Dreaming and hallucinations - continuity or discontinuity? Perspectives from dementia with Lewy bodies

Comparing the phenomenology, neurochemical pathology, and psychopharmacology of hallucinations and dreaming is limited by the available data. Evidence to date reveals no simple correspondence between the two states. Differences in the phenomenology of visual hallucinations and the visual component of dreams may reflect variations in visual context acting on the same underlying mechanism – the minimal visual input during dreaming contrasts with the more substantial perceived context in hallucinations. Variations in cholinergic, dopaminergic and serotonergic neurotransmitter function during sleep and during hallucinations in Lewy body dementias, together with relevant drug effects suggest that, on the whole, different, potentially opposite, changes characterise the two states. A similar analysis of other psychotic features in Lewy body dementia and other disorders suggests that, in contrast to hallucinations, there may be more convincing parallels between dreaming and delusional states.     

Revisiting Jung's concept of innate sensitiveness

Jung suggested that innate sensitiveness predisposes some individuals to be particularly affected by negative childhood experiences, so that later, when under pressure to adapt to some challenge, they retreat into infantile fantasies based on those experiences and become neurotic. Recent research by the author and others is reviewed to support Jung's theory of sensitiveness as a distinctly thorough conscious and unconscious reflection on experiences. Indeed, this probably innate tendency is found in about twenty percent of humans, and, in a sense, in most species, in that about this percentage will evidence a strategy of thoroughly processing information before taking action, while the majority depend on efficient, rapid motor activity. Given this thorough processing, sensitive individuals readily detect subtleties-including whatever is distressing or threatening. Hence, as Jung observed, given the same degree of stress in childhood as non-sensitive individuals, sensitive persons will develop more depression, anxiety, and shyness. Without undue stress, they evidence no more of these difficulties than the non-sensitive-or even less, being unusually aware of supportive as well as negative cues from caregivers. Given this interaction, one treatment task is to distinguish the effects of such childhood difficulties from what does not need treatment, which are the typical effects of the trait itself on an adult without a troubled developmental history.     

Repetition priming effects from attended vs. ignored single words in a semantic categorization task

The present research examines priming effects from a centrally presented single-prime word to which participants were instructed to either attend or ignore. The prime word was followed by a single central target word to which participants made a semantic categorization (animate vs. inanimate) task. The main variables manipulated across experiments were attentional instructions (attend vs. ignore the prime word), presentation duration of the prime word (20, 50, 80 or 100 ms), prime-target stimulus onset asynchrony (SOA; 300 vs. 800 ms), and temporal presentation of instructions (before vs. after the prime word). The results showed (a) a consistent interaction between attentional instructions and repetition priming and (b) a qualitatively different ignored priming pattern as a function of prime duration: reduced positive priming (relative to the attend instruction) for prime exposures of 80 and 100 ms, and reliable negative priming for the shorter prime exposures of 20 and 50 ms. In addition (c), the differential priming pattern for attend and ignore trials was observed at a prime-target SOA of 800 ms (but not at a shorter 300-ms SOA) and only when instructions were presented before the prime word. Methodological and theoretical implications of the present findings for the extant negative priming literature are discussed.