidence of a third component was obtained, but only when exposure and test movements were the same (i.e., active-active and passive-passive conditions). The acquisition of such movement-specific response tendencies was interpreted as indicating that the third component represents a change in a central program or schema, which is responsible for guiding a limb to an externally specified location. Target location had no effect on the presence or magnitude of the third component, and there was no indication that the third component transferred intermanually.