Neuropsychologia
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Previous lesion studies demonstrate that patients who underwent a unilateral temporal lobe resection show impaired skin conductance responding (SCR) to aversively conditioned stimuli. The aim of the current lesion study was to examine whether the amygdala is also critically involved in differential SCR during a more explicit form of fear learning. A simple discrimination task was presented to a unilaterally amygdala-damaged patient group and a control group, in which one neutral stimulus was always followed by an electric shock (CS+), whereas a second stimulus always appeared alone (CS-). ⋯ The two-level account of Ohman and Mineka [Ohman, A., & Mineka, S. (2001). Fears, phobias, and preparedness: Toward an evolved module of fear and fear learning. Psychological Review, 108, 483-522] is proposed in order to explain the diverse lesion data obtained so far.
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The contralesional line bisection error in hemianopia is a well-known clinical phenomenon. Its origin, however, is still unclear. ⋯ Our results suggest that the contralesional bisection error is neither a consequence of the visual field defect itself nor a manifestation of strategic adaptation of attention and eye movements into contralesional hemispace. Additional extrastriate brain injury, presumably to occipito-temporal areas including the occipital white matter, seems to be critical for the emergence of the contralesional bisection error that is frequently associated with but separable from homonymous hemianopia.
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The critical attributes of episodic memory are self, autonoetic consciousness and subjectively sensed time. The aim of this paper is to present a theoretical overview of our already published researches into the nature of episodic memory over the course of time. ⋯ The multifaceted and complex nature of episodic memory is emphasized and it is suggested that mental time travel through subjective time, which allows individuals to re-experience specific past events through a feeling of self-awareness, is the last feature of autobiographical memory to become fully operational in development and the first feature to go in aging and most amnesias. Our findings highlight the critical role of frontotemporal areas in constructive autobiographical memory processes, and especially hippocampus, in re-experiencing episodic details from the recent or more distant past.
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Case Reports
Retrograde episodic memory and emotion: a perspective from patients with dissociative amnesia.
With his recent definition of episodic memory Tulving [Tulving, E. (2005). Episodic memory and autonoesis: Uniquely human? In H. Terrace & J. ⋯ To illustrate the connection of emotion and retrograde episodic memory we shortly present neuropsychological data of two cases of dissociative amnesia. Both cases serve to point to the protective mechanism of a block of self-endangering memories from the episodic memory system, often described as the mnestic block syndrome. On the basis of these cases and supportive results from further cases we will conclude by pointing out similarities and differences of patients with organic and dissociative (psychogenic) amnesia.
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We previously reported that patients with Parkinson's disease (PD) demonstrate reduced psychophysiologic reactivity to unpleasant pictures as indexed by diminished startle eyeblink magnitude [Bowers, D., Miller, K., Bosch, W., Gokcay, D., Pedraza, O., Springer, U., et al. (2006). Faces of emotion in Parkinsons disease: Micro-expressivity and bradykinesia during voluntary facial expressions. Journal of the International Neuropsychological Society, 12(6), 765-773; Bowers, D., Miller, K., Mikos, A., Kirsch-Darrow, L., Springer, U., Fernandez, H., et al. (2006). ⋯ Instead, the PD patients showed reduced reactivity to mutilation pictures relative to other types of negative pictures in the context of normal subjective ratings. Further analyses revealed that controls displayed a pattern of increased startle eyeblink magnitude for "high arousal" versus "low arousal" negative pictures, regardless of picture category, whereas startle eyeblink magnitude in the PD group did not vary by arousal level. These results suggest that previous findings of decreased aversion-modulated startle is driven by reduced reactivity to highly arousing negative stimuli rather than to a specific category (i.e., fear or disgust) of emotion stimuli.